Cardiac Physiology Flashcards
1
Q
Number 1 cause of death
A
Cardiovascular disease
2
Q
Major underlying cause of cardiovascular disease
A
Ischemia
3
Q
Ischemia can be due to
A
Atherosclerosis
Artery spasm
4
Q
White thrombus
A
Platelet plug
5
Q
Red thrombus
A
Blood coagulation
6
Q
Inflammatory mechanisms couple dyslipidemia to
A
Atheroma formation
7
Q
2 things that characterize early atherogeneis
A
Leukocyte recruitment
Proinflammatory cytokines
8
Q
Inflammatory pathways promote
A
Thrombosis
9
Q
___ responsible for MI and most strokes
A
Thrombosis
10
Q
___ can modulate inflammation
A
NS
11
Q
Hemostasis
A
Prevention of blood loss
12
Q
Mechanisms of hemostasis
A
Vascular spasm
Platelet plug
Blood coagulation
Fibrous tissue
13
Q
Vascular constriction can be due to
A
Neural reflexes
Local myogenic spasms
Local humoral factors
14
Q
Local humoral factors include
A
Thromboxane A2 (from platelets) Serotonin
15
Q
___ important in small vessels
A
Local humoral factors
16
Q
Responsible for most constriction
A
Local myogenic spasms
17
Q
Platelets cannot
A
Divide
18
Q
Platelet cell membrane contains
A
Phospholipids with platelet factor 3
19
Q
Mechanisms of platelet activation
A
- Swell
- Irregular form (spikey)
- Contractile proteins cause granule release
- Secrete ADP, thromboxane A2, and serotonin
20
Q
Constrictors
A
Thromboxane A2
Serotonin
21
Q
___ potentials release of granule contents but is not essential
A
Thromboxane A2
22
Q
Platelets are important in
A
Minute ruptures
23
Q
Platelets are eliminated primarily by
A
Macrophage action
24
Q
Endothelium prevents
A
Platelet aggregation
25
Endothelium produces
PGI2
26
PGI2 acts as a _____ and stimulates platelet adenyl cyclase, which ____
Vasodilator
Suppresses release of granules
27
Endothelium produces ___ important in clotting
Factor VIII
28
COX2 pathway produces prostacyclin, which is
Cardioprotective
29
Aspirin and ibuprofen both block ____ and ____
Thromboxane A2 and prostacyclin
30
COX inhibitors are a type of
NSAID
31
Inhibition of COX1 effects
Low thromboxane A2
32
Inhibition of COX2 effects
Endothelium (low PGI2)
33
Anticoagulants
Prevents clots form forming
34
Lysis of clots
Dissolves clots
35
Anticoagulants
| Chelators
Tie up calcium
36
Anticoagulants
| Heparin
Complexes with antithrobin 3
37
Anticoagulants
| Dicumarol
Inhibition of Vit k dependent factors
38
___ is needed for lysis of clots
Plasmin
39
There are both ___ and ____ activators or plasminogen
Endogenous activators
Exogenous activators
40
Endogenous activators of plasminogen
Tissues
Plasma
Urine
41
Exogenous activators of plasminogen in
Streptokinase
TPA
42
Administration of tPA has a ____ for MI and stoke
3 hr window
43
Reperfusion injury
ROS flood damaged area when pressure on tissues relieved and blood returns
44
Collateralization
Ability to open up alternative routes of blood flow to compensate for blocked vessel
45
3 methods of collateralization
1. Angiogenesis
2. Vasodilation
3. SNS
46
The SNS may ___ or ____ collateralization
Impede
Augment
47
SNS may impede collateralization by
Vasoconstriction
48
SNS may augment collateralization by
NPY
49
Extrinsic thrombosis
Initiated by chemical factors released by damaged tissues
50
Intrinsic thrombosis
Components in blood and trauma to blood or exposure to collagen
51
Coumarin depresses liver formation of clotting factors by blocking
Vit K
52
Hemophilia is
Sex linked
53
85% of hemophilia defect in
Factor VIII
54
15% hemophilia defect in
Factor IX
55
Without ____, blood won’t clot
Calcium
56
Intrinsic and extrinsic pathways of coagulation meet at formation of
Factor X
| Factor V
57
Key step in clotting
Conversion of fibrinogen to fibrin
58
Clots are dissolved by ___ which is activated by ___
Plasmin
TPA
59
Conversion of fibrinogen to fibrin requires
Thrombin
60
Antiphospholipid antibody syndrome
Autoimmune
Body makes Ab against phospholipids
Causes abnormal clots
61
Homocysteine
AA that may irritate blood vessels, promoting atherosclerosis
62
Homocysteine can make blood more likely to
Clot
63
Homocysteine levels can be reduced by
Increasing folic acid
B6
B12
64
A and B antigens on RBCs are known as
Agglutinogens
65
O is
Functionless
66
Agglutinins are formed
Spontaneously
67
Ab titers peak at
Age 10
68
Hemolysis occurs to ____ in mismatched transfusion
Donors RBCs
69
Primary Ab in lysis of RBCs
IgM
70
