Lecture Exam 3 Flashcards
(216 cards)
1
Q
Define arteries
A
LARGE, branching vessels that take blood AWAY from the heart
2
Q
Define arterioles
A
SMALL, branching vessels with HIGH resistance
3
Q
How can arterioles control blood pressure?
A
by changing their diameter, thus resistance
4
Q
Define capillaries
A
the site of exchange between blood & tissue
5
Q
Define venules
A
small converging vessels
6
Q
Where do WBCs exit?
A
venules
7
Q
Define veins
A
large converging vessels that take blood TO the heart
8
Q
Where is 2/3 of the blood held?
A
within the veins
9
Q
Where does gas exchange occur, thus causing the blood to become deoxygenated?
A
capillaries
10
Q
What are erythrocytes?
A
RBCs
11
Q
What are leukocytes?
A
WBCs
12
Q
What transports oxygen & carbon dioxide?
A
RBCs (erythrocytes)
13
Q
What defends the body against pathogens?
A
WBCs (leukocytes)
14
Q
What are important in blood clotting?
A
platelets
15
Q
What is serum?
A
plasma without proteins
16
Q
What is the most important protein in plasma?
A
albumin
17
Q
What is blood flow driven by?
A
blood pressure
moves from high to low pressure
18
Q
Where is there SERIES flow?
A
within the cardiovascular system
19
Q
Where is there PARALLEL flow?
A
within one specific circuit
20
Q
How does O2 get into the blood?
A
through the pulmonary circuit (in capillaries)
O2 diffuses from alveoli into the blood
21
Q
What side of the heart carries OXYGENATED blood?
A
left
22
Q
What side of the heart carries DEOXYGENATED blood?
A
right
23
Q
What causes valves to open?
A
pressure change
24
Q
What do valves do?
A
prevent back flow of blood
25
What do AV valves have that semilunar valves don't?
chorde tendineae
26
What cells provide the rhythm to heartbeat?
pacemaker cells
27
What conduct the action potentials initiated by pacemaker cells?
conduction fibers
28
Which node is the pacemaker of the heart?
SA node
29
Which node has a FAST firing rate?
sinoatrial (SA) node
30
Which node has a SLOW firing rate?
atrioventricular (AV) node
31
Where is the sinoatrial (SA) node found?
in the RIGHT atrium
32
Where is the atrioventricular (AV) node found?
between the ventricle & atrium
33
A gap junction is used for what?
electrical coupling
34
What makes up intercalated disks?
desmosomes
35
Intercalated disks are used for what?
resisting mechanical stress
36
What causes the slow firing rate of the AV node?
AV nodal delay
37
Do the ventricles or the atria contract first?
atria
38
Removal of what from the cytosol allows cardiac muscle to relax?
calcium
39
A slowed conduction through the AV node would result in what?
2nd degree heart block
40
A loss of conduction through the AV nodes would result in what?
3rd degree heart block
41
When atrial & ventricular contractions become independent, what kind of heart block is that?
3rd degree heart block
42
Extra systole is caused by what?
a premature atrial contraction (PAC)
43
Define systole
ventricular CONTRACTION
44
Define diastole
ventricular RELAXATION
45
When do AV valves open?
when ATRIAL pressure is GREATER than ventricular pressure
46
When do semilunar valves open?
when VENTRICULAR pressure is GREATER than arterial pressure
47
What phase of the cardiac cycle does aortic pressure change?
phase 3 (ventricular ejection)
48
During what phases of the cardiac cycle is ventricular volume CONSTANT?
phase 2 (ventricular contraction)
phase 4 (ventricular relaxation)
49
What causes the dicrotic notch during aortic diastole?
back flow of blood causing an increase in pressure
50
During aortic diastole how do the aortic valves behave?
they are closed
51
During aortic systole how do the aortic valves behave?
they are open
52
What is the lowest pressure?
diastolic pressure
53
What is the highest pressure?
systolic pressure
54
Define EDV
end diastolic volume
the volume of blood in the ventricle at the end of diastole
55
Define ESV
end systolic volume
the volume of blood in the ventricle at the end of systole
56
How can you calculate stroke volume?
EDV - ESV
57
Define SV
stroke volume
the volume of blood ejected from the ventricle with each beat
58
Define EF
ejection fraction
fraction of EDV ejected during a heart beat
59
How do you calculate ejection fraction (EF)?
