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
True or False: Water reabsorption in the proximal tubule is generally active
False
True or False: Action potentials in neurons involve increases in permeability (ie increased gion) of the cell membrane for more than one ion
True
True or False: If PPAH is so high that it is not completely secreted, CPAH will overestimate effective renal plasma flow.
False
True or False: Calcium plays a central role in contraction of skeletal muscle in that calcium ions “turn on” contraction by stimulating oxidative phosphorylation in the muscle mitochondria, increasing the supply of ATP available to contractile proteins
False
Slow-twitch motor units can maintain activity for extended periods of time because of the characteristics of the (excitatory/metabolic) component of the muscle fibers in the motor unit.
Metabolic
True or False: Compared to reabsorption, carrier mediated transport for secretion is highly specific
False
True or False: Synaptic potentials and receptor potentials are actively propagated, regenerative events
False
True or False: The Na-K ATPase moves Na+ ions against their concentration gradient
True
True or False: In a typical myelinated axon, the action potential moves more rapidly through the internode (ie the myelinated portion) than it does through the node (ie the unmyelinated portion)
True
True or False: If a tissue exhibits autoregulation, then an acute increase in arterial pressure will not lead to a steady state increase in blood flow
True
True or False: Protein is normally reabsorbed passively
False
A move from point “A” to which point most likely reflects a decrease in inotropic state
G
True or False: A substance appears in urine when the amount filtered (Fx) is less than the maximum absorbed (Tm)
false
True or False: Calcium plays an important role in the control of contraction in cardiac and skeletal muscle by activating beta oxidation and increasing available ATP
False
True or False: The Na+-K+ ATPase is required for repolarization after each action potential.
False
True or False: The greatest rate of rise of ventricular pressure occurs during the rapid ejection phase of the cardiac cycle
False
True or False: Increasing contractility decreases ESV and therefore increases SV, with preload and afterload held constant.
True
True or False: Receptor potentials may be depolarizing or hyperpolarizing
True
True or False: The inside of a neuron is typically negative with respect to the outside
True
True or False: Calcium release from the SR is not essential for excitation-contraction coupling in skeletal muscle
False
True or False: The sympathetic nervous system tends to constrict skeletal muscle vasculature due to activation of alpha-1 adrenergic receptors
True
True or False: During an action potential in a typical neuron, there are changes in Na+ conductance (gNa+) but not gK+
False
True or False: A motor unit is composed of an alpha motor neuron and all the muscle fibers it innervates.
True
True or False: The concentration of Na+ inside the cell is the same as the concentration of K+
False
True or False: Increasing activity of the NA-K ATPase will increase both Na+ reabsorption and K+ secretion
True
True or False: The internal environment of a normal mammal (eg body temperature) never changes
False
If the trachea and lungs were removed from the chest cavity and alowed to equilibrate iwth the atmosphere the volume of gas contained would then approximate:
- 0 mL
- FRC
- residual volume
- minimal volume
minimal volume
True or False: Secondary active transport uses ATP to move Na+ against its concentration gradient.
False
True or False: Reabsorption of K+ in the distal tubule and collecting duct is the primary mechanism for maintaining K+ balance
False
What is the name for the volume of gas that remains in the respiratory system at the end of a normal exhalation?
FRC, functional residual capacity
True or False: The myelin sheath on axons should have roughly the same biochemical composition as a typical cell membrane
True
Name two differences between the pulmonary and arterial circulation.
Pulmonary- low Resistance, thin walled Arterial- high resistance, thicker walled
True or False: Water-filled channels in the cell membrane are the most important for the movement of lipid-soluble molecules
False
True or False: Presynaptic inhibition is due to increased entry of Ca++ into the presynaptic terminal
False
True or False: In a typical neuron, the equilibrium potential for K+ (EK+) is more negative than ENa+
True
What cell type is primarily responsible for surfactant production?
Type II alveolar epithelial cell
Intrathoracic airways are most likely to collapse during (inspiration/exhalation)
Exhalation
The response to an increase in plasma oncotic pressure would most likely be (increased/decreased/unchanged) fluid flux out of a pulmonary capillary and into the interstitial space.
