Nervous, Endocrine, and Sensory Systems lecture questions

Which of the following incorrectly pairs a glial cell type with an associated function?

A. Astrocytes; support and nourishment of neurons

B. Microglia; immune defense in the CNS

C. Oligodendrocytes; formation of myelin sheaths on axons in the PNS

C. Oligodendrocytes; formation of myelin sheaths on axons in the PNS

Which statement best describes a sensory neuron?

A. It carries information from a receptor toward the CNS.

B. It carries information from the CNS to skeletal muscle.

C. It is found only within the brain and spinal cord.

A. It carries information from a receptor toward the CNS.

Which statement correctly distinguishes a neuron from a nerve?

A. A neuron is a bundle of axons, while a nerve is one cell.

B. A nerve is found only in the CNS, while a neuron is found only in the PNS.

C. A neuron contains only dendrites, while a nerve contains only axons.

D. A neuron is one cell, while a nerve is a bundle of many axons in the PNS

D. A neuron is one cell, while a nerve is a bundle of many axons in the PNS

Which of the following contribute to the negative resting membrane potential of a neuron?

A. Large negatively charged proteins remain inside the cell.

B. K+ leaks out of the neuron through leak channels.

C. A small amount of Na+ leaks into the neuron.

D. All of the above contribute to resting membrane potential.

D. All of the above contribute to resting membrane potential.

Why is the Na+/K+ pump important?

A. It maintains high concentrations of both Na+ and K+ outside the cell.

B. It maintains high concentrations of both Na+ and K+ inside the cell.

C. It maintains high Na+ outside the cell and high K+ inside the cell.

C. It maintains high Na+ outside the cell and high K+ inside the cell.

A patient has an abnormally high concentration of K+ outside neurons. What is the most likely immediate effect on resting membrane potential?

A. It becomes more negative because more K+ leaves the neuron.

B. It becomes less negative because the K+ concentration gradient is reduced.

C. It immediately becomes +30 mV and remains there.

B. It becomes less negative because the K+ concentration gradient is reduced.

Which of the following describes a graded potential?

A. It occurs only along the axon and is always the same amplitude.

B. It always reaches approximately +30 mV.

C. It occurs in response to a stimulus and can vary in size.

C. It occurs in response to a stimulus and can vary in size.

What part of the neuron must reach threshold for an action potential to begin?

A. Axon hillock

B. Dendrite

C. Synaptic knob

A. Axon hillock

What happens when the membrane potential reaches threshold (about -55 mV)?

A. Voltage-gated Na+ channels begin to open

B. Voltage-gated K+ channels begin to close

C. Voltage-gated Na+ channels immediately become inactivated

A. Voltage-gated Na+ channels begin to open

Which direction will Na+ move when voltage-gated Na+ channels open during an action potential?

A. Out of the neuron

B. Into the neuron

C. Equally in both directions

B. Into the neuron

At approximately +30 mV, which combination best describes the voltage-gated channels?

A. Na+ channels are closed and reset; K+ channels are closed.

B. Na+ channels are open and K+ channels are closed.

C. Na+ channels are inactivated and K+ channels are open.

C. Na+ channels are inactivated and K+ channels are open.

What is the condition of the voltage-gated Na+ channel during the refractory period that begins near +30 mV?

A. The activation gate is closed and the inactivation gate is open.

B. The activation gate is open and the inactivation gate is closed

C. The activation and inactivation gates are both open

B. The activation gate is open and the inactivation gate is closed

Put the following events in the order they occur to generate an action potential on a sensory neuron:

1. Voltage-gated Na+ channels open and depolarization proceeds toward +30 mV.

2. A stimulus opens a gated Na+ channel in the receptive region.

3. Na+ channels become inactivated while voltage-gated K+ channels open.

4. The axon hillock depolarizes to threshold (about -55 mV).

A. 1, 3, 2, 4

B. 1, 2, 3, 4

C. 2, 4, 1, 3

C. 2, 4, 1, 3

How does myelin increase the speed of action potential conduction?

