2: Circulatory System Flashcards
(113 cards)
1
Q
What are the layers of the heart from inside out?
A
endocardium, myocardium, pericardium
2
Q
What is the endocardium epithelium?
A
simple squamous
3
Q
What is the endocardium loose connective tissue?
A
fibro-elastic ct
4
Q
What other irregular tissue is in the endocardium?
A
more collagen I, elastic fibers, some smooth muscle
5
Q
What is the sub-endocardial layer of endocardium?
A
loose CT, blood vessels, nerves, most PURKINJE FIBERS
6
Q
What are purkinje fibers?
A
modified cardiac myocytes fewer myofibrils, peripherally placed contained stored glycogen attached via: gap junctions & macula adherens (desmosomes) fxn: conduct contraction impulse rapidly
7
Q
What is the myocardium of the atria like?
A
less muscle, more elastic fibers
8
Q
What is the myocardium of the ventricles like?
A
well developed muscle layer
9
Q
What is the structure of the intercalated discs of myocardium?
A
Transverse portion: “risers of stairs”; macula adherens, fascia adherens
Longitudinal portion: “step of the stairs”; LARGE GAP JUNCTIONS (ions & sarcoplasm travel through here
10
Q
What are the functions of the intercalated discs of myocardium?
A
1) attach cardiac myocytes in a row using MACULA ADHERENS
2) attach and stabilize myofibrils using FASCIA ADHERENS
3) cell to cell communication using LARGE GAP JUNCTIONS
11
Q
How does the autonomic nervous system affect the heart beat?
A
SYMPATHETICS: increase the heart rate, increase contraction force
PARASYMPATHETICS: slow the heart rate, decrease the contraction force
12
Q
What are the specialized cardiac muscle cells called that secrete hormones?
A
myoendocrine cells
13
Q
Where are the hormones secreted by the myoendocrine cells released?
A
surrounding capillaries
14
Q
What do the myoendocrine hormones function in?
A
fluid and electrolyte balance: KIDNEYS
decrease blood pressure: SMALL ARTERIES & ARTERIOLES
15
Q
What is another name for the pericardium?
A
serous pericardium
16
Q
What are the two layers of the pericardium?
A
epicardium & parietal pericardium
17
Q
What are the two layers of the epicardium?
A
sub-epicardium & mesothelium
18
Q
What is the sub-epicardium made of?
A
fibro-elastic CT (thin layer) with coronary vessels, nerves, and some adipose
19
Q
What does the mesothelium of the epicardium do?
A
secretes a serous lubricating fluid
20
Q
What is the parietal pericardium made of?
A
mesothelium: secretes serous fluid
layer of fibro-elastic CT
21
Q
What makes of the pericardial sac?
A
parietal and fiberous pericardium
22
Q
What is the pericardial cavity made of?
A
parietal and visceral pericardium
23
Q
How much fluid is held in the pericardial cavity?
A
15-50 mL
24
Q
What is the general valve histology?
A
endothelium w/ dense irregular CT (collagen 1 & elastic fibers); mostly avascular
25
What is the cardiac skeleton made of ?
dense irregular CT
26
What is are the three main components of the cardiac skeleton?
annuli fibrosi, trigonum fibrosum, septum membranaceum (also chordae tendinae)
27
Where are the annuli fibrosum?
around the base of the aorta, pulmonary artery, and chamber openings
28
Where are the trigonum fibrosum?
by aortic valve cusps
29
What is the septum mebranaceum?
upper portion of the interventricular
30
What is the function of the septum mebranaceum?
to produce an origin and insertion for the cardiac myocytes
31
What is the general function of the cardiac skeleton?
isolates atrial and ventricular myocardia to ensure individual chamber contractions
32
What is angina?
chest pain usually brought on by exhertion
33
What is the cause of angina?
slow progressive narrowing of coronary vessels therfore less oxygen
34
What is dysrythmia?
abnormal heart beat
35
How can dysrythmia result?
when death or damage occurs to the purkinje fibers and other conducting tissues
36
What is pericarditis?
often due to an infection on the pericardial cavity and therfore inflammation of the serous pericardium (visceral & parietal layers)
37
What are the three major luminal wall layers in all but the smallest blood vessels?
tunica intima, tunica media, and tunica adventitia
38
T/F: The 3 major luminal wall layers are a continuation of the hearts histological layers.
true
39
The tunica intima is a continuation of...
endocardium
40
The tunica media is a continuation of...
myocardium
41
The tunica adventitia is a continuation of...
epicardium
42
What is another name for elastic arteries?
conducting arteries
43
What are examples of elastic arteries?