SV / EDV
found as a percent!
60
What does ejection fraction (EF) reflect?
cardiac function
61
What is the normal range for ejection fraction (EF)?
50% - 70%
62
What causes the first (soft) thump of the heart beat?
AV valves closing
63
What causes the second (loud) thump of the heart beat?
semilunar valves closing
64
What phases of the cardiac cycle can you hear heart beats?
phases 2 & 4
65
Define CO
cardiac output
the volume of blood pumped from the heart per MINUTE
66
How do you calculate CO (cardiac output)?
SV x HR
measured in L/min
or mean arterial pressure/total resistance
67
How can you control cardiac output?
regulate HR and SV
68
How can the sympathetic nervous system affect CO?
1. increase sympathetic activity
2. epi binds to B1 receptors in SA node
3. increase opening of Ca2+ & Na+ channels
4. increase rate of depolarization
5. increase HR & CO
69
How can the parasympathetic nervous system affect CO?
1. increase parasympathetic activity
2. norepi or acetylcholine bind to muscarinic receptors in SA node
3. open K+ channels & close Ca2+ channels
4. decrease rate of depolarization
5. decrease HR & CO
70
What hormones can increase CO?
epinephrine & glucagon increase HR & CO
71
What primary factors affect SV?
1. ventricular contractility
2. EDV (preload)
3. afterload (increasing this decreases SV)
72
What factors affect EDV (preload)?
1. filling time
2. atrial pressure
3. venous pressure
73
What factors affect afterload?
1. blood pressure in aorta during ejection
2. aortic valvlar stenosis
74
What does increasing afterload cause on SV?
increasing afterload, increases resistance, DECREASES stroke volume
75
The circulatory system is what kind of system?
a closed system
76
What is the typical mean arterial pressure (MAP)?
93 mm Hg
77
What is the typical mean central venous pressure (CVP)?
0 mm Hg
78
Which circuit, systematic or pulmonary, has the greatest resistance?
systematic
79
What is the biggest effector of resistance?
RADIUS
80
Define vasoconstriction
decreased radius
thus increased resistance
81
Define vasodilation
increased radius
thus decreased resistance
82
In the vessel wall, what do endothelial cells do?
line inner layer of blood vessels
83
In the vessel wall, what does smooth muscle do?
contract or relax to change blood flow
84
In the vessel wall, what does connective tissue do?
line the outside of blood vessels
85
What determines systolic pressure?
elastic arteries
86
What determine diastolic pressure & tissue perfusion?
arterioles
87
What are the properties of elastic arteries?
high elasticity
low compliance
88
How do you calculate compliance?
change in volume / change in pressure
89
The heart is what kind of pump?
discontinuous pump
90
The role of elastic artery is what?
hydraulic filter
expand as blood enters then recoils during diastole
91
Define compliance
how well something can stretch
92
Define elasticity
how well something can recoil after being stretched
93
How are compliance & elasticity related?
inversely
94
What can affect pulse pressure?
SV and compliance
95
Which arm is the best to use when measuring blood pressure?
left arm
96
What is the first sound, during compression, that you hear when manually taking blood pressure?
systolic pressure
97
What is the second sound, after release, that you hear when manually taking blood pressure?
diastolic pressure
98
What serve for regional blood flow?
arterioles
99
High metabolic activity (large amounts of metabolic byproducts) causes what?
vasodilation
100
What are the metabolic factors?
CO2
K+
H2
organic acids
101
Define active hyperemia
increases blood flow in response to increased metabolic activity
102
Define reactive hyperemia
increased blood flow in response to a pervious reduction in blood flow
(blockage then blockage released)
103
What does an increase in transmural pressure cause in blood vessels?
vasoconstriction
104
Stretch of a vessel induces what?
contraction
105
What happens to blood vessels during exercise?
vasodilation
106
In order to cause vasoconstriction in smooth muscle, what does norepi bind to?
alpha adrenergic receptors
107
What happens to blood vessels when alpha adrenergic receptors get bound to?
vasoconstriction
108
What happens to blood vessels when beta 2 receptors get bound to?
vasodilation
109
What releases epinephrine?
adrenal medulla
110
What releases vasopressin?
posterior pituitary
111
What does vasopressin cause?