Decreased
True or False: Skeletal muscle only contracts because of a neural stimulus, and never because of a hormonal stimulus
True
True or False: Autoregulation refers to maintaining renal blood flow constant at the level of single individual nephrons.
False
True or False: Most of the oxygen consumption of the kidneys is related to sodium reabsorption
True
True or False: In a typical unmyelinated nerve fiber, the action potential decays (ie is reduced in size) with time and distance as it moves along the axon
True
True or False: If a neuron is exposed to extracellular fluid with a lower concentration of dissolved ions than what is present inside the cell, water will enter the cell.
True
True or False: The atrioventricular valves open at the onset of diastole
False
True or False: Stimulation of Beta-1 adrenergic receptors results in increased HR and contractility
True
True or False: Sodium reabsorption is critical for the reabsorption of water
True
True or False: The concentration of amino acids in Bowman’s capsule is similar to that in plasma
True
True or False: In skeletal muscle, troponin is a protein that binds calcium
True
True or False: Normal filtration fraction is approximately 40% of renal plasma flow
False
True or False: Doubling GFR without changing the plasma concentration of inulin doubles inulin clearance
True
True or False: In a normal animal, CO is generally well maintained despite increases in MAP (afterload) because it is compensated by an increase in EDV.
True
True or False: Vasoconstriction of ARTERIOLES will incresae capillary hydrostatic pressure
False
True or False: Neurotransmission at the synapse may be terminated by diffusion of the transmitter away from the synapse.
True
True or False: The muscle pump is important in compensaztion for the effects of gravity
True
True or False: Aldosterone secretion is controlled in response to factors associated with extracellular fluid volume
True
Sympathetic nervous system effects on the heart result from the release of (norepinephrine or acetylcholine) from the sympathetic nerves and activation of (beta-1 or muscarinic) receptors
Norepinephrine; beta-1
True or False: A large QRS complex indicates a strong ventricular contraction
False
True or False: The autonomic nervous system is primarily involved with controlling activity in skeletal muscle
False
True or False: For a given end diastolic volume and inotropic state, increasing afterload tends to decrease stroke volume
True
True or False: The atrioventricular valves open at the onset of ventricular diastole.
False
How are infectious or irritating particles cleared from the alveolus?
Macrophages engulf and clean
True or False: Postsynaptic potentials are all-or-none, actively propagated events
False
True or False: If aortic diastolic pressure is increased, the aortic valve will open later in systole
True
Which of the following is true with regard to the alveolus:
- Type I epithelial cells cover the majority of the alveolar surface
- The mucociliary apparatus removes the thick mucus that covers the alveolar surface
- alveolar colapse is prevented by cartilaginous support of alveolar walls
- the major phagocytic cell type found in the alveolus is the polymorphonuclear cell
Type I epithelial cells cover the majority of the alveolar surface
True or False: The relationship between active tension and muscle length in both cardiac and skeletal muscle is the result of the fact that changes in muscle length alter sarcomere length and the alignment of the myosin heads and active sites on actin
True
name two things that can decrease alveolar oxygen tension:
Decreased VA; decreased FIO2
During the twitch of a skeletal muscle fiber, relaxation is the result of decreases in intracellular calcium that result from closed SR-Calcium channels and (increased/continued) activity of the SR-Calcium ATPase(Ca++-pump)
Continued
True or False: If a tissue exhibits autoregulation, then an acute increase in arterial pressure will increase vascular smooth muscle tone
True
True or False: Baroreceptor afferent activity increases during decreases in arterial pressure
False
True or False: You must have changes in conductance to have current.
False
True or False: The physical connection between an efferent interneuron and skeletal muscle is called a neuroeffector junction.
False
True or False: The Na+ channels which open during the action potential are opened (ie gated) by a change in the membrane potential (Vm)
True
True or False: Stimulation of the sympathetic nervous system to mobilize blood from the veins
True
True or False: Biological control systems are usually negative feedback systems
True
What is the rate-limiting step in the diffusion path of an oxygen molecule from the alveolus to red blood cell hemoglobin.
