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| Thursday, August 17, 2006 |
| Wound, Bleeding and Shock (under construction) |
WOUND , BLEEDING & SHOCK
2. Type of Wound
2.1. Close Wound
Injury to tissue under the skin cause by bumping, contusion or falling down OR the breaking of a blood vessel under the skin due to a blow to the skin like bruise.
2.2. Open Wound
Any break or opening in the skin or an organ caused by violence or surgical incision.
2.1. Close Wound & Treatment
Bruise/Contusion
Definition
Bruise due to blunt blow on the body that cause injury to tissue under the skin like bumping, contusion or falling down.
Sign and symptoms
- Pain on the injured area
- Injury to tissue and capillary that leaking the blood flow. The blood and the human excretion( sweat & fluid) will pool around the injured tissue causing bluish skin discoloration.
- Serious injury called ‘Hematoma” happen when there’re higher amount of blood and fluid. Hematoma can cause severe blood lost and shock.
Type of Bruise
- hematoma : Bruise becomes firm and seems to become larger due to large amount of blood wall is off the wound, rather than clean it up. It may need to be drained by doctor.
- heterotopic ossification: When the body deposits calcium in the area of the injury that cause it becomes tender and firm and requires x-rays and a trip to the doctor.
- Petechiae: Little (3-3 millimeters) red dots; are tiny little accumulations of blood. Often there are few of them and they usually indicate some sort of serious health problem.
- Bruising around the belly button could be a result of bleeding in the abdomen
- Bruising behind the ear can indicate a skull fracture
- Bruises that are raised, firm, and occur without any injury may be signs of a “autoimmune” disease, in which the body attacks it’s own blood vessels.
First Aid Treatment
Apply the RICE method
- Rest : Rest the injured body part
- Ice : Put wrap-up ice on the injured part
- Compress : Bandage the injured area over a thick cotton layer
- Elevate : Raise the injured part
Get help if needed
Caution
- Dont put ice directly on the injured area without cover
- Don’t elevate the injured part if there is any symptom of internal bleeding.
2.2. Open Wound & Treatment
Classification of Open Wounds
i. Incision:
o These cuts result of some sharp object such as broken glass, knives and sharp edges.
o The amount of bleeding varies on the depth and extension of the cut.
o Some of these wounds require stitches.
ii. Laceration:
o These are jagged irregularly shaped cuts or tears in the skin. Most lacerations are serious and require stitches, because of heavy bleeding.
o Chances of infection depend on the size, cause, and depth of the laceration. Severe laceration should be treated by a doctor.
iii. Punctures:
o Puncture wounds are caused by an object piercing the skin.
o These wounds range from minor to severe and should often be looked at by a doctor.
o Because the wound penetrates the skin (and in some cases, several layers of skin) they are often difficult to clean and infections are common.
o If bone puncture is suspected, visit doctor as soon as possible.
iv. Abrasion
o Abrasion happen when layer of skin loose due to continuous friction on the skin.
o The skin outer layer loose and exist several drop of bloods or body fluid on the injured area.
Treatment
Abrasion Treatment:
- Clean the skin with water and soap to rid of any foreign object embedded on the wound (Don’t scrub)
- Put antiseptic cream /solution.
- Cover the whole area using padding or plaster .
If the abrasion is only on the skin first layer, leave the wound open without padding after applying antiseptic cream/solution for faster healing.
Cuts and Scrapes Treatment
- Clean out the wound. Make sure you wash your hands before cleaning a wound to avoid transferring more dirt to the cut.
- Wipe away from the wound when removing dirt and other particles that may be in the wound.
- Washing the wound use soap and water, but do not scrub because that may do more damage.
- Apply direct pressure with a clean dry cloth or sterile gauze bandage, while elevating limb (if possible) above the heart. This will slow bleeding and help a clot to form.
- If bleeding is spurting out of wound or bleeding continues heavily after pressure has been applied for 5-10 minutes stitches may be needed, so go to the hospital and have the wound checked out by doctor as soon as possible.
- If the bleeding slows, cover the wound with a clean bandage.
- Apply a thin layer of antibacterial ointment to the wound first, to protect against infection.
- If the wounds are on the hands or feet avoid using these ointments after the first day. Make sure the wound is kept clean and dry while it heals.
- Caution:
o Apply only a thin layer of ointment to ensure the best protection.
o Always apply the ointment with a clean swab or gauze. Applying ointment from the tube may contaminate the tube and put future wounds at risk.
o Make sure to wash the wound before applying fresh ointment.
o When applying fresh bandages make sure your hands are clean and the bandage remains sterile. It is advised that the bandage is opened over the wound and that the pad remains untouched except by the wound.
Severe bleeding injuries
- Lay the person down. If possible, position the person's head slightly lower than the trunk, or elevate the legs. This position reduces the chances of fainting by increasing blood flow to the brain. If possible, elevate the site of bleeding.
- Remove any obvious debris or dirt from the wound using sterile tools.
- Do not remove any objects pierced into the victim.
- Do not probe the wound or attempt to clean it at this point. Your principal concern is to stop the loss of blood.
o Apply pressure directly on the wound with a sterile bandage, clean cloth or even a piece of clothing. (Avoid direct contact with wound)
o Maintain pressure until the bleeding stops for 10 minutes or more.
o When bleeding stop:
- bind the wound tightly with adhesive tape or a bandage. If none is available, use a piece of clean clothing.
- If the bleeding continues and seeps through the gauze or other material you are holding on the wound, do not remove it. Instead, add more absorbent material on top of it.
o If the bleeding does not stop with direct pressure:
- apply pressure to the major artery that delivers blood to the area of the wound.
- In the case of a wound on the hand or lower arm, for example, squeeze the main artery in the upper arm against the bone. Keep your fingers flat; with the other hand, continue to exert pressure on the wound itself.
- Immobilize the injured body part once the bleeding has been stopped. Leave the bandages in place and get the injured person to the emergency room as soon as possible or, if they cannot be moved for help.
SHOCK
Shock happens when the heart and blood vessels are unable to pump enough oxygen-rich blood to the vital organs of the body.
Although every illness involves shock to some degree, it can be a life-threatening problem.
The best way to protect people from the serious damages that shock can have on the system is to recognize the symptoms before the person gets into serious trouble.
In most cases, only a few of the symptoms will be present, and many do not appear for some time.
1. Common Symptoms
- Pale, cold, clammy and moist skin
- Vacant or dull eyes, dilated pupils
- Anxiety, restlessness, and fainting
- Weak, rapid, or absent pulse
- Nausea and vomiting
- Shallow, rapid, and irregular
breathing
- Excessive thirst
- Person may seem confused
- Look tired and fatigue
2. Classification of shock:
i. Hypovolemic Shock:
• Brought on by a decrease in the amount of blood vessels or other fluids in the body.
• Cause by excessive bleeding from internal and external injuries, fluid loss due to diarrhea, burns, dehydration, and severe vomiting.
ii. Neurogenic Shock:
• The blood vessels become abnormally enlarged and the pooling of the blood disallows an adequate blood flow to be maintained.
