Cardiovascular System (quiz 3) Flashcards
The main function of blood vessels is to transport blood and control flow/diameter. What does this mean and how is it done?
-changes BP to regulate blood flow
-smaller diameter= less blood flow
-larger diameter= more blood flow
-blood flow is controlled by the ANS
Does blood follow a pressure gradient?
yes! happens mostly in small vessels and blood will only go from high pressure to low pressure
What texture is the lining in blood vessels?
smooth
Walls of both arteries and veins have 3 tunics. What are they?
tunica intima, tunica media, tunica externa (also called adventitia)
The innermost tunica, tunica intima consists of the endothelium (simple squamous epithelia) and a thin sub-endothelial layer of _______________ tissue (sometimes containing smooth muscle fibers)
loose CT
In arteries, the tunica intima includes a thin layer, the ______________________, composed of elastin
internal elastic lamina (near basal lamina)
The tunica media, the middle layer, consists chiefly of concentric layers of helically arranged _______________ cells. In arteries, the media may also have an external elastic lamina separating it from the outermost tunica
smooth muscle
The outer adventitia, or tunica externa, is connective tissue consisting principally of….
type I collagen fibers and elastic fibers (allow tunica externa to recoil/distend)
The adventitia/tunica externa is ______________ with and bound to the stroma of the organs through which the blood vessel runs
continuous
Large vessels usually have vasa vasorum (“vessels of the vessel”): ____________, _________________, and ____________ in the adventitia/tunica externa and outer part of the tunia media. Blood in the lumen does not supply the tunics alone. The adventitia of larger vessels also contains a network of unmyelinated autonomic nerve fibers
arterioles, capillaries, venules
The aorta is what type of artery?
elastic artery
List the arteries, capillaries, and veins in order of flow
-elastic a. (aorta)
-muscular a.
-arteriole
-continuous capillary
-fenestrated capillary
-venule
-mid-sized and large sized vein
Which artery branches off of elastic artery?
muscular artery
What tissue is the muscular artery made up of?
smooth muscle
What is another name for the muscular arteries?
distribution arteries (helps distribute blood)
What is the arteriole missing compared to other blood vessels?
missing the outer tunica layer- tunica externa
Which blood vessel is the “first within the target”?
the arteriole (found within femur, kidney, deltoid, tibia, etc)
What are the smallest blood vessels?
capillaries (this is why they exist in capillary beds, so theres multiple little ones near each other)
What is feeding and draining the capillary beds?
1 artery feeds cap bed, 1 vein drains it
What are the exchange vessels working with concentration gradients?
capillaries
The capillaries contain endothelial cells, which means it is made of up ___________________ tissue
simple squamous
Where do fenestrated capillaries drain into?
the smallest vein vessel, aka the venule
Who is the first to receive blood from capillaries?
venules
What is the venule missing compared to other blood vessels?
missing the tunica media (smooth muscle layer)
What blood vessels unite/fuse with neighbors?
venules> mid-size veins> large size veins
What do blood vessels require to constrict/dilate?
tunica media
So:
-arteries can constrict/dilate
-arteriole can
-capillaries cannot
-venule cannot
-veins can
Elastic arteries are the aorta, ___________________, and their largest branches.
pulmonary artery
What is another name for elastic arteries?
conducting arteries (bc their major role is to carry blood to smaller arteries)
Elastic arteries have a _________ tunica media in which elastic lamellae alternate with layers of smooth muscle fibers. Between the tunica intima and the tunica media is the ___________________
thick, internal elastic lamina
____________ arteries, also called distributing arteries, distribute blood to the organs and help regulate blood pressure by contracting or relaxing smooth muscle in the tunica media
Muscular
In muscular arteries, the tunica media may contain up to _____ layers of large smooth muscle cells interspersed with a variable number of elastic lamellae. The external CT contains lymphatic capillaries, vasa vasorum, and nerves, all of which may penetrate to the outer part of the ______________
40, tunica media
With distance from the heart, arteries gradually have relatively less __________ and more ________________ in their walls
elastin, smooth muscle
Most arteries, large enough to have names are of the ______________ type
muscular
Muscular arteries are _____________ arteries
efferent (away from heart)
Muscular arteries branch repeatedly into smaller and smaller arteries, until reaching a size with 3/4 layers of _________________ muscle.
medial smooth
The smallest arteries branch as….
arterioles
How many layers do arterioles have of smooth muscle?
1-2 layers (has no external layer, are very thin)
What blood vessel is the beginning of an organs microvasculature?
arterioles
Arterioles branch to form anastomosing networks of capillaries that surround the ________________ cells of the organ
parenchymal
At the ends of arteries, smooth muscle fibers act as sphincters (________________) and produce periodic blood flow into capillaries
pre-capillary sphincter
Capillary beds are supplied by _____________ and drain into ____________
arterioles, venules
What does red represent?
oxygenated blood
What does blue represent?
de-oxygenated blood
Do capillaries exchange in both directions?
yes!
The right and left ventricles propel blood to the ______________ and _______________ circuits
pulmonary and systemic