The binding of oxygen to hemoglobin
True or False: Synaptic transmission in vertebrates is mostly chemically mediated
True
True or False: Increasing the permeability of the cell membrane to Na+ (ie increase gNa+) will depolarize the cell
True
True or False: Increasing contractility tends to decrease oxygen consumption of the heart
False
True or False: Membrane channels can be selective for particular ions
True
True or False: ADH tends to counteract an increase in plasma osmolality by increasing reabsorption of water in the proximal tubule
False
True or False: One mechanism to increase excretion of a substance “X” would be to increade secretion of “X”
True
True or False: If we put a typical mammalian cell in a solution with an osmolality = 450 milliosmols/kg wwater, the cell will shrink
True
At rest and in a normal lung with an open glottis:
- Alveoli are approximatelt one cm in diameter
- Alveolar size is greatest “top” of the lung (dorsal) in the quadruped
- the volume of gas in the lung is approximately VT
- Pleural pressure is approximately -9cm H2O
Alveolar size is greatest “top” of the lung (dorsal) in the quadruped
True or False: The concentration of K+ ions is higher in intracellular fluid than in extracellular fluid
True
True or False: Stimulation of arterial baroreceptors results in a decrese in sympathetic nervous system activity
True
True or False: Velocity of flow in the capillaries is greater than that in the aorta.
False
True or False: Larger myelinated fibers conduct faster than smaller myelinated fibers
True
True or False: The greatest rate of ventricular pressure rise during the cardiac cycle occurs during the early phase of ejection of blood
False
True or False: Coronary blood flow generally increases during stimulation of sympathetic nerves to the heart
True
Why is arterial oxygen tension less than alveolar oxygen tension in the normal animal?
Due to the “physiologic shunt” from pulmonary circulation dumping into the pulmonary vein (w/ no gas exchange)
True or False: During an action potential, VM transiently reverses (ie the inside of the cell becomes positive compared to the outside)
True
True or False: If reabsorption of glucose were to decrease, the renal threshold for glucose also would decrease
True
True or False: If Na+ ions enter a normal neuron, the potential difference across the cell membrane will decrease and the neuron will be more excitable
True
True or False: Temporal and spatial summation result from post-synaptic potentials that sum in time
False
True or False: The aorta is important in converting pulsatile flow from the ventricles into continuous flow to the tissues
True
True or False: If reabsorption of glucose were to decrease, the renal threshold for glucose also would decrease
True
True or False: Capillary hydrostatic pressure always tends to favor filtration into a tissue (note: I am not saying that capillary hydrostatic pressure is not variable from one moment to the next, but just that it ALWAYS favors filtration)
True
True or False: Glomerulotubular balance tends to blunt changes in sodium excretion due to spontaneous changes in GFR
True
True or False: Pressures in the pulmonary circulation are normally higher than pressures in the systemic circulation
False
True or False: Large molecules are more easily filtered at the glomerulus than are small molecules
False
True or False: Increasing the permeability of the cell membrane for an ion will cause Vm to move closer to the equilibrium potential for that ion
True
True or False: In skeletal muscle, striations are present because of repeating sarcomeres
True
True or False: Fast-twitch glycolytic fibers would be rich in capillaries
False
True or False: Most of the renal oxygen consumption is related to Na+ reabsorption
true
True or False: Myocardial oxygen consumption is likely greater in response to an increase in arterial pressure
True
True or False: Atrial contraction normally contributes ~50% of ventricular filling
False
True or False: Sensory information from the muscle stretch receptors involved in the myotatic reflex enters the spinal cord in the ventral roots
False
True or False: Tubular fluid concentration at the bottom of the Loop of Henle is hyperosmotin (concentrated)
True
v Colloid osmotic pressure in the peritubular capillaries tneds to favor filtration
False
True or False: The contractile component of smooth muscle is similar to skeletal muscle in that it is normally activated in an all or none (on or off) manne
False
True or False: Increasing ventricular filling tends to increase stroke volume
True
True or False: Ion channels in the cell membrane can be opened by physical forces (eg stretch) acting on the cell membrane.