• Fainting is an example of this sort of shock, as the blood temporarily pools as the person stands. When the person falls the blood rushes back to the head and the problem is solved.
iii. Psychogenic Shock:
• This shock is more common, and is known as a “shock like condition”. It is produced by excessive fear, joy, anger, or grief. “Shell shock” is a psychological adjustment reaction to stressful wartime experiences.
• Treatment for shell shock is limited to emotional support and help from a medical facility.
iv. Anaphylactic Shock:
This form of shock is brought on by an allergic reaction from a food, bee sting or other insect bite, and inhalants.
3. General Treatment
- Call local emergency help provider for help
- Lay the victim face up, on a blanket or coat if possible, and raise the feet above the head unless they are fractured.
- Check the injured person's airway, breathing and circulation. Open and maintain the airway, and perform rescue breathing or CPR if necessary
If the person is bleeding from the mouth or vomiting, tilt their head to the side to avoid fluids going into the lungs and airways. If you are unsure of injuries keep the person laying flat.
- Loosen tight clothing, braces, belts, jewelry etc to avoid constriction of the waist, neck and chest.
- Keep the victims comfortable and warm enough to be able to maintain their own body heat. If possible, remove wet clothing and place blankets beneath the victim. NEVER use artificial sources of heat eg electric blanket.
If they are bleeding severely do not apply heat to the wounded area, as it will prevent the blood from clotting as easily.
- Check for other injuries, such as bleeding and burns and treat the other injuries according to first aid procedures.
If possible try to splint sprains or broken bones. If you are unsure of how to do this, leave them as they are to avoid further damage.
- If they claim they are thirsty moisten their lips with water but DO NOT give them anything to drink, as it may induce vomiting.
- Try to keep the victim calm, excitement and excessive handling will worsen their condition try to assure them help is on the way.
These treatment if apply before shock has completely developed you may prevent its occurrence and if it had developed you may stop it from becoming fatal.
If shock is left unattended to the victim will die, it is extremely important that first aid be performed as soon as possible.
Give fluids only if the following conditions are met:
The injured person can hold the cup and drink by himself;
surgery is not likely within six hours;
there is no abdominal injury;
evacuation is more than six hours away; and
there are no downward changes in the person's level of consciousness.
FIRST AID KIT
Remember the Three Mechanisms of Injury:
• Trauma – due to high impact e.g. car accident
• Medical – illness e.g high blood pressure, diabetic
• Environmental- e.g tsunami
The Complete KIT
The First aid kit must be well organized, weather proof, accessible in an emergency, and user friendly. The simplest way to organize is:
- to separate bandages, dressings, meds, etc. with ziplocks, or some sort of waterproof dividers.
- Writing what's in the bag can help when the adrenaline is pumping, or some people even color code what is what.
- Having gloves, pocket mask, and other protection readily available is very important.
Not only is the first aid kit itself important, it is how easily you can assemble all your resources.
Suggested Personal First Aid Kit List
1 - roll 1" cloth tape
4 - 4" x 4", or 3" x 3" general gauze pads
2 - non-adherent gauze pads
1 - 8" x 7" combine (bulk) dressing
8 - band-aid bandages
2 - 3" or 4" stretch roller gauze
3 - 3" or 4" occlusive dressings
2 - triangular bandages
1 - 4" ace wrap
1 - Sam Splint or wire splint
4pr - vinyl exam gloves
1 - CPR pocket mask w/ 1 way valve or shield
1 - Airways, nasal and/or airway
1 - blister kit (personal preference)
5 - povodine iodine packets
1 - trauma scissors
1 - splinter tweezers
1 - thermometer
1 - med kit (personal preference)
1 - blanket pin
2 - safety pins
1 - 12 to 60cc syringe
1 - 20-30' duct tape
-Medication
Carrying Device
One that works best in environment in which you travel.
o Dry Bag/Box, fanny pack, compartmentalized pouch, ziplock bags, etc.
Personal Protection
Must be easily accessible. Gloves can be placed in various places e.g in your pack, a lifejacket in a film canister, etc.
- Vinyl or Latex Gloves - 2 to 4 pairs per person*
- CPR Mask - or at the very least, a CPR Shield
- Airways - dependent on level of training
Wound Care
Bandages - narrow piece of cloth tie around wound or dressing :3" and/or 4" roller gauze that stretches and possibly self-adhering
Dressings – material used 2 cover and protect wound: carry multiple sizes of sterile gauze bandages or a 4" x 4". Different dressings may help make wound care much more manageable.
General Purpose Gauze Pads - uses for wound care, from padding to absorbency.
Combine and Trauma Dressing - used where high absorbency and/or padding are necessary. Larger sizes in these are usually recommended e.g Surgipad.
Occlusive Dressings - dressing to keep a wound dry in a wet environment. Care must be taken to remove these dressings during rest periods to help promote healing in a prolonged context. Examples include Bioclusive and Tegaderm.
Bandage Strips - a bandage with an attached dressing, better known as Band-Aids. It is important to change these regularly, so bring enough.
Tape – To secure bandages or closing wounds. 1" cloth tape is usually all that is needed in a basic first aid kit.
Duct, packaging and other tapes make great securing tools for bandages, splints, clothing, etc. Be careful to watch for constriction and other circulation problems. 20-30 ft.
Wound Cleansing
The risk of infection is greater when the wound is close, so prior wound cleansing is vital.
Clean water for washing off residue
Povidine Iodine (PI) used in a solution with water, to adequately irrigate the wound and surrounding area. Some people are allergic to iodine, so check their medical history first.
Soaps, as well as medical "scrubs" that can be used for cleansing around wounds.
Splinting
The most improvised skill there is. Lifejackets, packs, paddles, ski poles, etc. all make great splints.
- Use the injured’s person equipment first!
- Remember to watch for constriction, comfort, and compatibility.
Hardware
Tool that can expedite and assist during treatment:
Tweezers – to pull out splinter or hold cotton for wound cleaning
Pins - to secure materials such as using a sleeve as a improvised sling, or securing a tarp as a shelter.
Plastic bags - make great irrigators, improvised glove, or occlusive layer. Big trash bags are perfect for vapor barriers when wrapping up a patient, emergency shelter, and to put trash in.
Thermometer - A digital indoor/outdoor thermometer with a probe is a good resource to tell temp. variations of a patient who is either immobilized during or waiting for evac, although not as accurate as a medical version.
Trauma shears - for removing clothing, cutting improvised splints to size etc
Heat/Cold Packs - again usually carried in major med kits, these will help in short term context. Water bottles with warm water, cooled wet towels, filled ziplocks, can be improvised heat/cold packs.
Mirror/signal device - a compass with a mirror show a spruce speck in the eye, or help locate tick or leech. It can also be used to signal aircraft or other groups.
Whistle - can be use as signals.
Flashlight/headlamp - Select a light appropriate to your activity
Lighter/ waterproof matches- if traveling in wet, cold environments it is also good to carry a fire catalyst, such as fire ribbon, or fire gel.
Medications
Adequate training, written policies and procedures and medical control should all be considered.
- Topical antibiotic cream - such as Neosporin, has been proven to promote healing in shallow wounds and help maintain a good barrier.
- Analgesic, Antipyretic and Anti-inflammatory – pain killer such as Tylenol, Ibuprofen, and aspirin. It is personal preference to what has worked best for you.
