Question 1

Which of the following best describes the difference between graded potentials and action potentials in neurons?

Accepted Answer

Graded potentials can summate and decrease with distance, while action potentials are propagated without decrement and are all-or-none.

Question 2

A patient presents with muscle weakness, weight loss, and low blood pressure. Which endocrine disorder is most likely responsible for these symptoms?

Accepted Answer

Addison's disease (adrenal insufficiency)

Question 3

Why do action potentials have an absolute refractory period?

Accepted Answer

Because voltage-gated sodium channels are inactivated and cannot reopen until the membrane repolarizes.

Question 4

Which of the following best explains the mechanism of neurotransmitter release at the synaptic terminal?

Accepted Answer

Neurotransmitters are released by exocytosis triggered by an influx of $$Ca^{2+}$$ through voltage-gated calcium channels.

Question 5

A person is unable to adapt to darkness after being in a brightly lit environment. Which process is most likely impaired?

Accepted Answer

Regeneration of rhodopsin in rod cells

Question 6

Which of the following best describes the pathway of sound from the external ear to perception in the brain?

Accepted Answer

Sound waves vibrate the tympanic membrane, move the ossicles, create pressure waves in the cochlea, stimulate hair cells, and send signals via the vestibulocochlear nerve to the auditory cortex.

Question 7

A patient with severe nasal cavity inflammation reports a loss of taste. Which of the following best explains this phenomenon?

Accepted Answer

Inflammation blocks the olfactory receptors, reducing the sense of smell, which contributes significantly to flavor perception.

Question 8

Compare the sensory systems for gustation and olfaction. Which statement is correct?

Accepted Answer

Gustation uses chemoreceptors located on the tongue, while olfaction uses chemoreceptors in the nasal epithelium; both systems rely on G-protein coupled receptors for signal transduction.

Question 9

Which of the following is a consequence of the loss of dark adaptation for vision?

Accepted Answer

Difficulty seeing in low-light conditions due to insufficient regeneration of photopigments in rods

Question 10

A patient has low plasma $$Ca^{2+}$$ levels and brittle bones. Which hormone is most likely deficient?

Accepted Answer

Parathyroid hormone (PTH)

Question 11

Which of the following best describes the role of 1,25-(OH)$$_2D ($$calcitriol) in calcium homeostasis?

Accepted Answer

It increases intestinal absorption of calcium and phosphate.

Question 12

Which of the following is true regarding the sympathetic and parasympathetic divisions of the autonomic nervous system?

Accepted Answer

The sympathetic division generally prepares the body for 'fight or flight,' while the parasympathetic division promotes 'rest and digest' activities.

Question 13

A person is exposed to a loud noise and subsequently experiences hearing loss. Which structure is most likely damaged?

Accepted Answer

Cochlear hair cells

Question 14

Which of the following best explains the role of the hypothalamus in controlling epinephrine and norepinephrine secretion?

Accepted Answer

The hypothalamus stimulates the adrenal medulla via sympathetic preganglionic neurons to secrete epinephrine and norepinephrine.

Question 15

Which of the following best describes the effect of parathyroid hormone (PTH) on bone composition?

Accepted Answer

PTH stimulates osteoclast activity, increasing bone resorption and releasing $$Ca^{2+}$$ into the blood.

Comprehensive Study Guide: Nervous and Endocrine Systems, Sensory Physiology, and Homeostasis

Study Guide - Practice Questions

Study Guide - Flashcards