A. It allows current to spread farther so action potentials are regenerated mainly at nodes of Ranvier.

B. It makes each action potential reach a much higher voltage.

C. It causes the Na+/K+ pump to move ions more quickly.

A. It allows current to spread farther so action potentials are regenerated mainly at nodes of Ranvier.

A stronger stimulus is applied after threshold has already been reached. Which response is most likely?

A. Each action potential becomes progressively taller.

B. The neuron loses its resting membrane potential permanently.

C. Action potentials may occur more frequently, but each action potential remains all-or-none.

C. Action potentials may occur more frequently, but each action potential remains all-or-none.

Which sequence best follows information through a neuron during this lecture's signaling pathway?

A. Axon terminal -> dendrite -> axon hillock -> cell body

B. Axon -> dendrite -> cell body -> axon hillock

C. Dendrite/cell body -> axon hillock -> axon -> axon terminal

C. Dendrite/cell body -> axon hillock -> axon -> axon terminal

An action potential reaches the presynaptic terminal. Which event directly triggers synaptic vesicle fusion?

A. Na⁺ enters the postsynaptic neuron

B. Ca²⁺ enters the presynaptic terminal

C. K⁺ enters the presynaptic terminal

B. Ca²⁺ enters the presynaptic terminal

Which sequence correctly describes chemical synaptic transmission?

A. Neurotransmitter binds → Ca²⁺ enters → AP arrives → exocytosis

B. AP arrives → Ca²⁺ enters → exocytosis → neurotransmitter binds postsynaptic receptor

C. AP arrives → neurotransmitter binds → Ca²⁺ leaves → vesicle forms

B. AP arrives → Ca²⁺ enters → exocytosis → neurotransmitter binds postsynaptic receptor

Which structure stores neurotransmitter before it is released?

A. Synaptic cleft

B. Postsynaptic membrane

C. Synaptic vesicle

C. Synaptic vesicle

Which change is most consistent with an EPSP?

A. Na⁺ enters and the postsynaptic membrane depolarizes

B. K⁺ enters and the postsynaptic membrane depolarizes

C. Cl⁻ leaves and the postsynaptic membrane hyperpolarizes

A. Na⁺ enters and the postsynaptic membrane depolarizes

Which change is most consistent with an IPSP?

A. Na⁺ enters and the membrane moves toward threshold

B. K⁺ leaves and the membrane becomes more negative

C. Ca²⁺ enters the presynaptic terminal

B. K⁺ leaves and the membrane becomes more negative

A neuron receives several EPSPs and IPSPs at the same time. Where is their combined effect evaluated to determine whether a new action potential begins?

A. Synaptic cleft

B. Axon hillock

C. Dorsal root ganglion

B. Axon hillock

Which pathway carries information from sensory receptors toward the CNS?

A. PNS sensory division

B. Somatic motor division

C. PNS motor division

A. PNS sensory division

Which effector is controlled by the somatic motor system?

A. Cardiac muscle

B. Sweat gland

C. Skeletal muscle

C. Skeletal muscle

Which response is most associated with sympathetic activity?

A. Lower heart rate and increased digestion

B. Increased heart rate and ventilation

C. Increased digestion and energy conservation

B. Increased heart rate and ventilation

Which statement correctly describes gray and white matter in the cerebrum?

A. Gray matter is deeper; white matter forms the outer cortex

B. Gray matter forms the outer cortex; white matter is deeper

C. Both gray and white matter are only found in the spinal cord

B. Gray matter forms the outer cortex; white matter is deeper

Damage to which lobe would most directly affect primary processing of touch and body position?

A. Frontal

B. Parietal

C. Temporal

B. Parietal

A patient can hear speech but cannot understand the words. Which area is most likely affected?

A. Broca's area

B. Wernicke's Area

C. Primary motor cortex

B. Wernicke's Area

Which pairing is correct?

A. Hypothalamus - movement coordination

B. Cerebellum - homeostatic control of thirst and temperature

C. Medulla oblongata - heart rate, breathing, blood pressure

C. Medulla oblongata - heart rate, breathing, blood pressure

A sensory signal enters the spinal cord from the body. Which root does it use?