- Antihistamine – for allergies: such as Benadryl and Sudafed for
- Antacid – for stomach discomfort/ burning feeling due to e.g overeating : Mylanta, Gelusil, Pepto Bismol, Maalox
- Antidiarrheal - Pepto, Keopectate, Immodium, Lomotil
- Anticonsptipation - Metmucil, glycerine suppositories
- Antifungal/yeast - Tinactin, Mystatin
- Dental Problems - pain relief from clove oil, Orabase
- Special Needs and Medications - such as prescription antibiotics, asthma inhalers, altitude meds, epineherine, etc
- Glucose - liquid glucose in a single use tube
- Oral Electrolyte Replacement Solution - such as Gookinaid, Gatorade, etc.
- Tincture of Benzoin - helps keep bandages attached
- Activated Charcoal – poisoning emergencies
BANDAGE, TRIANGULAR BANDAGE & CRAVAT
1. DEFINITION
Standard bandages are made of gauze or muslin and are used over a sterile dressing to secure the dressing in place, to close off its edge from dirt and germs, and to create pressure on the wound and control bleeding.
A bandage can also support an injured part or secure a splint. The most common types of bandages are the roller and triangular bandages.
2. General Application
- Applied evenly, firmly, but not too tightly. Excessive pressure may cause interference with the circulation and may lead to disastrous consequences e.g gangrene.
- It is safer to apply a large number of turns of a bandage, rather than to depend upon a few turns applied too firmly to secure a compress.
- In applying a wet bandage, or one that may become wet, you must allow for shrinkage.
- The turns of a bandage should completely cover the skin, as any uncovered areas of skin may become pinched between the turns, with resulting discomfort.
- The terminal end of the completed bandage is turned under and secured to the final turns by either a safety pin or adhesive tape. When these are not available, the end of the bandage may be split lengthwise for several inches, and the two resulting tails may be secured around the part by tying
Bandaging any extremity (arms or legs)
- leave the fingers or toes exposed so the circulation of these parts may be readily observed. (capillary refill)
- Include the whole member (arm or leg, excepting the fingers or toes) so that uniform pressure may be maintained throughout.
- It is also desirable in bandaging a limb that the part is placed in the position it will occupy when the dressing is finally completed, as variations in the flexion and extension of the part will cause changes in the pressure of certain parts of the bandage.
- The initial turns of a bandage on an extremity (including spica bandages of the hip and shoulder) should be applied securely, and, when possible, around the part of the limb that has the smallest circumference
- In bandaging the arm or hand the initial turns are usually applied around the wrist.
- in bandaging the leg or foot, the initial turns are applied immediately above the ankle.
- The final turns of a completed bandage are usually secured in the same manner as the initial turns, by employing two or more overlying circular turns.
- As both edges of the final circular turns are exposed, they should be folded under to present a neat, cuff like appearance.
3. Bandage Technique
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ROLLER BANDAGE FOR HAND AND WRIST
- Figure-eight bandage is ideal.
- Anchor the dressing, whether it is on the hand or wrist, with several turns of a 2- or 3-inch bandage.
- If on the hand, anchor the dressing with several turns and continue the bandage diagonally upward and around the wrist and back over the palm.
- Make as many turns as necessary to secure the compress properly
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ROLLER BANDAGE FOR ARM AND LEG
- Use the spiral reverse bandage to cover wounds of the forearms and lower extremities
- Make two or three circular turns around the lower and smaller part of the limb to anchor the bandage and start upward, going around making the reverse laps on each turning, overlapping about one-third to one-half the width of the previous turn.
- Continue as long as each turn lies flat.
- Continue the spiral and secure the end when completed
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ROLLER BANDAGE FOR ANKLE AND FOOT
- Use figure-eight bandage for dressings of the ankle, as well as for supporting a sprain.
- While keeping the foot at a right angle, start a 3-inch bandage around the instep for several turns to anchor it.
- Carry the bandage upward over the instep and around behind the ankle, forward, and again across the instep and down under the arch, thus completing one figures eight.
- Continue the figure-eight turns, overlapping one-third to one-half the width of the bandage and with an occasional turn around the ankle, until the compress is secured or until adequate support is obtained
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ROLLER BANDAGE FOR HEEL.
- Place the free end of the bandage on the outer part of the ankle and bring the bandage under the foot and up.
- Then carry the bandage over the instep, around the heel, and back over the instep to the starting point.
- Overlap the lower border of the first loop around the heel and repeat the turn, overlapping the upper border of the loop around the heel.
- Continue this procedure until the desired number of turns is obtained, and secure with several turns around the lower leg
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TRIANGULAR BANDAGE
The longest side of the triangular bandage is called the base; the corner directly opposite the middle of the base is called the point; and the other two corners are called ends
The triangular bandage is useful because it can be folded in a variety of ways to fit almost any part of the body. Padding may be added to areas that may become uncomfortable.
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TRIANGULAR BANDAGE FOR HEAD
- This bandage is used to retain compresses on the forehead or scalp.
- Folds back the base about 2 inches to make a hem.
- Place the middle of the base on the forehead, just above the eyebrows, with the hem on the outside.
- Let the point fall over the head and down over the back of the head.
- Bring the ends of the triangle around the back of the head above the ears, cross them over the point, carry them around the forehead, and tie in a SQUARE KNOT.
- Hold the compress firmly with one hand, and, with the other, gently pull down the point until the compress is snug; then bring the point up and tuck it over and in the bandage where it crosses the back part of the head.
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TRIANGULAR BANDAGE FOR SHOULDER
- Cut or tear the point, perpendicular to the base, about 10 inches.
- Tie the two points loosely around the patient’s neck, allowing the base to drape down over the compress on the injured side.
- Fold the base to the desired width, grasp the end, and fold or roll the sides toward the shoulder to store the excess bandage.
- Wrap the ends snugly around the upper arm, and tie on the outside surface of the arm.
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TRIANGULAR BANDAGE FOR CHEST
- Cut or tear the point, perpendicular to the base, about 10 inches.
- Tie the two points loosely around the patient’s neck, allowing the bandage to drape down over the chest.
- Fold the bandage to the desired width, carry the ends around to the back, and secure by tying.
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TRIANGULAR BANDAGE FOR HIP OR BUTTOCK
- Cut or tear the point, perpendicular to the base, about 10 inches.
- Tie the two points around the thigh on the injured side.
- Lift the base up to the waistline, fold to the desired width, grasp the ends, fold or roll the sides to store the excess bandage, carry the ends around the waist, and tie on the opposite side of the body.
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TRIANGULAR BANDAGE FOR FOOT OR HAND
This bandage is used to retain large compresses and dressings on the foot or the hand.
- For the foot: After the compresses are applied, place the foot in the center of a triangular bandage and carry the point over the ends of the toes and over the upper side of the foot to the ankle. Fold in excess bandage at the side of the foot, cross the ends, and tie in a square knot in front.
- For the hand: After the dressings are applied, place the base of the triangle well up in the pal mar surface of the wrist. Carry the point over the ends of the fingers and back of the hand well up on the wrist. Fold the excess bandage at the side of the hand, cross the ends around the wrist, and tie a square knot in front
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CRAVAT BANDAGE
A triangular bandage can be folded into a strip for easy application during an emergency.
