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313 Cards in this Set
- Front
- Back
Does increased EDV increase or decrease ventricular contraction?
|
increase
|
|
T or F. The heart will always pump whatever it receives.
|
F. Not always. Within limits it will.
|
|
Which part of the heart prevents decomposition?
|
the pericardium
|
|
How does posture affect venous return?
|
raising arms improves venous return, venous pooling decreases it
|
|
Which factors decrease during an acute hemorrhage?
|
SV, CO and MAP
|
|
How can you prevent the heart from going into decomposition? (POSSIBLE SHORT ANSWER?)
|
blood letting via leeches
|
|
Are ESV and SV proportional or inversely proportional?
|
inversely proportional
|
|
How much blood does the ventricle hold when filled?
|
130 ml
|
|
How much blood is in the ventricle after systole?
|
60 ml
|
|
How much blood is ejected from the heart?
|
70 ml
|
|
What happens when the overlap of actin and myosin in the heart is not optimal?
|
decomposition
|
|
afterload?
|
??
|
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The PSNS can ____ contractility via ___ receptors.
|
decrease, M2
|
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Epinephrine can ____ contractility via ____ receptors.
|
increase, Beta1
|
|
Does SNS activity lead to an increase or decrease in SV?
|
increase (at any given EDV)
|
|
T or F. The PSNS and epinephrine affect SV similarly.
|
False. The SNS and epinephrine both increase SV, the PSNS decreases it.
|
|
How do the SNS and epinephrine increase contractility?
|
1. Increase Ca2+ entry from ECF
2. Increase rate of myosin ATPase activity 3. Increase rate of Ca2+ reuptake by sarcoplasmic reticulum |
|
Which factor(s) decrease(s) during mild exercise?
|
TPR
|
|
T or F. MAP increases greatly during mild exercise.
|
False. MAP does not change very much.
|
|
What is the role of the baroreceptors?
|
to keep systemic MAP as close to 100 mmHg as possible
|
|
Are baroreceptor reflexes short or long term regulators of MAP?
|
short-term
|
|
Where are the arterial baroreceptors located?
|
carotid sinus & aortic arch
|
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Baroreceptors are also known as ______ receptors.
|
stretch
|
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Arterial pressure increases as action potential frequency _______.
|
increases
|
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What happens to sympathetic and parasympathetic activity during a compensatory response?
|
sympathetic activity increases, parasympathetic activity decreases
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T or F. Due to a compensatory response, MAP returns to normal shortly after an actue hemorrhage.
|
F. It does not quite reach the normal value. There is a persistent error signal.
|
|
T or F. Baroreceptors help to restore blood plasma volume.
|
T. They facilitate reabsorption of fluid from the interstitial space and lymph.
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|
T or F. Kidneys help maintain body pH.
|
True
|
|
How is glucose produced in the kidneys?
|
Via gluconeogenesis (opposite of glycolysis). Glucose is made form amino acids during fasting.
|
|
T or F. Ureters lack smooth muscle and are composed mainly of cartilage and epithelial cells.
|
F. Ureters contain smooth muscle which allows wave-like contractions to help conduct urine from the kidney to the bladder.
|
|
Where is epinephrine produced?
|
in the adrenal gland
|
|
Is the PSNS active or inactive while the bladder fills?
|
inactive
|
|
Is the SNS active or inactive while the bladder fills?
|
active
|
|
Is the somatic NS active or inactive while the bladder fills?
|
active
|
|
The detrusor is under the control of the ___ NS.
|
PS
|
|
The external urethral sphincter is under the control of the ___ NS.
|
somatic
|
|
The internal urethral sphincter is under the control of the __ NS.
|
S
|
|
What induces the micturition reflex?
|
stretch receptors in the bladder
|
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When the micturition reflex is voluntary, the signal from the stretch receptors is routed through the ______________.
|
cerebral cortex
|
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When the micturition reflex is involuntary, the signal from the stretch receptors is routed through the ______________.
