Histology of Cv System Flashcards
describe the structure of capillaries
it is lined by endothelial cells
has a thin basal lamina
pericytes (help maintain viability of endothelial cells)
-7-9 in diameter
what are the three different types of capillaries
continous
fenestrated
sinusoidial
capillaries that have tiny
openings, or pores.
* Allow larger molecules and
proteins to move from your blood
into organs and glands. (eg.
Intestine)
fenestrated
capillaries are tiny
blood vessels that deliver blood,
nutrients and oxygen to our cells.
* Contains pinocytic vesicles
* Present in the skin, lungs, and
blood-brain barrier
continuous
larger
than other capillaries and have a
discontinuous endothelium. (eg.
Liver, spleen, bone marrow)
* Kupffer cells are present in the
lumen
sinusoidal
what are some capillary exchange mechanisms
open pores/ gaps
diffusion,filtration, vesicular transport “transcytosis”
transendothelial channels
what are some secretory and metabolic functions of endothelial cells
Adhesion molecules
(diapedesis)
▪Produce vasoactive
compounds
▪ NO for vasodilation,
▪endothelin for
vasoconstriction
▪ Anti-thrombogenic
factors
▪Metabolic conversions
(angiotensin I to II)
i.e. vasoconstriction
structure includes endothelium subendothelial layer and internal elastic lamina
tunica intima
structure includes smooth muscle and elastic fibers
external elastic lamina
tunica media
structure includes collagen fibers
tunica externa
this structure is thicker in arteries and thinner in veins
tunica media
this structure is thinner in arteries and thicker in veins
tunica adventitia
phentotype is Branched networks Tapered in each end Long & cylindrical,
between cells
Single nucleus Single nucleus Multi-nucleated
Straited with Non-straited Straited
intercalated discs
cardiac muscle
tapered in each end
single nucleus
non straited
smooth muscle
long and cylindrical
multi nucleated
straited
skeletal muscle
location and control of action
cardiac muscle
walls of heart
cardiovascular pump
involuntary
location and control of smooth muscle
walls of hollow
visceral organs
produces peristalsis
involuntary
location and control of skeletal muscle
attattched to bones
movement of joints
voluntary
post capillary- collecting and mascular venule
describe order of flow
a - arteriole
c -capillary
pcv- post capillary venule
cv collectiing venule
mv muscular vein
structure of heart
homologous to tunica media
endocardium
structure of heart
homologous to tunica media
myocardium
structure of heart
homologous to tunica adventitia
epicardium
describe purkinje fibers
specialized cardiac muscle cell that conducts impulses 5
times faster than surrounding cells. Gap junctions allow the wave of
depolarization to first induce cardiac muscle contraction from the apex of the
heart.
lymphatic vessels and lymph nodes do what
return excess 10% of interstitial fluid to blood
transport lipids absorbed from intestines
immunologic support
describe lymphokinteic flow from highest pressure to lowest pressure
High to low
blood capillaries - interstirial fluid- lymph capillaries -lymph veins-lymph ducts - large circ veins
lymphatic capillaries have have unique permeability characteristics like
filaments (elastic fibers) anchor to connective tissue
all lymph gets filtered by at least one lymph node before it re enters the blood
T or F
True
______ are related to defects in the tunica media of cerebral arteries
berry aneurysms
valve insufficiency
develops due to the weakness of the vein wall and loss of valve function
lower legs
vericose veins
