Physiology Exam Practice Questions

1-3: Match a receptor feature (a-e) with each choice. 2. Defines the strength of receptor binding to a messenger Receptor feature: a. affinity b. saturation c. competition d. down-regulation e. specificity

A

1-4: Match the state of consciousness (a-d) with the correct electroencephalogram pattern (use each answer once): 3. Irregular, slow-frequency, large-amplitude, "alpha" rhythm State of consciousness: a. relaxed, awake, eyes closed b. stage N3 non-rapid eye movement (NREM) sleep c. rapid eye movement (REM) sleep d. epileptic seizure

A

Choose the true statement: a. The modality of energy a given sensory receptor responds to in normal functioning is known as the "adequate stimulus" for that receptor. b. Receptor potentials are "all-or-none," that is, they have the same magnitude regardless of the strength of the stimulus. c. When the frequency of action potentials along sensory neurons is constant as long as a stimulus continues, it is called "adaptation." d. When sensory units have large receptive fields, the acuity of perception is greater. e. The "modality" refers to the intensity of a given stimulus

A

If a ligand-gated ion channel equally permeable to both Na+ and K+ was briefly opened at a specific location on the membrane of a typical resting neuron, what would result? a. Local currents on the inside of the membrane would flow away from that region. b. Local currents on the outside of the membrane would flow away from that region. c. Local currents would travel without decrement all along the cell's length. d. A brief local hyperpolarization of the membrane would result. e. Fluxes of Na+ and K+ would be equal, so no local currents would flow.

A

Match each type of molecule with the correct choice (a-e); a given choice may be used once, more than once, or not at all. Molecule: example of a first messenger a. neurotransmitter or hormone b. cAMP-dependent protein kinase c. calmodulin d. Ca2+ e. alpha subunit of G proteins

A

What region of the brain contains the primary visual cortex? a. the occipital lobe b. the frontal lobe c. the temporal lobe d. the somatosensory cortex e. the parietal lobe association area

A

Which cell structure contains the enzymes required for oxidative phosphorylation? a. inner membrane of mitochondria b. smooth endoplasmic reticulum c. rough endoplasmic reticulum d. outer membrane of mitochondria e. matrix of mitochondria

A

Which correctly associates a neurotransmitter with one of its characteristics? a. Dopamine is a catecholamine synthesized from the amino acid tyrosine. b. Glutamate is released by most inhibitory interneurons in the spinal cord. c. Serotonin is an endogenous opioid associated with "runner's high." d. GABA is the neurotransmitter that mediates long-term potentiation. e. Neuropeptides are synthesized in the axon terminals of the neurons that release them.

A

Which correctly describes a step in auditory signal transduction? a. Displacement of the basilar membrane with respect to the tectorial membrane stimulates stereocilia on the hair cells. b. Pressure waves on the oval window cause vibrations of the malleus, which are transferred via the stapes to the round window. c. Movement of the stapes causes oscillations in the tympanic membrane, which is in contact with the endolymph. d. Oscillations of the stapes against the oval window set up pressure waves in the semicircular canals. e. The malleus, incus, and stapes are found in the inner ear, within the cochlea

A

Which is a false statement about skeletal muscle structure? a. A myofibril is composed of multiple muscle fibers. b. Most skeletal muscles attach to bones by connective-tissue tendons. c. Each end of a thick filament is surrounded by six thin filaments. d. A cross-bridge is a portion of the myosin molecule. e. Thin filaments contain actin, tropomyosin, and troponin.

A

Which is a true statement about memory? a. Consolidation converts short-term memories into long-term memories. b. Short-term memory stores information for years, perhaps indefinitely. c. In retrograde amnesia, the ability to form new memories is lost. d. The cerebellum is an important site of storage for declarative memory. e. Destruction of the hippocampus erases all previously stored memories

A

Which is incorrect regarding ligand-protein binding reactions? a. Allosteric modulation of the protein's binding site occurs directly at the binding site itself. b. Allosteric modulation can alter the affinity of the protein for the ligand. c. Phosphorylation of the protein is an example of covalent modulation. d. If two ligands can bind to the binding site of the protein, competition for binding will occur. e. Binding reactions are either electrical or hydrophobic in nature.