|
spinal cord
|
|
T or F. The osmolarity outside the nephron gets higher and higher.
|
True
|
|
Approx. how many nephrons are in the human body?
|
2-3 million
|
|
T or F. The urine is fully formed by the time it leaves the nephron.
|
True
|
|
T or F. The glomerulus receives the primary urine via filtration.
|
F. The Bowman's capsule receives the primary urine by filtration from the glomerulus
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Which is the largest part of the nephron?
|
PCT
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Where in the nephron does the majority of reabsorption and secretion occur?
|
PCT
|
|
What is the role of the loop of Henle?
|
concentrates urine, conserves H20, establishes medullary osmotic gradient
|
|
Which components of the nephron are part of the counter-current system?
|
loop of henle & CCD
|
|
Where is the majority of K+ secreted?
|
DCT & CCD
|
|
Where does variability in reabsorption and secretion in the nephron occur and why?
|
DCT & CCD; due to hormone actions
|
|
Which hormones affect reabsorption and secretion in the nephron?
|
aldosterone, ADH/vasopressin, ANH, angiotensin II
|
|
What is the 1st important site of vascular resistance control in the nephron?
|
afferent arteriole
|
|
Where is the 2nd important site of vascular resistance control in the nephron?
|
efferent arteriole
|
|
Where is the 2nd capillary bed and site of reabsorption and secretion in the nephron?
|
peritubular capillary bed & vasa recta
|
|
T or F. Glomerular filtration is an active process.
|
F. Passive due to Starling-Landis forces
|
|
T or F. Tubular reabsorption can be both active and passive.
|
T. Many active transport processes for ions and nutrients as well as passive diffusion for ions and nutriets (osmosis for H20).
|
|
Is tubular secretion active or passive?
|
active
|
|
How much of the plasma flowing through the glomerular capillaries is filtered to form the primary urine?
|
20%
|
|
What is faster: the rate of plasma flow or the GFR?
|
plasma flow
|
|
T or F. The primary urine contains protein.
|
False
|
|
How much plasma is filtered per day?
|
180 L
|
|
How often is the entire plasma volume filtered?
|
every 25 mins
|
|
How much urine is excreted daily?
|
1.5 L
|
|
T or F. The kidney can excrete virtually any waste or foreign substance.
|
True.
|
|
What is the role of the basement membrane matrix?
|
has a negative charge which repels proteins
|
|
T or F. The pressure after a resistance is higher than the pressure before the resistance.
|
False. The pressure after a resistance is lower than the pressure before a resistance.
|
|
Which Starling-Landis forces favor filtration?
|
Pgc and Pibc
|
|
T or F. Constricting the efferent arteriole causes GFR to increase.
|
True.
|
|
T or F. Pgc increases as GFR decreases.
|
False. Pgc increases as GFR increases.
|
|
T or F. Increasing resistance decreases Pgc and GFR.
|
True.
|
|
How is Pcap/Pgc controlled intrinsically?
|
myogenic response and paracrine
|
|
Ca2+ channels open when the afferent arteriole is stretched causing the arteriole smooth muscle to _____. This is an example of ____ control of GFR.
|
constrict; intrinsic
|
|
Which NS is involved in extrinsic control of GFR?
|
SNS
|
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A drop in MAP causes a(n) ____ in SNS output resulting in ______ of afferent and efferent arterioles. The overalll effect is a(n) ____ in Pcap and GFR. This is an example of ____ control of GFR.
|
increase; constriction;decrease; extrinsic
|
|
How much of the BMR of the whole body are the kidneys responsible for?
|
20%
|
|
T or F. The urine of a healthy individual does not contain glucose.
|
True.
|
|
What is the primary barrier for reabsorption in the kidney?
|
tubule epithelia
|
|
T or F. Paracellular transport between epithelial cells is an important part of reabsorption in the kidney.
|
False. Paracellular transport is restricted by tight junctions.
|
|
Which part(s) of the nephron has/have the most microvilli and why?
