Download Cardiovascular System

CARDIOVASCULAR SYSTEM
CP Anatomy & Physiology
CARDIOVASCULAR SYSTEM
 blood, heart, blood vessels
 functions
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transportation
O2 (to cells) CO2 (away)
nutrients (glucose)
cellular wastes
hormones (endocrine gland secretions)
any other homeostatic substances (cells, antibodies)
maintain body temperature
CARDIOVASCULAR SYSTEM~THE HEART
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location and size
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fist
hollow, cone shaped
< a pound
lies medial to lungs
apex  tip; points
toward left
base  great vessels emerge;
points to right
CARDIOVASCULAR SYSTEM~THE HEART
coverings and wall (muscle
 pericardium
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= membraneous sac enveloping the heart
endocardium
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myocardium
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=endothelial membrane lining the interior of the heart
=middle layer of heart wall composed of cardiac muscle
epicardium (visceral pericardium)
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=thin outermost layer
CARDIOVASCULAR SYSTEM~THE HEART
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chambers and associated great vessels
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4 hollow chambers
2 atria
 2 vetnricles
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atria
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ventricles
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superior  receiving chambers receive blood from veins
inferior  pumping chambers; contract—pump blood out of
heart & into circulation
septum
divides the heart longitudinally
 interventricular or interatrial
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CARDIOVASCULAR SYSTEM~THE HEART
CARDIOVASCULAR SYSTEM~THE HEART
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chambers (con’t)
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right side
pulmonary circuit pump
 rec’s O-poor blood from veins
through superior & inferior
vena cava
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left side
systemic pump
 blood returned
 out of aorta (away)
 O-poor blood circulates from tissues back
to R atrium (via systemic veins) empty into S or I vena cava
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CARDIOVASCULAR SYSTEM~THE HEART
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valves
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atrioventricular valves (AV)
one-way valve (flaps of tissue) separating
each atrium from the ventricle
 tricuspid valve right side
 mitral (bicuspid) valve  left side
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as ventricles pump, BP (blood pressure)
closes the AV valves, preventing
blood from flowing backward from
ventricles to atria
from the ventricles, blood flows
out of heart into large vessels
CARDIOVASCULAR SYSTEM~THE HEART
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valves
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semilunar valves (SV)
separates the ventricles from
the large vessels
 prevents blood from
flowing backward
 guard the bases of the 2
large arteries leaving the
ventricular chambers
 1. pulmonary  right side
 2. aortic semilunar  left side
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CARDIAC CIRCULATION
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blood that nourishes & oxygenates the heart is
provided by R and L coronary arteries
= branch from base of aorta and encircle the heart in
the atrioventricular groove @ junction of atria and
ventricles
 major branches
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L anterior interventricular circumflex arteries
 R posterior interventricular and marginal arteries
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myocardium
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drained by cardiac veins (empty into an enlarged vessel
on backside of heart  coronary sinus (empty into R
atrium)
CARDIAC CIRCULATION
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blood pathway in the heart
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1st
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2nd
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deoxygenated blood flows from
R atrium to R ventricle (pumped OUT of
heart through the pulmonary arteries)
3rd
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deoxygenated blood from the body
returns through the S & I vena cava
(veins that bring blood back from
body and head) to R atrium
oxygenated blood returns from lungs
through the pulmonary veins
(carries oxygenated blood from lungs to heart)
to L atrium
4th
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blood flows from L atrium to L ventricle to aorta (main artery that
blood flows out of)
pulmonary circulation
•blood travels between
heart and lungs
systemic circulation
• blood travels between
the heart and other
body tissues
coronary circulation
 subsystem of systemic
circulation that supplies
blood to the heart itself
PHYSIOLOGY OF THE HEART
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conduction system of the heart
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heart contracts as a unit
contract spontaneously and independently
atrial cells  60 x/minute
ventricular cells  20-40/min
controlling systems
1. nerves of autonomic nervous system (ANS)
 2. intrinsic conduction system (nodal system)
 sinoatrial node (S-A) in R atrium (“pacemaker”)
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cells can initiate impulses on their own
activity is rhythmic
atrioventricular (AV) node junction of atria & ventricles
PHYSIOLOGY OF THE HEART
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conduction system of the heart
SA node
 AV node
 AV bundle
 R & L bundle
branches
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interventricular
Purkinje fibers
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spread w/in muscle of
ventricle walls
ELECTROCARDIOGRAM (ECG) CONDUCTION OF
ELECTRICAL SIGNALS THROUGH THE HEART