A

Which is incorrect? a. Diffusion of a solute through a membrane is considerably quicker than diffusion of the same solute through a water layer of equal thickness. b. A single ion, such as K+, can diffuse through more than one type of channel. c. Lipid-soluble solutes diffuse more readily through the phospholipid bilayer of a plasma membrane than do water-soluble ones. d. The rate of facilitated diffusion of a solute is limited by the number of transporters in the membrane at any given time. e. A common example of cotransport is that of an ion and an organic molecule.

A

Which of the following intracellular or plasma membrane proteins requires Ca2+ for full activity? a. calmodulin b. janus kinase (JAK) c. cAMP-dependent protein kinase d. guanylyl cyclase

A

Which of the following is incorrect? a. Equilibrium requires a constant input of energy. b. Positive feedback is less common in nature than negative feedback. c. Homeostasis does not imply that a given variable is unchanging. d. Fever is an example of resetting a set point. e. Efferent pathways carry information away from the integrating center of a reflex arc.

A

Which would result in reflex contraction of the extensor muscles of the right leg? a. stepping on a tack with the left foot b. stretching the flexor muscles in the right leg c. dropping a hammer on the right big toe d. action potentials from nociceptors of the right leg e. action potentials from muscle-spindle receptors in flexors of the right leg

A

1-3: Match a receptor feature (a-e) with each choice. 1. Defines the situation when all receptor binding sites are occupied by a messenger Receptor feature: a. affinity b. saturation c. competition d. down-regulation e. specificity

B

1-4: Match the state of consciousness (a-d) with the correct electroencephalogram pattern (use each answer once): Regular, very slow-frequency, very large-amplitude "delta" rhythm State of consciousness: a. relaxed, awake, eyes closed b. stage N3 non-rapid eye movement (NREM) sleep c. rapid eye movement (REM) sleep d. epileptic seizure

B

According to the law of mass action, in the following reaction, CO2 + H2O H2CO3 a. increasing the concentration of carbon dioxide will slow down the forward (left-to-right) reaction. b. increasing the concentration of carbonic acid will accelerate the rate of the reverse (right-to-left) reaction. c. increasing the concentration of carbon dioxide will speed up the reverse reaction. d. decreasing the concentration of carbonic acid will slow down the forward reaction.

B

If a small amount of urea were added to an iso-osmotic saline solution containing cells, what would be the result? a. The cells would shrink and remain that way. b. The cells would first shrink but then be restored to normal volume after a brief period of time. c. The cells would swell and remain that way. d. The cells would first swell but then be restored to normal volume after a brief period of time. e. The urea would have no effect, even transiently.

B

Inhibition of which enzyme/enzymes would inhibit the conversion of arachidonic acid to leukotrienes? a. cyclooxygenase b. lipoxygenase c. phospholipase A2 d. adenylyl cyclase e. both b and c

B

Match each type of molecule with the correct choice (a-e); a given choice may be used once, more than once, or not at all. Molecule: enzyme a. neurotransmitter or hormone b. cAMP-dependent protein kinase c. calmodulin d. Ca2+ e. alpha subunit of G proteins

B

Most of the water in the human body is found in a. the interstitial fluid compartment. b. the intracellular fluid compartment. c. the plasma compartment. d. the total extracellular fluid compartment.

B

The function of myosin light-chain kinase in smooth muscle is to a. bind to calcium ions to initiate excitation-contraction coupling. b. phosphorylate cross-bridges, thus driving them to bind with the thin filament. c. split ATP to provide the energy for the power stroke of the cross-bridge cycle. d. dephosphorylate myosin light chains of the cross-bridge, thus relaxing the muscle. e. pump Ca2+ from the cytosol back into the sarcoplasmic reticulum.

B

The process by which monomers of organic molecules are made into larger units a. requires hydrolysis. b. results in the generation of water molecules. c. is irreversible. d. occurs only with carbohydrates. e. results in the production of ATP.

