histology Arteries and Veins Flashcards
Large elastic arteries
aorta, large aortic branches and pulmonary arteries
large aortic branches eg
brachiocephalic, subclavian, common carotids, iliac arteries
Large elastic arteries اكتر اشي مميز
contains large amount of elastic fibres
الفرق بين الarteries وveins
من ناحية الwalls
walls of arteries are thicker than that of veins ليش
to withstand pulsatile flow
الفرق بين الarteries وveins
من ناحية ال blood pressure
blood pressures of arteries are higher than that of veins
احفظيها زي ما هي
As arteries become smaller, wall thickness gradually decreases but the ratio of wall thickness to lumen diameter increases
in large elastic artery
there are no smooth muscle, elastic fibers only.
Medium-sized muscular arteries eg
coronary and renal arteries
The media of Medium-sized muscular arteries contains
large amount of smooth muscle cells with some elastin and collagen
Adventitia of Medium-sized muscular arteries is
very broad, and mostly
contains collagen and elastin.
media of Small arteries and arterioles consists almost
of one or two layers of smooth muscle cells, and there is no External Elastic Lamina
adventitia of Small arteries and arterioles is
same size as the tunica media layer
merges in with surrounding tissue
intima of Small arteries and arterioles is
thin
single layer of squamous epithelium
primary site of vascular resistance
Layers of smooth muscle →cفي الوريداتontrolling systemic blood pressure
Arterioles
Small arteries and arterioles (in the substance of organs and tissues) extends and branches out
from an artery and leads to capillaries
nucleus of the smooth muscle appears
in a longitudinal shape arranged in a circular manner.
nucleus of the intima
in circular shape because the cells are
arranged longitudinally.
neuromuscular bundle”.
vein , artery, and nerve being together in the body
الفرق بين الarteries وveins
من ناحية ال قطر
veins have larger diameters than arteries →larger lumens
veins كمية الدم يلي بتحملها ال
two thirds of all circulating blood.
الفرق بين الarteries وveins
من ناحية الmedia
the media is much thinner in the veins due to significantly less smooth muscle and elastic tissue.
veins اشي ما بصير في ال
do not have the same capacity for elastic recoil and vasoconstriction due to Internal and External elastic layers are not seen in the veins
How Blood is propelled forward in veins
by contraction of surrounding muscles and pressure created during inspiration
and expiration.
Reverse flow is prevented in veins by
the presence of venous valves.
type of wall of the veins
The flaccid walls
The flaccid walls شو لازم اتذكر
The flaccid walls of veins predispose venous valves to penetration by tumor and inflammatory processes
Venule has
clear tunica intima layer, without any elastic fibres
Larger Vein Media layer contains
2-3 layers of muscle cells.
Larger Vein Adventitia is
the broadest layer. It contains longitudinal collagen fibres, and vasa vasorum.
Larger Vein Intima
A thin endothelial lining, (in some veins,
you may be able to see the valves).
الفرق بين الarteries وveins
vasa vasorumمن ناحية ال
Adventitia in veins contains a larger number of vasa vasorum comparing with arteries because blood which
pass through veins do not contain nutrients, so veins need another source of nutrients (vasa vasorum).
الفرق بين الarteriesMuscular وveins Muscular
there are no internal or external elastic layers surrounding the muscle layer
Muscular veins
DISTINGUISHING FEATURES
سلايد 17
Capillaries consist only of
a single layer of endothelial cells on a basement membrane. There is no media
or adventitia.
Capillaries diameter
is just wide enough for passage of a red blood cell
Capillaries flow
is very slow
Capillaries function
exchange of oxygen, nutrients and other substances between blood and tissues.
types of capillaries
Continuous
fenestrations
sinusoid capillaries
Continuous capillaries
they only allow smaller molecules, such
as water and ions to pass through their intercellular clefts
Continuous capillaries are found in
skeletal muscles, fingers, gonads, and skin and the central nervous system.
Continuous capillaries
blood–brain barrier
Fenestrated capillaries located in
the endocrine glands, intestines, pancreas, and the glomeruli of the kidney
Fenestrated capillaries have
- Have pores in the endothelial cells
2. have continuous basement membran
Sinusoid blood vessels are primarily located in
the bone marrow, lymph nodes and
adrenal glands, and are present in the liver and spleen, where greater movement
of cells and materials is necessary
Sinusoidal (discontinuous) capillaries
open-pore capillary
discontinuous basement membrane
allow red and white blood and serum proteins to pass
Sinusoidal (discontinuous) capillaries permeability
is increased by large inter-cellular clefts and fewer tight junctions
broad adventitia
- large vein
2. medium size artery
collagen
- media in general
- media of medium size muscular artery
- adventitia of large vein
- adventitia of medium size muscular artery
elastin
media of medium size muscular artery
adventitia of medium size muscular artery
media
venule, the lumen (containing)
RBC red blood cells) and
endothelial cells
internal elastic lamina is present in
Arteries although it is less distinctive in large elastic
arteries).
internal elastic membrane is absent in
Veins
adventitia in veins
thickest layer
adventitia in Arteries
thin