- When folded as shown, the bandage is called a cravat. To make a cravat bandage, bring the point of the triangular bandage to the middle of the base and continue to fold until a 2-inch width is obtained.
- The cravat may be tied, or it may be secured with safety pins (if the pins are available).
- When necessary, a cravat can be improvised from common items such as T-shirts, bed linens, trouser legs, scarves, or any other item of pliable and durable material that can be folded, torn, or cut to the desired size.
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Cravat Bandage for Temple, Cheek, or Ear
After a compress is applied to the wound, place the center of the cravat over it and hold one end over the top of the head.
- Carry the other end under the jaw and up the opposite side, over the top of the head, and cross the two ends at right angles over the temple on the injured side.
- Continue one end around over the forehead and the other around the back of the head to meet over the temple on the uninjured side.
- Tie the ends in a square knot. (This bandage is also called a Modified Barton.)
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Cravat Bandage for Eye
- After applying a compress to the affected eye, place the center of the cravat over the compress and on a slant so that the lower end is inclined downward.
- Bring the lower end around under the ear on the opposite side.
- Cross the ends in back of the head, bring them forward, and tie them over the compress.
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Cravat Bandage for Elbow or Knee
- After applying the compress, and if the injury or pain is not too severe, bend the
- elbow or knee to a right-angle position before applying the bandage.
- Put on middle of a rather wide cravat over the point of the elbow or knee, and carry the upper end around the upper part of the elbow or knee, bringing it back to the hollow, and the lower end entirely around the lower part, bringing it back to the hollow.
- See that the bandage is smooth and fits snugly; then tie in a square knot outside of the hollow.
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Cravat Bandage for Arm or Leg
- The width of the cravat you use will depend upon the extent and area of the injury.
- For a small area, place a compress over the wound, and center the cravat bandage over the compress.
- Bring the ends around in back, cross them, and tie over the compress.
- For a small extremity, it may be necessary to make several turns around to use all the bandage for tying.
- If the wound covers a larger area, hold one end of the bandage above the compress and wind the other end spirally downward across the compress until it is secure, then upward and around again, and tie a knot where both ends meet.
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Cravat Bandage for Axilla (Armpit)
- This cravat is used to hold a compress in the axilla.
- It is similar to the bandage used to control bleeding from the axilla.
- Place the center of the bandage in the axilla over the compress and carry the ends up over the top of the shoulder and cross them.
- Continue across the back and chest to the opposite axilla, and tie them.
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Spiral Bandage Technique
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posted at 2:23 PM   |
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| Thursday, August 10, 2006 |
| THE MUSCULAR SYSTEM |
5. THE MUSCULAR SYSTEM
5.1 Overview
The muscular system is the biological system of humans that allows them to move. It is the body's network of tissues that controls movement both of the body and within it. Walking, running, jumping is possible only because of the contraction (shortening) and relaxation of muscles. These major movements, however, are not the only ones directed by muscular activity. Muscles make it possible to stand, sit, speak, and blink. Beside that it allows blood rush through blood vessels, air fill the lungs, and food move through the digestive system. In short, muscles are the machines of the body, allowing it to work.
Muscle tissue is composed of a series of fibers, similar to neurons in shape, that operate in a coordinated manner under the supervision of the nervous system to:
i) support movement in the body, and
ii) assist in maintaining body temperature through shivering to create heat.
There is three forms of muscles in the human body:
-Smooth muscle, involuntary, uninucleated, non-striated found on the walls of internal organs
-Cardiac muscle, involuntary, uninucleated, striated (*with intercalated disc) found only in the heart
-Skeletal muscle, voluntary, multinucleated, striated which help strengthen the body and connect to bones.
Muscles are labeled as either voluntary or involuntary.
-Voluntary muscles are muscles that you can move whenever you want to.
-Involuntary muscles contract and relax automatically inside your body. We can not control our involuntary muscles.
-Muscles can only pull. They never push.
5.2 The muscular muscle cell
-Each muscle is made of hundreds to thousands of individual muscle cells, unusually shaped i.e elongated like a cylinder or a long rod.
-Because of their shape, muscle cells are normally referred to as muscle fibers.
-Whereas most cells have a single nucleus (the part of the cell that controls its activities), muscle fibers have as many as 100 or more nuclei. The nuclei are located on the surface of the fiber, just under its thin membrane.
-Another difference between muscle fibers and other body cells is their size. They can extend the entire length of a muscle. For example, a muscle fiber in a thigh muscle could measure 0.0004 inch (0.001 centimeter) in diameter and 12 to 16 inches (30 to 40 centimeters) in length.
5.3 Tendons
-Tendons attach muscles to bone
-It is layers of connective tissue that bundle the various parts of a muscle usually converge or come together at the end of the muscle to form a tough, white, cord-like tissue.
-Tendons are much stronger than muscle tissue because it contains fibers of the tough protein collagen.
-The collagen fibers are arranged in a tendon in a wavy way so that it can stretch and provide additional length at the muscle-bone junction. As muscles are used, the tendons are able to withstand the constant pulling and tugging.
-Muscles are always attached at both of their ends. The end that is attached to a bone that moves when the muscle contracts is called the insertion. The other end, attached to a bone that does not move when the muscle contracts, is called the origin.
-It is important to note that not all muscles are attached to bones at both ends. The ends of some muscles are attached to other muscles; some are attached to the skin.
5.4 The muscular major muscle
-Skeletal muscles support the skull, backbone, and rib cage are called axial skeletal muscles that include the muscles of the head and neck and those of the trunk.
-Roughly 60 percent of all skeletal muscles in the body are axial muscles.
-The skeletal muscles of the limbs (arms and legs) are called distal or appendicular skeletal muscles. These include the muscles of the shoulders and arms and those of the hip and legs.
-Muscle names are descriptive according to their;
*Location in the body like the frontalis muscle overlies the frontal bone of the skull.
*Relative size like maximus (largest), minimus (smallest), and longus (long). *Shape like the deltoid muscle has the shape of the Greek letter delta, which is triangular-shaped. *Actions like flexor (to flex or bend in), extensor (to extend or straighten out), adductor (to draw toward a line that runs down the middle of the body), and abductor (to draw away from a line that runs down the middle of the body)
5.6 THE MUSCULAR SYSTEM FUNCTIONS
-Muscles have three important functions: to produce movement, maintain posture, and generate heat.
-Almost all movements by the human body result from muscle contraction.
-Muscles lend support to the body and help it maintain posture against the force of gravity. Even when the body is at rest (or asleep), muscle fibers are contracting to maintain muscle tone.
-Any activity by muscles generates heat as a byproduct, which is vital in maintaining normal body temperature.
The link between nerve cells and muscle fibers
 Muscle fibers must be stimulated by nerve impulses sent through motor neurons or nerves.These impulses originate in the brain, then run down the spine to contract or shorten muscle.From there, they branch out to all parts of the body.
A single motor neuron may stimulate a few muscle fibers or hundreds of them. A motor neuron along with all the fibers it stimulates is called a motor unit. When a motor neuron reaches a muscle fiber, it does not touch the fiber, but fits into a hollow on the surface of the muscle fiber. This region where the end of the motor neuron and the membrane of the muscle fiber come close together is called the neuromuscular junction.