B

Using a single intracellular recording electrode, in what part of a sensory neuron could you simultaneously record both receptor potentials and action potentials? a. in the cell body b. at the node of Ranvier nearest the peripheral end c. at the axon hillock where the axon meets the cell body d. at the central axon terminals within the CNS e. There is no single point where both can be measured.

B

What prevents a drop in muscle fiber ATP concentration during the first few seconds of intense contraction? a. Because cross-bridges are pre-energized, ATP is not needed until several cross-bridge cycles have been completed. b. ADP is rapidly converted back to ATP by creatine phosphate. c. Glucose is metabolized in glycolysis, producing large quantities of ATP. d. The mitochondria immediately begin oxidative phosphorylation. e. Fatty acids are rapidly converted to ATP by oxidative glycolysis.

B

When a skeletal muscle fiber undergoes a concentric isotonic contraction, a. M lines remain the same distance apart. b. Z lines move closer to the ends of the A bands. c. A bands become shorter. d. I bands become wider. e. M lines move closer to the end of the A band.

B

Which best describes "habituation"? a. seeking out and focusing on momentarily important stimuli b. decreased behavioral response to a persistent irrelevant stimulus c. halting current activity and orienting toward a novel stimulus d. evaluation of the importance of sensory stimuli that occur prior to focusing attention e. strengthening of synapses that are repeatedly stimulated during learning

B

Which best describes an afferent neuron? a. The cell body is in the CNS and the peripheral axon terminal is in the skin. b. The cell body is in the dorsal root ganglion and the central axon terminal is in the spinal cord. c. The cell body is in the ventral horn of the spinal cord and the axon ends on skeletal muscle. d. The afferent terminals are in the PNS and the axon terminal is in the dorsal root. e. All parts of the cell are within the CNS.

B

Which best describes the vision of a person with uncorrected nearsightedness? a. The eyeball is too long; far objects focus on the retina when the ciliary muscle contracts. b. The eyeball is too long; near objects focus on the retina when the ciliary muscle is relaxed. c. The eyeball is too long; near objects cannot be focused on the retina. d. The eyeball is too short; far objects cannot be focused on the retina. e. The eyeball is too short; near objects focus on the retina when the ciliary muscle is relaxed.

B

Which is a correct statement regarding the hierarchical organization of motor control? a. Skeletal muscle contraction can only be initiated by neurons in the cerebral cortex. b. The basal nuclei participate in the creation of a motor program that specifies the pattern of neural activity required for a voluntary movement. c. Neurons in the cerebellum have long axons that synapse directly on alpha motor neurons in the ventral horn of the spinal cord. d. The cell bodies of alpha motor neurons are found in the primary motor region of the cerebral cortex. e. Neurons with cell bodies in the basal nuclei can form either excitatory or inhibitory synapses onto skeletal muscle cells.

B

Which of the following is one of the four basic cell types in the body? a. respiratory b. epithelial c. endocrine d. integumentary e. immune

B

Which of the following is/are not found in DNA? a. adenine b. uracil c. cytosine d. deoxyribose e. both b and d

B

Which of the following statements is incorrect about disulfide bonds? a. They form between two cysteine amino acids. b. They are noncovalent. c. They contribute to the tertiary structure of some proteins. d. They contribute to the quaternary structure of some proteins. e. They involve the loss of two hydrogen atoms.

B

Which of these synapses does not have acetylcholine as its primary neurotransmitter? a. synapse of a postganglionic parasympathetic neuron onto a heart cell b. synapse of a postganglionic sympathetic neuron onto a smooth muscle cell c. synapse of a preganglionic sympathetic neuron onto a postganglionic neuron d. synapse of a somatic efferent neuron onto a skeletal muscle cell e. synapse of a preganglionic sympathetic neuron onto adrenal medullary cells

B

Which sequence regarding protein synthesis is correct? a. translation → transcription → mRNA synthesis b. transcription → splicing of primary RNA transcript → translocation of mRNA → translation c. splicing of introns → transcription → mRNA synthesis translation d. transcription → translation → mRNA production e. tRNA enters nucleus → transcription begins → mRNA moves to cytoplasm → protein synthesis begins

