Human Physiology Test 1
A viral infection involving the vestibular nuclei may result in a sense of dizziness. loss of hearing. loss of sight. local paralysis high blood pressure.
sense of dizziness
The resting membrane potential in a typical nerve cell is approximately +70 mV. -70 mV. +35 mV. -35 mV. 0 mV.
-70 mV
Normal saline contains ______ grams of sodium chloride per 100 ml of water. 0.9 9 100 58.5
0.9
Which of the following statements are true regarding the generation of a single action potential? An action potential does not diminish in strength as it travels along the cell membrane. As long as a stimulus is above threshold, the strength of the stimulus does not affect the shape of the action potential. Each action potential has the same characteristic waveform. Only A and C are true. A, B and C are true
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Which of the following statements about trophic hormones is false? Trophic hormones are hormones that control the secretion of another hormone. Prolactin is not an example of a trophic hormone. Trophic hormones are found in the anterior pituitary. Luteinizing hormone is not a trophic hormone.
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Human cell membranes are ______ to potassium than sodium. 40 times more permeable 40 times less permeable equally permeable not permeable
40 times more permeable
There are _______ primary taste sensations. 2 5 12 20 more than 50
5
A 5% glucose solution in water would be considered __________ relative to the value for normal plasma osmolarity that we used in class. hypotonic hypertonic isotonic hyperosmotic
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Solution A has 3 non-penetrating solute particles and 4 penetrating solute particles in it for a total of 7 particles/L. It is separated from solution B by a cell membrane. Solution B has 3 non-penetrating particles/L. At equilibrium, what is the relative osmolarity and tonicity of Solution A to Solution B? Solution A is hyperosmotic and isotonic to Solution B. Solution A is isosmotic and isotonic to Solution B. Solution A is hyperosmotic and hypertonic to Solution B. Solution A is isosmotic and hypotonic to Solution B.
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When Golf is activated, a second messenger cascade is activated. olfactory epithelial cells depolarize. an odorant is allowed to combine with olfactory binding protein. A and B A, B and C
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Which of the following hormones would you expect to have the shortest half-life? Insulin Estrogen Cortisol Testosterone
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Which of the following statements about the Na+/K+ pump is FALSE? It transports Na+ out of the cell and K+ into the cell. It is present in neurons. Its activity requires the expenditure of metabolic (cellular) energy. It transports Na+ and K+ in a 1:1 ratio.
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Which of the following cortisol hypersecretion scenarios points to an example of a primary endocrine disorder?: Increased CRH, leading to increased ACTH, leading to increased adrenal secretion of cortisol A tumor in the anterior pituitary, leading to increased ACTH and cortisol but decreased CRH secretion. A thyroid tumor resulting in increased T3 and T4, but decreased TRH and TSH secretion. A adrenal tumor leading to increased cortisol, but decreased CRH and ACTH secretion.
A adrenal tumor leading to increased cortisol, but decreased CRH and ACTH secretion.
For a short period of time after the initiation of an action potential, a second action potential cannot be triggered, no matter how large the stimulus. This time period is called the absolute refractory period. the relative refractory period. Ranvier redundancy. synaptic delay. temporal summation.
Absolute refractory period
Information sent to the central nervous system is referred to as __________. motor afferent efferent autonomic
Afferent
The brain area acknowledged as the center for emotions is the amygdala. hypothalamus. suprachiasmatic nucleus. pons. cerebellum.
Amygdala
The intracelluar signaling molecule which triggers exocytosis of secretory vesicles is ____: sodium. potassium. calcium. chloride. cobalt.
Calcium
The ciliary muscle helps to control the amount of light reaching the retina. control the shape of the lens. control the production of aqueous humor. move the eyeball. none of the above
Control the shape of the lens
The structure that connects the two cerebral hemispheres is the basal nuclei suprachiasmatic nucleus corpus callosum hippocampus gray matter
Corpus Callosum
Which term describes the change from resting membrane potential to -50 mV. (Mark your answer with a capital letter - no period) overshoot hyperpolarized depolarized repolarized more than one of these
Depolarized
Which of the following statements is FALSE? Diffusion is the movement of solute molecules from an area of low solute concentration to an area of high solute concentration. Diffusion is slow over long distances. The smaller the molecule, the faster the molecule will diffuse. The larger the surface area, the more molecules can diffuse across per unit time. All of these statements are true.
Diffusion is the movement of solute molecules from an area of low solute concentration to an area of high solute concentration.