|
proximal tubules; high SA for reabsorption
|
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Which part(s) of the nephron has/have the tightest tight junctions?
|
DCT and CCD
|
|
Which part(s) of the nephron has/have the most mitochondria and why?
|
PT due to many active transport processes
|
|
T or F. Clearance rates can be used to estimate GFR and renal blood flow.
|
True.
|
|
T or F. H20 is completely reabsorbed.
|
False. Largely but not completely reabsorbed.
|
|
T or F. PAH (para-amino hippuric acid) is completely reabsorbed.
|
False. It is completely cleared from the blood.
|
|
Is inulin net secreted or net reabsorbed??
|
neither
|
|
Is urea net secreted or net reabsorbed?
|
44% reabsorbed therefore net secreted
|
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If CRx >1 then the substance is net _____.
|
secreted
|
|
T or F. Na+ follows Cl- passively.
|
False. Cl- follows Na+ passively.
|
|
Where is the majority of Na+ reabsorbed?
|
PT
|
|
Where does passive H2O reabsorption oocccur?
|
in the CCD (via osmosis)
|
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Tubular fluid is _____-osmotic to the medulla.
|
hypo
|
|
T or F. The counter current multiplier system (loop of Henle) creates a high osmotic gradient in the ISF and blood vessels.
|
True.
|
|
The PT is ______-osmotic to the cortex.
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iso (due to leaky tight junctions)
|
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Which limb of the loop of Henle is permeable to H2O and why?
|
descending limb due to presence of aquaporins
|
|
What is urine like when the DCT and CCD are impermeable to H2O?
|
dilute (low osmolarity), high volume
|
|
In the proximal tubule, active transport occurs in the _____ membrane and drives secondary active transport in the ______ membrane.
|
basolateral; apical
|
|
When is aldosterone released and from where?
|
in response to low NaCl in the ECF or indirectly by a fall in blood volume, released from the adrenal cortex
|
|
Where does aldosterone bind?
|
to a cytoplasmic receptor in principal cells
|
|
What happens when aldosterone activates a cytoplasmic receptor?
|
Na+ and K+ channels in the apical membrane open, more Na+ and K+ channels are synthesiszed, more Na+/K+ ATPases are synthesized
|
|
Where are Na+/K+ ATPasees located?
|
in the basolateral membrane
|
|
What is the overall effect of aldosterone?
|
increases permeability of DT/CCD to Na+, increase NaCl reaborption and K+ secretion, increased water reabsorption, increased blood volume, increased blood pressure
|
|
T or F. Na+ reabsorption is coupled to K+ secretion
|
True.
|
|
Which cells secrete renin?
|
granular/juxtaglomerular cells
|
|
T or F. Angiotensinogen is always present in large amounts in the plasma.
|
True.
|
|
What is the role of renin?
|
cleaves angiotensinogen to angiotensin I
|
|
What is the role of ACE?
|
cleaves angiotensin I to angiotensin II
|
|
What is the role of angiotensin II?
|
stimulates aldosterone release from adrenal cortex, increasing Na+ reabsorption
|
|
T or F. Angiotensin II increases vasoconstriction, aldosterone secretione, ADH secretion, thirst stimulation and MAP.
|
True.
|
|
When is urine flow rate the highest?
|
When ADH and aldosterone is low.
|
|
When is urine [NaCl] highest?
|
When ADH is high and aldosterone is low.
|
|
Is high ADH associated with high or low urine flow rate?
|
low
|
|
T or F. High aldosterone is associated with low urine flow rate.
|
False. It is associated with low urine [NaCl].
|
|
When is ANH released?
|
in response to high venous filling pressure (usually associated with high NaCl content in the body)
|
|
How does ANH impact NaCl content in the body and GFR?
|
increases NaCl and H2O excretion by raising GFR and inhibiting active Na+ reabsorption
|
|
What is the afferent division of the PNS?