B

1-4: Match the state of consciousness (a-d) with the correct electroencephalogram pattern (use each answer once): 2. Small-amplitude, high-frequency waves, similar to the attentive awake state State of consciousness: a. relaxed, awake, eyes closed b. stage N3 non-rapid eye movement (NREM) sleep c. rapid eye movement (REM) sleep d. epileptic seizure

C

A standing subject looking over her left shoulder suddenly rotates her head to look over her right shoulder. How does the vestibular system detect this motion? a. The utricle goes from a vertical to a horizontal position, and otoliths stimulate stereocilia. b. Stretch receptors in neck muscles send action potentials to the vestibular apparatus, which relays them to the brain. c. Fluid within the semicircular canals remains stationary, bending the cupula and stereocilia as the head rotates. d. The movement causes endolymph in the cochlea to rotate from right to left, stimulating inner hair cells. e. Counterrotation of the aqueous humor activates a nystagmus response.

C

Broca's area a. is in the parietal association cortex and is responsible for language comprehension. b. is in the right frontal lobe and is responsible for memory formation. c. is in the left frontal lobe and is responsible for articulation of speech. d. is in the occipital lobe and is responsible for interpreting body language. e. is part of the limbic system and is responsible for the perception of fear.

C

In a reflex arc initiated by touching a hand to a hot stove, the effector belongs to which class of tissue? a. nervous b. connective c. muscle d. epithelial

C

In the absence of any environmental cues, a circadian rhythm is said to be a. entrained. b. in phase. c. free running. d. phase-shifted. e. no longer present.

C

In the stretch reflex, a. Golgi tendon organs activate contraction in extrafusal muscle fibers connected to that tendon. b. lengthening of muscle-spindle receptors in a muscle leads to contraction in an antagonist muscle. c. action potentials from muscle-spindle receptors in a muscle form monosynaptic excitatory synapses on motor neurons to extrafusal fibers within the same muscles. d. slackening of intrafusal fibers within a muscle activates gamma motor neurons that form excitatory synapses with extrafusal fibers within that same muscle. e. afferent neurons to the sensorimotor cortex stimulate the agonist muscle to contract and the antagonist muscle to be inhibited

C

The mesolimbic dopamine pathway is most closely associated with a. shifting between states of consciousness. b. emotional behavior. c. motivation and reward behaviors. d. perception of fear. e. primary visual perception

C

Where is the primary motor cortex found? a. in the cerebellum b. in the occipital lobe of the cerebrum c. between the somatosensory cortex and the premotor area of the cerebrum d. in the ventral horn of the spinal cord e. just posterior to the parietal lobe association cortex

C

Which incorrectly pairs a glial cell type with an associated function? a. astrocytes; formation of the blood-brain barrier b. microglia; performance of immune function in the CNS c. oligodendrocytes; formation of myelin sheaths on axons in the PNS d. ependymal cells; regulation of production of cerebrospinal fluid e. astrocytes; removal of potassium ions and neurotransmitters from the brain's extracellular fluid

C

Which ion channel state correctly describes the phase of the action potential it is associated with? a. Voltage-gated Na+ channels are inactivated in a resting neuronal membrane. b. Open voltage-gated K+ channels cause the depolarizing upstroke of the action potential. c. Open voltage-gated K+ channels cause afterhyperpolarization. d. The sizable leak through voltage-gated K+ channels determines the value of the resting membrane potential. e. Opening of voltage-gated Cl− channels is the main factor causing rapid repolarization of the membrane at the end of an action potential.

C

Which is true regarding the structure of smooth muscle? a. The thin filament includes the regulatory protein troponin. b. The thick and thin filaments are organized in sarcomeres. c. Thin filaments are anchored to dense bodies instead of Z lines. d. The cells have multiple nuclei. e. Single-unit smooth muscles do not have gap junctions connecting individual cells.

