Circulatory System: Quiz 2 Material Flashcards
1
Q
What is the cardiovascular systems role in homeostasis?
A
Main Transport System for Integrating Homeostasis
2
Q
Diffusion only supports life when the source is what distance away?
A
100 micometers
3
Q
What is the one exception for the required distance of a cell to a capiallary?
A
cells in the cornea
4
Q
What are the components of the cardiovascular system? What are their roles?
A
Heart: the biological pump, generates force to move the blood, two parts: a mechanical and an electrical
Blood: the medium through which O2/CO2/waste/nutrients and messengers like hormones are transported
Blood Vessels: the ‘tubing’ through which the blood flows; they play an active role in the movement of blood
5
Q
Name the electrical components of the heart.
A
-pacemakers and conductors
-action potentials
-voltage-gated channels
-automaticity
-conduction sequence
-ECG (Lead I)
6
Q
Name the mechanical components of the heart
A
-muscle contraction
-EC-Coupling (CICR)
-Pressure gradients
-valves
-sounds
7
Q
What components make up the blood? Include percentages.
A
plasma = 55%
leukocytes and platelets (buffy coat) = insignificant volume
erythrocytes (hematocrit) = 45%
8
Q
What causes people to have a higher “hematocrit”?
A
more testosterone
9
Q
What is the main purpose of RBC’s?
A
gas transport (oxygen)
10
Q
Which is heavier, plasma or RBCs?
A
RBCs
11
Q
What do all blood cells start out as?
A
stem cells
12
Q
What are the four commitments of stem cells?
A
- Reticulocyte
- Megakaryocyte
- White Blood Cells
- Lymphocytes
13
Q
Name the different examples of white blood cells.
A
monocyte, neutrophil, eosinophil, basophil
14
Q
What type of white blood cell turns into a macrophage?
A
monocyte
15
Q
What is the main purpose of platelets?
A
clotting
16
Q
What is the main purpose of white blood cells?
A
immunity defense
17
Q
What are the two types of lymphocytes?
A
B and T
18
Q
Describe the characteristics of a red blood cell
A
-biconcave discs
-large surface area
-lots of hemoglobin
-organelles are extruded (no DNA)
19
Q
What is Hemoglobin?
A
oxygen binding protein
20
Q
Where do forensics have to get DNA from?
A
buffy coat
21
Q
What is the underlying cause of Sickle-Cell?
A
carrier of a gene, sickle-cell anemia
22
Q
Distinguish between sickle-cell trait (SCT) and sickle-cell disease (SCD)
A
SCT is heterozygous
SCD is homozygous
23
Q
How does the spleen factor into Sickle Cell pathology?
A
the spleen removes misshaped or damaged cells, but when there are too many the spleen is overfilled and becomes painfully enlarged
24
Q
How does blood flow change when RBC’s become sickle shape?
A
can block small blood vessels, slow flow
25
What is the cardiovascular system made up of?
2 pumps and 2 circulatory systems
26
Which side of the heart has thicker walls?
left because it has to produce more pressure, do more work
27
Define Perfusion
blood goes through capillary beds
28
Locate parallel capillary beds vs. series
Pulmonary = Series
Systemic = Parallel
29
What color is blood?
maroon
30
What would happen if the capillary beds of the systemic circulation were in series instead of parallel?
1. Blood quality to all organs
2. Flow regulation to individual organs
3. Amount of initial pressure required
pressure is required for flow
when blood goes through a capillary bed, pressure is lost
31
What is the resting blood flow through the body?
5L/min
32
What is flow during strenuous excersize?
17.5
33
What is the equation for Flow
delta P / R
34
What is flow a measurement of?
Volume/time
L/min
35
What is delta P
Pressure difference between two points (mmHg)
It is the GRADIENT, not the absolute pressures to see
36
What is the silent killer?
high BP
37
What is the equation for resistance?
R= (8xLxeta)/(pixr^4)
38
What is the longer equation for the equation of flow?
flow = (deltaPxpixr^4)/(8xLxeta)
39
Describe the path that blood takes through the heart
1. Blood enters the heart through the superior and inferior Vena Cava
2. enters right atrium
3. goes through right atrial ventricular valve
4. enters right ventricle
5. goes through pulmonary semilunar valve
6. enters pulmonary trunk
7. goes through right and left pulmonary arteries
8. goes to lungs
9. enters right and left pulmonary veins
10. enters left atrium
11. enters left atrial ventricular valve
12. enters left ventricle
13. goes through aortic semilunar valve
14. goes through aorta, then out to body
40
What is another name for the Right Arterial Ventricular Valve?
