Physiology HW for test 2
During a menstrual cycle, follicle stimulating hormone peaks (FSH) during ____________ and lutenizing hormone (LH) peaks during ____________. A secretory phase, estrous B ovulation, ovulation C late luteal phase, early folliclular phase D day 0 - 5, day 14
B [middle of graph]
You taste a fruit that tastes very sweet. Which of the following is most likely involved in this reception of flavor? A ionotropic receptors B secondary messengers C K+ channels D Cl- channels
B
The Nernst Equation tells us that if a positively charged ion is ten times more concentrated inside the cell, its Nernst equilibrium potential is ____________ . a) zero b) negative c) positive
B
Q11
- glucagon levels go up [w/ insulin] to raise blood sugar after have something like meat [a lot of protein, little sugar] - glucagon levels go down, and insulin levels go up when have something like donuts [a lot of sugar, no protein]
11) A neuron receives signals from five other neurons, A-E. Assuming local signal strength is equal, poisoning which synapse would result in the largest decrease of the neuron's likelihood of reaching threshold potential?
A
22) The simple circuit diagram above shows three sensory nerves A, B and C forming synapses on the dendrites of motor nerve D. Sensory nerves B and C are inhibitory, and sensory nerve A is excitatory. Assuming local synapse strength is equivalent, which of the following would be most likely to generate action potentials in motor nerve D? a) simultaneous action potentials in nerves A and B b) action potentials in nerve B c) simultaneous action potentials in nerves A and C d) simultaneous action potentials in nerves B and C e) action potentials in nerve C
A
A single EPSP from a sensory neuron is not sufficient to bring about an action potential in the postsynaptic cell. In addition, a nearby synapse causes an IPSP of relatively equivalent in strength to the EPSP. Which would most increase the odds of reaching an action potential? a) If we trigger another EPSP quickly after the first b) If the IPSP and EPSP were generated simultaneously. c) If neuron that causes the IPSP releases more neurotransmitter d) If the EPSP synapsed farther from the axon hillock
A
Action potential propagation rate is not influenced by: A stimulus strength B myelination C axon diameter
A
Of chemical and electrical synapses, which statement is best? a) Chemical synapses influence learning b) Both carry electrical signals between axons c) Electrical synapses use synaptic vesicles d) Both can be either excitatory or inhibitory
A
Prolactin is a hormone that promotes development of mammary glands during pregnancy in females, and caring for young in both males and females. How can we explain this action by prolactin? a Both sexes have prolactin receptors but differ in their target cell sensitivity b Prolactin has a longer half life in males c Males upregulate prolactin receptor genes d Both sexes have prolactin receptors but females produce less prolactin e Males lack target cells that respond to prolactin
A
The ____________ enable an action potential to be regenerated in vertebrate neurons, while _____________ minimizes leak of the signal. a) Nodes of Ranvier, Myelination b) Propagation, Myelination c) Nodes of Ranvier, leak channels d) Inactivation of Na+ channels, leak channels
A
To conduct a signal at relatively comparable speeds, a smaller diameter axon needs more ____________, to compensate for the _____________ as axon size decreases. Myelination, Increased resistance Current, Lower conductance Hyperpolarization, Lack of myelination Refraction, Loss of propagation
A
You are quantifying response of a vertebrate under stress. Which hierarchy of hormone response do you expect? A) neurohormones in hypothalamus -> anterior pituitary -> tropic hormones -> adrenal cortex -> cortisol B) tropic hormone -> anterior pituitary -> hypothalamus -> cortisol C) posterior pituitary -> neurosecretory hormone -> adrenal cortex -> non-glandotropic hormones D) adrenal cortex -> tropic hormone -> parasympathetic nervous system -> thyroid hormones
A
A snail initially only tucks into its shell when dropped. Physiologists repeatedly applied the dropping sensation neurotransmitter simultaneous with an unrelated neurotransmitter that normally is present during high temperature. Now the snail tucks in whenever its too warm even if it's not dropping. What happened? A long term potentiation B habituation C facilitation D sensitization
A Long-term potentiation = increase in synaptic strength following high-frequency stimulation of a chemical synapse facilitation = postsynaptic potentials (PSPs) (EPPs, EPSPs or IPSPs) evoked by an impulse are increased when that impulse closely follows a prior impulse. PPF is thus a form of short-term synaptic plasticity. habituation = lower response after get used to stimulus Sensitization = repeated administration of a stimulus results in the progressive amplification of a response. respond more to new stimuli in addition to the one that is repeated.
