The Blood Vessels Flashcards
(52 cards)
What vessels have the highest pressure?
Arteries
What vessels have the lowest pressure?
Veins
3 histology layers of vessels
Tunica interna
Tunica media
Tunica externa
What type of epithelium is found in the endothelium
Simple squamous
What layer is thicker in arteries and why?
The tunica media, bc they need to withstand higher pressures
Define vasa vasorum
Large blood vessels that have their own blood supply
What is it called where the end of a arteriole that connects to a capillary?
Metarteriole
Arteriole have a huge impact on what?
Blood pressure in the body
Where is the only place where nutrient exchange happens?
The capillaries
3 types of capillaries
Sinusoidal
Continuous
Fenestrated
Where are continuous capillaries found? Why?
In most tissues except for cartilage & epithelium, bc there are no pores here
(Not very leaky at all)
Where are fenestrated capillaries found and why?
In the GI tract, kidneys, bc the rapid exchange of h20 and solutes
(Pores included so leaky)
Where are sinusoidal capillaries found and why?
Found in the liver, bc large proteins need to pass
(Large pores, very leaky)
Define Vasomotion
Sphincters in the metarterioles that regulate capillary blood flow
Conditions that cause capillary sphincters to open
Low o2
High co2
High temp
Low pH
What vessels have the slowest blood flow
Capillaries
What vessels has the fastest blood flow
Aorta
At any time, where is the most blood found and how much
The veins, 60-65%
What layer is thicker in a vein and why?
The tunica externa, bc veins have extra elastic and collagen fibers bc veins are flexible
Purpose of valves in veins
Prevent back flow, follows direction
List 3 factors that help venous return in veins
Valves-prevent backflow
Respiration-changes thoracic and abdominal pressures
Skeletal muscle milking-contracting skeletal muscle to push blood to heart
Define blood pressure
The force of blood on the walls of a blood vessel
Pressure in aorta
100mmhg
Pressure on pulmonary artery
12-16mmhg