|
information conducted from external and internal sensors to CNS
|
|
T or F. Integration occurs in the PNS.
|
False. CNS
|
|
What do visceral neurons detect?
|
sensory information from with8in the body
|
|
T or F. Baroreceptors are sensory neurons.
|
False. Visceral
|
|
What do proprioreceptors detect?
|
position of limbs and the body
|
|
Which NS is associated with voluntary activity? (somatic NS or autonomic NS)
|
somatic NS
|
|
Which NS is associated with excitatory info only? (somatic NS or autonomic NS)
|
somatic NS
|
|
Which NS is associated with neurons which reguate internal organs and structures? (somatic NS or autonomic NS)
|
autonomic NS
|
|
Which cells account for 90% of the cells of the nervous system?
|
glial cells
|
|
Which part of the neuron is responsible for metabolic functions?
|
the cell body/soma
|
|
Where does most integration in a neuron occur?
|
axon hillock
|
|
When is a pre-synaptic neuron not a pre-synaptic neuron?
|
When it is a post-synaptic neuron.
|
|
What is the range in length of a human neuron?
|
1mm-1m
|
|
What are the 3 structural classes of neurons?
|
bipolar, pseudo-unipolar, multipolar
|
|
Which glial cells are primarily found in the CNS?
|
oligodendrocytes
|
|
Where are schwann cells most numerous?
|
in the PNS
|
|
Where are glial cells often wrapped around multiple axons?
|
CNS
|
|
T or F. Glial cells can take up neurotransmitters and remove that signal.
|
True.
|
|
Which 3 things are membrane potentials associated with?
|
1. unequal distribution of ions across membranes
2. Active transport mechanism 3. differential permeability of the membrane to different ions |
|
How many ions move to result in a membrane potential?
|
less than 1/100 000
|
|
Is the conductance of K+ or Na+ greater?
|
K+
|
|
Which ion plays a major role in establishing a negative resting membrane potential?
|
K+
|
|
How is membrane leakage counteracted?
|
by the Na+/K+ ATPase
|
|
What information does Eion represent?
|
whether chemical or electrical driving forces predominate for that ion
|
|
What is the equilibrium potential for K+?
|
-94 mV
|
|
What is the equilibrium potential for Cl-?
|
-80 mV
|
|
What is the equilibrium potential for Na+?
|
+ 60 mV
|
|
The driving force for diffusion is greatest for which ion?
|
Na+
|
|
Depolarization occurs when the membrane potential becomes more ______.
|
positive
|
|
How are GPs conducted away from the site of origin and how are they affected as they move further away?
|
decremental local flow; decrease in size
|
|
T or F. The size of the GP depends on the size of the stimulus.
|
True.
|
|
T or F. Opening of K+ or Cl- channels results in depolarization.
|
False. Hyperpolarization
|
|
Which channel(s) open(s) at excitatory synapses and what is the net effect?
|
Na+ and K+; depolarization
|
|
What is the charge of a single EPSP?
|
+ 0.5 mV
|
|
What happens as Vm approaches threshold?
|
Na+ channels start to open
|
|
What happens when Vm reaches threshold?
|
voltage gated Na+ channels open explosively (+ feedback loop)
|
|
What is the membrane potential at threshold?
|
-55 mV
|
|
What happens when Vm reaches +30 mV?
|
voltage-gated Na+ channels close and voltage-gated K+ channels open
|
|
Why does hyperpolarization occur?
|
some voltage-gated K+ channels are slow to close
|
|
How does Vm return to resting after hyperpolarization
|
mostly due to K+ leak channels
|
|
Na+ channels are ____ or _____ during the refractory period.
|
open; inactivated
|
|
T or F. The absolute refractory period is longer than the relative refractory period.
|
False.
|
|
During which refractory period is a greater than normal stimulus required to generate another AP?
|
relative
|
|
T or F. Phasic receptors adapt very slowly.
|
False. Tonic receptors adapt very slowly
|
|
T or F. Tonic receptors are generally associated with life-critical sensation such as pain.