Oxytocin acting on the uterine muscles is an example of... A a positive feedback mechanism B a negative feedback mechanism C antagonism D synergism
A Oxytocin causes uterine contraction which in turn causes more oxytocin to be released: positive feedback.
Which is true as the membrane potential moves farther away from the equilibrium potential? B resistance for ion increases A or B C ionic current decreases A electromotive force increases B or C
A (emf inc)
Metabotropic synapses involve __________ receptors while ionotropic synapses involve __________ receptors. A none of these B G-protein coupled...ligand-gated C enzyme-linked...G-protein coupled D ligand-gated...G-protein coupled
B
10) Ex 1 and Ex 2 are EPSPs located at different locations on an axon, and In1 is an IPSP. In the above diagram, ____ would represent ____________. C, spatial summation B, temporal summation D, habituation A , two action potentials
B
A hormone which passes freely through a cell membrane also would likely ___________________ . A be a peptide hormone B be a steroid C include catecholamines D have a faster cell response than one which does not pass E have extracellular receptors
B
Asynchronous insect flight muscle contraction is activated by A one action potential per twitch B getting stretched by the antagonist C release of Ca2+ from SR D release of ATP from SR
B
At which site are action potentials formed? a) Schwann cell b) Axon hillock c) Dendrite d) Soma
B
If the equilibrium potential for K+ is -58 mV and +58 mV for Na+, which is true the ions at a membrane potential of -58mV? (assume that the membrane is permeable to both ions) a) K+ should diffuse out of the cell b) Na+ should diffuse into the cell c) K+ should diffuse into the cell d) Na+ should diffuse out of the cell
B
12) You place a mouse in a new cage and are examining a mouse's tendency to explore that same cage over time. Which mouse likely has had a valuable habituation gene knocked out on accident? C A
C
As you move your finger to touch your nose, specialized neurons called Purkinje cells in the cerebellum are receiving weak motor function signals from hundreds of thousands of other neurons. What aspect of Purkinje cells would you expect to be more extensively developed than other neurons? a) Increased axon length b) Less myelination c) More dendrites d) Smaller soma e) More axon terminals
C
During dehydration, the body secretes ______ ADH and ________ aldosterone. a zero, more b less, more c more, more d less, less
C
For the majority of sensory receptors, how do they deliver information about the intensity of a stimulus? A Neuronal action potential strength varies B Receptors do not adapt to sustained stimuli C Frequency of sensory action potentials varies D Action potentials vary by sensory axon
C
Neural control is __________ than endocrine control, and ____________. a slower, longer-lasting b faster, longer-lasting c faster, shorter-lasting d slower, shorter-lasting
C
Neurons excite muscle cells to contract at the neuromuscular junction. Which of the following is not a feature that occurs at this junction? A Acetylcholine receptors on the muscle cell bind to ligand B Opening of voltage gated ion channels in motor neuron C Release of calcium by the motor neuron D Depolarization of the motor neuron axon terminal
C
The skin of frogs is quite permeable to water, and because frogs that live in freshwater are hypertonic to the surrounding water, water will tend to enter the animal across the skin by osmosis. To avoid overhydration, frogs produce large amounts of very dilute urine, but this causes loss of Na+ in the urine. Frogs do not drink, so how do they replace the lost Na+? Can they obtain it from pond water across their skin? To test this hypothesis, you place a piece of skin from the abdomen of a frog in diffusion chamber, such that the apical surface of the skin is facing half-chamber A and the basolateral surface is facing half-chamber B. You then fill both half-chambers with frog Ringer's solution (containing 85 mM NaCl, 25 mM NaHCǑ, 2 mM KCl and 1 mM CaCl2). Under these conditions, you measure a net Na+ flux from A to B of 1.5 nanomole/sec. Based on the results of your experiment, which of the following statements is most likely FALSE? a) The K+ flux rate in this system is -1.0 nanomole/sec. b) Addition of the Na+/K+-ATPase inhibitor ouabain would decrease the Na+ flux. c) The Na+ flux rate could also be calculated from the Nernst equilibrium potential for Na+, provided Na+ conductance (gNa) is known. d) Reversing the orientation of the skin (such that the apical surface faces half-chamber B) would reverse the direction of net Na+ flux. e) Replacing the Ringer's solution with "potassium-free Ringer's solution" (87 mM NaCl, 25 mM NaHCǑ and 1 mM CaCl2) would reduce the Na+ flux rate.
