vascular bio 3 Flashcards
what does high FLOW do to the outside diameter and the luminal diameter of blood vessels?
- increases the outside diameter
- increases the inner luminal diameter
- low flow does the opposite
- no change in thickness of the vessel
What happens to a large artery under INCREASED PRESSURE?
small artery?
- outward hypertrophy-vessel becomes larger in diameter as wall becomes thicker and diameter of lumen remains unchanged
- inward hypertrophy - outside diameter remains unchanged as wall becomes thicker and diameter of lumen decreases
what are the three responses arterioles have to higher pressure systems?
- inward hypertrophy- wall gets thicker and luminal diameter gets smaller
- inward eutrophic remodeling- wall gets thinner, diameter gets smaller
- rarefaction-vessels disintegrate
What are the three layers of the heart?
- endocardium- tunica intima
- myocardium- tunica media
- epicardium- tunica adventicia
what are the three types of cells (cardiocytes) that exist in the myocardium?
- contractile
- myoendocrine
- specialized conductive
Endocardium- 4 layers
- simple squamous endothelium and basal lamina
- subendothelial layer
- myoelastic layer- sm and elastic and collagen fibers
- subendocardium
what does the subendocardium have in it
loose connective tissue
small blood vessels
nerve fibers
purkinji cells or fibers (IN VENTRICLES)
what are the myoendocrine cells of the myocardium
- atrial natriuretic factor
- B type natriuretic factor (elevated in CHF)
- BOTH do diuresis and vasodilation
what are the two layers of the epicardium
esothelium- simple squamous epithelium and basal lamina
subepicardium
how does the epicardium change when we are near a sulcus?
- near a sulcus, we see venous and arterial systems with adipose tissue
- not near sulcus- mostly fibrocollagenous layer, no art, ven or adipose
cardiac skeleton
- dense connective tissue (FIBROUS) where cardiac muscle and valves are anchored
- layer of separation of conduction system of ventricles and atria
what are the layers of the AV valves
- on each side of the valve- (atrial side and venous side)- get endothelial layer with basal lamina
- from the atrial side, get the atrialis, spongiosa, fibrosa
atrialis, spongiosa, fibrosa
- atrialis- elastic and collagenous layer that lies under the basal lamina and helps with CONTRACTION OF VALVES
- Spongiosa- shock absorber
- fibrosa- maintains mechanical integrity of the valve
mitral or triscuspid valve regurge is due to…
- myxomatous state of atrialis that causes the valve to be floppy and insufficient
- elastin and collagen disorganization
- increased deposition of dermatin sulfate (used in wound repair)
what are the layers of the semilunar valves?
FROM VENTRICLE TO AORTA/PULM CIRC
- endothelial layer with basal lamina
- ventriculosa (instead of atrialis)
- spongiosa
- fibrosa
how does the fibrosa of AV valves compare to that of the semilunars?
semilunar valves have larger fibrosa layer to accommodate for larger pressure systems such as the one in the aorta
what patients are at higher risk of developing calcified semilunar valves?
-pt with atherosclerotic risk factors
what occurs in the SA node as we age?
- we lose up to 90% of our SA nodal cells by age 80
- accounts for our decrease in resting heart rate as we age
Bundle of His
- atrioventricular bundle
- purkinji cells present and are located in the subendocardial layer of the endocardium
- purkinji fibers are connected to muscle cells by gap jxns
- abundant glycogen
- 1 or 2 nuclei per cell
what can be activated to reconstitute necrotic myocardium? How?
- cardiac stem cells, early committed cells
- to develop into smooth muscle cells, cardiomyocytes and endothelial cells
where are cardiac stem cells and early committed cells usually located?
in the AV sulcus and they migrate from AV sulcus to the site of injury
over a lifetime, how many times do we replace our cardiac cells?
11-15 times
Lymphatic capillaries
- thin blind ended vessels
- lined by a single layer of endothelial cells w/o basal lamina b/c wanna provoke lymph to come into the lymphatic capillary
- NO PERICYTES- passive flow
- have microfibrils that prevent the capillary from collapsing on itself
- NO RBCS
Lymphatic vessels
-formed by joined lymphatic capillaries
similar to veins though walls are thinner
has valves
IF THEY ARE DENSER THAN USUAL, ARE A PROGNOSTIC INDICATOR FOR SPREAD OF MALIGNANT TUMORS
