Biomedical Flashcards
(167 cards)
1
Q
trace the path of an RBC from vena cava to vena cava
A
vena cava, right atrium, tricuspid, right ventricle, pulmonary valve, pulmonary artery, pulm. circulation pulmonary vein, left atrium, bicuspid valve, left ventricle, aortic valve, aorta, systemic circulation, vena cava
2
Q
what are the main functions of the cardiovascular system?
A
deliver O2 and nutrients, remove waist
3
Q
What are the components of cardiac output
A
heart rate and stroke volume (CO = HR * SV)
4
Q
what is automaticity
A
ability of the heart to beat on its own without input from the brain due to unstable resting membrane potential of the SA node
5
Q
why is the sinoatrial note the pacemaker of the heart
A
the SA node has the highest intrinsic rate of the conducting cells there fore it takes president in setting the pace, this is known as overdrive suppression
6
Q
what is an ectopic foci
A
other conducting cells can become pacemakers in pathological stress
7
Q
what are the components of normal sinus rhythm
A
regular rhythm, rate between 60-100bpm, normal shape of wave formation (ECG)
8
Q
what does the signal that makes the heart beat result from?
A
depolarization of cardiac myocytes
9
Q
what is the ion response during contraction/systole
A
Ca++ influx during action potential triggers release of Ca++ from scaroplasmic reticulum; Ca++ bonds to troponin, causing it to shift and allowing myosin-actin interaction and contraction
10
Q
what is the ion response during relaxation/diastole
A
[Ca++] falls as it is transported (into SR via SERCA pump, out of cell by membrane CA++ pump and Na=Ca exchanger); fall in [Ca++] causes troponin to shift, blocking actin-myosin interaction and contraction
11
Q
What is the prominent ion in excitation-contraction coupling
A
CALCIUM
12
Q
what is stroke volume
A
the volume of blood ejected by the heart each beat (SV=EDV-ESV)
13
Q
what is ejection fraction
A
the fraction of the end diastolic volume ejected each beat (EF = SV/EDV)
14
Q
your patient’s end diastolic volume is 140ml, end systolic volume is 70ml, HR is 75.
What is stroke volume?
A
70ml
15
Q
your patient’s end diastolic volume is 140ml, end systolic volume is 70ml, HR is 75.
What is ejection fraction?
A
50%
16
Q
your patient’s end diastolic volume is 140ml, end systolic volume is 70ml, HR is 75.
What is cardiac output?
A
5250ml/minute
17
Q
what is stenosis?
A
narrowing of the valve opening
18
Q
what is regurgitation?
A
valve allows backflow of blood
19
Q
what can go wrong with the heart beat
A
valve disease, systolic disfunction, diastolic dysfunction
20
Q
what is systolic disfunction
A
decreased contractility during systole
21
Q
what is diastolic disfunction
A
decreased relaxation during diastole
22
Q
what are the phases of the cardiac cycle
A
atrial systole, isovolumetric ventricular contraction, ejection, isovolumetric ventricular relaxation, passive ventricular filling
23
Q
what phases of the cardiac cycle are ventricular systole
A
aka contraction; isovolumetric contraction & ejection of blood into aorta
24
Q
what phases of the cardiac cycle are ventricular diastole
A
aka relaxation; isovolumetric relaxation, passive filling of ventricle, active filling of ventricle (atrial systole)
25
What is the first principle of flow
fluids flow from high to low pressure
26
what factors affect resistance
viscosity, vessel length, vessel radius - radius is the most important!
27
what is the second principle of flow
anytime there is flow, there is resistance to flow
28
what is the third principle of flow
flow in = flow out
29
what is the forth principle of resistance
for resistances in a series, total R=R1+R2+R3..
30
what is the 5th principle of resistance
total flow equals the sum of the flow through the parallel segments Qin=Qout= Q1+Q2+Q3...