C
Three ions are permeable in a cell, A, B, and C. Ea = +50 mV, Eb = -50 mV, Ec = 0 mV. 500 ion A channels are open. 10,000 ion B channels are open, and 20,000 ion C channels are open. What is the approximate membrane potential of the cell? a) -50 mV b) 0 c) 0 to - 50 mV d) +50 mV e) 0 to +50 mV
C
Which area of the human brain is proportionally much larger than a fish or amphibian? A medulla B midbrain C cerebrum D cerebellum
C
Which of the following most ensures a one way movement of signal along a neuron? a) synapses b) gap junctions c) inhibition of ion channels d) neurotransmitters e) connexons
C
Which of the following would most likely increase the likelihood of generating an action potential in a cell? a) inhibition of voltage gated Cl- channels b) increasing the refraction period in voltage gated Na+ channels c) inhibition of K+ leak channels d) inhibition of voltage gated Na+ channels
C
Which is the best example of negative feedback at work? A two anterior pituitary hormones which are synergistic B an inhibiting hormone with twice the half life as a release hormone C an anterior pituitary hormone that supresses hypothalamus secretion D glucagon opposing the action of insulin
C synergistic = combination of two or more drugs display a more strong therapeutic effect than that of individual drugs at equal concentrations
Uterine contraction and milk ejection are examples of _____________ control by _____________ cells. A adrenal, hypothalamus B neural, anterior pituitary C posterior pituitary, neurosecretory D nonneuronal, anterior pituitary
C oxytocin.
Q24 hw 1 [3]
Cl, K+ (both - potential)
8) MS is a disease which damages the myelin sheath of neurons. What problem would this cause with signal propagation? a) neuron threshold lower b) signal conducted too fast c) impulse triggered too often d) lower resistance to leakage
D
A cell at resting membrane potential is triggered by a neurotransmitter to open up Na+ ion channels. Which of the following is then least accurate? a) Na+ equilibrium potential will not change b) Resulting Na+ concentrations will not change very much c) Na+ resistance is lowered d) The membrane will hyperpolarize
D
Absolute and relative refractory periods are caused, respectively, by: D Na+ channels inactivated, K+ channels still open A K+ channels still open, Na+ channels inactivated B Na+ channels still open, K+ channels inactivated C K+ channels inactivated, Na+ channels still open
D
By themselves, two hormones ADH and CRH each cause a small increase on ACTH secretion. During stress the brain signals release of CRH, which travels from the hypothalamus to the anterior pituitary where it causes a larger ACTH release than when only ADH or itself are present. Which is a good descriptor of CRH? A enhances parasympathetic nervous system B antagonist with ADH C positively modulated by ACTH D synergism with ADH
D
During stress we would expect higher _______________ levels and lower ___________ levels. A glucagon, sympathetic activation B insulin, glucagon C acetylcholine, epinepherine D catecholamine, insulin
D
In vertebrate skeletal muscle, Ca2+ ions bind to __________ in response to __________. A actin...myosin binding ATP B t-tubule...sarcoplasmic reticulation C myosin...troponin moving aside D troponin...an action potential
D
When is a neuron membrane potential closest to its Nernst equilibrium for Na+? A at resting membrane potential B during absolute refractory period C during hyperpolarization D at the peak of the action potential
D
Which ion would have the fastest flux rate in a resting neuron (Vm = -65 mV)? a) Ion 4: È = -50 mV; 50 channels open b) Ion 1: Ē = -50 mV; 100 channels open c) Ion 2: É = -100 mV; 50 channels open d) Ion 3: Ě = +50 mV; 100 channels open e) Ion 5: E = +50 mV; 10 channels open
D
Which of the following does not involve metabotropic transduction? A tasting bitter B seeing flowers C smelling flowers D tasting salt
D
Which of the following statements is not accurate? A the oocyte is mature prior to ovulation B females in estrous may release pheromones C ovulation alone does not imply menstruation D increases in lutenizing hormone inhibits ovulation
