Circulatory System Flashcards
(93 cards)
1
Q
What makes up the endocardium?
A
endothelium
loose CT layer
dense irregular CT
sub-endothelial layer
2
Q
What makes up the subendothelial layer?
A
losse CT layer and dense irregular CT layer
3
Q
Where are the purkinjie fibers located?
A
sub-endothelial layer
4
Q
What is stored in purkinje fibers?
A
glycogen
5
Q
What are purkinje fibers?
A
modified cardiac myocytes
6
Q
How are purkinje attached?
A
gap junctions and macula adherens
7
Q
What is the difference between atria and ventricles?
A
- atria: less muscle, more elastic fibers
- ventricles: well-developed muscle layer
8
Q
Which part of intercalated discs are described as the “risers of stairs”?
A
transverse portion
9
Q
What is the transverse portion of intercalated discs made up of?
A
macula adherens
fascia adherens
10
Q
What portion of the intercalated discs are described as the “step of stairs”?
A
longitudinal portion
11
Q
What makes up the longitudinal portion of intercalated discs?
A
large gap junctions
12
Q
What are the functions of intercalated discs?
A
- attach cardiac myocytes using macula adherens
- attach and stabalize myofibrils using fascia adherens
- cell to cell communication using large gap junctions
13
Q
What affect does the sympathetic NS have on heart rate and contraction force?
A
increases both
14
Q
What affect does the parasympathetic NS have on heart rate and contraction force?
A
decreases both
15
Q
What specialized cardiac cells deal with hormone secretion in the atria and interventricular septum?
A
myoendocrine cells
16
Q
What will the hormones from the myoendocrine cells target?
A
- fluid and electrolyte balance = target kidneys
2. decrease BP = target muscle in arterioles, small arteries and arterioles
17
Q
What is another name for the pericardium?
A
serous pericardium
18
Q
What makes up the pericardium?
A
epicardium & parietal pericardium
19
Q
What is another term for epicardium?
A
visceral pericardium
20
Q
What is contained in the sub-epicardial layer?
A
coronary vessels
nerves
adipose (sometimes)
21
Q
What is the function of the mesothelium in the epicardium?
A
secretes a serous lubricating fluid
22
Q
What is the function of the mesothelium in the parietal pericardium?
A
secretes serous fluid
23
Q
What composes the pericardial sac?
A
parietal pericardium
fibrous pericardium
24
Q
What is found between the parietal pericardium and visceral pericardium?
A
pericardial cavity
25
What are valves made up of?
endothelium with dense irregular CT below
26
What are some characteristics of the dense irregular CT in valves?
- has many collage I and elastic fibers
| - almost avascular
27
What is the cardiac skeleton made up of?
dense irregular CT
28
What are the three components of the cardiac skeleton?
1. annuli fibrosi
2. trigonum fibrosum
3. upper portion of interventricular septum
29
Where do you find annuli fibrosi?
around base of aorta, pulmonary artery and openings to chambers
30
Where do you find the trigonum fibrosum?
by cusps of aortic valve
31
What is the septum membranaceum?
upper portion of interventricular septum
32
What is the general function of the cardiac skeleton?
isolate atrial and ventricular chambers to ensure individual chamber contractions
33
What type of CT is found in the chordae tendinae?
dense regular CT
34
The tunica intima is a conitnuation of the...?
endocardium
35
The tunica media is a continuation of the...?
myocardium
36
The tunica aventitia is a continuation of the...?
epicardium
37
What type of tissue composed the endothelium?
simple squamous
38
What are the 6 basic functions of vascular endothelium?
1. maintain selective permeability
2. prevent & promote clotting along surface
3. influence blood flow
4. regulate cell growth in surrounding tissues
5. influence local immune responses
6. maintain extracellular matrix
39
Which major luminal wall layer is thicker in elastic arteries?
tunica intima
40
What are the two primary components of the tunica media in elastic arteries?
thin layers of smooth muscle alternating with fenestrated sheets of elastic lamina
41
What structure is typically on the outer portion of the tunica media?
vasa vasorum
42
What is another term for muscular arteries?
distributing arteries
43
Which major luminal wall layer is very thin in muscular arteries?
tunica intima
44
What is an important structural componant in the tunica intima of muscular that helps with differentiation?
internal elastic lamina
45
Which major luminal wall layer is the thickest in muscular arteries?
tunica media
| >this is also the case in arterioles
46
How does the smooth muscle in the tunica media in arterioles contribute to an individual's BP?