31
what is the 6th principle of resistance
for resistances in parallel, 1/Rtotal = 1/R1 + 1/R2 + 1/R3; total resistances is less than any of the individual resistances
32
what has the biggest contributions to peripheral resistance
arterioles
33
how does vasculature regulate flow?
```
local mechanisms (tissue metabolites, myogenic, endothelial factors)
distant mechanisms (neural & hormonal)
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34
What valve closes at the beginning of isovolumetric contraction?
Bicuspid on the left, tricuspid on the right
35
what valve opens at the end of isovolumetric contraction
aortic valve, because the pressure in the ventricle exceeds that in the aorta
36
what causes the aortic valve to close
the aortic valve closed when ventricular pressure falls below that of aortic pressure, marking the beginning of isovolumetric relaxation
37
what electrical event most closely corresponds to the closing of the mitral(bicuspid) valve
QRS complex
38
what are the components of cardiac output
heart rate and stroke volume
39
what are the components fo blood pressure
cardiac output and total peripheral pressure
40
what is mean arterial pressure
diastolic pressure + 1/3(pulse pressure)
41
what is pulse pressure
the difference between systolic and diastolic pressure
42
what is directly proportional to pulse pressure
stroke volume
43
what is inversely proportional to pulse pressure
vessel compliance (ex: decreased compliance due arteriosclerosis = increased pulse pressure)
44
which has a high pressure gradient, systemic or pulmonary circulation
systemic
45
how do tissue metabolites regulate flow
dilation of vessels
46
how does the myogenic response regulate flow
both dilation and constriction
47
how do endothelial factors regulate flow
both dilation and constriction
48
how does the sympathetic NS regulate flow
veddel constriction
49
what is reactive hyperemia
an increase in blood flow in response to a period of occlusion
50
what tissue metabolites are responsible for vasodilatation
K+, phosphate, adenosine, prostaglandins, etc
51
what is active hyperemia
increase in blood flow in response to increase in a tissues metabolic activity (exercise)
52
describe the myogenic auto-regulation of blood vessels
smooth muscle in the vessels respond to changing pressure; dilates to maintain flow when pressure decreases, constricts to maintain flow when pressure increases
53
how does the sympathetic NS control PB
blood vessels innervated by the SymNS vasoconstrict in response to norepi acting on alpha1 receptors; also stimulates adrenal cortex to release epi
54
explain the renin-angiotensin-aldosterone system
a decrease MAP leads to decrease in renal perfusion -> incresae in renin ->increase in angiotensinogen -> angiotensin I -> angiotensin II -> aldosterone & ADH
- KEY for long term management of BP
55
what are the effects of angiotensin II
increased sympathetic activity; increased tubular Na+ and Cl+ reabsorption, K+ excretion, water retention; stimulates adrenal cortex to release aldosterone; stimulates arteriolar vasoconstriction; stimulates antidiuretic hormone(ADH) release
56
what are pharmacologic management methods of HTN
- decrease cardiac output via calcium channel blockers and beta blockers; decrease TPR via angiotensin converting enzyme inhibitors; decrease volume via diuretics
57
discribe the baroreceptor reflex
sensors detect change, processors develop response, effectors carry out response. in BP decreases: CO increased via parasympathetic withdraw and sym. activation; TPR increases via sym. mediated vasoconstriction; sympatheric constriction of veins to increase venous return.