aorta, common iliacs, common coratids, brachiocephalics, subclavians
44
What is the structure of the tunica intima of elastic arteries?
attenuated endothelium
thin/incomplete internal elastic lamina
thicker CT w/ elastic fibers, collagen 1, fibroblasts & smooth muscle
45
What is the structure of the tunica media of elastic arteries?
fenestrated sheets of elastic fibers w/ some collagen 1 & smooth muscle
thin external elastic lamina possible
outer portion typically has: VASA VASORUM
46
What is the vasa vasorum?
small BV's supplying large BV's
47
What is the structure of the tunica adventitia of elastic arteries?
loose fiberelastic CT
| vasa vasorum numerous
48
What is the thin cellular layer covering the inside of large blood vessels?
endothelium
49
What are muscular arteries also called?
distributing arteries
50
What is the structure of the tunica intima of muscular arteries?
VERY THIN
endothelium
some CT- few smooth muscle cells possible
internal elastic lamina
51
What are examples of muscular arteries?
brachial, radial, renal, femoral
52
What layer of muscular arteries has a wavy appearance?
tunica intima- internal elastic lamina
53
What is the structure of the tunica media of muscular arteries?
primarily circular smooth muscle
gap junctions btwn smooth muscle cells
elastic & reticular fibers, chondrotin sulfate
external elastic lamina possible
richly innervated w/ sypathetics --> strong contraction over a small area
54
What is the thickest most dominant layer of muscular arteries?
tunica media
55
What part of blood vessels blocks products of inflammation?
tunica media
56
What is the structure of the tunica adventitia of muscular arteries?
fibroelastic CT w/ sulfated GAGs
FIBROBLASTS
vasa vasorum is present
57
What is the relative size of arterioles?
lumen size is ~ equal to width of the vessel
58
In arterioles, is the tunica intima present?
maybe
59
In arterioles, is tunica media present?
no
60
In arterioles, what is the tunica adventitia structure?
??????????
61
What happens to elastic arteries as you age?
```
width increases into your 20's
# of elastic laminae increase in the tunica media
```
62
What happens to muscular arteries as you age?
collagen & proteoglycans increase after middle age: decreases flexibility
coronary vessels greatly affected
63
What is hypertension?
an increase in systolic BP, can occur ~50 yrs, due to a decrease in elastic fibers & increase in collagen 1
64
What is arteriosclerosis?
athrosclerosis "hardening of arteries" - primarily the largest
TUNICA INTIMA: infiltrated w/ soft lipids causing decreased lumen diameter
TUNICA MEDIA: often affected - collagen 1 and sulfated GAGs can accumulate here
65
What are metarterioles?
short terminal arteriole branches that LACK A TRUE TUNICA MEDIA
lead to capillaries and thoroughfare channels taht lead to venules
66
What controls metarteriole blood flow?
pre-capillary sphincters: allow blood to pulse through capillaries
Found in all capillary beds
67
What is an AVA?
arteriovenous anastamosis = AV shunt
thicker tunica media & tunica adventitia
many ANS nerves (sympathetic & parasympathetic)
FXN: control AVA lumen size & therefore the amount of blood into the capillaries
68
If the AVA is closed...
blood to capillary bed is normal
69
If the AVA is open...
blood by-passes capillary bed
70
How is the blood flow into capillaries controlled/influenced?
1) metarterioles
2) AVA (some locations)
3) lumen size of terminal arteriole
4) pre-capillary sphincter
71
What is the general capillary structure?
Cells: single layer of flattened endothelial cells
Pinocytotic vesicles: form tiny pockets through cytoplasm
FXN: mvmnt of large molecules
Cell junctions: FASCIAE OCCLUDENS-btwn endothelial cells
FXN: move macromolecules, allows cell mvmnt
72
What are the types of capillaries?
continuous capillaries, fenestrated capillaries, sinusoidal capillaries (sinusoids)
73
What are continuous capillaries?
most common capillary type
| found in: muscle, ct, many organs
74
What are pericytes?
considered "residual mesenchyme cells"
numerous on capillaries & venules
secrete: basement membrane & matrix components
can divide
75
What can pericytes change into?
1) smooth muscle cells
2) endothelial cells
3) fibroblasts
76
What are the functions of pericytes?
1) healing
| 2) regulate blood flow????
