BIO 360 - Exam 3 - Chapter 11 Concept Check Questions Flashcards
The afferent division of the nervous system has what two components?
Afferent division consists of sensory receptors and sensory neurons.
The central nervous system consists of the ______ and the ______.
The CNS consists of brain and spinal cord.
Define homeostasis.
Homeostasis is the maintenance of a relatively stable internal environment.
A nerve that carries both sensory and motor information is called a(n) ______ nerve.
Mixed nerves carry sensory and motor signals.
Name the four regions of the spinal cord in order, starting from the brain stem.
The regions of the spinal cord are cervical, thoracic, lumbar, and sacral.
In what organelle is most intracellular Ca2+ stored?
Ca2+ is stored in the endoplasmic reticulum.
What enzyme (a) converts ATP to cAMP? (b) does cAMP activate?
(a) Adenylyl cyclase converts ATP to cAMP. (b) cAMP activates protein kinase A.
Is the adrenal medulla most like the anterior pituitary or the posterior pituitary? Explain.
The adrenal medulla is neurosecretory and therefore like the posterior pituitary.
Predict whether chromaffin cells have nicotinic or muscarinic ACh receptors.
Chromaffin cells are modified postganglionic neurons, so they have nicotinic receptors.
Is the ventral horn of the spinal cord, which contains the cell bodies of somatic motor neurons, gray matter or white matter?
The ventral horn is gray matter.
Compare gating and ion selectivity of acetylcholine receptor-channels in the motor end plate with that of ion channels along the axon of a somatic motor neuron.
The nAChR of the motor end plate is a ligand-gated monovalent cation (Na+ and K+) channel. The axon contains voltage-gated channels, with separate channels for Na+ and K+ [p. 240].
A nonsmoker who chews nicotine-containing gum might notice an increase in heart rate, a function controlled by sympathetic neurons. Postganglionic sympathetic neurons secrete norepinephrine, not ACh, so how could nicotine affect heart rate?
Postganglionic sympathetic neurons are activated by ACh acting on nicotinic receptors. This means that nicotine also excites sympathetic neurons, such as those that increase heart rate.
