Lab 6: circulatory system Flashcards
name layers from lumen outwards
intima
media
adventitia
describe intima
endothelium - simple squamous with BM
subendothelium - loose CT between endothelium and IELM
internal elastic membrane (IELM) - not in all vessels, like elastic fibers in tunica media but thicker
describe media
smooth muscle
collagen type 3 - reticular fibers
elastic fibers
describe elastic fibers of media
visible layers that separate smooth muscles into clear layers
fenestrated elastic membrane
not present in all vessel types
describe adventitia
collagen type 1 (normal CT)
vasa vasorum - supply blood to large blood vessels, vessels of vessels
vasa nervosum
describe plane of section for endothelium
run length of blood vessel
describe plane of section for smooth muscle
when present = run circularly around blood vessel
describe plane of section in cross section
endothelium in cross section
smooth muscle in longitudinal section
describe plane of section in longitudinal section
endothelium in longitudinal section
smooth muscle in cross section
describe capillaries - gen
only see endothelium (simple squamous with BM) and nucleus
smallest vessel
8-10um in diameter - enough to let one rbc 7um through
abundant in brain and heart
what do capillaries not have
no media or adventitia
describe lumen of capillaries
lined with 1-2 endothelial cells
allows only 1 rbc to fit through
name the 3 types of capillaries
continuous
fenestrated
fenestrated sinusoids
what do the 3 types of capillaries define
3 layers of permeabilization
describe intima of arteriole
endothelium
Subendothelium thin
IELM likely absent
describe media of arteriole
1-3 layers
appears longitudinal in cross section
describe adventitia of arteriole
very little/no adventitia
describe intima of venule
endothelium present
subendothelium thin
no IELM
describe media of venule
no smooth muscle layers
incomplete or absent media
describe adventitia of venule
very little/no adventitia
how to distinguish venule from arterioles and capillaries
different from ateriole since no media
different from capillaries since more than one rbc can flow at a time
more than 2 endothelial cells surround lumen in cross section
describe intima of muscular artery
endothelium (endothelial cell)
IELM very clear
describe media of muscular artery
4-10 layers of smooth muscle
describe adventitia of muscular artery
dense irregular CT
thin - in larger vessels can have vasa vasorum
describe how smooth muscle cells look in cross section and longitudinal section of muscular artery
cross section = nuclei of smooth muscle appears longitudinal
longitudinal section = smooth muscle appears in cross section
describe intima of elastic artery
endothelial cell
IELM present but difficult to differentiate between elastic fibers in media
describe media of elastic artery
smooth muscle appears longitudinal (when in cross section)
10-50 layers of smooth muscle with distinct elastic fibers
describe adventitia of elastic artery
vasa vasorum for nutrients and oxygen
can elastic arteries be easily seen in light microscopy
NO
so large that they may not be seen in light microscopy field all at once
describe intima of large vein
no IELM (absent or undefined)
endothelial cells
describe media of large vein
can contain some smooth muscle but much less than artery of equivalent size
describe adventitia of large vein
looks thicker than size of media
has vaso vasorum