KEY for short them management of BP
58
what are the two branches of autonomic nervous system
sympathetic and parasympathetic
59
what used to be thought of as the 3rd division of the of the ANS
enteric
60
where are the SyNS pre ganglionic neurons located
in the spinal cord T1-L3 - lateral horn. "thoracolumbar"
61
Where are the SyNS post ganglionic neurons located
pre and paravertebral chain of ganglia
62
where are the PsNS preganglionic neurons located
brainstem nuclei, spinal cord S2-S4; "craniosaccral"
63
where are the PsNS post ganglionic neurons located
close to the effector in parasympathetic ganglia
64
what is different about the autonomic nervous system circuit structure as apposed to the somatic
the ANS circuit has 2 neurons in series while somatic has 1 neuron
65
What is released from all preganglionic neurons in the ANS
acetylcholine (Ach)
66
where do the axons of the preganglionic neurons exit the spinal cord in the SyNS
through the ventral root
67
what are the prevertebral sympathetic ganglion
celiac ganglion, superior mesenteric ganglion, inferior mesenteric
68
where do the majority of PsNS neurons originate
cranial nerve X (Vagus nerve)
69
what are the PsNS cranial preganglion neuron regions
edinger-westphal nucleus (CN III); salivatory nucleus (CN VII and IX); dorsal motor nucleus of vagus (CN X)
70
what are the 3 trajectories of a preganglionic neuron in the SyNS
enter the paravertebral chain & synapse at same level then exit to effector; enter the paravertebral chain and travel up or down the chain before synapsing; enter the paravertebral chain, travel, exit and synapses in prevertebral ganglion
71
what are some examples of parasympathetic ganglia
ciliary ganglion, pterygopalatine ganglion, submaxiliary ganglion, otic ganglion, etc.
72
what are the holes of the hypothalamus
the five Fs and one S: Food metabolism, Furnace (body temp), fight response, flight response, fuck (sex behaviors), sleep-wake cycles
73
describe food metabolism as controlled by the hypothalmus
controls hunger/feeding behavior; autonomic control of digestion; hormone release
74
describe regulation of body temperature controlled by the hypothalamus
thermoregulatory behavior; autonomic control of heat conservation/loss; hormone secretion controlling metabolic rate
75
how does the hypothalamus play a roll in sexual behavior
autonomic modulation of reproductive organs and endocrine regulation of gonads
76
what role does the hypothalamus plat in sleep wake cycles
controls the sleep cycle and levels of arousal when awake
77
whaat are the main ANS neurotransmitters
norepinephrine, epinephrine, acetylcholine
78
what types of receptors respond to Ach
cholinergic
79
what are the 2 types of cholinergic receptors
nicotinic - autonomic ganglia
| muscarinic - heart, sm, glands
80
what types of receptors respond to NE and Epi
adrenergic
81
what are the 5 types of adrenergic receptors
alpha 1 &2, Beta 1,2&3
alpha 1- smooth muscle
Beta 1 - heart
82
give examples of muscarinic receptors that react to Ach
sweat glands and blood vessels (SyNS)
| glands, SM, heart (PnSN)
83
give examples of androgenic receptors for norepinephrine and epinephrine
heart & blood vessels
84
what is the major example of Ach acting on a nicotinic receptor
SyNS and PsNS pre-post ganglion synapse
85
what are examples of autonomic reflexes
baroreceptors, micturition, pupillary response, peristalsis, respiratory
86
what are the phases of an autonomic reflex arc
afferent pathways (input); integration/processing; efferent pathways (output) - > back to afferent to maintain control constantly
87
what are the types of sensory receptors
mechanoreceptors, chemoreceptors, nociceptors, thermoreceptors
88
give examples/locations of mechanoreceptors
aortic baroreceptors, carotid sinuses, lungs, bladder, veine, intestines
89
give examples/locations of chemoreceptors
carotid/aortic bodies, medulla, hypothalamus, stomach, taste buds, olfactory bulbs
90
where are nociceptors located
throughout viscera, arterial walls
91
where are thermoreceptors located
hypothalamus, cutaneous
92
give an example of a negative feedback loop
baroreceptor reflex to control BP - baroreceptors sense decrease in pressure, relay to hypothalamus, signal sent to increase heart activity and peripheral resistance
93
what is ventilation
the bulk flow of air into and out of the lungs
94
what are the main principles of ventilation
air flows from high to low pressure; for air to flow into the lungs PinPout
95
how does air get into the lungs?
contraction of inspiratory muscles increases thoracic volume therefore decreasing thoracic pressure making creating the pressure gradient needed
96
how does air get out of the lungs?