77
Where are fenestrated capillaries found?
pancreas, intestines, endocrine organs, kidneys
78
What is the structure of fenestrated capillaries?
pores with thin protein diaphragm containing 8 fibrils "wheel structure"
79
What is the function of fenestrated capillaries?
allows greater movement of molecules and cells
80
Where are sinusoidal capillaries (sinusoids) found?
bone marrow, liver, spleen, lymphatic organs, certain endocrine organs
81
What is the structure of sinusoids?
enlarged diameter
| many large fenestrae w/ NO PROTEIN DIAPHRAGM
82
What is the function of sinusoids?
enhanced exchange btwn blood & tissues
83
How are veins similar to arteries?
they have 3 tunics (intima, media, externa)
84
How are veins different from arteries?
1) not as uniform in structure
2) often larger
3) higher number
85
What are vein valves like?
Structure: 2 flaps of tunica intima and fibroelastic ct
FXN: 1) protection by preventing back flow
2) works with skeletal muscle to keep blood moving
86
What are venules?
determined by tunics not diameter
87
What are post capillary venules?
THINNEST
tunica intima: endothelium, small amount of ct & numerous pericytes
tunica media & adventitia: NONE
88
What are collecting venules?
tunica intima: endothelium & small amounts of ct
tunica media: NONE
tunica advetitia: ct, fibroblasts, some pericytes
89
What is the set up of muscular venules?
tunica intima: present
tunica media: NONE
tunica adventitia: CT, fibroblasts, some pericytes
90
What allows products of inflammation through and loosens endothelial call junctions resulting in LEAKY VENULES?
incomplete tunica media
91
What is the structure of small veins?
similar to venules EXCEPT COMPLETE TUNICA MEDIA
92
what is the structure of medium veins?
VALVES COMMON
tunica intima: endothelium, BL, CT w/ reticular fibers, sometimes and elastic fiber network
tunica media: smooth muscle, collagen, fibroblasts
tunica adventitia: CT w/ collagen, elastic fibers, few smooth muscle cells, vasa vasorum possible
93
What is usually the thickest, most dominant layer of medium veins?
tunica adventitia
94
What is the structure of large veins?
tunica intima: similar to medium veins, thicker CT w/ fibroblasts & elastic fibers
tunica media: complete but thin
tunica adventitia: much fibro-elastic CT w/ vasa vasorum
95
What is usually the thickest layer of large veins?
tunica adventitia
96
How are the superficial veins of the legs different from the typical structure?
the tunica media is well developed
97
How are the pulmonary veins different from the typical structure?
tunica media is well developed
| tunica adventitia: some cardiac muscle close to the heart
98
How is the superior vena cava different from the typical structure?
tunica adventitia: some cardiac muscle close to the heart
99
How is the inferor vena cava different from the typical structure?
tunica adventitia: some cardiac muscle close to the heart is possible & longitudinal smooth muscle
100
What are varicose veins?
enlarged and winding SUPERFICIAL veins in the legs
101
What are 3 possible causes of varicose veins?
1) loss of skeletal muscle tone around the veins
2) degeneration of vessel wall
3) valve incompetence
102
What are esophageal varices?
varicose veins in lower esophagus
103
In what population are esophageal varices common?
alcoholics; caused by portal hypertension
104
What are hemorrhoids?
varicose veins at the end of the anal canal
105
What are the functions of lymphatic vessels?
1) drains excess interstitial fluid
2) transport lymph to lymph nodes - foreign antigen detection n lymph nodes
3) transport lymph to blood stream
106
What type of capillaries to lymph capillaries resemble?
continuous blood capillaries
107
How are lymphatic capillaries different from continuous blood capillaries?
1) blind ended - suddenly begin
2) NO pericytes
3) endothelial cells can overlap, create clefts btwn cells
(easy movement of materials in and out)
4) NO fenestrae & NO tight junctions btwn endothelial cells
5) has bundles of lymphatic anchoring filaments
108
What does the structure of small lymphatic vessels resemble?
venules (a little thinner)
109
What is the structure of medium and large lymphatic vessels?
larger lumen and thinner walls, tunics blend together more than in veins
110
What are the layers of med & lrg lymphatic vessels set up like?
tunica intima: endothelium and thin layer of CT with elastic fibers
tunica media: thin smooth muscle layer
tunica adventitia: CT w/ collagen and elastic fibers
valves: present and closely packed
111
Where do lymphatic ducts empty?
into the venous system at the junction of R&L internal jugular and subclavian veins
112
What ducts are included in the lymphatic ducts?
short right lympahtic duct and the thoracic duct
113
What is the general structure of lymphatic ducts?
tunica intima: endothelium - several layer of collagen and elastic fibers; layer of condensed elastic fibers (similar to internal elastic lamina)
tunica media: longitudinal & circular layers of smooth muscle
tunica adventitia: longitudinal smooth muscle cells; collagenous ct; vasa vasorum-like vessels