smooth muscle is typically partially contracted
47
The width of elastic arteries increase in your 20s due to an increase number of elastic lamina in which major luminal wall layer?
tunica media
48
What happens to collagen & proteoglycans in muscular arteries as you age?
increase causing a decrease in flexibility
49
What is a cause of HTN?
decrease in elastic fibers and increase in collagen I
50
How can the tunica media be affected in HTN?
collagen I and sulfated GAG's can accumulated
51
Why is the endothelium of the tunica intima prone to develop problems?
blood is moving fast
52
What major luminal wall layer is absent in metarterioles?
tunica media
| >(thoroughfare channels)
53
What do the metarterioles allow?
blood to pulse through true capillaries
54
Where are metarterioles found?
in all capillary beds
55
What major luminal wall layer is thicker in arteriovenous anastomosis?
tunica media & tunica adventitia
56
What is the function of ANS nerves on arteriovenous anastomosis?
control AVA lumen size and therefore the amount of blood into capillaries
57
Are AVAs typically closed or open in the skin & stomach?
closed: blood goes into capillary beds
| if open it bypasses capillary beds
58
Are AVAs typically closed or open in erectile tissues?
open: less blood into erectile tissue capillaries
59
What controls blood flow into capillaries?
1. metarterioles
2. AVAs (some locations)
3. lumen size of terminal arteriole
4. pre-capillary sphincters*
60
What type of cells are seen in capillaries?
single layer of flattened endothelial cells
61
What is the function of pinocytic vesicles in capillaries?
movement of large molecules
62
What type of cell junctions are seen in capillaries?
fasciae occludens (tight junctions)
63
What is the function of cell junctions in capillaries?
- move macromolecules
| - allows cell movement
64
What is the most common capillary type?
continuous capillary
65
What are some locations for continous capillaries?
muscle, CT, many organs
66
What are some characteristics of pericytes?
- considered residual mesenchyme cells
- numerous in capillaries and venules
- secrete basement membrane & matrix components
- can DIVIDE
67
What can pericytes change into?
smooth muscle, endothelial cells & fibroblasts
68
What are some functions of pericytes?
healing
| regulate blood flow?
69
What type of capillary is found in the CNS?
modified continuous capillary
70
What type of gap junction is found on the capillaries in the CNS?
zonula occludens (instead of fasciae occludens)
71
What are some locations of fenestrated capillaries?
pancreas, intestines, endocrine organs, kidneys*
72
What is the function of fenestrated capillaries?
allow greater movement of molecules and cells
73
What are some locations of sinusoidal capillaries?
bone marrow, liver, spleen, lymphatic organs & certain endocrine organs
74
What is the function of fenestrated capillaries?
enhanced exchange between blood and tissues
75
How are veins different than arteries?
1. not as uniform in structure
2. often larger diameter
3. higher number*
76
What are the function of valves?
1. protection by preventing backflow
| 2. works with skeletal muscle to keep blood moving
77
What are valves made of?
tunica intima & fibroelastic CT
78
Do postcapillary venules have all luminal wall layers?
Not all
| -no tunica media or adventitia
79
What is there a lot of in the tunica intima of postcapillary venules?
pericytes
80
Do collecting venules have all luminal wall layers?
Not all
| -no tunica media
81
Do muscular venules have all luminal wall layers?
yes
82
What is different about the tunica media in muscular venules?
they have an incomplete smooth muscle layer
83
What happens when venules become inflamed?
will end up with leaky venules since it has an incomlete tunica media
84
Small veins are similar to muscular venules except...?
they have a complete tunica media
85
What is the most dominant major luminal wall layer in medium veins?
tunica adventitia
86
What is the most dominant luminal wall layer in large veins?
tunica adventitia
87
What is the major luminal wall layer in superficial veins of the legs?
tunica media: pump blood back up
88
What is different about pulmonary veins?
- well-developed tunica media
| - tunica adventitia has some cardiac muscle close to heart
89
What is different about the superior vena cava?
the tunica adventitia has some cardiac muscle close to the heart
90
What is different about the inferior vena cava?
the tunica adventitia has some cardiac muscle clos to the heart and some longitudinal smooth muscle
91
What are 5 things that make lymphatic capillaries different than blood capillaries?
1. blind ended - begin suddenly
2. no pericytes
3. endothelial cells can overlap but create clefts
4. no fenestrae or tight junctions
5. contain bundles of lymphatic anchoring filaments
92
What do the lymphatic anchoring filaments contain?
elastic fibers
93
What is the function of lymphatic anchoring filaments?
support endothelial walls so capillaries stay open and hold to CT