muscles relax decreasing thoracic volume and compressing the lungs and alveoli reversing the pressure gradient and expelling air
97
what is spirometry
measures that allow us to look at lung volumes and capacity
98
what is functional residual capacity
the point where the collapsing force of the ling is balanced by the expanding force of the thorax
99
what is minute ventilation
tidal volume * respiratory rate
100
what is the conducting zone?
anatomic dead space that does not participate in gas exchange (~150mL)
101
what is alveolar ventilation
(tidal volume-dead space)*respiratory rate; accounts for dead space; basically how much air per minute participated in gas exchange
102
how does gravity affect ventilation
gravity causes a gradient in internal pressure; upper regions are more stretched and there for less compliant. therefore base of lungs are more compliant and can expand more
103
what is a pheumothorax
collapsed lung; results from the decoupling of the lung and chest wall
104
how is ventilation affected with a SCI at C3 or above
diaphragm is paralyzed; requires mechanical ventilation
105
how is ventilation affected with a low cervical SCI
diaphragm remains innervated, but accessory muscles not. contraction of diaphragm collapses thoracic cage, loss of abs leads to diaphragm flattening and expansion of abdomen during inspiration
106
how does asthma affect ventilation
vasospasms causes narrowing of airway which increased resistance; therefore a greater pressure gradient is required to maintain flow executed by an increase in muscle effort/ work of breathing
107
what is dynamic compression
changing of airway diameter during ventilation phases to aid in controlling air flow - expands during inspiration and compresses during expiration
108
what disease can increase compliance in the lungs
emphysema - increases compliance by destroying elastic fibers in lung
109
what diseases can decrease compliance in the lungs
pulmonary fibrosis & chest wall disorders
110
what are the consequences of decreased compliance of the lung
increased muscle effort for inspiration, increased work of breathing, lower functional residual capacity
111
what are the consequences of increased compliance of the lung
decreased elastic recoil, elevated functional residual capacity, increased work of breathing
112
what is the roll of surfactant in the lungs
reduce surface tension on the alveoli walls to keep alveoli from collapsing
113
what is respiratory distress syndrome
loss of surfactant that leads to alveolar collapse; this gives rise to decreased lung compliance and decreased area for gas exchange
114
what is the driving force for diffusion of gases
partial pressure
115
what is the PO2 of dry air
160mmHg
116
what is the PO2 of tracheal air
150mmHg; because you have to account for water vapor in the trachea
117
What is PAO2
100mmHg; reflects balance between O2 entry to and exit from alveoli
118
what is PACO2
40mmHg; due to CO2 diffusing into alveoli from venous blood
119
why are partial pressures of O2 and CO2 equal in the alveolus and arterial blood
arterial blood "equilibrates" with alveolar air under normal circumstances
120
what determines the rate of gas diffusion
pressure gradient, thickness of the membrane, surface area
121
how much of blood oxygen is pound to hemoglobin
98% - Measured by % saturation (SaO2)
122
how many oxygen binding sites are on hemoglobin
4
123
how much of blood oxygen is dissolved in plasma
2% - measured by PO2
124
what are the 3 modes fo CO2 transport
- dissolved in plasma (5%)
- bound to hemoglobin (3%)
- chemically modified as H+ and HCO3- (92%)
125
what does changing oxygen affinity do?