A. Ventral root

B. Dorsal root

C. Motor root

B. Dorsal root

Which sequence correctly describes a basic reflex arc?

A. Receptor → motor neuron → interneuron → sensory neuron → effector

B. Effector → sensory neuron → receptor → motor neuron → interneuron

C. Receptor → sensory neuron → interneuron → motor neuron → effector

C. Receptor → sensory neuron → interneuron → motor neuron → effector

Which statement correctly compares the touch pathway with the voluntary motor pathway used in this course?

A. Touch uses 2 neurons; motor uses 3 neurons

B. Touch uses 3 sensory neurons with synapses in the spinal cord and thalamus; motor uses 2 motor neurons with a spinal synapse

C. Both use 3 neurons and synapse only in the thalamus

B. Touch uses 3 sensory neurons with synapses in the spinal cord and thalamus; motor uses 2 motor neurons with a spinal synapse

A hormone is released into the bloodstream and travels throughout the body. Why do only certain cells respond to it?

A. Only certain cells receive blood flow

B. Only certain cells contain the appropriate receptor

C. Hormones enter only endocrine cells

B. Only certain cells contain the appropriate receptor

A water-soluble hormone reaches its target cell. Where should its receptor be located?

A. Inside the nucleus

B. In the cytoplasm

C. In the plasma membrane

C. In the plasma membrane

Which sequence correctly describes control of the anterior pituitary?

A. Hypothalamic neuron → action potential → posterior pituitary → hormone

B. Hypothalamus → releasing hormone → portal blood → anterior pituitary

C. Anterior pituitary → hypothalamus → target gland

B. Hypothalamus → releasing hormone → portal blood → anterior pituitary

ADH is produced in the hypothalamus and released from the posterior pituitary. What is its major effect?

A. Increase urine production

B. Increase water reabsorption by the kidneys

C. Increase blood calcium

B. Increase water reabsorption by the kidneys

Which sequence correctly describes the thyroid axis?

A. Hypothalamus → TSH → pituitary → T3/T4

B. Hypothalamus → TRH → anterior pituitary → TSH → thyroid → T3/T4

C. Thyroid → TSH → hypothalamus → T3/T4

B. Hypothalamus → TRH → anterior pituitary → TSH → thyroid → T3/T4

Blood levels of T3 and T4 increase. What should happen through negative feedback?

A. TRH and TSH increase

B. TRH increases but TSH decreases

C. TRH and TSH decrease

C. TRH and TSH decrease

Blood calcium falls below its normal range. Which response would help restore homeostasis?

A. Calcitonin increases and blood calcium falls further

B. PTH increases and blood calcium rises

C. Insulin increases and calcium enters cells

B. PTH increases and blood calcium rises

Which statement correctly compares the adrenal cortex and adrenal medulla?

A. Both are controlled directly by sympathetic neurons

B. The medulla releases cortisol and the cortex releases epinephrine

C. The medulla participates in the rapid sympathetic response, while the cortex produces steroid hormones involved in longer-term regulation

C. The medulla participates in the rapid sympathetic response, while the cortex produces steroid hormones involved in longer-term regulation

A person suddenly becomes frightened. Which response would occur most rapidly?

A. ACTH → adrenal cortex → cortisol

B. Sympathetic activation → adrenal medulla → epinephrine

C. TSH → thyroid → T3/T4

B. Sympathetic activation → adrenal medulla → epinephrine

During a prolonged stress response, ACTH primarily targets which structure?

A. Adrenal medulla

B. Adrenal cortex

C. Thyroid gland

B. Adrenal cortex

What is one major physiological effect of cortisol during prolonged stress?

A. Lower blood glucose

B. Increase available blood glucose

C. Increase insulin secretion after a meal

B. Increase available blood glucose

Aldosterone acts primarily on the kidneys. Which response would you expect?

A. Na⁺ excretion increases and water loss increases

B. Na⁺ retention increases and water follows

C. K⁺ retention increases while Na⁺ is lost

B. Na⁺ retention increases and water follows

Blood glucose rises after a meal. Which response should occur?