When a nerve impulse reaches the end of the motor neuron at the neuromuscular junction, acetylcholine (a neurotransmitter chemical) is released. Acetylcholine then travels across the small gap between the motor neuron and the muscle fiber and attaches to receptors on the membrane of the muscle fiber. This triggers an electrical charge that quickly travels from one end of the muscle fiber to the other, causing it to contract.
Muscle fiber energy
In order to contract, muscles need energy. That energy comes from adenosine triphosphate (ATP), a high-energy molecule found in every cell in the body. ATP is the only energy source that muscles can use to power their activity.
In the human body, the liver stores glucose by converting it to glycogen. When the body needs energy, the liver is stimulated to change glycogen back into glucose and secrete it into the bloodstream for use by the cells.
In the cells, glucose combines with oxygen to yield or produce carbon dioxide, water, heat, and ATP. This process of energy production that uses oxygen in the reaction is called aerobic ("with air") metabolism.
-Carbon dioxide, water, and heat are all waste products of this chemical reaction.
-Carbon dioxide moves from the cells into the blood to be carried to the lungs, where it is exhaled.
-The water becomes a necessary part of a cell's internal fluid.
-The heat contributes to normal body temperature. If too much heat is generated, such as during vigorous physical activities, the excess heat is carried away and removed from the body through the process of sweating.
WHY DOES THAT HAPPEN?
Q: Why do I shiver when I become cold?
A: When the
temperature of the body drops below normal, the brain signals the muscles to
contract rapidly—what we perceive as shivering. The heat generated by these
rapid muscle contractions helps to raise or at least stabilize body temperature.
When lactic acid builds up in muscle fibers, it increases the acidity in the
fibers. Key enzymes in the fibers are then deactivated, and the fibers can no
longer function properly. As a result, muscles are not as effective, contracting
less and less. This condition is known as muscle fatigue.
In a state of
fatigue, muscle contractions may be painful. Finally, muscles may simply stop
working.
Movement and muscle arrangement
-Muscles cannot push; they can only pull. In order to create movement, muscles must act in pairs.
-Muscles are arranged on the skeleton in such a way that the flexing or contracting of one muscle or group of muscles is usually balanced by the lengthening or relaxation of another muscle or group of muscles. Thus, when a muscle performs an action, another can undo or reverse that action.
-For example, when the biceps (muscle on the front of the upper arm) contracts, the forearm moves in at the elbow toward the biceps; at the same time, the triceps (muscle on the rear of the upper arms) lengthens. When the forearm is moved out in a straight-arm position, the opposite occurs: the triceps contracts and the biceps lengthens.
-A muscle whose contraction is responsible for producing a particular movement is called a prime mover (or an agonist).
-A muscle that opposes or reverses the movement of a prime mover is called an antagonist. Generally, antagonistic muscles are located on the opposite side of a limb or portion of the body from prime mover or agonist muscles.
-Most muscles do not act by themselves to produce a particular movement. Muscles that help prime movers by producing the same movement or by reducing unnecessary movement are called synergists. When the biceps flexes the elbow, smaller muscles in the upper arm also come into play. If the elbow is flexed with the palm of the hand up, the biceps is the prime mover. However, if the elbow is flexed with the palm down or the thumb up (palm in), the other muscles become the prime movers. These particular synergistic muscles allow for greater mobility or movement of the hand when the elbow is flexed.
-Although prime movers are mainly responsible for producing certain body movements, the actions of antagonists and synergists are equally important. Without the combined efforts of all three types of muscles, body movements would not be smooth, coordinated, and precise.
Muscle tone
-Even when the body is at rest, certain muscle fibers in all muscles are contracting. This activity is directed by the brain and cannot be controlled consciously.
-This state of continuous partial muscle contractions is known as muscle tone are not strong enough to produce movement, but do tense and firm the muscles. In doing so, they keep the muscles firm, healthy, and ready for action.
-Muscles with moderate muscle tone are firm and solid, whereas ones with little muscle tone are limp and soft.
-Muscle tone is the result of different motor units throughout a muscle being stimulated by the nervous system in an orderly way. First one group of motor units is stimulated, then another. Alternate fibers contract so the muscle as a whole does not become fatigued.
-Muscle tone is important because it helps human beings maintain an upright posture. Without muscle tone, an individual would not be able to sit up straight in a chair or hold his or her head up. Muscle tone is also important because it generates heat to help maintain body temperature. Normal muscle tone accounts for about 25 percent of the heat in a body at rest.
5.7 Muscle Disorder
-Spasm: Sudden, involuntary muscle contraction.
-Strain: Slight tear in a muscle; also called a pulled muscle.
-Botulism (BOCH-a-liz-em): Form of food poisoning in which a bacterial toxin prevents the release of acetylcholine at neuromuscular junctions, resulting in paralysis.
-Muscular dystrophy (MUS-kyu-lar DIS-tro-fee): One of several inherited muscular diseases in which a person's muscles gradually and irreversibly deteriorate, causing weakness and eventually complete disability.
-Myasthenia gravis (my-ass-THEH-nee-ah GRA-vis): Autoimmune disease in which antibodies attack acetylcholine, blocking the transmission of nerve impulses to muscle fibers.
-Tetanus (TET-n-es): Bacterial disease in which a bacterial toxin causes the repetitive stimulation of muscle fibers, resulting in convulsive muscle spasms and rigidity.
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| posted at 11:28 AM |
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| THE SKELETAL SYSTEM |
4. THE SKELETAL SYSTEM
The Skeletal System serves many important functions; it provides the shape and form for our bodies in addition to supporting, protecting, allowing bodily movement, producing blood for the body, and storing minerals.
4.1. Functions
i. Its 206 bones form a rigid framework to which the softer tissues and organs of the body are attached.
ii. Vital organs are protected by the skeletal system. The brain is protected by the surrounding skull as the heart and lungs are encased by the sternum and rib cage.
iii. Bodily movement is carried out by the interaction of the muscular and skeletal systems. For this reason, they are often grouped together as the musculo-skeletal system. Muscles are connected to bones by tendons. Bones are connected to each other by ligaments. Where bones meet one another is typically called a joint. Muscles which cause movement of a joint are connected to two different bones and contract to pull them together. An example would be the contraction of the biceps and a relaxation of the triceps. This produces a bend at the elbow. The contraction of the triceps and relaxation of the biceps produces the effect of straightening the arm.
iv. Blood cells are produced by the marrow located in some bones. An average of 2.6 million red blood cells are produced each second by the bone marrow to replace those worn out and destroyed by the liver.
v. Bones serve as a storage area for minerals such as calcium and phosphorus. When an excess is present in the blood, buildup will occur within the bones. When the supply of these minerals within the blood is low, it will be withdrawn from the bones to replenish the supply.
4.2 Types of Bone
The bones of the body fall into four general categories: long bones, short bones, flat bones, and irregular bones.
Long bones are longer than they are wide and work as levers. The bones of the upper and lower extremities (ex. humerus, tibia, femur, ulna, metacarpals, etc.) are of this type.