|
True
|
|
Which receptors detect changes in the environment? (tonic or phasic)
|
Phasic
|
|
What prevents an AP from moving backwards?
|
the absolute refractory period
|
|
T or F. APs are relatively rapid events.
|
False.
|
|
What allows APs to travel at the speed of electricity?
|
saltatory propagation from one node to another
|
|
T or F. The larger the diameter of an axon, the faster the propagation.
|
True
|
|
Saltatory propagation accelates AP conduction velocity up to _____ times.
|
1000
|
|
T or F. Decremental local current flow is not effective over longer distances in myelinated axons due to insulation.
|
False. It is effective.
|
|
What are the advantages of electrical synapses via gap junctions?
|
high speed, low cost
|
|
What are the advantages of chemical synapses?
|
rectifying, facilitate integration
|
|
Which synapses are most common in cardiac and smooth muscle?
|
electrical synapses
|
|
Which synapses are most common in the nervous system?
|
chemical synapses
|
|
T or F. Arrival of an AP opens voltage-gated Ca2+ channels.
|
True
|
|
What is the cause of 90% of the delay in chemical synapses?
|
docking of synaptic vesicalse (upon activation by Ca2+) and release of n/t into synaptic cleft by exocytosis
|
|
What is the cause of 10% of the delay in chemical synapses?
|
diffusion of n/t across synaptic cleft
|
|
Which mechanisms decrease n/t concentration in the cleft?
|
1. active transport of n/t back into pre-synaptic membrane for re-packaging into vesicles
2. n/t diffuses away from cleft 3. n/t actively taken up and metabolized by glial cells |
|
Where is the all or none law valid?
|
in the neuromuscular junction
|
|
T or F. Contact area, amount of n/t released and number of receptors are greater in neuron-neuron synapses than in the synapse between a somatic motor neuron and a skeletal muscle cell.
|
False.
|
|
T or F. The all or none rule always applies to neuro-muscular junctions due to integration.
|
False. There is no capacity for integration. So much acetylcholine is released that one E.P.P (GP on post syn membrane) is +50mV (suprathresold)
|
|
T or F. Gas exchange occurs in the conducting zone.
|
False. Respiratory zone.
|
|
Which zone has more cartilage, the conducting or the respiratory zone?
|
conducting zone
|
|
The SNS releases ______ which acts on _____ receptors to cause broncho_____.
|
norepinephrine, Beta2 adrenergic, dilation
|
|
The PSNS releases _____ which acts on ______ receptors to cause broncho____.
|
ACh; muscarinic; constriction
|
|
What are the functions of the conducting zone?
|
phonation (larynx), strength (cartilage and smooth muscle), warms air to 37 deg C, humidifies air to 100% R.H., cleanses air
|
|
What is the role of alveolar pores?
|
allow equalization of pressure in the lungs
|
|
Which cells secrete surfactant?
|
type II cells
|
|
T or F. The respiratory membrane is more permeable to O2 than to CO2.
|
False
|
|
T or F. The driving force for O2 is greater than the driving force for CO2.
|
True
|
|
What is the role of surfactant?
|
reduces surface tension up to 90%, prevents collapse of smaller alveoli
|
|
T or F. Larger alveoli hold more surfactant due to their higher volume.
|
False. Surfactant is higher in smaller alveoli.
|
|
What is a pneumothorax?
|
a rupture which connects the intrapleural space to the atmosphere, eliminating outside pressure, making breathing ineffective and causing lung to collapse
|
|
T or F. Rebound of chest wall during expiration increases alveolar pressure.
|
True
|
|
When is inhalation active?
|
During rest and exercise
|
|
When is exhalation active?
|
During exercise
|
|
During inhalation, external intercostal muscles pull ribs ____ (up/down) and _____ (in/out), the diaphragm _________ (shortens/lengthens) and moves _______ (up/down). Thoracic volume ________ (increases/decreases) and a ___ (-/+) P is developed.
