Exam 4: Principles of Neural and Hormonal Communication

____________________ cells form myelin around neurons in the peripheral nervous system.

Indicate whether the characteristics below apply to the endocrine system or the nervous system by writing the appropriate letter in the blank using the following answer code: -Has an influence on other major control system.

Steroid hormones act through the second-messenger system.

Steroid hormones are derived from ____________________.

Indicate whether the membrane is more permeable to K⁺ or to Na⁺ or is equally permeable to these ions under the stated conditions by writing the appropriate letter in the blank using the following answer code: -during an EPSP

Indicate the solubility characteristics of each of the classes of hormones by writing the appropriate letter in the blank using the following answer code: -peptides

When EPSPs originating from a single presynaptic input occur so close together in time that they add together or sum, thereby bringing the postsynaptic cell to threshold, it is called ____________________.

A single nerve cell or ____________________ typically consists of the following three basic parts: ____________________, ____________________, and ____________________.

Cholesterol is a common precursor for steroid synthesis.

Indicate whether the characteristics below apply to the endocrine system or the nervous system by writing the appropriate letter in the blank using the following answer code: -Secretes chemical messengers that affect target cells.

Neurohormones are hormones that specifically modify neural activity.

The nerve fiber is another name for the nucleus of a neuron.

In a graded potential the direction of current flow is designated by the movement of positive charges.

MATCHING: ART The following questions refer to the accompanying diagram of an action potential. Segments of the action potential are labeled A-D. Match the letters to the corresponding statements below. -Depolarizing phase

Use the answer code to answer the questions in this section: -Ion movement responsible for the falling phase of the action potential.

Which statement regarding graded potentials is false?

The following question refers to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation by filling the appropriate letter in the blank using the following answer code: -A. permeability of a resting nerve cell membrane to K⁺ B. permeability of a nerve cell membrane to K⁺ during the falling phase of an action potential

The same chemical messenger may be either a hormone or a neurotransmitter, depending on its source and mode of delivery to the target tissue.

Schwann cells stimulate the formation of a(n) ____________________ tube to rebuild damaged neurons.

During the rising phase of the action potential,