True
True or False: Juxtamedullary nephrons tend to have longer loops of Henle compared to outer cortical nephrons
True
True or False: In a resting (ie inactive) neuron, the conductance of the cell membrane for Na+ ions (gNa+) is greater than gK+
False
True or False: Aldosterone is important because it controls the greatest amount of sodium reabsorption.
False
Which of the following is true regarding the normal pulmonary circulation:
- mean pulmonary artery pressure is greater than mean aortic pressure
- the pulmonary circulation contains approximately 80% of total blood volume
- there is increased blood flow to dependent ventral lung regions compared to the ‘top’ (dorsal ) of the lung
- the bronchial circulation is supplied by deoxygenated blood from the right atriu,
there is increased blood flow to dependent ventral lung regions compared to the ‘top’ (dorsal ) of the lung
True or False: Tubular fluid at the bottom of the Loop of Henle (entering distal tubule) is hyposmotic(dilute)
False
True or False: Calcium influx from the extracellular space is essential for excitation-contraction coupling in skeletal muscle
False
True or False: Clearance of creatinine can be used as a measure of GFR because it is filtered, not reabsorbed and not secreted.
True
True or False: vascular smooth muscle can contain at least two general types of adrenergic receptors, one that when activated signals contraction by activating phospholipase-C and another that signals relaxation by activation of adenylate cyclase
True
Which of the following is true with regard to pulmonary mechanics?
- Intrathoracic airway collapse is most likely to occur during inhalation
- Patients with obstructive airway disease will have an increased respiratory rate
- at peak inspiration, pleural pressure is approx -8 cm H2O
- Horses with laryngeal paralysis will usually display difficulty breathing during expiration
at peak inspiration, pleural pressure is approx -8 cm H2O
As described in lecture, the physiologic characteristics of skeletal muscle can be understood from knowledge of the enzymes and other proteins in the muscle fibers. These biochemical systems can be grouped into 3 general components: _____(1) component, _____(2) component, and _____(3) component.
(1)excitation (2)contraction (3)metabolic
True or False: During hemorrhage, renin secretion is inhibited
False
True or False: The resting membrane potential (VR) is characteristic of excitable cells (ie nerve and muscle), but is not present in other types of cells.
False
True or False: The concentration gradient for Na+ as well as the electrical gradient favor movement of Na+ ions out of the cell
False
True or False: ADH controls permeability to sodium in the late distal tubule and collecting duct
False
True or False: Venous compliance is greater than arterial compliance
True
Acetylcholine produces a (decrease or increase) in heart rate through (depolarization or hyperpolarization) of the SA node via increased K+ conductance.
decrease; hyperpolarization
True or False: Increasing the number of parallel resistances tends to increase the total resistance
False
True or False: Postsynaptic potentials may be depolarizing or hyperpolarizing
True
True or False: Aldosterone increases potassium reabsorption at the distal tubule and collecting duct.
False
True or False: Secretion of a substance would tend to increase the amount excreted
True
True or False: Myelination increases the capacitance of the axonal membrane
False
True or False: Release of neurotransmitter by a presynaptic cell requires Ca++ entry into the presynaptic ending.
True
True or False: Cardiac and skeletal muscle are similar in that they both have action potentials formed primarily by the actions of Na, Ca, and K channels in the sarcolemma
True
True or False: Substances which are conserved by the kidneys have a high Tm for reabsoption
True
True or False:Excretion of a given substance “X” can be increased by decreasing secretion of X
False
True or False: The overall resistance of capillaries is less than that of arterioles because individual capillaries are larger vessels than individual arterioles
False
True or False: In a neuron at rest, the resting membrane potential (VR) is negative AND K+ ions are more concentrated inside the cell than outside.
True
True or False: Calcium is also important for the excitation of the skeletal muscle sarcolemma
False
True or False: During an action potential in a neuron, K+ ions enter the cell and Na+ ions leave the cell.
False
