Exam 3: Cardiovascular System Flashcards
What is the function of veins?
collect blood from microvasculature and bring to heart
What are the 3 tunics of all vessels?
Tunica intima
Tunica media
Tunica adventitia
Parts of Tunica Intima
Endothelium
Subendothelial Layer
Internal Elastic Membrane/Lamina
What orientation is the Tunica Intima seen in?
longitudinal orientation
What makes up the subendothelial layer of the tunica intima?
Fine collagen fibers + elastic (sometimes)
What is characteristic about the internal elastic lamina of the tunica intima?
thick, elastic present
“sheet” NOT fiber
holes for diffusion
What orientation is the Tunica Media?
Circular orientation
What are the two components of Tunica Media?
Smooth muscle
Connective tissue
What is the function of the Tunica Media?
constricting to facilitate blood flow
What orientation is the Tunica Adventitia?
longitudinal orientation
What two structures are seen in the Tunica Adventitia?
Vasa vasorum
Nervi vasorum
What makes up the Tunica Advenitita?
collagen and/or elastic fibers
Vasa vasorum
little vessels that branch and go into adventitia & media
ONLY sympathetic innvervation
Nervi vasorum
nerves within vasa vasorum
seen in larger vessels
What are examples of Elastic Aa?
Aorta
Brachiocephalic Trunk
What layer is the thickest in Elastic Aa and what makes it characteristic?
Tunica media
alternating smooth muscle & elastic layers
What part of the Tunica Intima is thick in Elastic Aa?
subendothelial layer
What part of the Tunica Intima is thin in the Elastic Aa?
Internal Elastic Lamina
What structures are easiest to see in the Elastic Aa?
Vasa vasorum & Nervi vasorum
What are examples of Muscular Aa?
renal A
brachial A
femoral Aa
What part of the Tunica Intima is thick in Muscular Aa?
Internal Elastic Lamina
Muscular Aa have the thickest of the all the vessels in which layer?
Tunica Media
What is characteristic of the Tunica Media of Muscular Aa?
smooth muscle dominates
less elastic lamina
What is different about the Tunica Adventitia in Muscular vs. Elastic Aa?
More elastic fibers in MUSCULAR than ELASTIC Aa
What tunic is seen in arterioles and what is it characterized by?
Tunica Media
1-3 layers of smooth muscle
Meta-arteriole
arterioles right before capillaries
What tunic and what is it characterized by in Meta-arterioles?
Tunica Media
incomplete smooth muscle layer
Arteriovenous Anastomoses
direct connection from arteriole to venule (bypasses capillary bed when open)
Where are arteriovenous anastomoses located?
Skin & Intestines
bypassed in fight or flight
Capillary Tunics Characterization
ONLY endothelium layer
NO smooth muscle
NO adventitia
Pericytes
supportive, undifferentiated mesenchymal cells that change based on need
Where are pericytes located?
endothelial cell basal lamina
List Capillary Types
Continuous
Fenestrated
Porous
Sinusoid