Cardio- Blood Vessels Flashcards
tunics of blood vessels + functions
- Tunica intima: gas/fluid exchange
- Tunica media: regulates blood flow
- Tunica externa/adventitia: integrates the blood vessel into its surroundings
transition of heart layers to tunics of vessels
epicardium > t external
myocardium > t media
endocardium >t intima
explain tunica intima
inner layer
1 cell thick
explain tunica media
smooth muscle + elastic fibres
explain tunica external
made of collagen + elastic
vasa vasorum
what separates the tunica intima, media and externa
- Separating I + M= internal elastic lamina
- Separating M + E= external elastic lamina
which vessels contain smooth muscle
artery, arterial, vein
which vessels contain elastic tissue
artery an vein
which vessels contain fibrous tissue
artery, venule, vein
what are the types of large/medium arteries, tunica media characteristics, and roles
elastic= media has large elastic fibres > allows expansion (e.g. aorta)
muscular= media mostly smooth muscle > regulation of vascular tone (coronary art)
characteristics of veins
- Thin tunica media.
- Large lumens.
- Valves often present.
difference between arteries and veins
- Media
• Artery= more smooth muscle + elastic fibres - Intima
• Artery: Internal elastic membrane (blue squiggle)
• Endothelium smooth in vein, rough in artery - Externa
• Vein= Smooth muscle in externa
• Artery= Vasa vasorum (supply tissue of vessels)
size differences of types of arteries
- Arteriole= less than 30 micrometers (4 erythro) + 3 layers of muscle
- Large arteriole= 100-300 micro + 5/6 layers of smooth
- Muscular arteries= 100micro to 10 milimeters
- Elastic= 10milimeters+
Differences between walls of arteries & arterioles
- Elastic= more elastic fibres (exist closer to heart) + thin externa (no nerves or vasora) as role is to receive and pump blood
Intima of elastic:
- thicker than other
- Layer of loose connect. Tissue beneath endo allows intima to move independently from layers
- E.g. extend with inc SBP
- Arteriole= only 2 layers of muscle= needs transport across
Differences between walls of veins & venules
- Large diameter: Low pressure system = veins need large lumen but thin wall
- M= valve present, prevent backflow
- V= solute moving through