Short bones are short, cube-shaped, and found in the wrists and ankles.
Flat bones have broad surfaces for protection of organs and attachment of muscles (ex. ribs, cranial bones, bones of shoulder girdle).
Irregular bones are all others that do not fall into the previous categories. They have varied shapes, sizes, and surfaces features and include the bones of the vertebrae and a few in the skull.
4.3 Bone Composition
Bones are composed of tissue that may take one of two forms.
Compact, or dense bone, and spongy, or cancellous, bone. Most bones contain both types.
Compact bone is dense, hard, and forms the protective exterior portion of all bones.
Spongy bone is inside the compact bone and is very porous (full of tiny holes). Spongy bone occurs in most bones. The bone tissue is composed of several types of bone cells embedded in a web of inorganic salts (mostly calcium and phosphorus) to give the bone strength, and collagenous fibers and ground substance to give the bone flexibility
4. 4. Divisions of the Skeleton
 The human skeleton is divided into two distinct parts:
The axial skeleton consists of bones that form the axis of the body and support and protect the organs of the head, neck, and trunk.
o The Skull
o The Sternum
o The Ribs
o The Vertebral Column
The appendicular skeleton is composed of bones that anchor the appendages to the axial skeleton.
o The Upper Extremities
o The Lower Extremities
o The Shoulder Girdle
o The Pelvic Girdle--(the sacrum and coccyx are considered part of the vertebral column)
o Tendons and ligaments are strong bands of fibrous connective tissue that attach muscles to bones, and bones to bones, respectively.
 Overview of Axial Skeleton
 The Skull
Cranial bones are flat, rounded, and fused to protect the brain.
oFacial bones provide a framework for the facial muscles, form eye sockets, and form jaws for the teeth.
oThe hinged mandible (jaw bone) moves freely during mastication (chewing) and speech.
The Vertebral
~The vertebral column has three groups of vertebrae and two sets of fused bones;
o vertebrae include seven cervical (neck) vertebrae,
o twelve thoracic (upper back) vertebrae
o and five lumbar (lower back) vertebrae.
~Five fused vertebrae form the sacrum and from three to five fused small vertebrae form the coccyx (tail bone).
~The vertebrae form a column of bone that protects the spinal cord. The thoracic vertebrae have facets (indentations) upon their surfaces that articulate (meet) with the ribs.
The Ribs
~The twelve pairs of ribs are long, flattened, and curved bones that form a protective cage for the heart, lungs, and other internal organs.
~The vertebrosternal (true) ribs are the first seven ribs; they are "true" because they attach directly to the sternum (breast bone).
~Ribs eight through twelve are the false ribs because they indirectly attach to the sternum or they lack a sternal attachment.
~Ribs eight through ten are the vertebrochondral ribs because they attach indirectly to the sternum by cartilage.
~Ribs eleven and twelve are called floating (vertebral) ribs because they do not attach to the sternum. Instead, their floating position allows them to bend sideways while providing protection for the kidneys.
Overview of Appendicular skeleton
The Pectoral Girdle Bones
~include two scapulae (shoulder blades) and two clavicles (collar bones).
oThe scapula is in the upper back and articulates with two bones: the humerus and the clavicle. Because the scapula is part of the shoulder joint, the scapula must be mobile to allow the upper extremities freedom of movement.
oThe clavicle articulates with the sternum and the scapula, giving support to the pectoral girdle and adding stability to the shoulder joint.
The Bones Of The Upper Extremities
oConsist of the humerus, ulna, radius, carpals (wrist bones), metacarpals (hand bones), and phalanges (finger bones).
oThe humerus in the arm articulates with the scapula at the shoulder joint and with the ulna and radius at the elbow.
oThe radius and ulna in the forearm articulate with the carpals at the wrist. The ulna articulates with the humerus and forms the elbow.
oThe carpals are small, flat, irregularly shaped wrist bones. They articulate with the metacarpals in the hand. The metacarpals articulate with the phalanges.
The Bones Of The Lower Extremities
~The Pelvic
o In the pelvic girdle are two hip bones. Each coxa (hip bone) forms from fused bones. The two coxae, sacrum, and coccyx form the pelvis, a bowl-shaped cavity that supports and protects many abdominal organs.
o The pelvic girdle articulates with the femur (thigh bone) at the acetabulum (hip joint) and with the sacrum at the sacroiliac joint. Also, the coxae articulate with each other at the pubic symphysis, a joint with limited movement.
~The femur
 o is the longest and heaviest bone in the body and helps in weight-bearing while standing.
o At the knee, the femur articulates with the tibia (shin bone). Suspended within muscle tendons at the front of the knee joint is the patella (kneecap). The patella is an example of a sesamoid bone (small bone) that is within a tendon.
~The Fibula
o Attaching to the lateral (outer side) of the tibia is the fibula (leg bone).
o The fibula provides points of attachment for muscles of the foot and leg and increases the lateral stability of the ankle.
o The fibula is not a weight-bearing bone like the tibia.
~The Foot
o In the foot are specialized bones designed for weight-bearing. Among these are the tarsals (ankle bones), metatarsals (foot bones), and phalanges (toe bones).
o These foot bones form a system of arches that allow the foot to support much weight.
4.5 Bone marrow
Within the long bones are two types of bone marrow: red marrow and yellow marrow. The yellow marrow has fatty connective tissue and fills the marrow cavity. During starvation, the body uses the fat in yellow marrow for energy.
 The red marrow of some bones is an important site for blood cell production.
Here all erythrocytes (red blood cells), platelets, and most leukocytes (white blood cells) form in adults. From the red marrow, erythrocytes, platelets, and leukocytes migrate to the blood to do their special tasks.
Red blood cells carry oxygen and nutrients to the body tissues. Platelets help in blood clotting. White blood cells help fight disease and infection.
4.6 Joints
~Bones of the skeleton articulate at joints.
~A joint, or articulation, is the place where two bones come together. There are three types of joints classified by the amount of movement they allow: immovable, slightly movable, and freely movable.
~Immovable joints are synarthroses. In this type of joint, the bones are in very close contact and are separated only by a thin layer of fibrous connective tissue. An example of a synarthrosis is the suture in the skull between skull bones.
 ~Slightly movable joints are called amphiarthroses. This type of joint is characterized by bones that are connected by hyaline cartilage (fibro cartilage). The ribs that connect to the sternum are an example of an amphiarthrosis joint.
~Most of the joints in the adult human body are freely movable joints. This type of joint is called a diarthrosis joint. There are six types of diarthroses joints. These are:
o Ball-and-Socket: The ball-shaped end of one bone fits into a cup shaped socket on the other bone allowing the widest range of motion including rotation. Examples include the shoulder and hip.
o Condyloid: Oval shaped condyle fits into elliptical cavity of another allowing angular motion but not rotation. This occurs between the metacarpals (bones in the palm of the hand) and phalanges (fingers) and between the metatarsals (foot bones excluding heel) and phalanges (toes).
o Saddle: This type of joint occurs when the touching surfaces of two bones have both concave and convex regions with the shapes of the two bones complementing one other and allowing a wide range of movement. The only saddle joint in the body is in the thumb.
o Pivot: Rounded or conical surfaces of one bone fit into a ring of one or tendon allowing rotation. An example is the joint between the axis and atlas in the neck.
o Hinge: A convex projection on one bone fits into a concave depression in another permitting only flexion and extension as in the elbow and knee joints.
o Gliding: Flat or slightly flat surfaces move against each other allowing sliding or twisting without any circular movement. This happens in the carpals in the wrist and the tarsals in the ankle.