C

Which of the following can be used to synthesize glucose by gluconeogenesis in the liver? a. fatty acid b. triglyceride c. glycerol d. glycogen e. ATP

C

Which of the following reactions involve/involves hydrolysis? a. formation of triglycerides b. formation of proteins c. breakdown of proteins d. formation of polysaccharides e. a, b, and d

C

Which properties are characteristic of ion channels? a. They are usually lipids. b. They exist on one side of the plasma membrane, usually the intracellular side. c. They can open and close depending on the presence of any of three types of "gates." d. They permit movement of ions against electrochemical gradients. e. They mediate facilitated diffusion.

C

Why is the latent period longer during an isotonic twitch of a skeletal muscle fiber than it is during an isometric twitch? a. Excitation-contraction coupling is slower during an isotonic twitch. b. Action potentials propagate more slowly when the fiber is shortening, so extra time is required to activate the entire fiber. c. In addition to the time for excitation-contraction coupling, it takes extra time for enough cross-bridges to attach to make the tension in the muscle fiber greater than the load. d. Fatigue sets in much more quickly during isotonic contractions, and when muscles are fatigued the cross-bridges move much more slowly. e. The latent period is longer because isotonic twitches only occur in slow (type I) muscle fibers.

C

1-4: Match the state of consciousness (a-d) with the correct electroencephalogram pattern (use each answer once): Very large-amplitude, recurrent waves, associated with sharp spikes State of consciousness: a. relaxed, awake, eyes closed b. stage N3 non-rapid eye movement (NREM) sleep c. rapid eye movement (REM) sleep d. epileptic seizure

D

Antidepressant medications most commonly target what neurotransmitter? a. acetylcholine b. dopamine c. histamine d. serotonin e. glutamate

D

Consider the following five experiments in which the concentration gradient for Na+ was varied. In which case(s) would Na+ tend to leak out of the cell if the membrane potential was experimentally held at +42 mV? Experiment/ Extracellular Na (mmol/L)/ Intracellular Na A 50 15 B 60 15 C 70 15 D 80 15 E 90 15 a. A only b. B only c. C only d. A, B, and C e. D and E

D

During excitation-contraction coupling in a skeletal muscle fiber, a. the Ca2+-ATPase pumps Ca2+ into the T-tubule. b. action potentials propagate along the membrane of the sarcoplasmic reticulum. c. Ca2+ floods the cytosol through the dihydropyridine (DHP) receptors. d. DHP receptors trigger the opening of terminal cisternae ryanodine receptor Ca2+ channels. e. acetylcholine opens the DHP receptor channel.

D

If a patient suffers a stroke that destroys the optic tract on the right side of the brain, which of the following visual defects will result? a. Complete blindness will result. b. There will be no vision in the left eye, but vision will be normal in the right eye. c. The patient will not perceive images of objects striking the left half of the retina in the left eye. d. The patient will not perceive images of objects striking the right half of the retina in the right eye. e. Neither eye will perceive objects in the right side of the patient's field of view.

D

If implanted electrodes were used to stimulate action potentials in gamma motor neurons to flexors of the left arm, which would be the most likely result? a. inhibition of the flexors of the left arm b. a decrease in action potentials from muscle-spindle receptors in the left arm c. a decrease in action potentials from Golgi tendon organs in the left arm d. an increase in action potentials along alpha motor neurons to flexors in the left arm e. contraction of flexor muscles in the right arm

D

If the extracellular Cl− concentration is 110 mmol/L and a particular neuron maintains an intracellular Cl− concentration of 4 mmol/L, at what membrane potential would Cl− be closest to electrochemical equilibrium in that cell? a. +80 mV b. +60 mV c. 0 mV d. −86 mV e. −100 mV

D

Match each type of molecule with the correct choice (a-e); a given choice may be used once, more than once, or not at all. Molecule: second messenger a. neurotransmitter or hormone b. cAMP-dependent protein kinase c. calmodulin d. Ca2+ e. alpha subunit of G proteins

D

Of the bonding forces between atoms and molecules, which are strongest? a. hydrogen bonds b. bonds between oppositely charged ionized groups c. bonds between nearby nonpolar groups d. covalent bonds e. bonds between polar groups

D

Single-unit smooth muscle differs from multiunit smooth muscle because a. single-unit muscle contraction speed is slow, and multiunit is fast. b. single-unit muscle has T-tubules, and multiunit muscle does not. c. single-unit muscles are not innervated by autonomic nerves. d. single-unit muscle contracts when stretched, whereas multiunit muscle does not. e. single-unit muscle does not produce action potentials spontaneously, but multiunit muscle does.

