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Heart and Circulatory system
>Heart is a complex closed hydraulicsystem
>Heart weighs between 7 to 15 ounces>Little larger than the size of our fist
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L ocation of HeartHeart is located in between our lungs in the middle of our chest
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Functions of the circulatory system:
D istribute nutrients ,
Transport and exchange oxygen and carbon
dioxideRemove waste materials
D istribute secretions of endocrine glands,
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P revent excessive bleeding ,
P revent infection , and
Regulate body temperature .
>Heart is divided into two parts (Right and Left)
>Each part has two chambers called atriumand ventricle
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>The h eart is a funnel-shaped, hollow,muscular organ that is responsible for pumping blood to all parts of the body.
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he Heart wall consists of three layers
P ericardiumOuter layer of the Heart
Myocardiummiddle layer of the Heartmain muscle of the HeartMade up of short cylindrical fibres
EndocardiumInner layer of the Heart
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F unctions:
P ericardium----keeps the outer layer moist .P revents friction as the Heart beats.
Myocardium---Is automatic in action,contracting and relaxing rhythmicallythroughout lifeEndocardium---smooth lining of blood to flow
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Heart valves
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The tricuspid valve regulates blood flowbetween the right atrium and right ventricle.
The pulmonary valve controls blood flow fromthe right ventricle into the pulmonary arteries,which carry blood to your lungs to pick upoxygen.
The mitral valve lets oxygen-rich blood fromyour lungs pass from the left atrium into theleft ventricle.
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blood from the heart gets around
the body through blood vessels
There are 3 types of blood vessels
a. ARTERY
b. VEIN
c. CAPILLARY
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The ARTERY
thick muscle andelastic fibres
Arteries carry blood away from the heart.
the elastic fibres allow
the artery to stretchunder pressure
the thick muscle cancontract to push the
blood along.
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The VEINVeins carry blood towards from the heart.
thin muscle and
elastic fibres
veins have valveswhich act to stop the
blood from going inthe wrong direction.
body muscles surround the veinsso that when they contract tomove the body, they also squeezethe veins and push the blood alongthe vessel.
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The CAPILLARYCapillaries link Arteries with Veins
the wall of a capillaryis only one cell thick
they exchange materialsbetween the blood and
other body cells.
The exchange of materialsbetween the blood and thebody can only occur throughcapillaries.
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artery vein
capillariesbody cell
The CAPILLARYA collection of capillaries is known as a capillary bedcapillary bed .
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The Heart
Left Ventricle
Left A triumRightA trium
Right Ventricle
valve
Vein from Lungs
Artery to Head and BodyArtery to Lungs
Vein from Head and Body
valve
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How does the Heart work?
blood from thebody
blood fromthe lungs
The heart beat begins when the
heart muscles relax and blood
flows into the atria.
STEP ONE
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The atria then contract andthe valves open to allow blood
into the ventricles.
How does the Heart work?
STEP TWO
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How does the Heart work?
The valves close to stop blood
flowing backwards.
The ventricles contract forcing
the blood to leave the heart.
A t the same time, the atria are
relaxing and once again filling with
blood.
The cycle then repeats itself .
STEP THREE
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Lungs
Body cells
Our circulatory system is a double circulatory system.This means it has two parts parts.
the right side ofthe system
deals with
deoxygenatedblood.
the left side ofthe system
deals with
oxygenatedblood.
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lungs
h ead & arms
liver
digestive system
kidneys
legs
pulmonary artery
aorta
pulmonary vein
main vein
LeftRight
How does this system work?
Circulatory System
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P ulmonary circulation
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S ystemic circulation
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Coronary Circulation
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The heart muscle, like every other organ or tissue inyour body, needs oxygen-rich blood to survive.Blood is supplied to the heart by its own vascular
system, called coronary circulation.The aorta (the main blood supplier to the body)branches off into two main coronary blood vessels(also called arteries). These coronary arteriesbranch off into smaller arteries, which supply
oxygen-rich blood to the entire heart muscle.The right coronary artery supplies blood mainly tothe right side of the heart. The right side of the heartis smaller because it pumps blood only to the lungs.The left coronary artery, which branches into the left
anterior descending artery and the circumflex artery,supplies blood to the left side of the heart. The leftside of the heart is larger and more muscular because it pumps blood to the rest of the body.
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The Heart rate is partly controlled byautonomic nervous system and partly byhormone action
The condition of the cardiovascular system isexamined by haemodynamic measurementsElectrocardiography( Recording the electricalactivity of the heart muscle)
P honocardiography (listening to heartsounds)
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NasalCavity
Nose
Mouth
Bronchus
Bronchiole
Alveolus
Diaphragm
Throat
(pharynx)
Windpipe
(Trachea)Left lungs
Ribs
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D iagram of D iaphragm
JH
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D ia phra g m E x pe rim e nt
JH
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F un F acts
* At rest, the body takes in and breathes out about 10 liters of air eachminute.