____ most lethal effect on transfusion reaction
Kidney failure
71
__ from lysed RBCs precipitates and blocks renal tubules
Hemoglobin
72
In Rh blood types, spontaneous agglutinins _____
Never arise
73
Rh blood: ___ antigen MC and means you are
D antigen
Rh+
74
Lacking D antigen means you are
Rh-
75
Erythroblastosis Fetalis aka
Hemolytic Disease of newborn
76
Released hemoglobin is converted by ____ into ____ which can cause jaundice
Macrophages
Bilirubin
77
Most cases of erythroblastosis Fetalis, mother is ___, father is ___, and fetus is ___
Rh-
Rh+
Rh+
78
Erythroblastosis Fetalis only occurs after the ____
Initial exposure
79
Kernicterus
Bilirubin precipitating in neurons causing mental impairment
80
Prevention of erythroblastosis Fetalis
Rh immunoglobulin globulin (RhoGAM)
Anti-D antibody
81
Heart muscle is ___ and has 1-2 centrally located __
Striated
Nuclei
82
Heart muscle contains specialized ____ and ____ muscle fibers
Excitatory
Conductive
83
Syncytium
Many acting as one
84
Cardiac muscle follows “all or none” law due to presence of
Intercalated discs
85
Gap junctions allow flux of
Na+
86
Duration of action potential
.2-.3 Sec
87
Channels in cardiac muscle
Fast Na
Slow Ca/Na
K channels
88
Permeability changes in heart muscle
Na sharp increase as onset of depolarization
Ca increases during plateau
K increased during resting polarized state
89
Time for entire heart to depolarize
.22 sec
90
AV node delay
.12 seconds
91
Purpose of AV node delay
Allows atria to contract before ventricles
92
___ blocks fast Na channels
Tetradotoxin
93
Specialized excitatory cells only have _____
Slow Ca/Na channels
94
Nernst equilibrium potential
Concentration gradient favoring ion movement in one direction offset by electrical gradient
95
During Er, ____ are closed, ___ is open
Fast Na and slow Ca/Na
K
96
During Er, ___ are free to move
K ions
97
___ binds and inhibited Na/K ATPase pump
Digitalis
98
Digitalis is used to
Increase strength of contraction (make heart stronger)
99
If Na/K pump inhibited, more ____ allowed to accumulate and ____ increased
Ca
Contractile strength
100
Absolute refractory period
Unable to re-stimulate
Occurs during plateau
101
Relative refractory period
Requires Supra-normal stimulus
Occurs during repolarization
102
In slow response cardiac muscle cell, relative refractory period is ___ and refractory period is
Prolonged
25% longer
103
Prolonged refractory period serves to
Protect ventricles from Supra-ventricular arrhythmias
104
Normal pacemaker of heart
SA node
105
SA node is ___ due to ___
Self excitatory
Leaky membrane to Na/Ca
106
In SA node, only ___ are operational
Slow Ca/Na channels
107
SA node spontaneously ___ at fastest rate
Depolarizes
108
___ lacks stable resting Er
SA node
109
Overdrive suppression
Drive self-excitatory cell at rate faster than inherent rate, you will suppress cell’s automaticity
110
Cells of AV node and purkinje system are under overdrive suppression of
SA node
111
Function of AV node
Delays wave of depolarization from entering ventricle
112
In absence of SA node, ___ may act as pacemaker, but at a lower rate
AV node
113
As HR increases, CL
Decreases
114
At resting HR, systole ____ diastole
<
115
As HR increases, both S and D shorten, but ___ shortens to greater extent
D
116
During S, perfusion of myocardium is restricted by
Contracting cardiac muscle
117
Systole associated with
Isovolumic contraction
118
Isovolumic contraction means
BP increasing
119
Diastole associated with
Isovolumic relaxation
120
Isovolumic relaxation means
BP decreasing
121
Ventricles are sealed ___ during cardiac cycle
2X
122
Valves open under
Forward pressure
123
Valves close under
Backward pressure
124
End diastolic volume
Volume in ventricles at end of filling
125
End systolic volume
Volume in ventricles end of ejection
126
Stroke volume
Volume ejected by ventricles
127
A wave associated with
Atrial contraction
128
C wave associated with
Ventricular contraction
129
V wave associated with
Atrial filling
130
AV valves
Mitral and tricuspid
131
Semilunar valves
Aortic and pulmonary
132
Semilunar valves are
Stronger construction
133
AV valves are thin so need
Chorda Tendineae
Papillary muscles
134
Valvular dysfunction creates
Vibrational noise (murmurs)
135
Valve not opening fully
Stenotic
136
Heart murmur during both S and D
Patent ductus arteriosis
Combined valvular defect