|
up; out; shortens; down; increase; -
|
|
What do the internal intercostal muscles and abdominal muscles do during exhalation during exercise?
|
intercostal muscles pull ribs in and down, abdominal muscles push guts in, displacing diaphragm upwards
|
|
What does spirometry assess?
|
pulmonary function
|
|
What is the value for tidal volume?
|
0.5 L
|
|
What is the value for inspiration reserve?
|
3 L
|
|
What is the value for expiration reserve?
|
1.5 L
|
|
What is the value for residual volume?
|
1L
|
|
What is the value for inspiration capacity?
|
3.5 L
|
|
What is the value for vital capacity?
|
5.0 L
|
|
What is the value for total lung capacity?
|
6.0 L
|
|
T or F. Minute ventilation is also known as alveolar ventilation.
|
False. Anat. dead space must be considered for alveolar ventilation.
|
|
What makes up the anatomical dead space
|
stale air which is stuck in the conducting zone and does not participate in gas exchange
|
|
T or F. The volume of air in the anatomical dead space is approximately equal to 1.5 L.
|
False. 150 ml
|
|
Aprox. what percentage of alveolar air is replaced per breath?
|
10%
|
|
T or F. Alveolar O2 is much lower and alveolar CO2 is much higher than in outside air.
|
True.
|
|
Is it better to breath more deeply or more quickly?
|
deeply
|
|
T or F. Gases dissolve according to their concentrations.
|
False. According to their partial pressures.
|
|
What is the total pressure of room air?
|
760 mm Hg
|
|
What is the partial pressure of O2?
|
160 mm Hg
|
|
What is the partial pressure of CO2?
|
0.3 mm Hg
|
|
What is the partial pressure of H2O?
|
0.47 mm Hg
|
|
T or F. The partial pressure of O2 is higher in the air than in water.
|
False. PP is the same in air and water, concentration of O2 in air is higher than in water.
|
|
What is the capacity of water to hold O2?
|
7ml / 1000ml
|
|
What is the capacity of air to hold O2?
|
210 ml / 1000 ml
|
|
About how many times more soluble is CO2 in water than O2?
|
30x
|
|
What is the capacity of water to hold CO2? Of air to hold CO2?
|
0.4; 0.39
|
|
T or F. PO2 increases with each step in O2 transport.
|
False. It decreases
|
|
What are PO2 and PCO2 in atmospheric air?
|
160; 0.3
|
|
What are PO2 and PCO2 in alveolar air?
|
100; 40
|
|
What are PO2 and PCO2 in pulmonary arteries?
|
40; 46
|
|
What are PO2 and PCO2 in the cells?
|
less than or equal to 40; greater or equal to 46
|
|
What are PO2 and PCO2 in the systemic arteries?
|
100; 40
|
|
What are PO2 and PCO2 in the systemic veins?
|
40; 46
|
|
What are PO2 and PCO2 in the pulmonary veins?
|
100; 40
|
|
Is diffusion fast or slow at the lungs?
|
fast
|
|
How saturated is Hb as it leaves the lungs?
|
98%
|
|
What happens to Hb at the tissues?
|
becomes desaturated (deoxyhemoglobin), only 75% of binding sites are occupied by O2
|
|
T or F. Hb delivers 4 O2 molecules when it reaches the tissues.
|
False. One O2. Hb never has 0 O2 mols.
|
|
T or F. O2 bound to Hb does not contribute directly to blood PO2.
|
True. only dissolved O2 does
|
|
T or F. The 1st O2 that binds to Hb helps the second which helps the third which helps the fourth.
|
False. The fourth is not helped.
|
|
O2 is a _____ (+/-) allosteric modulator for further O2 binding and a ________(+/-) allosteric modulator of H+, CO2 and phosphate binding.
|
positive; negative
|
|
What happens to the bond between Fe2+ and O2 as temperature increases?
|
it weakens
|
|
What is the shape of the oxygen dissociation curve?