* The right lung is slightly larger than the left.* The highest recorded "sneeze speed" is 165 km per hour.* The surface area of the lungs is roughly the same size as a tennis court.
* The capillaries in the lungs would extend 1,600 kilometers if placed endto end.
* We lose half a liter of water a day through breathing. This is the water vapor we see when we breathe onto glass.
* A person at rest usually breathes between 12 and 15 times a minute.* The breathing rate is faster in children and women than in men.
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N ervous S ystem
Is the Complex System in the bodyP erforms 3 CsControl
Communication network for the bodyCo-ordinates the functions of the variousorgans
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The central processing un it (CentralInformation P rocessor)
The brain is the control center of the body
It is about 2% of your body weig h t and uses
20% of your bodys oxygen
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P arts of the N ervous S ystem
Central Nervous System (CNS): brain andspinal cord
P eripheral Nervous System ( P NS):craniospinal nerves
Autonomic Nervous System (ANS): nervesthat control vital organs: heart, lungs, brain,etc.
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P arts of the Brain
D ivided into th ree parts
CerebrumCerebellumBrain Stem
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Brain
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CerebrumCerebrum
Cerebellum
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Cerebrum
Largest part of the brain
2 h emisp h eres- Right and Left
Connected by the Corpus CallosumRig h t side controls- left side
Left side controls right side of body
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Cerebral Cortex - The outermost layer of gray mattermaking up the superficial aspect of the cerebrum.
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G yri (ridge)
Fissure(deep groove)
Sulci(groove)
http://williamcalvin.com/BrainForAllSeasons/img/bonoboL H- humanL H- viaTWD.gif
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Cerebral Features:
Sulci Small grooves dividing the gyri Central Sulcus Divides the Frontal Lobe from the ParietalLobe
Fissures Deep grooves, generally dividing large
regions/lobes of the brain Longitudinal Fissure Divides the two Cerebral Hemispheres
Transverse Fissure Separates the Cerebrum from theCerebellum
Sylvian/Lateral Fissure Divides the Temporal Lobe from theFrontal and Parietal Lobes
Gyri Elevated ridges winding around the brain.
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4 lobes( 2 in Right Hemisphere and 2 inthe L eft Hemisphere)
F our sections -LOBES
1.FrontalLobe2. ParietalLobe
3.OccipitalLobe4.TemporalLobe
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F rontal lobe:>Intelligence>Constructiveimagination>thought
>largequantities of information canbe storedtemporarily
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Temporary lobe:>Hearing centre
>located just abovethe ear> N eurons respondto different
frequencies of sound input>long-termmemory
> Organization/Comprehension of language
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P arietal lobe:> S enses and integrates
sensation>The sensory input comesfrom legs, arms, hands,fingers, face and throat
> Awareness of body/ body parts in space and inrelation to each other>Motor-centre (body
movement
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Occipital lobe
>Its primary function is the
processing, integration,interpretation, etc. of VIS IO N and visual stimuli.
> This is the primary area of the brain responsible forsight -recognition of size,color, light, motion,
dimensions, etc.
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Primary VisualCortex
VisualAssociation Area
Modified from: http://www.bioon.com/book/biology/whole/image/1/1 -8 .tif.jpg
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Cerebellum:> S econd largest
locatedbel ow
thecerebrum at back of skull
>This part is responsible
for the bala nc e andm usc le coordination
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P ons
P ituitary gland
Hypothalamus
Cerebrum
Medulla oblongata Spinal cord
Cerebellum
P inealgland
Thalamus
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Brain S tem
The brain stem connects the spinal cord tothe centre of the brain just bellow the cerebralcortexEssential parts are:Medulla Ablongatathe ponsmidbrainD iencephalon
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Medulla Ablongata
Lowest section of Brain StemM edulla Oblongata Controls h eart
rate, breath
ing rate, and flow of blood t h roug h th e blood vessels.Respiratory Centre which controls the
ventilation of the lungs
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P ons
Located just above the medullaP rotruding in front of brain stemRelays signals between the cerebrum and the
cerebellumC ontrols muscles of the face.