decreasing affinity facilitates O2 unloading in tissues by making it harder for hemoglobin to hold on to oxygen
126
what is hypoxemia
decreased arterial PO2 (<80mmHg)
127
what is hypercapnia
increased PaCO2 (>45mmHg)
128
how is hypercapnia sensed
central chemoreceptors in the brainstem - VERY SENSITIVE to pCO2 and pH of cerebrospinal fluid
129
how is hypoxemia sensed
by peripheral chemoreceptors in carotid and aortic bodies,
130
where are hypoxia and hypercapnia processed
respiratory centers in medulla and pons
131
what is the effect of hypoxia and hypercapnia
increased ventilatory drive to expel more CO2 or inhale more O2
132
causes of hypoxemia
breathing hypoxic gas, hypoventilation, diffusion limitation, ventilation-perfusion matching
133
what is the normal ventilation perfusion ratio
0.8
134
what is gravities affect on ventilation
ventilation at base> apex; alveoli at apex pulled open at rest, at base much larger increase during inspiration
135
what is gravities affect on perfusion
perfusion at base> apex; caps in apex are underperfused while those at base are overperfused
136
what happens when V/Q is high
ventilation >> perfusion; blood coming out of lung looks more like atmospheric air
137
what happens when V/Q is low
ventilation << perfusion; blood coming out of lungs looks more like venous blood
138
how does ventilation change with exercise
ventilation increases in proportion to VO2 and VCO2
139
what are the 3 phases of ventilation with exercise
phase I - fast
Phase II- Primary
Phase III - steady state
140
what is pharmacokinetics
how the body processes the drug
141
what is pharmacodynamics
how the body interacts with the drug
142
what is the therapeutic index
the ratio of median toxic dose to median beneficial dose; the greater the ratio the more safe the drug is
143
what are the routes of administration of a drug
enteral (GI tract) & parenteral
144
give examples of enteral drug administration
oral, buccal, sublingual, rectal
145
give examples of parenteral drug administration
inhalation, intranasal, injection, topical, transdermal
146
what is the issue with oral drug administration
subject to first pass effect - liver removes some before it gets to target
147
what are the main ways drugs move across the cell membrane
passive diffusion and active transport
148
what is bioavailability
how much of the drug is available for use
149
what factors affect absorption and distribution
route of administration, prosperities of the drug, endogenous carriers, endogenous barriers, PT (heat and ice)
150
what are the drug storage sites
adipose (most common), bone, muscle, organs
151
what is biotransformation
metabolic process of breaking down lipid soluble drugs into water soluble parts
152
how are drugs excreted
Renal (pee), respiratory, other uncommon paths include - GI, sweat, saliva and lactation
153
what are the energy pathways available for muscle
phosphocreatine, anaerobic glycolysis, oxidative phosphorylation
154
describe phosphocreatine ATP generation
high power, low capacity; makes ATP from ADP and nearby PCr
155
describe anaerobic glycolysis
moderate power and capacity; associated with acidosis makes ATP from glycogen
156
describe oxidative phosphorylation
Low power, high capacity, aerobic, makes ATP from lipids, carbs, and proteins; occurs in mitochondria
157
what are the yields of the substrates for oxidative phosphorylation
glucose - 36 ATP
lipids - 130 ATP
proteins - somewhere between
158
when is each substrate primarily used in oxidative phosphorolyation
lipids - at rest
carbs - during heavy exercise
proteins - disease states and starvation
159
when is each method of ATP production primarily used
phosphocreatine - temporal and spatial buffer for high power activity and transition from rest to exercise
glycolysis- transition from rest to exercise, heavy exercise and when O2 is lacking
oxidative phosphorylation - primary means always
160
what are the aerobic changes with training
high intensity, short duration activity increases anaerobic substrates, increases quantity and activity of key glycolytic enzymes
161
what are the aerobic energy changes with training
mod intensity long duration activity increases # of mitochondria in use, increases oxidation of fats at rest and submax exercise; increased ability to oxidize carbs at max exercise
162
what are the changes with aerobic training to cardiovascular system
increases stroke volume via increased left ventricle volume
decreased HR at rest and submax exercise
increased peripheral vasodilation capacity
163
what are the ventilatory changes with aerobic training
increased tidal volume and RR at submax exercise, greater time for O2 diffusion, lower energy cost of breathing
164
what mechanisms control blood pressure
heart rate, stroke volume, peripheral resistance
165
what is the affect of sympathetic activation to the heart
increased heart rate,
increased contractility
(increased BP)
166
what is the affect of parasympathetic activation to the heart
decreased HR, decreased contractility
| decreased BP
167
what are the autonomic higher level cardiac regulation regions
cardiac accelerator center, cardiac inhibitory center; both in medulla