vasoconstriction
112
What does angiotensin II cause?
vasoconstriction
113
Define continuous capillaries
SMALL gaps between endothelial cells
114
Define fenestrated capillaries
LARGE gaps between endothelial cells that form fenestrations
115
Define discontinuous capillaries
FULL gaps between the basal membranes of endothelial cells
116
What kind of capillary is most common?
continuous
117
How do gasses & lipophilic molecules move across capillaries?
free diffusion
118
How do small lipophobic solutes move across capillaries?
pass through cleft or cell-cell junction
119
How do large lipophobic solutes move across capillaries?
transcytosis (bound to transport vesicles)
120
What pressures pull H2O in (absorption)?
capillary osmotic & interstitial fluid hydrostatic pressures
121
What pressures force H2O out (filtration)?
capillary hydrostatic & interstitial fluid osmotic pressures
122
Define hydrostatic pressure
the pressure of fluid exerted against capillary wall
123
Where does filtration occur?
arterioles, capillary, & venuoles
124
When does absorption occur?
immediately after a hemorrhage or arteriolar constriction in capillaries
125
What do venules do?
connect capillaries to veins
126
Veins function as a blood reservoir, which means...?
they expand with little pressure change
127
Do veins or arteries have higher compliance?
veins
arteries have higher elasticity
128
When skeletal muscles contract, what happens to veins?
veins get squeezed which increases their pressure & sends blood towards the heart
129
How does inspiration affect venous pressure & return?
decreases pressure in thoracic cavity
increases pressure in abdominal cavity
increases venous pressure
increase venous return
130
How does increasing venomotor tone (through sympathetic stimulation) affect venous compliance, pressure, & return?
increasing venomotor tone, decreases compliance, increases pressure & return
131
What is the main function of the lymphatic system?
to collect & return things to circulation
act as a defense system against foreign bodies
132
What are the determinants of mean arterial pressure (MAP)?
HR, SV, resistance
133
Define HYPOtension
inadequate blood flow
134
Define HYPERtension
too much blood flow
is a stressor for heart & blood vessels
135
During hypotension, how does MAP compare to normal?
it is LESS than normal
136
During hypertension, how does MAP compare to normal?
it is MORE than normal
137
Long-term regulation of MAP regulates what?
blood volume
138
Short-term regulation of MAP regulates what?
CO & resistance
139
Define external respiration
exchange of O2 & CO2 between the atmosphere & body tissues
140
Define internal respiration
use of O2 in mitochondria to produce CO2
141
What zone is there no gas exchange?
conducting zone
142
What is the purpose of the conducting zone?
functions as a "dead space"
purpose is to deliver air
143
What zone is there gas exchange?
respiratory zone
144
What are the structures of the thoracic cavity?
lungs, chest wall, intrapleural space
145
What are the bones in the chest wall?
rib cage, sternum, thoracic vertebrae
146
What are the respiratory muscles in the chest wall?
internal & external intercostals, diaphragm
147
Elastic forces of the lungs & chest wall work to do what?
EXPAND the chest wall & collapse the lung
148
At the end of exhalation, what is the intrapleural space pressure?
-4 mm Hg
149
During a pneumothorax, what is the intrapleural pressure?
0 mm Hg
150
At the end of exhalation, what is the atmospheric pressure?
0 mm Hg
151
At the end of exhalation, what is the intra-alveolar pressure?
0 mm Hg
152
At the end of exhalation, what is the transpulmonary pressure?
4 mm Hg
153
How do alveolar pressure & atmospheric pressure compare during inspiration?
atmospheric pressure is GREATER than alveolar pressure
154
How do alveolar pressure & atmospheric pressure compare during expiration?
atmospheric pressure is LESS than alveolar pressure
155
What alters the driving force of airflow?
changes in alveolar pressure
156
Greater surface tension in alveoli creates higher resistance to what?
alveolar expansion
157
What 2 factors affect surface tension?
surfactant & alveolar size
158
Smaller alveoli have more of what compared to larger alveoli?
more surface tension, thus more surfactant to decrease the surface tension & even out the pressure
159
Why is total resistance in small airways lower?
because they run in parallel
160
Which airway generations have higher resistance?
first 8 generations, larger airways
161
How does FEV1 / FVC look for obstructive diseases?
lower FEV1 / FVC due to restricted expiration
below 80%
162
How does FEV1 / FVC look for restrictive diseases?
same or increased as FEV1 can be normal but FVC is DECREASED
above 80%
163
Example of obstructive disease
COPD or asthma
164
Example of restrictive disease
fibrosis
165
What is the normal FEV1 / FVC?