D

Two neurons, A and B, synapse onto a third neuron, C. If neurotransmitter from A opens ligand-gated ion channels permeable to Na+ and K+ and neurotransmitter from B opens ligand-gated Cl− channels, which of the following statements is true? a. An action potential in neuron A causes a depolarizing EPSP in neuron B. b. An action potential in neuron B causes a depolarizing EPSP in neuron C. c. Simultaneous action potentials in A and B will cause hyperpolarization of neuron C. d. Simultaneous action potentials in A and B will cause less depolarization of neuron C than if only neuron A fired an action potential. e. An action potential in neuron B will bring neuron C closer to its action potential threshold than would an action potential in neuron A.

D

Which best describes "lateral inhibition" in sensory processing? a. Presynaptic axo-axonal synapses reduce neurotransmitter release at excitatory synapses. b. When a stimulus is maintained for a long time, action potentials from sensory receptors decrease in frequency with time. c. Descending inputs from the brainstem inhibit afferent pain pathways in the spinal cord. d. Inhibitory interneurons decrease action potentials from receptors at the periphery of a stimulated region. e. Receptor potentials increase in magnitude with the strength of a stimulus.

D

Which category of taste receptor cells does MSG (monosodium glutamate) most strongly stimulate? a. salty b. bitter c. sweet d. umami e. sour

D

Which correctly characterizes a "fast-oxidative-glycolytic" type of skeletal muscle fiber? a. few mitochondria and high glycogen content b. low myosin ATPase rate and few surrounding capillaries c. low glycolytic enzyme activity and intermediate contraction velocity d. high myoglobin content and intermediate glycolytic enzyme activity e. small fiber diameter and fast onset of fatigue

D

Which is correct? a. cAMP-dependent protein kinase phosphorylates tyrosine residues. b. Protein kinase C is activated by cAMP. c. The subunit of Gs proteins that activates adenylyl cyclase is the beta subunit. d. Lipid-soluble messengers typically act on receptors in the cell cytosol or nucleus. e. The binding site of a typical plasma membrane receptor for its messenger is located on the cytosolic surface of the receptor.

D

Which of the following does not directly or indirectly require an energy source? a. primary active transport b. operation of the Na+/K+-ATPase pump c. the mechanism used by cells to produce a calcium ion gradient across the plasma membrane d. facilitated transport of glucose across a plasma membrane e. secondary active transport

D

Which of the following is true? a. Triglycerides have the least energy content per gram of the three major energy sources in the body. b. Fat catabolism generates new triglycerides for storage in adipose tissue. c. By mass, the total-body content of carbohydrates exceeds that of total triglycerides. d. Catabolism of fatty acids occurs in two-carbon steps. e. Triglycerides are the major lipids found in plasma membranes

D

1-3: Match a receptor feature (a-e) with each choice. 3. Reflects the fact that a receptor normally binds only to a single messenger Receptor feature: a. affinity b. saturation c. competition d. down-regulation e. specificity

E

A molecule that loses an electron to a free radical a. becomes more stable. b. becomes electrically neutral. c. becomes less reactive. d. is permanently destroyed. e. becomes a free radical itself.

E

In considering diffusion of ions through an ion channel, which driving force/forces must be considered? a. the ion concentration gradient b. the electrical gradient c. osmosis d. facilitated diffusion e. both a and b

E

Match each type of molecule with the correct choice (a-e); a given choice may be used once, more than once, or not at all. Molecule: part of a trimeric protein in membranes a. neurotransmitter or hormone b. cAMP-dependent protein kinase c. calmodulin d. Ca2+ e. alpha subunit of G proteins

E

Which is a true statement about the resting membrane potential in a typical neuron? a. The resting membrane potential is closer to the Na+ equilibrium potential than to the K+ equilibrium potential. b. The Cl− permeability is higher than that for Na+ or K+ c. The resting membrane potential is at the equilibrium potential for K+. d. There is no ion movement at the steady resting membrane potential. e. Ion movement by the Na+/K+-ATPase pump is equal and opposite to the leak of ions through Na+ and K+ channels.