4.7 Bone Cells
There are five main types of bone cells in bone tissue.
oOsteogenic cells respond to traumas, such as fractures, by giving rise to bone-forming cells and bone-destroying cells.
oOsteoblasts (bone-forming cells) synthesize and secrete unmineralized ground substance and are found in areas of high metabolism within the bone. Osteocytes are mature bone cells made from osteoblasts that have made bone tissue around themselves.
oThese cells maintain healthy bone tissue by secreting enzymes and controlling the bone mineral content; they also control the calcium release from the bone tissue to the blood. oOsteoclasts are large cells that break down bone tissue.
They are very important to bone growth, healing, and remodeling. The last type of cells are bone-lining cells. These are made from osteoblasts along the surface of most bones in an adult.
Bone-lining cells are thought to regulate the movement of calcium and phosphate into and out of the bone.
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| posted at 10:38 AM |
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| Sunday, August 06, 2006 |
| Human Anatomy |
Anatomy
The study of body shape and structure and its correlationship
Physiology
The study of bodies function.
Physiology and anatomy go hand and hand, as the study of one subject relates to the study of the other as a system.
Human systems include circulatory, respiratory, digestive, urinary, muscularskeletal, immune, nervous, endocrine, reproductive, and integumentary
In this course, we will concentrate on 5 main human systems: 1.The Nervous System 2.The Circulatory System 3.The Respiratory System 4.The Skeletal System 5.The Muscular System **you can click directly to the titles to be drectly linked to the chapter site.
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| posted at 1:57 AM |
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| The Respiratory System |
3. RESPIRATORY SYSTEM
All the body cells metabolically consume oxygen, and discharge carbon dioxide. To cover this need, respiration takes place internally (at the cellular level) and externally (ventilation/breathing).
Ventilation involves the inhalation of atmospheric air into the lungs via the nose and mouth through branching passageways, and the exhalation of carbon dioxide.
The lung key function is to bring air and blood into intimate contact in the alveolar air sacs so that oxygen can enter the blood, and carbon dioxide can leave.
At rest, humans breathe about twelve times a minute, bringing in approximately a pint of air.
Exercise and certain diseases result in a marked increase of breathing.
The respiratory system also is vital in maintaining normal blood pH and body temperature.
3.1 Lungs and air passages
The lungs are paired organs that lie on either side of the heart and fill up the thoracic (chest) cavity. Inferior to (below) the lungs is the diaphragm, a broad thin muscle that separates the thoracic cavity from the abdominal (gut) cavity. On the medial (inner) surface of each lung is the hilus, where blood vessels, nerves, and bronchi (air passages) enter the lungs.
The lungs differ in size and shape. Because the heart is slightly larger on the left side, the left lung has a cardiac notch (indented border). The left lung is also slightly smaller than the right.
Each lung is divided into lobes (partitions) by fissures. The right lung has three lobes: lower, middle, and upper. These horizontal and oblique fissures create these lobes. The left lung has upper and lower lobes that are divided by the oblique fissure.
3.2 Breathing Mechanism
- Air enters the body through the mouth or nose.
In the nose, thick hairs lining the nostrils prevent small objects from entering the nasal cavity. This cavity is lined with cells that produce mucus. Small foreign matter that enters the nasal cavities is trapped in the mucus, while tiny cilia (small hair-like projections) push the mucus to the pharynx (throat), where it is swallowed and digested in the stomach or expectorated.
- From the pharynx,
the air passes to the larynx, which is called the voice box because it contains the vocal cords. To prevent food or liquid from entering the larynx, the epiglottis (a small flap of tissue) closes over the opening of the larynx during deglutition (swallowing). If this process works improperly, a cough reflex expels the foreign material.
- When air travels past the larynx, it enters the trachea (windpipe).
The trachea is a strong tube containing rings of cartilage that prevents it from collapsing. The mucosa that lines the airway warms and moistens the air before it reaches the trachea.
- Within the lungs, the trachea branches into a left and right bronchus,
which divide into increasingly smaller branches called bronchioles. The smallest bronchioles end in a cluster of air sacs, collectively called an acinus. The acinus comprises individual air sacs called alveoli. Alveoli are like small balloons that inflate and deflate with air during respiration.
Gas exchange
Gas exchange occurs in the lungs between the alveoli and a capillary network within the alveolar wall.
Capillaries are microscopic blood vessels that exchange material between the blood and body tissues. In the lung capillaries, blood from tissues where cellular metabolism is occurring is called deoxygenated blood because it contains many carbon dioxide molecules and few oxygen molecules.
Respiration
The respiration process has two parts: inspiration (inhaling) and expiration (exhaling).
During inspiration, the diaphragm contracts, moves downward, and causes the thoracic cavity volume to increase.
Because the lungs are closely associated with the interior chest wall, they expand as the thoracic cavity expands.
When the diaphragm relaxes (upward position), the thoracic volume decreases and the lungs partially deflate. This process is called expiration. The elastic recoil of the expanded thoracic wall and lungs also helps expiration.
After inhalation, the alveoli contain many oxygen molecules. The alveoli are in close contact with the capillary network.
This proximity enables the minuscule oxygen molecules to diffuse (pass freely) from the alveolus to the bloodstream, flowing from a region of higher concentration to a region of lower concentration.
In the bloodstream, the oxygen attaches to red blood cells and is transported to the rest of the body. Likewise, carbon dioxide diffuses from the bloodstream into the alveolus where it is transported out of the body during exhalation.
During respiration, the pleurae (pleural membranes) help the lungs to expand and contract. These membranes are sacs that tightly cover the lungs and the chest inside wall. Between these two linings is a space called the pleural cavity that contains a thin layer of fluid. This fluid allows the lungs to move freely against the thoracic cavity inside.
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| posted at 1:30 AM |
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| The Circulatory System |
2. THE CIRCULATORY SYSTEM
The circulatory system, also called the cardiovascular system, consists of blood, heart, and blood vessels. The circulatory system is close circuited (i.e., there is no opening to external environment of the body).
2.1 The System Anatomy
1. Blood
Is fluid tissue composed of formed elements (i.e., cells) suspended in plasma. It is pumped by the heart through arteries, capillaries, and veins to all parts of the body. Total blood volume of the average adult is 5 to 6 liters or 7% of the body weight.
Blood Pressure
o Is the pressure the blood exerts on the walls of the arteries.
o The highest pressure is called systolic pressure when the heart is in systole, or contraction.
o A certain amount of blood pressure is maintained in the arteries even when the heart is relaxed i.e. diastolic pressure.
o The difference between systolic and diastolic pressure is known as pulse pressure.
Normal blood pressure vary with an individual's age, weight, and general condition e.g. young adults systolic pressure is 120 to150 mm of mercury, and the diastolic pressure is between 70 and 90 mm of mercury. On average, women have lower blood pressure than men.