Tricuspid Valve
41
What is another name for the Left Atrial Ventricular Valve? (there are two)
Bicuspid valve, Mitral Valve
42
What is the largest and most dominant part of the heart?
left ventricle
43
What is are Chordae Tendineae? Where are they found? Where do they attach?
-fibrous connective tissue
-both ventricles
-one end attaches to the valve leaf/cusp, and the other attaches to the papillary muscle
44
Describe the layers of the heart starting from inner most
Myocardium: bulk of ventricle muscle that develops pressure
Epicardium: secretory epithelial
Pericardial Fluid/Space: reduces friction and pain
Pericardium: outter most layer, sack around the heart
45
Does more volume indicate more or less pressure?
more pressure
46
What two parts of the heart work together to prevent Prolapse?
papillary muscle, chordae tendinae
47
What happens during prolapse?
the cusps open back into the atrium, blood flows in the wrong direction
48
What is the purpose of heart valves?
to promote a one-way direction of blood flow
49
What are the 2 types of valves?
Atrioventricular Valves (AV)
- Right AV valve
- Left AV Valve
Semilunar Valves
- Pulmonar semi-lunar valve
- Aortic semi-lunar valve
50
What induces opening and closing of heart valves?
pressure gradients
51
What supplies blood to the heart?
Coronary Arteries
52
What do coronaries do?
supply blood to the myocardium
53
Why can't the myocardium get it's blood supply via diffusion from chamber lumen?
too thick
54
What are the FIRST branches off the aorta?
Coronaries
55
Where do blockages most commonly occur?
coronaries
56
Name and describe the three types of cardiac muscle cells
autorhythmic cells: determine heart rate (pacemakers), spontaneous active electrical activity
conducting cells: responsible for rapidly spreading the electrical stimulus throughout the chambers
contractile cells: make up 99% of cardiac muscle
57
What is considered the "true" pacemaker? Why?
SA node because it oscillates to threshold first
58
What delays propogation? Why?
AV node
-it is a chain of cells
-ion channel density
59
What are some of the names of conducting cells?
bundle branches, bundle of His, and Purkinje Fibers, ventricular contractile cells
60
What is the only expected electrical connection between atria and ventricle?
AV node
61
is AP propogation fast or slow?
fast
62
What does the Apex refer to?
bottom 'point' of heart
63
What does the Base refer to?
the top portion of the heart
64
Describe the conduction pathway or the path of excitation signal
1. SA node
2. Atrial contractile cells depolarize
3. AV node
4. Bundle of His
5. Bundle branches
6. Purkinje Fibers
7. Ventricular contractile vells
65
What is the conduction pathway useful for?
1.fast conduction of AP through the ventricles
2. in an ordered pathway through heart
66
What are the 4 implications of the conduction pathway?
1. all cells connected by gap junction, only one needs to reach threshold to start
2. only 1 cell needs to go bad to mess things up
3. external pacemakers can be inserted to overcome bad cells
4. every cell participates, no breaks
67
What does a p-wave represent?
SA node got to threshold, atria are depolarizing
68
What causes the flatline in the wave?
1. Atrial contractile cells uniformly depolarized
2. AV nodal delay
69
What does the R-wave represent?
-ventricular depolarization (contraction)
70
What does the T-wave represent?
ventricular repolarization (relaxation)
71
Why can we not see the atrial relaxation (repolarization) in the wave?
hidden in the R-wave
72
What delivers the excitation to the apex of the heart so that ventricular contraction occurs in an upward sweep?
The Bundle of His and Purkinje fibers
73
Define Automaticity.
capable of spontaneous, rhythmical self excitation
74
List the Intrinsic Depolarization Rates
1) SA Node Intrinsic Rate is 100-120 APs/min
2) AV Node Intrinsic Rate is 60-80 APs/min
3) Purkinjie Fiber Intrinsic Rate is 30-50 APs/min
75
What is the definition of Sinus Rhythm?
normal cardiac excitation-contraction sequence beginning at the SA node
76
Define Latent Pacemaker
lying quiet or hidden, not active potential pacemakers. Indcludes AV Node and Conducting cells
77
Define Ectopic Pacemaker
abnormal, any site driving ventricular excitation-contraction sequence that is NOT the SA Node
78
What is the relationship between Latent Pacemaker and Ectopic Pacemaker?
latent becomes ectopic
79
What happens during Tachycardia?
heart rate greater than 100 beats/min
80
What happens during Bradycardia?
heart reater slower than 60 beats/min
81
What happens during fibrillation?
totally irregular and chaotic AP propogation. See the muscle undulating like a bag of worms. Totally dysfunctional pump with no organized sequence or pattern of excitation
82
ventricular fibrillation is dangerous and fatal if not corrected, how does an AED machine help?
depolarizes every cell, SA node is (hopefully) able to take back over
83
What is an action potential? What causes it?
electrical signal causing significant membrane depolarization
-due to changes in ion permeability via opening/closing of ion channels
84
What are the three different AP types for the difference cardiac muscle cells?