sinus tachycardia
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rapid heartrate
ventricular fibrillation
the heart's electrical activity
becomes disordered
 the heart's lower (pumping)
chambers contract in a rapid,
unsynchronized way
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mitral stenosis
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blood flow through the narrowed valve opening is reduced
the volume and pressure of blood in the L atrium increases, it
enlarges
beats rapidly in an irregular pattern (atrial fibrillation)
the heart's pumping efficiency is ↓
pressure ↑ in the blood vessels of the lungs, resulting in heart failure
with fluid accumulation in the lungs and a low level of oxygen in the
blood
CARDIOVASCULAR SYSTEM~BLOOD VESSELS
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characteristics
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arteries (leave the heart)  arterioles  capillary
beds  venules  veins
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arteries & arterioles carry blood AWAY from heart
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capillaries= site of exchange
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venules, veins return blood TO heart
CARDIOVASCULAR SYSTEM~BLOOD VESSELS
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microscopic anatomy
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tunics (coats or layers)
1. tunica interna
 a thin layer of endothelium that lines the lumen
(interior) of vessels
 2. tunica media
 thick middle coat consisting of mostly smooth muscle and
elastic tissue
 3. tunica externa
 outermost layer made of fibrous CT
that supports & protects vessel
 vascularized
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CARDIOVASCULAR SYSTEM~BLOOD VESSELS
arteries
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carry blood AWAY
elasticity
contractility
various types
classified acc’d to tissue
types
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muscular
elastic
veins
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carry blood TO
thinner walls (same 3
layers but diff properties)
larager lumens
small amts of muscle in
media
contains valves
arterioles
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smaller arteries that deliver
blood TO capillary network
capillaries
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1-6 layers of smooth muscle
vasoconstriction to affect
lumen size
greatly affects distribution of
blood during times of
hypoperfusion (=↓ blood flow
through an organ)
simple squamous epithelium
responsible for ex∆ of
nutrients and waste between
blood & tissues
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flow is accomplished in beds
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1. continuous
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2. fenestrated (porous)
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muscle, brain CT
intestines & kidneys
3. sinusoidal
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liver, bone marrow & some
endocrine glands
venules
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vessels that drain
blood from capillaries
RECAP
heart
↑
veins


arteries

venules 
arterioles
↓
capillaries
MAJOR ARTERIES
MAJOR VEINS
CARDIOVASCULAR SYSTEM~BLOOD
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= complex CT (solid & liquid) in which living blood cells
(formed elements) are suspended in a nonliving fluid
matrix (plasma)
formed elements~45%
erythrocytes (RBCs) 4-6 million/mm3
 leukocytes (WBCs) 4-11 thousand/mm3
 platelets 250-500 thousand/mm3
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plasma~55%
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water
electrolytes
proteins
functions
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1. transport nutrients and oxygen (to cells) and CO2 (away)
2. transfer heat to body surfaces
3. defending body against disease
RED BLOOD CELLS
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RBCs~erythrocytes
 a biconcave disc that is round and flat
without a nucleus
 contain hemoglobin, an iron carrying protein
that carries the bulk of the oxygen that is
carried in the blood
 changes shape without breaking, as it
squeezes single file through the capillaries.
WHITE BLOOD CELLS
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WBCs~leukocytes
 Several types and each contains a big nucleus
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lymphocytes~form in bone marrow, mature in lymphoid
tissue
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macrophages~phacocyte;antigen presenter to T & B cells
basophil~contain anticoagulant heparin which prevents
blood from clotting too quickly & contain the vasodilator
histamine, which promotes blood flow to tissues
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eosinophil~one of the immune system components
responsible for combating multicellular parasites and certain
infections
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neutrophil~most abundant
monocyte~single nucleus
BLOOD GROUPS