80%
166
What is minute volume?
the total amount of air that flows in & out within a minute
167
How do you calculate minute volume (MV)?
tidal volume (TV) x breaths per min
168
Define alveolar ventilation
the amount of fresh air that enters the alveoli each minute
OR
volume of air reaching gas exchange areas per minute
169
How do you calculate alveolar ventilation (Va)?
breaths per min x (TV - dead space volume)
170
How do you calculate partial pressure of a gas?
% gas x sum of total gases in mixture
171
Which gas is more soluble in water than O2?
CO2
172
What are the 2 places gas exchange occurs?
lungs & capillaries (terminally tissues)
173
As the length of the capillary increases, what increases & what decreases?
PO2 increases
PCO2 decreases
174
Which way does O2 diffuse?
from blood to cells
175
Which way does CO2 diffuse?
from cells to blood
176
What is gas diffusion rate determined by?
surface area
pressure gradient
membrane thickness (inversely related)
177
PO2 in arterial blood
100 mm Hg
178
PCO2 in arterial blood
40 mm Hg
179
What relationship determines alveolar PO2 & PCO2?
rate of alveolar ventilation relative to the rate of O2 use & CO2 production
180
Define hyperpnea
an increase in ventilation to meet an increase of metabolic demands
(body is using more O2, producing more CO2, increase ventilation, increase blood flow to accommodate)
181
Define dyspnea
labored/ difficulty breathing
182
Define apnea
temporary stop of breathing
183
Define tachypnea
rapid, shallow breathing
184
Define hypoxia
low O2 to the tissues
185
Define hypoxemia
low O2 in the BLOOD
186
Define hypercapnia
too much CO2 in the blood
187
Define hypocapnia
low CO2 in the blood
188
Define hyperventilation
ventilation exceeds CO2 production
arterial PO2 increases
arterial PCO2 decreases
189
Define hypoventilation
CO2 production exceeds ventilation
arterial PO2 decreases
arterial PCO2 increases
190
How is the majority of O2 transported by blood?
bound to Hb (hemoglobin)
191
The amount of O2 dissolved in plasma is determined by what?
alveolar PO2
192
Define oxyhemoglobin
O2 bound to all sites of Hb
193
Define deoxyhemoglobin
O2 is not bound to all sites of Hb
194
Define carbaminohemoglobin
CO2 bound to Hb
195
Define carboxyhemoglobin
CO bound to Hb
196
How many O2 binding sites does Hb have?
4
197
Define capacity
the max amount something can hold
dependent on Hb concentration
198
Define content
the actual amount something is holding
199
How do you calculate blood oxygen content?
capacity x % (as a decimal) filled
200
When completely saturated, how much O2 does 1g of Hb carry?
1.34 ml O2
201
Normal blood Hb levels
12-16 g/dL
202
In arterial blood, how saturated is Hb?
above 95%
203
In venous blood, how saturated is Hb?
75%
204
How is the affinity of Hb for O2 affected?
by temp, pH, PCO2
205
What (other than increasing temp, PCO2 & decreasing pH) can lower O2 to Hb binding affinity?
presence of 2,3-DPG & CO
206
How is the majority of CO2 transported in the blood?
through plasma bicarbonate
207
What are the 2 respiratory control centers?
medulla & pons
208
What part of the medulla controls expiration?
VRG (ventral respiratory group)
209
What part of the medulla controls inspiration?
DRG (dorsal respiratory group)
210
What in the pons regulates the medulla?
PRG (pontine respiratory group)
211
What controls the firing pattern & frequency of the neurons of the VRG & DRG?
central pattern generator (CPG)
212
What do peripheral chemoreceptors do?
respond directly & indirectly to PCO2 & PO2 changes
213
What do central chemoreceptors do?
respond indirectly to PCO2 changes ONLY
214
pH is inversely related to what?
PCO2
215
PO2 in venous blood
40 mm Hg
216
PCO2 in venous blood
46 mm Hg
