cardiovascular anatomy Flashcards
where is the heart located and how big is it?
located in the mediastinum (area of thoracic cavity between lungs)
it is fist-sized (250-350g)
what is the systemic vs. pulmonary circuit
systemic- heart pumping oxygenated blood to body, body bringing deoxygenated blood to heart
pulmonary- heart pumping deoxygenated blood to lungs, lungs bringing oxygenated blood to heart
what are the coverings of the heart called?
pericardium
coverings of the heart from outermost to innermost
fibrous pericardium
parietal pericardium
pericardial cavity (serous fluid)
visceral pericardium (“epicardium”)
what are the 3 layers of the heart
- epicardium (visceral pericardium)= simple squamous+areolar
- myocardium (cardiac muscle)
- endocardium (membrane lining chambers)= simple squamous+areolar
explain the 2 atria
right atrium- receives blood from body
left atrium- receives blood from lungs
explain the 2 ventricles
right ventricle- receives blood from r. atrium
left ventricle- receives blood from l. atrium
what is the septum?
left side is separated from right side by a thick wall (SEPTUM)
L&R atria, L&R ventricles contract TOGETHER
what are heart valves?
flaps of endocardium=dense CT
=prevent backflow of blood
what are the atrioventricular valves (AV)
- between atria and ventricles
- prevent backflow
- triscupid valve (between RA and RV)
- biscuspid valve (between LA and LV)
what are the atrioventricular valves anchored to?
papillary muscles by chordae tendineae
=these strands of CT prevent collapse of valves when ventricles contract
what are the semilunar valves (SL)
- between ventricles and large arteries of the heart
- prevent backflow into ventricles from arteries leaving heart
- pulmonary semilunar valve (between pulmonary trunk and RV)
- aortic semilunar valve (between aorta and LV)
what is blood turbulence associated with?
valve closure
explain the sounds produced by the heart
2 distinct sounds
-“lubb” (S1) AV valve closure (following atrial contraction)
-“dupp” (S2) SL valve closure (following ventricular contraction)
faint third and fourth can be heart in healthy heart
S3= blood into ventricles
S4= atria contract
what is a heart murmur?
abnormal sounds heard during auscultation of the heart
3 blood vessels
arteries+veins+capillaries
what is the basic structure (3 layers) of blood vessels
- tunica externa (superficial)= fibrous C.T
- tunica media (middle)= smooth muscle&elastic C.T
- tunica interna (deep)= endothelium, basement membrane, elastic membrane
how many layers do capillaries have?
only one layer. endothelium with thin basement membrane
explain arteries (blood flow, pressure, layers)?
- blood AWAY from heart
- most OXYGENATED
- HIGH PRESSURE (elastic membrane facilitates stretching
- THICK tunic media (smooth muscle allows constriction)
types of arteries?
1) large arteries- (aorta) thick layer of elastic tissue, high pressure
2) distributing (muscular)- mid-sized, thick smooth muscle
3) arterioles- smallest, no externa, thin smooth muscle
explain veins (blood flow, pressure, layers)?
- blood TOWARD heart
- most DEOXYGENATED
- LOW PRESSURE
- thin tunica media (less smooth muscle)
- VALVES (prevent backflow)
- venules (smallest)- no smooth muscle
how does the venous system return blood to heart if pressure is low?
- “skeletal muscle pump”= muscle contraction massages veins (valves prevent backflow)
- “respiratory pump”- changes in thoracic and abdominal pressure
- expansion of rib cage
what are varicose veins?
valves do not close properly, weakened walls, inflammation
explain capillaries?
- SMALL (about diameter of one RBC)
- form CAPILLARY BEDS
- SITE of EXCHANGE (between blood and tissues)
- endothelium ONLY, thin and permeable
