Chapter 12 Connect

Which are functions of astrocytes?

1. Regulate chemical composition of tissue fluid 2. Convert blood glucose to lactate for neurons to use for fuel 3. Form blood-brain barrier 4. Secrete nerve growth factors

Choose all that are names for the cell body of a neuron.

1. Soma 2. Neurosoma

Choose all statements that are true about Schwann cells

1. They assist in the regeneration of damaged nerve fibers. 2. They form the myelin sheath in the PNS.

Choose all that are characteristics of neuroglia

1. They protect the neurons and help them function 2. They bind neurons together and provide a supportive scaffold

List in chronological order, beginning at the top, the stages of regeneration of a nerve fiber

1. degeneration of axon and myelin distal to injury 2. swelling of soma; dispersal of Nissl bodies 3. sprouting of axon growth processes 4. growth process enters regeneration tube5. reestablishment of synaptic contact

Choose all the factors that influence the speed of nerve signal conduction

1. diameter of axon 2. residence of myelin

Beginning at the top, place these events into the order in which they occur during a single action potential

1. local potential depolarizes membrane 2. threshold is reached 3. depolarization spike 4. repolarization 5. hyperpolarization

The autonomic nervous system is subdivided into the _____ division which tends to arouse the body for action and the ______ dicision which tends to have a calming effect.

1. sympathetic 2.parasympathetic

Choose all of the following statements that are true about signal conduction along unmyelinated fibers

1.A zone of depolarization excites voltage-gated channels immediately distal to the action potential. 2. Unmyelinated fibers have voltage-gated channels along their entire length.

Which types of glial cells are found in the central nervous system?

1.Ependymal cells 2. Astrpcytes 3. Microglia 4. Oligodendrocytes

local potential is what type of change in voltage

A short-range change only

Which term describes all neurons that carry signals towards the CNS?

Afferent

Which term applies to the small swellings at the distal end of the axon of a neuron that contain synaptic vesicles?

Axon terminals

Anaxonic neurons are missing which of the following?

Axons

Which describes the location of the initial segment of an axon?

Between the axon hillock and first glial cell

Choose the name of the thin layer of fibrous connective tissue found around myelin in nerve fibers of the peripheral nervous system

Endoneurium

Which of the following is required for nerve fiber regeneration

Endoneurium

In the CNS; line cavities of the brain and spinal cord; secrete and circulate CSF

Ependymal cells

Which glial cell produces and helps circulate cerebrospinal fluid

Ependymal cells

In the CNS; phagocytize microorganisms, foreign matter, and dead nervous tissue

Microglia

Which division of the PNS carries signals from the CNS to glands and muscle cells

Motor

Which term refers to the thick outermost coil of a Schwann cell

Neurilemma

Choose all of the following that are part of a regeneration tube

Neurolemma Basal lamina Endoneurium

Which glial cell insulates nerve fibers from extracellular fluids and speeds up signal conduction in the brain?

Oligodendrocyte

An electrical potential is a form of what type of energy

Potential energy

Which term refers to the period of time after a nerve cell has responded to a stimulus in which it cannot be excited by a threshold stimulus

Refractory period

Dynenin

Retrograde transport

Choose all that are usually found inside the cell body (or soma) of a mature neuron?

Rough ER Nucleus Mitochondria

In the PNS; surround somas of neurons in ganglia, provide electrical insulation, and regulate the chemical environment of neurons

Satellite cells

Which type of glial cell produces the myelin sheath in the PNS?

Schwann cell

In the PNS; form neurilemma around all PNS fibers and myelin around most of them; aid in regeneration of damaged nerve fibers

Schwann cells

Which type of glial cell aids in regeneration of damaged peripheral nerve fibers by forming a regeneration tube to help reestablish the former connection

Schwann cells

Which two types of neuroglia are found only in the peripheral nervous system

Schwann cells and satellite cells

Afferent neurons are what type of neurons?

Sensory

Which is true about a neuron with a large diameter, myelinated axon as compared to a neuron with a small diameter, unmyelinated axon

Signal conduction will be faster

What are the two divisions of the visceral motor division

Sympathetic and parasympathetic

Continuous conduction occurs in what type of axon

Unmyelinated only

Neurons that convey information to the CNS are called sensory, or ______, neurons.

afferent

Movement away from the neuron cell body toward an axon ending is called Blank______ transport

anterograde

Kinesin

anterograde transport

Which type of cell plays a role in the establishment of the blood-brain barrier

astrocyte

What are the two major anatomical subdivisions of the nervous system?

central and Peripheral nervous system

The process of neurons that usually receive signals from the other neurons are called _______

dendrites

The processes that branch from the somas of most neurons are called?

dendrites

Motor, or _______ , neurons carry signals away from the CNS and they lead to effectors (muscle and gland cells)

efferent

difference in the concentration of charged particles between one point and another is called a(n) __________ potential

electrical

List the fundamental physiological properties of neurons

excitability, conductivity, secretion

The trigger zone includes the axon hillock and the ________ segment, a region between the axon hillock and the first glial cell

initial

Which term refers to the segment of an axon between the axon hillock and the first glial cell

initial segment

Which type of neuron lies entirely within the CNS and carries out the integrative function of nervous system?

interneuron

The myelin sheath is composed mostly of which of the following

lipids and protein

The neurons indicated by a letter "A" are structurally classified as Blank______ neurons. The neurons indicated by a letter "B" are structurally classified as Blank______ neurons

multipolar, bipolar

What are the effectors of motor neurons?

muscle and gland cells

The structure that consists of spiral layers of insulation around an axon is called a(n) _________ sheath

myelin

Sensory, Inter, and motor are the three classes of?

neurons

In the CNS, myelin is produced by glial cells called

oligodendrocytes

Which ion has the greatest influence on the resting membrane potential of most neurons

potassium

The axon hillock and initial segment play an important role in initiating a nerve signal. They are collectively called the _________ zone

trigger

The region indicated by the circle is the Blank______. It plays an important role in initiating a nerve signal. It is formed by the axon hillock and the initial segment

trigger zone