More Practice Qs Flashcards
True or False: The voltage-gated Na+ channels which open during the action potential will stay open and allow Na+ ions to pass as long as the cell membrane remains depolarized
False
Name two physiological causes for hypoxemia:
1.Ventilation perfusion-mismatching 2. Increased barrier to diffusion 3. R-L shunts
True or False: The greatest amount of water reabsorption occurs in the distal tubule
False
True or False: For a substance that is frely filtered and undergoes net reabsorption, its clearance will be less than the clearance of inulin
True
True or False: ADH controls permeability of the late distal tubule and collecting duct to water
True
True or False: ADH acts by increasing the permeability to water of the descending loop of Henle
False
True or False: Summation, observed as increased force of the second twitch with twin stimulation in skeletal muscle, results from the fact that intracellular Ca++ is maintained at an elevated level for a longer amount of time allowing cross-bridges to be active longer. Therefore, tension developed by the second twitch is applied to remaining tension developed by the first twitch.
True
True or False: A motor unit is composed of a skeletal muscle fiber and all the alpha motor neurons that innervate the fiber
False
True or False: During a normal action potential in a typical neuron, K+ channels open before Na+ channels. In other words, the increase in K+ conductance (gK+) precedes the increase in gNa+.
False
Name one part of the respiratory system where turbulent gas flow is present during normal breathing:
Trachea
True or False: The release of calcium from the SR, signaled by an action potential, is an important step in excitation-contraction coupling in both skeletal and cardiac muscle
True
True or False: Renal blood flow is less than that of most other tissues
False
True or False: reabsorption of K+ in the distal tubule and collecting duct is the primary mechanism for maintaining K+ balance
False
True or False: Inhibiting sodium reabsorption tends to inhibit reabsorption of glucose
True
name an airway that lacks cartilaginous support, is supported by surrounding parenchyma, and has muscular walls?
Bronchiole
True or False: the specificity of transport systems for secretion generally is less than that for reabsorption
True
True or False: The atrioventricular valves are normally open when pressures in the ventricle are lower than pressures in the artria.
true
True or False: Systole makes up approximately 2/3 of the cardiac cycle
False
Pulmonary airway resistance is higher at (low/high) lung volumes.
Low
True or False: Conduction velocity is faster in myelinated fibers than it is in unmyelinated fibers
True
Which of the following is true with regard to pulmonary volumes:
- Tidal volume is approx. 5 times larger than FRC in the dog
- the volume of gas present in the lungs at the end of a normal exhalation is residual volume
- The volume of gas left in the lung at the end of a maximal exhalation is minimum volume
- The volume of gas in the respiratory systm at rest with the glottis open is FRC
The volume of gas in the respiratory systm at rest with the glottis open is FRC
which of the following is FALSE with regard to diffusion across the alveolar membrane
- increasing the FIO2 willincrease the diffusion of oxygen across the alveolar membrane
- Carbon dioxide is les diffusible than is oxygen
- The diffusion coefficient of a gas is defined as solubility/electrical charge
- excercise may increase or decrease the quantity of oxygen that diffuses into the blood
Carbon dioxide is les diffusible than is oxygen
True or False: Reabsorption of bicarbonate is dependent on secretion of H+
True
True or False: During the ejection phase of the cardiac cycle, ventricular pressure is similar to aortic pressure
True
True or False: Fast-twitch glycolytic fibers would be rich in mitochondria
False
True or False: If a neurotransmitter binds with a postsynaptic receptor that opens membrane channels that only allow K+ ions to pass, the postsynaptic cell will be less excitable
True
True or False: Stimulation of alpha-1 adrenergic receptors results in vasodilation
False
True or False: For a nonspecific cation channel, the ion with the greatest driving force will have the greatest influence on the synaptic potential it generates.
True
True or False: Activation of muscarinic cholinergic receptors on the heart (ie cardiac muscle) will decrease heart rate
True
True or False: The osmolality of the interstitial fluid at the bottom of the renal medulla is higher than that of th ecortex
True
True or False: Glomerulotubular balance tends to blunt changes in sodium excretion that could occur due to spontaneous changes in GFR
True
True or False: The Frank-Starling mechanism is due to the length-tension relationship of striated muscle.
True
True or False: In resting skeletal muscle, actin and myosin do not interact because the active sites on actin are covered by the light chains of myosin
False
True or False: Activation of sensory receptors involves opening and/or closing of ion channels
True
True or False: Fast-twitch glycolytic fibers would be abundant in fatigue resisntant muslces
False
True or False: The capillaries contain the greatest percentage of blood volume
False
True or False: The output of a neuron is normally through the dendrites
False
True or False: Movement of ions through membrane channels is governed by the ion’s oil/water partition coefficient
False
True or False: Activation of muscle stretch receptors leads to refelx relaxation of the muscle that was stretched
False
True or False: diuretics acting at the proximal tubule or loop of henle can disturb potassium balance by decreasing the reabsorption of potassium
False
True or False: The greatest quantity of sodium reabsorption occurs in the distal tubule
False
During mild to moderate excercise pulmonary vascular resistance is likely to (increase/decrease/remain unchanged).