A. Glucagon increases and the liver releases glucose

B. Insulin increases and cells take up/store glucose

C. Cortisol increases and protein is broken down

B. Insulin increases and cells take up/store glucose

Several hours after eating, blood glucose begins to fall. Which pathway helps restore it?

A. Pancreas → glucagon → liver → glucose released into blood

B. Pancreas → insulin → liver → glucose released into blood

C. Pituitary → TSH → pancreas → glucose released

A. Pancreas → glucagon → liver → glucose released into blood

Which example best demonstrates nervous and endocrine systems working together?

A. A sensory neuron releases insulin into the blood

B. Sympathetic nerves activate the adrenal medulla, which releases epinephrine into the bloodstream

C. The thyroid sends action potentials to the hypothalamus

B. Sympathetic nerves activate the adrenal medulla, which releases epinephrine into the bloodstream

Hair cells involved in hearing are an example of which type of sensory receptor?

A. Photoreceptor

B. Chemoreceptor

C. Mechanoreceptor

C. Mechanoreceptor

Sensory transduction is the process of:

A. converting a stimulus into a change in membrane potential

B. carrying a motor command from the brain to skeletal muscle

C. releasing a hormone into the bloodstream

A. converting a stimulus into a change in membrane potential

After wearing a watch for several minutes, you may stop noticing its pressure on your wrist. This is an example of:

A. referred pain

B. sensory adaptation

C. hyperpolarization

B. sensory adaptation

Which receptor type is primarily responsible for detecting light?

A. Mechanoreceptor

B. Nociceptor

C. Photoreceptor

C. Photoreceptor

Which receptor type is most closely associated with smell and taste?

A. Chemoreceptor

B. Mechanoreceptor

C. Thermoreceptor

A. Chemoreceptor

Which sequence best traces sound toward the sensory receptors responsible for hearing?

A. Cochlea → ossicles → tympanic membrane → hair cells

B. Outer ear → tympanic membrane → ossicles → cochlea → hair cells

C. Tympanic membrane → cochlea → outer ear → hair cells

B. Outer ear → tympanic membrane → ossicles → cochlea → hair cells

What is the key sensory event that begins neural signaling in the cochlea?

A. The iris changes diameter

B. Hair cells bend in response to vibration

C. The lens changes shape

B. Hair cells bend in response to vibration

Which pairing is correct?

A. Vestibule = rotational movement; semicircular canals = hearing

B. Vestibule = head position relative to gravity; semicircular canals = rotational movement

C. Vestibule = vision; semicircular canals = smell

B. Vestibule = head position relative to gravity; semicircular canals = rotational movement

A person turns their head quickly. Which structures are most important for detecting the rotational movement?

A. Semicircular canals

B. Cochlea

C. Retina

A. Semicircular canals

Which structure contains the photoreceptors responsible for detecting light?

A. Cornea

B. Retina

C. Lens

B. Retina

Which sequence best traces visual information from incoming light to conscious visual processing?

A. Retina → lens → spinal cord → temporal cortex

B. Cornea/lens → retina → optic nerve → thalamus → visual cortex

C. Cornea → cerebellum → optic nerve → frontal cortex

B. Cornea/lens → retina → optic nerve → thalamus → visual cortex

The primary auditory cortex is located in which lobe of the cerebrum?

A. Frontal lobe

B. Occipital lobe

C. Temporal lobe

C. Temporal lobe

A person can detect light normally, but damage prevents the brain from recognizing what object is being viewed. Which step is most likely affected?

A. Light entering through the cornea

B. Photoreceptor transduction

C. Cortical interpretation

C. Cortical interpretation

Which situation is most consistent with conductive hearing loss?

A. Damage to cochlear hair cells

B. Damage to the vestibulocochlear nerve

C. A problem transmitting sound through the outer or middle ear

C. A problem transmitting sound through the outer or middle ear

Referred pain occurs when:

A. pain receptors stop responding to a constant stimulus

B. sensory information from different locations converges on shared CNS pathways

C. the vestibular system becomes overstimulated

B. sensory information from different locations converges on shared CNS pathways