ch. 12 anatomy and physiology

Which of the following are characteristics of neurons?

secretion, excitability, extreme longevity, amitotic, conductivity

The somatic division of the nervous system that receives information from the eyes, ears, and skin is the somatic ______division

sensory

Glial cells are ______ than neurons

smaller

The flow of ______ ion is the most common cause of depolarization.

sodium

Which of the following membrane transporters are present throughout the membrane of a neuron?

sodium leak channels, Na+/K+ pumps, potassium leak channels

Which nerves extend from the spinal cord?

spinal nerves only

Neurons integrate multiple synaptic inputs by the process of _____

summation

______ are found in mixed nerves.

Sensory and motor axons

______ are essential for the generation of an action potential.

Voltage-gated channels

______ are unique channels in that they have three states; resting, activation, and inactivation.

Voltage-gated channels

A substance synthesized at the cell body must undergo ______ transport to reach the synaptic knobs.

anterograde

The myelin sheath covers _____

axon

The central nervous system is made of the _____and_______ spinal

brain , spinal cord

The main activity of the ______ is the propagation of an action potential along the axolemma

conductive segment

Which terms are used for the structural classification of nerves?

cranial , spinal

A positive change in the membrane potential is called _____

depolarization

Glial cells ______ transmit electrical impulses

do not

Creating and transmitting ______ currents is central to the function of neuron physiology.

electrical

A difference in the number of charged particles between two sides of the membrane forms a(n) _____

electrical gradient

True or false: Ion channels use the energy of ATP to maintain concentration gradients across neuron membranes

false

The peripheral nervous system is made of nerves and _____

ganglia

A(n)______ is a cluster of neuron cell bodies within the peripheral nervous system.

ganglion

Negatively charged proteins and other large organic molecules are found in ______

greater amounts inside a neuron

The myelin sheath is made of a high percentage of ____

lipids

The resting membrane potential is measured in ______

millivolts

Most named nerves are ______ nerves.

mixed

The brain interprets the increased frequency of nerve signals as a ______ stimulus

more intense

The autonomic division of the nervous system is part of the ______ nervous system.

motor

If a neuron has many dendrites and a single axon, it is called a(n) ______ neuron.

multipolar

Most motor neurons are _____

multipolar

The components of nervous tissue that conduct electrical impulses are _____

neurons

_____ are released from neurons in response to conductive activity.

Neurotransmitters

______ are released from neurons in response to conductive activity

Neurotransmitters

_____ is a type of membrane transport protein that increases the potential energy across a membrane

a pump

Action potentials are always propagated along an axon at the same ______ but ______ can vary depending on the strength of the stimulus

amplitude; frequency

Cytoplasm within an axon is called _____

axoplasm

The presence of ______ ions causes the synaptic vesicles to bind to the membrane, allowing neurotransmitters to be released.

calcium

Most synapses in the human body are ______ synapses

chemical

Synapses are classified as _____

chemical synapses and electrical synapses

The total length of the axon is called the segment.

conductive

The electrical gradient in a resting neuron is such that the ________ of the cell is negative relative to the _____

inside , outside

A cablelike bundle of axons in the peripheral nervous system is called a _____

nerve

What is the primary tissue of the nervous system?

nervous tissue

A nerve is part of the ______ nervous system.

peripheral

The function of a neuron is dependent on _____

resting membrane potentials changing

Na+ and K+ leak channels and Na+/K+ pumps on the neuron are responsible for establishing and maintaining the ________membrane__________

resting, potential

The process by which postsynaptic potentials are added together at the initial segment is known as _____

summation

In retrograde transport, substances are moved ______ the cell body.

toward

True or false: Graded potentials vary in size depending on the stimulus

true

True or false: Most voltage-gated ion channels are closed until the electrical potential across a membrane changes

true