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midbrain: contains auditory (hearing), visual(sight), and muscle control centers.D iencephalon
ThalamusHypothalamus
ThalamusAct as a relay station for sensory
pathways
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Hypothalamus
connects the endocrine and nervoussystems.controlsthe autonomic nervous systembody temperaturecarbohydrate and fat metabolismappetiteemotions
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Body Temperature
In man, the deep body temperature mayfluctuate 1 degree Centigrade in daily activitycycles
Lowest in the morning and reaches a peak inlate evening
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Heat Balance and Body Temperature
Heat is continually being produced in thebody as a by-product of metabolismHeat is also continually being lost to thesurroundingsWhen the rate of heat production is exactlyequal to the rate of heat lost = HEAT
BALANCE
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Relationship of Body Heat to Body Temperature
The temperature of an object is a measure of the kinetic activity of its molecules
this is proportional to the amount of heatstored in the object
body temperature is directly proportional tothe heat in the body
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Heat capacity or S pecific heat
defined as the ratio of heat supplied (or remove) to thecorresponding temperature rise (or decrease)
= ( kilocalories/kg)/ TBT increases 1 C for each
BT increases 1 degree Centigrade for each calorie of
heat stored per kg of body weight
specific heat of tissues is said to be 0.83 calorie/kg
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N ormal Body Temperature
Internal or Core Temperature ( D eep BodyTemperature)temperature of the interior of the body
the body strives for a rather precise regulation of thistemperaturevalue normally varying from the mean by not morethan 1 F
2/3 of the body mass is at the core temperaturewhich is usually represented by the rectaltemperature
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S urface temperature
temperature of the skin or tissue immediatelyunderlying the skinrises and falls with the temperature of thesurroundings1/3 of the body mass
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Average Body Temperature
used when one wishes to calculate the total
amount of heat stored in the body
= (0.33 x surface temp) + (0.67 x internaltemp)
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P hysiologicalF luctuations
D iurnal variation minimum in AM; peaklate afternoon35 0 C early morning, cold weather 36 0-37 0 C usual range of normal38 0 C emotion and moderate exercise39 0 C hard work, emotions40 0 C hard exercise
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43 C (109.4 F ) Normally D EATH or serious braindamage
42 C ( 107.6 F ) May turn pale or remain flushed andredMay become comatoseBe in severe delirium, vomiting andconvulsionBlood pressure may be high or lowHeart rate fast
41 C ( 105.8 F ) F ainting, vomiting, severe headache,dizziness, confusion, hallucinations,delirium and drowsiness can occur P alpitation and breathlessness may
also occur
40 C(104F ) -F ainting, dehydration, weakness,vomiting, headache , dizziness,confusion, hallucination, delirium, anddrowsiness
39 C(102.2 F ) -Severe sweating, flushed n very red.-F ast heart rate and breathlessness
38 C(100.4 F ) -Sweating, feeling uncomfortable,
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37 C (98 .6 F) Normal body temp.
36 C ( 96.8 F ) Moderate shivering35 C ( 95.0 F ) Hypothermia intense shivering,
grayness skin34 C (93.2 F ) Severe shivering, loss movement of
finger, blueness and confusion
33 C ( 91.4 F ) Moderate to severe confusion,sleepiness, depressed reflexes, slowheart beat, shivering may stop
32 C ( 89.6 F ) Hallucination, delirium, completeconfusion, extreme sleepiness(comatose), shivering is absent
31 C (87.8 F ) Comatose, rarely conscious. No or slight reflexes, very shallow breathing
and sloe heart rate28 C ( 82.4 F ) Severe heart rhythm likely may stop
anytime.
24-26 C ( 75.2-78.8 F ) D EATH usually occurs
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Thermoregulation
D ef : an ability of an organism to keep thebody temperature within certain boundaries
One aspect of homeostasis process
Most enzymes are very sensitive
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F EVER
A fever is defined as a temperature 1 or more above the
normal 98.6 degrees F ahrenheit ( F ) or 37 degrees
Celsius (C).
F ever is not a disease.
F ever helps the body fight infections by making the
body's defense systems work more efficiently.
Bacteria and viruses cannot live at higher temperatures
and are killed by fever.
