Cardiovascular System: Blood Vessels Flashcards
Types of blood vessels
- Elastic arteries, muscular arteries, arterioles, capillaries, venules, veins
What does an artery do?
carries blood away from the heart, thick walls, and high pressure
Name 2 main arteries
- Elastic artery
- Muscular artery
What is the Elastic artery
abundant elastic fibers, large diameter, expand and recoil in response to blood flow and pressure. Aorta is main elastic artery
What is the muscular artery
fewer elastic fibers, smaller diameter
What does the arteriole vessel do
- slows down blood flow resulting in decreased blood pressure
What is capillaries
site of gas and nutrient exchange
name 3 capillaries
- Continuous capillary
- Fenestrated capillary
- Sinusoid capillary
Continuous capillary
most common, complete endothelial lining with tight junctions with intercellular clefts for exchange
Fenestrated capillary
has pores in endothelial lining allowing larger molecules to pass, common in small intestine and kidney
Sinusoid capillary
least common, flattened and have extensive intercellular gaps plus fenestrations, allow passage of large molecules, found in liver, spleen, bone marrow, lymph nodes, and some endocrine glands
What are venules
connects capillaries to larger veins
What are veins
returns blood to heart, thin walls, low pressure
name 3 blood vessel wall layers
- Tunica intima
- Tunica media
- Tunica externa/adventitia
Tunica intima
innermost layer, smooth, epithelial and connective tissue, only layer in capillaries
Tunica media
thicker in arteries than veins, connective tissue. layer that contains muscle
Tunica externa/adventitia
thickest layer in veins, connective tissue
capillary bed blood movement
blood flow through the capillary beds is controlled by precapillary sphincters to increase and decrease flow depending on the bodys needs and is directed by nerve and hormone signals
capillary bed pressure
Capillary pressure favors filtration of fluid into the interstitial space, so increasing PC leads to edema and lowering it favors reabsorption of fluid from the interstitial space into the blood
Whats the difference between capillary bed blood flow and pressure
Blood flow refers to the movement of blood through the vessels from arteries to the capillaries and then into the veins. Pressure is a measure of the force that the blood exerts against the vessel walls as it moves the blood through the vessels.