Nernst equation
Eion = (61/Z) log ([K+ out]/[K+ in])
The brain consumes about half of the __________ circulating in the blood stream. glucose oxygen sodium potassium fatty acids
Glucose
The receptors in the inner ear are the hair cells utricles saccules supporting cells ampullae
Hair Cells
When body temperature rises, a center in the brain initiates physiological changes to decrease the body temperature. This is an example of: feed forward control. positive feedback. homeostatic regulation. diagnostic regulation. disease.
Homeostatic Regulation
Which brain area is considered to be the integrating center for homeostasis? hypothalamus thalamus pituitary gland brain stem medulla
Hypothalamus
The ion that plays a key role in initiating an action potential in a neuron is __________. K+ Na+ Cl- Ca++
Na+
Which of the following is NOT a function of membrane proteins? assist in maintaining shape of the cell regulate the passage of ions act as transport molecules for various solutes anchor or stabilize the cell membrane produce energy
Produce energy
Which of the following is not a function of glial cells? support providing directions for growth and repair movement phagocytosis
Providing directions for growth and repair ????
The _______ of a sensory receptor may be irregular in shape and overlap with those of neighboring receptors. The size of this area determines the sensitivity to a stimulus. discriminatory area spatial field receptive field somatic esthetic none of the above
Receptive field
The correct order of the 5 basic steps in signal transduction are: Signal, target protein, receptor protein, intracellular signals, response Signal, receptor protein, target protein, intracellular signals, response Signal, target protein, intracellular signals, receptor protein, response Signal, receptor protein, response, target protein, intracellular signals Signal, receptor protein, intracellular signals, target proteins, response
Signal, receptor protein, intracellular signals, target proteins, response
How does O2 move from the bloodstream into the cells (enterocytes) of the GI tract? Simple Diffusion Primary Active Transport Facilitated Diffusion Receptor Enzyme
Simple diffusion
Application of the poison tetrodotoxin (TTX) to a neuron blocks voltage-gated Na+ channels. What effect will this have on an action potential in the neuron? TTX will increase the amplitude of the action potential. TTX will not affect action potentials because voltage-gated Na+ channels have no role in them. TTX will lengthen the depolarization phase of the action potential. TTX will diminish or abolish the depolarization phase of the action potential.
TTX will diminish or abolish the depolarization phase of the action potential.
With exception of olfaction, all sensory pathways first travel to the ________, which acts as a relay and processing station. thalamus cerebrum hypothalamus corpus callosum cerebellum
Thalamus
Which structures monitor rotational movements of the head? maculae of the sccule cristae and the semicircular canals maculae of the utricle A and C All of the above
cristae and the semicircular canals ????
The concentration of calcium inside a cell is 0.3%. The concentration of calcium outside the cell is 0.1%. How could the cell transport even more calcium to the inside? passive transport active transport osmosis exocytosis all of these will work.
active transport
Which of the following hormones would you expect to be the most lipophilic? Aldosterone Epinephrine Triiodothyronine Calcitonin
aldosterone
Sensations of prickling pain are carried by type A fibers. reach the CNS quickly. can trigger somatic reflexes. result in conscious attention. all of the above
all of the above
Receptor molecules for chemical signaling are located in the membrane. in the cytosol. in the nucleus. in the cytosol and in the nucleus all of these
all of these
Which of the structures below functions is most involved with the control of movement? hippocampus amygdala basal nuclei hippocampus and amygdala All of these contribute equally to the control of movement
basal nuclei
The secretion of __________ initiates the hypothalamic-pituitary-adrenocortical axis for the release of aldosterone. cortisol adrenocorticotropic hormone corticotropin-releasing hormone aldosterone releasing hormone
corticotropin-releasing hormone
Which of these does NOT contribute significantly to the protection of the brain? white matter cranium subarachnoid space cerebrospinal fluid (CSF) dura mater
white matter
Down-regulation may cause a target cell to increase its number of receptors for a ligand. decrease its number of receptors for a ligand. increase its binding affinity for a ligand. increase its number of receptors for a ligand and increase its binding affinity for a ligand
decrease its number of receptors for a ligand.