D
Unlike other stimulus receptors, those in the eye which have rhodopsin _____________. A Cause graded potentials B Far outnumber other receptor types C Activate ion channels D cause hyperpolarization E Adapt to sustained stimulation
D - depolarized in dark, hyperpolerized in light
In a life or death situation, which of the following is not taking place? A Suppression of digestion by the sympathetic B Sympathetic division release of catecholamines C Dilation of the pupil by the sympathetic division D Parasympathetic control of the heart rate
D Parasympathetic = rest / digest
__________ synergistically oppose(s) __________. A epinephrine... glucagon and cortisol B glucagon...insulin and epinephrine C insulin and glucagon...epinephrine D glucagon and epinephrine...insulin
D glucagon + epinephrine = stronger response, increase blood sugar. [fight/flight] oppose insulin lowering the blood sugar
Which of the following would contain mechanoreceptors? A taste bud B olfactory tissue C retina D semi-circular canals
D taste bud / olfactory = chemoreceptors retina = photoreceptors
A presynaptic nerve terminal releases a neurotransmitter that activates K+ conductance in the postsynaptic membrane. If the postsynaptic cell body had an initial voltage of -65 mV and ENa = +70 mV, ECl = -70 mV and EK = -90 mV, the new postsynaptic voltage will be: a) more negative than -90 mV b) between 0 mV and +70 mV c) between 0 mV and -70mV d) -70 mV e) between -70 mV and -90 mV
E
Which of the following situations would interfere with the ability to discriminate whether a stimulus was light or touch? A There was not an adequate stimulus of light receptors B Receptors normally have a low degree of specificity C Touch receptors are more sensitive D Sensory organs have high peripheral filtering of stimuli E The central nervous system can't tell which axon generated an action potential F Both light and touch receptors were stimulated
E
Which of the following would be the LEAST effective method birth control for the current reproductive cycle? a) Engaging in intercourse only during day 28 of the ovarian cycle b) Taking a drug that causes ovulation to occur on day 2 of the menstrual cycle c) Having a surgery that results in blockage of the oviduct d) Taking a pill that inhibits release of luteinizing hormone e) Taking a hormone supplement that rescues the corpus luteum
E The corpus luteum is a temporary endocrine structure involved in ovulation and early pregnancy. During ovulation, the primary follicle forms the secondary follicle and subsequently the mature vesicular follicle. At ovulation the follicle ruptures expelling the ovum into the fallopian tube. luteal = luteum = LH surge = progesterone = PROtects the embryo
While interning at a hospital, you take the blood of someone and find that she has high cortisol levels. Simultaneously finding which of the following in this person would be the most surprising? A High blood pressure B High ADH (AVP) levels C High epinephrine levels D High aldosterone levels E High insulin levels
E she's in fight or flight mode. - aldosterone / ADH raise blood pressure, epinephrine = fight/ flight and cortisol is fight / flight. insulin lowers blood sugar, so its rest and digest
You observe a cell with a membrane potential of approximately -20 mV. Which phase(s) of an action potential are potentially happening? C Undershoot B Repolarization A or B None of the above D Overshoot A Depolarization
a or b
A negatively charged ion has a negative equilibrium potential. What is its concentration? a) More concentrated on the outside of the cell b) More concentrated on the inside of the cell c) Equal on both sides of the membrane
a) More concentrated on the outside of the cell bc -, w/ neg equilibrium means it wants to go in to make it more -, which means its more concentrated on the outside
Q17
higher LH = reproduction [lunear phase]
Q9
under stress: glucocorticoid = higher [metabolizes glucose for quick energy --> gluco-corti[sol]-[ster]oid insulin = lower [dont wanna lower blood sugar, wanna raise it] gonadotropin = lower [not tryna fukk tryna get away]