1. nodal cell AP
2. conducting cell AP
3. contractile cell AP
85
What is the basic difference between the different types of AP?
different types of ion channels for the different AP types/ waveforms
86
What is the train of thought when considering events in the heart?
electrical events
mechanical events
pressure changes
valve changes
blood movement
87
Describe the events of a contractile cell action potential.
1. fast Na+ through normal voltage gated channels causes strong depolarization
2. transient K+ causes slight re-polarization
3. plateau caused by L-type calcium channels (plateau of depolarization)
4. K+ efflux causes re-polarization
88
Describe the events of a nodal cell action potential.
1. funny sodium channels (-60 to -50)
2. transient calcium (t-type) (-50 to -40)
3. L-type Calcium through DHPR (depolarization)
4. normal potassium efflux (re-polarization)
5. max diastolic hyper-polarization (-65mV)
89
What is everything that happens below threshold of a nodal cell AP called? What does it do?
pacemaker potential: sets the heart rate, cannot fire SA node until pacemaker potential is reached
90
Name examples of nodal cells
SA and AV
91
Describe the events of a conducting cell action potential.
1. fast voltage gated Na+ causes depolarization (-60 to -50)
2. transient calcium causes quick dip (-50 to -40)
3. L-type calcium causes plateau (DHPR)
4. Normal K+ efflux for re-polarization
92
What are the two main type of conducting cells?
-perkinje fibers
-bundle of his
93
What is unique about conducting cells?
-every ion, every channel participates
94
What are the phases of the cardiac cycle?
1 = Ventricular filling
2 = isovolumetric ventricular contraction
3 = Ventricular ejection
4 = Isovolumetric ventricular relaxation
95
Which side of the heart has LOWER pressure?
left side
96
What happens where pressure lines cross?
valves open or close
97
Describe the flow in a normal open valve.
laminar flow = quiet
98
Describe what happens in a stenotic valve.
poor opening, does not allow all blood flow through it, some pressure and volume stays upstream
narrowed valve
turbulent flow = murmur = whistle
99
Describe the flow of a normal closed valve.
no flow = quiet
100
Describe what happens in an insufficient valve.
poor closing, leaky, allows back flow of blood, inappropriate volume and pressure upstream
turbulent back flow = murmur = gurgle
101
What is similar about stenotic valve and insufficient valve?
both are abnormalities that cause inappropriate volume and pressure upstream
102
What does inappropriate volume lead to?
abnormally high pressure
103
What two events happen during diastole?
ventricular filling, isovolumetric relaxation
104
What two events happen during systole?
isovolumetric relaxation, ejection
105
What are the durations of diastole vs. systole?
DIASTOLE- 2/3 of time. 600-800 msec
SYSTOLE- 1/3 of time, 200-400 msec
106
Describe what happens during Ventricular Filling
majority is rapid passive filling
the rest is active filling
AV valves are open
SL valves are closed
atrial kick
EDV is reached
107
What does the atrial kick do?
adds 10-20% more blood to the ventricle (active)
108
What is end diastolic volume (EDV)?
the final volume in the ventricle after filling (135 mls)
109
What happens during isovolumetric contraction?
-ventricles contract (force development)
-pressure developing
-1st heart sound at start of phase (LUB)
-AV valves closed
-all valves are closed
-volume constant at EDV
P (atria) < P (ventricles) < P (aorta and PA)
110
What happens during ejection?
P(ventricles) > P(aorta and PA)
-blood flows out of ventricle
-SV ejected from each ventricle
-ESV remains
-AV valves closed, SL valves open
111
What is stroke volume (SV)?
volume of blood ejected from each ventricle
~70 mL
112
What is End Systolic Volume (ESV)? How is it calculated?
the volume of blood remaining in the ventricle after ejection
ESV = EDV - SV
ESV at rest = 135 mLs - 70 mLs = 65 mLs
113
What happens during Isovolumetric Relaxation?
2nd heart sound at start of phase
"Dup" : SL valves close
volume constant at ESV
P(atria) < P(ventricles) < P(aorta and PA)
-all valves closed
114
What is cardiac output? How is CO calculated? What is the normal cardiac output?
-the volume of blood coming out of each ventricle per unit time, usually expressed in Liters/min
CO = HR x SV = Flow
5 L/min
115
116
117