Degradation of the neurotransmitter acetylcholine is achieved mainly by enzymatic activity of monoamine oxidase diffusion away from the synaptic cleft reputake of acetylcholine by the post synaptic membrane enzymatic activity associate with the postsynaptic membrane long term potentiation
enzymatic activity associate with the postsynaptic membrane
An integrating center is the disturbance or change that sets the pathway in motion. is an electrical and/or chemical signal that travels to the effector. evaluates incoming signals and compares it with the setpoint. is the minimum stimulus that must be achieved to set the reflect response in motion.
evaluates incoming signals and compares it with the setpoint.
The neurocrine that acts as the main inhibitory neurotransmitter in the brain is __________. serotonin glutamate gamma-aminobutyric acid epinephrine
gamma-aminobutyric acid
The binding of lipophilic messengers, such as steroid hormones, to their receptors triggers adenyl cyclase activation. cyclic nucleotide formation. G protein inhibition. gene transcription and protein translation. protein kinase activation.
gene transcription and protein translation.
Photoreceptor use the neurotransmitter glutamate. dopamine. norepinephrine. acetylcholine.
glutamate
Hyposmotic solutions have higher concentrations of solutes than hyperosmotic solutions. have lower concentrations of solutes than other hyposmotic solutions. have the same concentration of solutes as hyperosmotic solutions. have lower concentrations of solutes than hyperosmotic solutions. none of these
have lower concentrations of solutes than hyperosmotic solutions.
The brain has a ________ demand for oxygen and receives about _______ % of the total circulating blood volume. high; 35 low; 10 low; 15 high; 15 high; 50
high; 15
Which of these structures is most important in both learning and memory? hippocampus hypothalamus medulla pons cerebellum
hippocampus
Which of the following terms describes the change in membrane potential as it moves from resting potential to -90 mV. (Mark your answer with a capital letter - no period) overshoot hyperpolarized depolarized repolarized more than one of these
hyperpolarized
If your vision is 20/25, this means that you can see objects at 20 feet that individuals with normal eyesight can see at 25 feet. see objects at 25 feet that individuals with normal eyesight can see at 20 feet. see 20 point type (font) at 25 feet. see 25 letters on an eye chart 20 feet away. only see objects that are not more than 25 feet away.
see objects at 20 feet that individuals with normal eyesight can see at 25 feet.
A molecule that blocks substance P from binding to its receptor would inhibit the perception of pain. stimulate a painful sensation. alter the perception of hot and cold stimuli. interfere with transduction from chemoreceptors. heighten the perception of touch.
inhibit the perception of pain.
Bitter and sweet taste transduction involves a specialized G-protein, gustducin. involves a specialized G-protein, glutamin. is a one step process. A and C B and C
involves a specialized G-protein, gustducin.
The osmotic pressure of a hypertonic solution ______________________ relative to that of a cell floating in it. is lower is equal is higher can't be predicted
is higher
According to the Goldman-Hodgkin-Katz Equation, what would happen the resting membranepotential if the cell became more permeable to K+? It would become more positive It would become more negative It would also become more permeable to Na It would not change Both C and D
it would become more negative
Slow axonal transport refers to __________ down the length of the axon away from the cell body (soma). impulse transmission movement of proteins packaged in vesicles mitochondrial transport sodium and potassium movement
movement of proteins packaged in vesicles
The only known example of a high rate of natural neuronal replacement in the adult human involves the gustatory receptors nociceptors. Pacinian corpuscles. olfactory receptors. retinal cells.
olfactory receptors
Which of these functions in NOT related to the reticular formation? regulation of the menstrual cycle arousal and sleep muscle tone pain modulation blood pressure regulation.
regulation of the menstrual cycle
Fast pain, usually described as sharp and localized, is carried by large, unmyelinated C fibers. small, myelinated A-delta fibers. small, unmyelinated C fibers. large, myelinated A-beta fibers
small, myelinated A-delta fibers.
Movement of the cupula in the ampullae of the semicircular canals stimulates hair cells alerting us to rotational movements. produces sound. allows us to hear sounds. allows us to perceive linear acceleration. stimulates hair cells alerting us to changes in body position with respect to gravity.
stimulates hair cells alerting us to rotational movements.
The most significant difference between a paracrine and an autocrine is the method of chemical release the cell that responds to it. the method of transport. the route of transport. There are no differences-they are the same.
the cell that responds to it.
When a rod cell in the eye is stimulated by light, the intracellular level of cGMP decreases. the cell membrane becomes depolarized. the inactive form of retinal associated with bleached opsin. transducin activity decreases. more neurotransmitter is release.
the intracellular level of cGMP decreases.
A solution that is hyposmotic to a cell will always be hypotonic to it as well. True False
true