|
sigmoidal (S-shaped)
|
|
What is on the x-axis of the oxygen dissociation curve?
|
PO2 (driving force)
|
|
What is on the y-axis of the oxygen dissociation curve?
|
% oxygen saturation of hemoglobin
|
|
What is the PO2 at the loading point?
|
100 mm Hg
|
|
What is the PO2 at the unloading point at rest? During exercise?
|
40 mm Hg; 20 mm Hg
|
|
What is the % saturation at the unloading point at rest? During exercise?
|
75% ; 35%
|
|
Does the unloading point occur in the systemic veins or the systemic arteries?
|
veins
|
|
Why is the flat region at the top of the oxygen dissociation curve important?
|
provides an important safety margin for O2 loading during high altitude exposure, respiratory disease and a shift in the curve to the right during exercise
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The knee and steep part of the oxygen dissociation curve is important because it allows for a large increase in O2 unloading during exercise for a ______ (large/small) ________ (increase/decrease) in PvO2.
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small; decrease
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T or F. An increase in the driving force for CO2 shifts the ODC to the right.
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True
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T or F. An increase in pH shifts the ODC to the right.
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False. a decrease in pH (more acidic) shifts the OCD to the rght
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T or F. pH increases as CO2 increases.
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False. pH decreases
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T or F. An increase in blood temperature shifts the curve to the right.
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True.
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T or F. An increase in RBC [phosphate] shifts the ODC to the right.
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True
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T or F. O2 loading is improved as the ODC shifts to the right.
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False. unloading to the systemic tissues improves
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Is fetal or normal Hb more sensitive to 2,3 DPG?
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normal Hb
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T or F. The fetal Hb curve is shifted to the left of the adult Hb curve.
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True
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Why isn't the Mb curve S-shaped?
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only has 1 binding site for O2
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T or F. The Mb curve is found to the left of the adult Hb curve but to the right of the fetal Hb curve.
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False. It is to the left of both.
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T or F. There is a lot more CO2 than O2 in the blood.
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True
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How does the majority of CO2 in the body exist?
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60% as the HCO3- ion, mainly dissolved in the plasma
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T or F. Carbonic anhydrase is the most abundant protein in rbc's.
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second most. Hb is the first
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T or F. Peripheral chemoreceptors are very sensitive to small changes in PaO2.
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False
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T or F. H+ does not easily cross the blood-brain barrier.
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True
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What is the normal pHa range?
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7.2 - 7.6
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T or F. pH 7 causes coma and pH 7.8 causes tetany of muscles.
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True
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Which system is able to cope with a change in pHa more quickly, the respiratory or the renal system?
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respiratory system
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Which system in the body is the only one that is actively physiologically regulated?
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bicarbonate buffer system
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What is the ratio of [HCO3-] to PaCO2 x aCO2?
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20:1
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The protein and CO2 buffer systems are in equilibrium with eachother and with all other less important buffer systems by the _____ principle.
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isohydric
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Hypoventilation occurs when CO2 _______ (production/excretion) exceeds ______ (production/excretion).
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production; excretion
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Respiratory ______ occurs as a results of hypoventilation.
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acidosis
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Respiratory _____ occurs as a result of hyperventilation.
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alkalosis
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Hyperventilation occurs when CO2 ________ (production/excretion) exceeds ______ (production/excretion).
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excretion; production
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How does the kidney compensate if respiratory acidosis is chronic? If respiratory alkylosis is chronic?
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accumulates HCO3- and excreting H+ ; excretes HCO3- and accumulates H+
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What is the CO2/HCO3- system (use arrows)?
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CO2 + H20 <==> H2CO3 <==> H+ + HCO3-
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When HCO3- is lost, metabolic _____ occurs. To compensate, ventilation _____.
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acidosis; increases
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When H+ is lost, metabolic ____ occurs. Ventilation ____ to compensate.
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alkalosis; decreases
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T or F. The endocrine system is completely separate from the nervous system.