2. The Heart
The heart is a four-chambered organ somewhat larger than the closed fist, located anteriorly in the chest and to the left of the midline with four main vessels, which either bring blood to or carry blood away from the heart. The four chambers of the heart are: the right atrium, the right ventricle, the left atrium, and the left ventricle.
The great vessels include the superior and inferior vena cava, which bring blood from the body to the right atrium. The pulmonary artery, which transports blood from the right ventricle to the lungs, and the aorta, the body's largest artery, which transports oxygen-rich blood from the left ventricle to the rest of the body.
3. Blood Vessels
Is a closed circuit of tubes that transport blood between the heart and body cells.
The several types of blood vessels include arteries, arterioles, capillaries, venules, and veins.
2.2 Function
a. The Pump (heart)
A series of one-way valves keep the blood flowing in one direction. The blood first enters the heart into the right atrium. A contraction of the right atrium then forces blood through the tricuspid valve and into the right ventricle. When the right ventricle contracts, the muscular force pushes blood through the pulmonary semilunar valve into the pulmonary artery.
The blood then travels to the lungs, where it receives oxygen. Next, it drains out of the lungs via the pulmonary veins, and travels to the left atrium.
From the left atrium, the blood is forced through the bicuspid valve into the critically important left ventricle. The left ventricle is the major muscular pump that sends the blood out to the body systems. When the left ventricle contracts, it forces the blood through the aortic semilunar valves and into the aorta. From here, the aorta and its branches carry blood to all the tissues of the body.
b. The blood vessel
i. Arteries and arterioles—distributors
Arteries are elastic tubes constructed to withstand high pressure that carry blood away from the heart to all parts of the body.
The smooth muscles of arteries and arterioles constrict and dilate in response to electrical impulses received from the autonomic nervous system.
ii. Arteries and Arterioles Capillaries—exchangers
At the end of the arterioles is a system of minute vessels that vary in structure, but which are spoken of collectively as capillaries from which the tissues of the body are fed.
There are approximately 60,000 miles of capillaries in the body. As the blood passes through the capillaries, it releases oxygen and nutritive substances to the tissues and takes up various waste products to be carried away by venules.
Venules continue from capillaries and merge to form veins
iii. Veins and venules—collectors
Veins and venules form the venous system that comprised of vessels that collect blood from the capillaries and carry it back to the heart.
The force of muscles contracting adjacent to veins aids in the forward propulsion of blood on its return to the heart. Valves, spaced frequently along the larger veins, prevent the backflow of blood.
The walls of veins are similar to arteries, but are thinner and contain less muscle and elastic tissue.
Summary of function
The blood travels throughout the body transporting oxygen, nutrients and wastes, and permitting the exchange of gases (carbon dioxide and oxygen).
To move blood between the cells and the organs of the integumentary, digestive, respiratory, and urinary system that communicates with the external environment of the body.
Control body heat
Fight disease
Stop bleeding
This function is facilitated by the heart pumping blood through blood vessels.
2.3 Possible complication to the system
Stressful situations can result in a temporary increase in blood pressure. If an individual were to have a consistent blood pressure reading of 140 over 90, he would be evaluated for having high blood pressure. If left untreated, high blood pressure can damage important organs, such as the brain and kidneys as well as lead to a stroke.
Blood loss will reduce oxygen and nutrient supply to the cell forcing the heart to pump faster to fulfill the body requirement. Failure to do so can induce shock.
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| posted at 1:10 AM |
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| The Nervous System |
1. NERVOUS SYSTEM
1.1 The nervous system anatomy is divided into:
1. central nervous system : the brain and spinal cord
It processes incoming sensory information and sends outgoing motor commands.
2. peripheral nervous system: the nerve cells that control voluntary and involuntary movements, includes all neural tissue outside the central nervous system divided into motor and sensory systems
The motor system is divided into the somatic (or skeletal) nervous system and the autonomic nervous system.
o The skeletal motor system allows voluntary control over skeletal muscle with a few exceptions.
o The autonomic nervous system is largely involuntary and controls cardiac and smooth muscles and glands.
In addition to the brain and spinal cord, principal organs of the nervous system are:
Eyes, ears, sensory organs of taste, sensory organs of smell, sensory receptors in skin, joints, muscles, and other parts of the body
1.2 Nervous system physiology (function)
The nervous system is a complex, highly specialized network. It organizes, explains, and directs interactions between human and his environment.
The brain as the main central of the nervous system controls:
-Sight, hearing, taste, smell, and feeling (sensation).
-Voluntary and involuntary functions, such as movement, balance, and coordination.
-the actions of most other body systems, such as blood flow and blood pressure.
-The ability to think and reason by being conscious and have thoughts, memories, and language.
Brain cell are sensitive to oxygen depletion, which can cause irreversible damage to the brain.
Impulses go to the central nervous system through sensory nerves and are carried away from it by the motor nerves.
A nerve impulse is an electrical change within a nerve cell or fiber; measured in millivolts, it lasts a few milliseconds and can be recorded by electrodes.
Reflexes is movement occur in direct response to an outside stimulus; thus, a tap on the knee causes a jerk, and a light shone into the eye makes the pupil contract.
Various nerve terminals called receptors constantly send impulses into the central nervous system. These are of three classes:
-exteroceptors, which are sensitive to pain, temperature, touch, and pressure;
-interoceptors, which react to changes in the internal environment; and
-proprioceptors, which respond to variations in movement, position, and tension.
-These impulses terminate in special areas of the brain, as do those of special receptors concerned with sight, hearing, smell, and taste.
1.3 Possible complication to the system
The symptoms of a nervous system problem depend on which area of the nervous system is involved and what is causing the problem.
Nervous system problems may occur slowly and cause a gradual loss of function (degenerative), or they may occur suddenly and cause life-threatening problems (acute). Symptoms may be mild or severe.
Some serious conditions, diseases, and injuries that can cause nervous system problems include:
~Blood supply problems (vascular disorders).
~Injuries (trauma), especially injuries to the head and spinal cord.
~Problems that cause a gradual loss of function (degenerative) Parkinson's disease. .
~Infections that may occur in the eg: Brain (abscesses).
~Organ system failure. Examples include: Respiratory failure, Heart failure.
A sudden (acute) nervous system problem can cause many different symptoms, depending on the area of the nervous system involved. Stroke and transient ischemic attack (TIA) are common examples of acute problems. You may experience the sudden onset of one or more symptoms, such as:
~Numbness, tingling, weakness, or inability to move a part or all of one side of the body (paralysis).
~Dimness, blurring, double vision, or loss of vision in one or both eyes.
~Loss of speech, trouble talking, or trouble understanding speech.
~Sudden, severe headache.
~Dizziness, unsteadiness, or the inability to stand or walk, especially if other symptoms are present.
~Confusion or a change in level of consciousness or behavior.
~Severe nausea or vomiting.
Most headaches are not caused by serious central nervous system problems. The pain that comes with a headache can range from a throbbing or a piercing pain, such as with a migraine, to severe pain that comes and goes over several days, such as with cluster headaches. Headaches are usually caused by problems with the sinuses, scalp, or muscles of or around the head.
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| posted at 12:59 AM |
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