E

Which is correct regarding a skeletal muscle sarcomere? a. M lines are found in the center of the I band. b. The I band is the space between one Z line and the next. c. The H zone is the region where thick and thin filaments overlap. d. Z lines are found in the center of the A band. e. The width of the A band is equal to the length of a thick filament.

E

Which is/are true of epithelial cells? a. They can only move uncharged molecules across their surfaces. b. They may have segregated functions on apical (luminal) and basolateral surfaces. c. They cannot form tight junctions. d. They depend upon the activity of Na+/K+-ATPase pumps for much of their transport functions. e. Both b and d are correct.

E

Which of the following describes a similarity between cardiac and smooth muscle cells? a. An action potential always precedes contraction. b. The majority of the Ca2+ that activates contraction comes from the extracellular fluid. c. Action potentials are generated by slow waves. d. An extensive system of T-tubules is present. e. Ca2+ release and contraction strengths are graded

E

Which pattern of neurotransmitter activity is most consistent with the awake state? a. high histamine, orexins and GABA; low norepinephrine b. high norepinephrine, histamine and serotonin; low orexins c. high histamine and serotonin; low GABA and orexins d. high histamine, GABA and orexins; low serotonin e. high orexins, histamine and norepinephrine; low GABA

E

Which type of receptor does not encode a somatic sensation? a. muscle-spindle stretch receptor b. nociceptor c. Pacinian corpuscle d. thermoreceptor e. cochlear hair cell

E

T/F In patients with Parkinson's disease, an excess of dopamine from neurons of the substantia nigra causes intention tremors when the person performs voluntary movements.

F

T/F Neurons descending in the corticospinal pathway control mainly trunk musculature and postural reflexes, whereas neurons of the brainstem pathways control fine motor movements of the distal extremities

F

T/F Patients with upper motor neuron disorders generally have reduced muscle tone and flaccid paralysis.

F

T/F Neurons in the primary motor cortex of the right cerebral hemisphere mainly control muscles on the left side of the body.

T

T/F The disease tetanus results when a bacterial toxin blocks the release of inhibitory neurotransmitter.

T

The strength of ligand-protein binding is a property of the binding site called

affinity

solution of pH greater than 7.0 is an (acidic/alkaline) solution, and has an H+ concentration that is (greater/less than) than 10−7 M.

alkaline, lower

Molecules containing both polar and nonpolar regions are known as _______________ molecules

amphipathic

The channels through which water moves across plasma membranes are called

aquaporins

The fluid inside cells but not within organelles is called

cytosol

The type of tissue involved in many types of transport processes, and which often lines the inner surfaces of tubular structures, is called

epithelial

In____________ , membrane-bound vesicles in the cytosol of a cell fuse with the plasma membrane and release their contents to the extracellular fluid.

exocytosis

All the fluid found outside cells is collectively called _____fluid, and consists _______ of and ______ fluid.

extracellular, plasma, interstitial

the name of the process by which glucose moves across a plasma membrane.

facilitated diffusion

Physiological changes that occur in anticipation of a future change to a homeostatic variable are called __________

feedforward

The membrane structures that form channels linking together the cytosols of two cells and permitting movement of substances from cell to cell are called

gap junctions

When loss of a substance from the body exceeds its gain, a person is said to be in _____________ balance for that substance.

negative

The difference between the fluxes of a solute moving in two opposite directions is the

net flux

A ___________is a chemical factor released by cells that acts on neighboring cells without having to first enter the blood.

paracrine factor

Mutations arise from changes to the _________ structure of a protein.

primary

The slowest step in a multienzyme pathway is called the

rate-limiting reaction