cardiovascular systems, circulatory system, heart Flashcards
what does the cardiovascular system consist of (3 things)
blood
heart
circulatory system
what are the 2 main function of the cardiovascular system
delivers gases, nutrients, and hormones to the cells and tissues
the circulatory system is made up of 3 parts what are they
pulmonary circulation (heart and lungs) systemic circulation (rest of the body) lymphatic circulation
the arteries/vessels carry blood which way in relation to the heart
blood travels away from the heart in the arteries and returns to the heart in the veins
what are arteries and veins connected by
capillaries (site of gas/nutrient exchange)
in systemic circulation, blood rich in oxygen comes from which side of the heart
left
heart is described from the point of view of the individual - not an onlooker
is the systemic circulation considered high or low pressure
high
what is there instead of a carotid vein
jugular
draw arterial/venous system
draw it
in the pulmonary circulatory system, blood low in oxygen travels from which side of the heart to the lungs
right
is the pulmonary circulatory system considered high or low pressure
low
blood vessels must…3 things
endure changes in pressure
move with surrounding structures
remain open under all conditions
blood vessels have 3 layers what are they from outside in
tunica externa (connective tissue) tunica media (muscle) tunica intima (endothelium)
blood vessel structure is modified according to function, what are the what are the five types
arteries (elastic and muscular) arterioles capillaries (continuous and fenestrated) venules veins
what are the 5 differences between arteries and veins
arteries have thicker walls arteries appear to have a smaller lumen arteries maintain their shape arteries are more resilient than a vein arteries do not contain valves - veins contain many valves
what are the features of elastic arteries and name 3
thick tunica media (muscle) with many elastic fibres
aorta, brachiocephalic, common carotid
what are the features of muscular arteries, what do they do and where are they found
lots of tunica media and think tunica externa
distribute blood to muscles and organs
most arteries are muscular arteries
what happens in capillaries and what is their structure
site of gaseous, nutrient and waste exchange thin walled (can be continuous fenestrated or sinusoid) found in skin, gonads, glomerulus, intestines, pancreas...
what is a capillary bed
10 - 100 capillaries supplied by a single metarteriole ( is a short vessel that links arterioles and venules)
have precapillary sphincters to control flow to individual beds
what are arteriovenous anastomoses
form direct communication between the arteiole and venule
serve as backup routes for blood to flow if one link is blocked or otherwise compromised
what do venules do
collect blood from the capillary beds and deliver it to small veins
what do veins (capacitance vessels) do and what is their structure
return deoxygenated blood to the heart
low pressure, thin walled, easily distensible
what 3 things does the lymphatic system consist of and what are its functions
a network of lymph vessels
lymph - fluid
lymphatic tissues and organs
functions: involved in the body’s defence mechanisms and provides a mechanism for the drainage of interstitial fluid (solution that bathes and surrounds the cells)
how does fluid move out of the lymphatic circulatory system
what is left behind
fluid moves into the interstitial space at the arterial end of the capillary (high pressure)
fluid moves back into the capillary at the b=venous end (low pressure)
15% of lymph is left which is then returned to the blood
what are lymph capillaries and where are they located
blind ended tubes what are located adjacent to capillary beds
what are the 2 lymphatic ducts called, what parts of the body do they drain and where does it empty into
Right lymphatic duct (right side of head and thorax and right upper limb) empties into right subclavian vein
Thoracic duct (remainder of the body) empties into left subclavian vein
lymph re-enters what
the blood vascular circulation
where is the heart located and what is it protected by
in the thorax between the lungs
protected by the ribs and the sternum (breastbone)
what is the pericardium
2 parts Fiberous pericardium (outer) - an inelastic sac of dense connective tissue that wraps around the heart which prevents overfilling
Serous pericardium - (inner) two layers parietal and visceral separated by pericardial cavity which contains serous fluid and prevents friction
what are the 3 layers of the heart wall from the outside in
epicarduim (visceral pericardium)
myocardium (muscle)
endocardium (endothelium)
draw the general organisation of the heart
draw it -NOT DRAWN!
draw the anterior view of the heart
draw it
draw the internal view of the heart
draw it
why does the fiberous connective tissue separate the artia from the ventricles
to create a pause
draw the heart valves
draw it - NOT PRINTED!
how are atrioventricular valves opened
by blood flowing from the atria to the ventricles
what prevents eversion (opposite of invert) of the valves during ventricular contraction
tendon anchorage to papillary muscles - prevent backflow
what initiates electrical impulses within the heart
non-contractile cells