Cardiac/Vascular Structure Flashcards
What are the 3 layers of the heart?
epicardium –> myocardium –> endocardium
Which layer of the heart is the muscular layer?
myocardium
Which tissue is a serous membrane with a dense fibrous layer that surrounds the heart?
Pericardium
What layer of the heart is composed of mesothelium and areolar tissue that coveres the outer surface of the heart?
epicardium
Which layer of the heart covers the inner surfaces of the heart, and is composed of endothelium and areolar tissue?
endocardium
In this layer of the heart, the blood vessels and nerves pass through it.
Epicardium (the outside)
Where in the cardiac muscle cells is the nucleus located?
in the center
True or False: cardiac muscle cells are striated, branched, and tightly connected by specialized jxns.
True
What is the name of the region where the ends of the cells are connected to another cell?
intercalated disk
The intercalated disc has what proteins to allow communication from cell –> cell?
gap jxns
These are accumulations of small muscle fibers that lack striations and intercalated disks.
Nodes
This is structure with non-contractile myocytes that originate at the AV node and terminate as Purkinje fibers.
bundle of His
Which bands of the sarcomere (H, I, Z, and A) shorten during contraction?
H, I, and Z (the sarcomere itself)
This layer of the heart valve is composed of loose connective tissue + endothelium and acts as a shock absorber.
Tunica spongiosa
“squishy sponge”
This layer of the heart valve is composed of dense fibrocollagenous plates, forming the core of the valve.
Tunica fibrosa
This layer of the heart valve is adjacent to the vetnricular or atrial surface of each valve, contains dense CT with elastic fibers, and continues into the chordae tendinae.
Tunica ventricularis
This is the network of collagen and elastin fibers that surrounds the myocardium, anchors the cardiac muscle fibers and 4 cardiac valves, and prevents overdilation of the valve openings.
Fibrous skeleton of the heart.
This is the innermost layer of the blood vessel, composed of simple squamous epithelial tissue, and bounded by internal elastic membrane.
Tunica intima
This is the middle layer of the blood vessel, composed of smooth muscle, and is present in large arteries.
Tunica media
This is the membrane that separates the tunica media and adventitia.
External elastic membrane
What tissues comprise the tunica adventitia?
collagen and elastic fibers.
Which 2 important structures run within the tunica adventitia?
vasa vasorum and nervi vascualris
This cell layer on the blood vessel acts as a barrier, maintains non-thrombogenic barrier between platelets and subendothelial tissue, modulates blood flow, cell growth, maintains ECM, lipoprotein metabolism, and immune responses
Endothelium
In atherosclerosis, after there has been endothelial cell injury, what cells adhere and release cytokines?
macrophages
The release of cytokines my macrophages causes hyperplasia of what layer of the vessel?
tunica intima
The macrophages then oxidize and modify LDLs, forming what type of cells within smooth muscle in atherosclerosis?
Foam cells
What then forms over the foam cells, which then calcified dystrophically?
fibrous cap
In what arrangement is the elastic fibers arranged in the tunica media in elastic arteries, which allows for expansion and contraction to deal with pressure changes?
circumfrentially
In these artieries, there are thin circumferential elastic fiber lamellae in the layers of the smooth muscle cells.
Muscular arteries
What can cause the decrease of the lumen diameter in small muscular arteries, leading to HTN?
lipid accumulation in the tunica media
These are short vessels that connect arterioles and venules.
Metarterioles
What happens when the precapillary sphincters are contracted?
blood flow is constricted for 1 vessel to the venule, so the blood can be overall diverted to other vessels.
This is the bypass of capillary beds via direct communication btwn arterioles and venules.
AV shunts
What happens when AV shunts are contracted?
blood is diverted to capillary beds to generate heat loss (opposite happens when relaxed)
These are capillary-like channels that are associated with macrophages.
Sinusoids
These vessels are large collecting vessels with no tunica media with more pericytes than capillaries.
Post-capillary venules
These vessels have a tunica media and drain into medium veins.
muscular venules
These vessels get blood from venules, have valves, and have a thin intima and media.
Medium veins
These vessels have a diameter > 10mm, have no valves, and have a thick elastic and collagenous adventitia layer
Large veins
Which layer of the vessels makes up the valves?
intima
True or False: lymph vessels have valves and a discontinuous basement membrane.
True