Decrease (due to capillary recruitment)
True or False: We would expect a charged particle such as a Cl- ion to have a difficult time diffusing through the lipid bilayer of the cell membrane
True
True or False: With everything else constant, if R to a given vascular bed decreases by half, flow to the vascular bed doubles
True
True or False: the vasculature to the skin tends to vasodilate during heating
True
True or False: Organic waste products are secreted primarily in the distal tubule
False
Which of the following is normally associated with th alveolus:
- macropahges
- ciliated epithelial cells
- cartilagionous support
- goblet cells
macropahges
True or False: For the clearance of a substance “X” to be used as a measure of effective renal plasma flow, X must be filtered, NOT secreted and NOT reabsorbed
False
True or False: In the cardiovascular system, the greatest proportion of the blood volume is in the venous system
True
An alveolus that is perfused but not ventilated has a ventilation perfusion ratio equal to:
Zero
True or False: Fast-twitch glycolytic fibers would have a low myosin ATPase activity
False
In the respiratory zone of the lung, gas movement is best described as: a. bulk flow b. diffusion
b. diffusion
when a cow is moved to a higher elevation without a chance to acclimate, pulmonary vascular pressures may increase dramatically. Name the physiologic reflex that is responsible for this pressure change:
Hypoxic Pulmonary Vasoconstriction
True or False: During diastole, left ventricular pressure is approximately 80 mmHg
False
True or False: In general, the kidneys compensate for an alkalosis by adding new bicarbonate to plasma
False
True or False: The Na-K ATPase is required for repolarization of the cell membrane after an action potential
False
True or False: Increasng axon diameter AND/OR myelination will increase conduction velocity.
True
What is the best estimate of normal arterial oxygen tension?
- 159 mmHg
- 90 mmHg
- 40 mmHg
- 25 mmHg
90 mmHg
True or False: The Na+/K+ pump pumps the same number of Na+ ions out of the cell as it pumps K+ ions into the cell.
False
True or False: Hydrostatic pressure in Glomerular capillaries is generally greater than pressure in systemic capillaries
True
True or False: The relationship between active tension and muscle length is the result of the fact that changes in muscle length alter sarcomere length and the alignment of the cross bridges
True
True or False: The specificity of transport systems for secretion generally is greater than that for reabsorption
False
True or False: During the action potential in a typical neuron, K+ ions leave the cell
True
True or False: Renal blood flow is low because the renal vascular bed is highly constricted at rest
False
True or False: During diastole, pressure in the left ventricle is approximately 80 mmHg
False
A move from point “A” to which point most likely reflects an increase in venous return
C
True or False: Slow-twitch motor units generally produce less total force than fast-twitch, fatigable motor units because slow myosin is not as powerful as fast myosin
False
True or False: The myotatic reflex is an intrinsic property of skeletal muscle. That is it does not require any connection with the central nervous system,
False
True or False: Cardiac output is proportional to oxygen consumption
True
True or False: In a chemical synapse, gap junctions permit the conductance of ions between two cells.
False
True or False: Receptor potentials are all-or-none, actively propagated events
False
when arterial CO2 increases (ie hypoventilation), what happens to alveolar oxygen tension and pH?
oxygen tension- decreases pH- decreases (more acidic)
True or False: In a typical neuron, if we increase the permeability to Na+ (gNa+), there will be net movement of Na+ ions into the cell
True
True or False: The decrease in HR that occurs during activation of the parasympathetic nervous system is due to activation of cholnergic nicotinic receptors at the SA node
False
True or False: In a neuron at rest K+ conductance (gK+) is greater than gNa+
True
True or False: During a typical excitatory postsynaptic potential (EPSP), the membrane potential (VM) moves in a depolarizing direction
True
True or False: Conduction velocity is faster in myelinated fibers than in unmyelinated fibers
True
True or False: Increasing the amount of Ca++ which enters a nerve terminal during an action potential will result in decreased transmitter release
False
True or False: The autonomic nervous system is primarily concerned with controlling activity in cardiac and smooth muscles.
True
True or False: Demyelinating diseases will reduce conduction velocity in affected nerves
True
True or False: When the filtered load of glucose is greater than the maximum reabsorption (Tm) glucose begins to appear in the urine
True
True or False: For the clearance of a substance “X” to be used as a measure of effective renal plasma flow, X must be filtered, secreted and NOT reabsorbed
True
True or False: An animal that is incapable of making ADH will have an osmotic diuresis
False
True or False: The membrane potential (Vm) is constant in nerve and muscle cells and DOES NOT change
False
True or False: Most synapses in the mammalian central nervous system are electrical
False
True or False: Doubling GFR without changing the plasma concentration of inulin doubles inulin clearance
True
True or False: Aldosterone secretion is controlled in response to factors associated with extracelluilar fluid volume
True
True or False: In an osmotic diuresis, there is a loss of both water and sodium
true
True or False: Dilation of the afferent arteriole tends to increase hydrostatic pressure in glomerular capillaries
True
True or False: The Na+-K+ ATPase (pump) is required for repolarization after an action potential
False
True or False: Glucose normally is completely reabsorbed because plasma concentration of glucose is less than the renal threshold for glucose
True
True or False: Large molecules in plasma are more likely to appear in the filttrate than are small molecules
False
True or False: Eating a bag of potato chips would tend to cause an animal to be in positive sodium balance
True