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F actors that affect heat productionand heat loss
HEAT P RO DU CTIONBMR causes continual heat productionnormal young adult male ordinarily produces at least 40 cal of heat/hour/sq meter body surface area
this raises the BT about 2F
in one hour if no heat were lost in thebodyabdominal viscera, heart, brain generates 63% of total body
heatskeletal muscle 30% of totalMuscular exercise as much as 75% of total heat produced inthe muscles when all the muscles of the body are contracted atmaximal rate of activity, the metabolic rate can rise to 1500 to2000 above the basal level
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>facilitation of anterior motoneurons causing anincreased muscle tone
rise in overall metabolic rate 50-100%>if degree of facilitation reaches a critical level
shivering begins;>the rate of heat production rises to 200-300%
above normalmajor mode of acutely increasing heat
production
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Thyroxine effect on cells
has a direct effect on all cells of the body toincrease the local rate of metabolism,causing greater than normal quantities of
heat to be released in the body
an increase of 100% above normal
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S pecific dynamic action of food
this increases the heat production of thebody
at high environmental temperature, thespecific dynamic action of food increases theheat production and adds extra burden to the
heat loss mechanism
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Heat L oss
The various methods by which heat loss iseffected are:
radiationconductionconvectionevaporation
The amount of heat loss by each of thesedifferent mechanisms varies withatmospheric conditions
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Radiation
loss of heat in the form of infrared heatrays
(electromagnetic waves)
the body radiates heat rays in all directions,and heat rays are being radiated from thewalls of other objects toward the body
varies directly with the temperaturedifference between the temperature of thebody surface and the average temperature of the surroundings
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The surface of the human body isextremely absorbent for heat rays
Rate of infrared absorption isapproximately equal for human beings with
either white or colored skin
The human skin absorbs 97% of incident
radiation
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The energy from the sun is transmitted mainly in
the form of light rays rather than infrared rays35% of these waves are reflected from the white
skin but only a small amount from the dark skinIn sunlight, a dark skin does absorb more heat
than white skinThe radiation surface of the standing human being
is only about 85% of the total surface area, since
exposed surfaces do not lose heat to theenvironment by radiation
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F actors influencing heat loss through radiation Temperature of surrounding objects relative to
that of the skin Humidity of the atmosphereAir with a high water vapor content is more
opaque to radiant heat than dry air
Heat loss through radiation is slightly reducedwhen the relative humidity is high
Rate of loss is proportional to Ts Te Ts absolute temperature of the skin surface Te absolute temperature of objects in
surroundingenvironment
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Conduction
Heat transfer between surfaces in contact1. Conduction to objects represents only a small
% of the total heat loss from the body (3%)
2. Conduction to air represents a sizeableproportion of the bodys heat loss even under normal conditions (12%)
Self-limited unless the air moves so that new,unheated air is continually brought in contact withthe skin
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Convection
Movement of air The clothed body has a layer of warm moist air in contact with the
skinWhen the atmosphere is cooler, convection currents are set up
which mix the air lying against the skin with fresh air When the body is exposed to wind, the layer of air immediately
adjacent to the skin is replaced by new air much more rapidly thannormally, and heat loss by convection increased accordingly
The loss increasing with the square of the wind velocity up to 60miles per hour
A wind velocity beyond this exerts little or no further effect Once the wind has cooled the skin to the temp of the air itself, a
further increase in the rate of heat loss cannot occur regardless of thewind velocity
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Evaporation
1. Invincible water loss about 25% of basal heat loss isattributable to evaporation of water even without sweatingThrough skin about 2/3Through respiratory tract 1/3
Heat loss by evaporation (E) is generally calculated fromwater loss, which maybe determined from body weightchanges after correction for metabolic and other weightlossesE (watts) = (0.7 x gms of H2O evaporated)/time in hours
Where: 0.7 = latent heat of evaporation (evaporation of 1gm of H2O per hour requires 0.7 watts or 0.6 K cal)
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S weat glands
Innervated by cholinergic nerve fibersTubular structures consisting of 2 parts:
D eep coiled portion that secretes the sweatD
uct portion passing outward through thedermis of the skinThe secretory portion secretes a fluid called
precursion Active secretory product of the epithelial cells
lining the coiled portion of the sweat gland Elicited by Cholinergic sympathetic nerve fibers
ending on or near the gland
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S weat
A water solution of an osmolar concentration wellbelow that of plasma
The principal constituent is sodium chloride
There are traces of potassium, urea and lactate,no protein or glucoseWhen the rate of sweat secretion is very low, most
of the sodium and chloride is reabsorbed from the
precursor secretion so that the fluid lost to thesurface of the body contains almost none of theseions
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Muscular S ystem
Muscles are responsible for all types of bodymovement3 basic muscle types are found in the body
Skeletal muscleCardiac muscleSmooth muscle
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k l l l h
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S keletal Muscle Characteristics
Striatedhave visible bindingVoluntaryMost attach to bones by tendonCells are multinucleateCells surrounded & bundled by connective tissueF unctions of Skeletal Muscle
P roduce MovementMaintain postureStabilize jointsGenerate Heat
Sites of Muscle AttachmentBonesCartilageConnective tissue coverings
S h l Ch i i
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S mooth Muscle Characteristics
Has no striationsSpindle-shapedcellsSingle NucleusInvoluntaryno
conscious controlF ound mainly in thewalls of holloworgans
Ch i i f C di M l
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Characteristics of Cardiac Muscle
Has striationsU sually has a single nucleusJoined to another cardiac
muscle cellInvoluntaryF ound only in the heart