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False
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Which complex serves as the neuro-endocrine interface?
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the hypothalamus-pituitary complex
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What are the 3 classes of hormones?
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1. Amines
2. Protein and Polypeptide hormones 3. Steroid hormones |
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T or F. All amine hormones are derived from tryptophan.
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False. Some are derived from tyrosine also.
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Name 6 amine hormones.
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dopamine, epi, norepi, serotonin,, t3, t4
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Which class of hormones are lipophilic (can't be stored in vesicles) and why?
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steroid; ring structure of cholesterol preserved
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ADH and oxytocin are released from the ____ pituitary.
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posterior
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The anterior pituitary releases _____________ hormones and _______ hormones.
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hypophysiotropic; anterior pituitary
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What do hypophysiotropic hormones do?
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stimulate the release of another hormone
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In which pituitary gland do the axons from the hypothalamus terminate?
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posterior
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Which type of muscle shows characteristics of both skeletal and smooth muscle?
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cardiac muscle
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Actin is a ___ filament and mysosin is a ____ filament.
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thin; thick
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What is the maximum osmolarity of urine and how is it determined?
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1400 mOsm ; by the peal osm. of the medulla gradient
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Which pathway does ADH activate?
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PKA pathway
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What does PKA do when activated by ADH?
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stimulates production of new aquaporin 2 and insertion of storied aquaproin 2 into the apical membrane of principal cells.... increasing permeability of DCT/CCD to H20, leading to an increase in H2O reabsorption
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Where is ADH produced?
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in the neurosecretory cells of the hypothalamus
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Which receptors stimulate ADH secretion?
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osmoreceptors
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What generates respiratory rhythm?
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I and E neurons and PBC
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Where are E neurons located?
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in the VRG of the medulla
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Which neurons fire during active exhalation, I or E?
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E
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What does the PBC do?
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neurons spontaneously depolarize, driving I neuron firing patterns
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Which centre switches off I neurons?
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pneumotaxic
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Which centre prevents I neurons from switching off?
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apneustic center
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What do peripheral chemoreceptors monitor?
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PaO2, pH and PaCO2
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What do central chemoreceptors monitor?
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PaCO2
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T or F. Peripheral chemoreceptors are more sensitiev and accurate than central chemoreceptors.
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False. Other way around.
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T or F. CO2 crosses the blood-brain barrier easily.
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True
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Why is there a lot of CA in the cerebrospinal fluid (CSF)?
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converts CO2 to HCO3- after in crosses the blood-brain barrier
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What are the most important controls of breathing?
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central chemoreceptors
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Does activation of chemoreceptors increase or decrease ventilation?
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increase
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T or F. A decrease in PO2, a decrease in pH and an increase in PCO2 activates the peripheral chemoreceptors.
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True
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Describe the A band.
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entire myosin bundle + overlapping regions of actin
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Describe the I band.
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regions of actin that do not overlap myosin
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Describe the H zone.
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area of sarcomere between opposing ends of of myosin
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What are Z and M lines?
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Z lines: anchor actin; M lines: where myosin filaments join
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Why are actin's myosin-binding sites inactive when a muscle cell is at rest?
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tropomyosin covers the binding sites
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T or F. Ca2+ binds to tropomyosin.
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False. Binds to troponin.
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T or F. Troponin is bound to tropomyosin.
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True
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What happens when Ca2+ binds to troponin?
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conformational change in troponin complex, tropomyosin shifts, myosin-binding sites exposed
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What are the 5 steps of the crossbridge cycle?
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1. myosin binds to actin
2. power stroke (Pi and ADP released, head pivots, actin pulled) 3. Rigor (low energy form, myosin and actin tightly bound, cycle stuck due to lack of ATP) 4. Unbinding of myosin and actin 5. cocking of the myosin head |
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An AP travels down _____ and causes a conformational change in _______________, opening _______ and causing ____ to be released.
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T-tubules; DHP receptors; ryanodine receptors; Ca2+
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