Smartbook Chapter 12 Part 1

Which correctly describe axonal transport?

- It involves transport of proteins within the axon (i.e. synaptic knob enzymes or proteins that maintain the axolemma). - It is bidirectional (retrograde and anterograde transport).

Which are functions of astrocytes?

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

Which statements are true about Schwann cells?

- They assist in the regeneration of damaged nerve fibers. - They form the neurilemma. - They form the myelin sheath in the PNS.

Choose the characteristics of neuroglia.

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

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

Astrocyte

axon hillock Axoplasm Axolemma Axon collateral

Axon hillock -> A mound located on one side of the soma from which the axon originates Axoplasm -> Cytoplasm of the axon Axolemma -> Plasma membrane of the axon Axon collateral -> Branch that originates from an axon

Which term refers to the passage of proteins, organelles and other materials along an axon?

Axonal transport

Sensory (afferent) neurons do which of the following?

Carry signals to spinal cord and brain

Which fundamental physiological property of neurons allows them to send signals quickly over long distances?

Conductivity

Which term is used to describe motor neurons because they send signals away from the CNS and out to muscle and gland cells?

Efferent

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

Endoneurium

True or false: Damaged nerve fibers in the CNS regenerate very fast whereas damaged nerve fibers in the PNS never regenerate.

False

______ cells protect the neurons and help them function.

Glial

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

Initial segment

List the three functional classes of neurons.

Interneurons Sensory neurons Motor neurons

Between the nodes of Ranvier are myelin-covered segments of axon encircled by Schwann cells. Which term refers to these segments?

Internodes

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

Mitochondria Rough endoplasmic reticulum Nucleus

Multipolar neurons Bipolar neurons Unipolar neurons Anaxonic neurons

Multipolar neurons -> One axon; multiple dendrites Bipolar neurons -> One axon; one dendrite Unipolar neurons -> A single process Anaxonic neurons -> No axon; multiple dendrites

Which two organ systems are primarily responsible for coordinating the other bodily systems so as to maintain homeostasis?

Nervous system Endocrine system

Which term refers to the outermost layer of myelin, containing the nucleus and cytoplasm of the Schwann cell?

Neurilemma

Which term refers to the gaps between segments of myelin along an axon?

Nodes of Ranvier

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

Oligodendrocyte

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

Oligodendrocytes Astrocytes Microglia Ependymal cells

Taken together, the sensory and motor subdivisions make up which of the following?

Peripheral nervous system

Which factors influence the speed of nerve signal conduction?

Presence of myelin Diameter of axon

Which neuroglial cell is found in the peripheral nervous system?

Satellite cell

Satellite cells Schwann Cells Ependymal cells Microglia

Satellite cells -> In the PNS; surround somas of neurons in ganglia, provide electrical insulation, and regulate the chemical environment of neurons Schwann cells -> In the PNS; form neurilemma around all PNS fibers and myelin around most of them; aid in regeneration of damaged nerve fibers. Ependymal cells -> In the CNS; line cavities of the brain and spinal cord; secrete and circulate CSF Microglia -> In the CNS; phagocytize microorganisms, foreign matter, and dead nervous tissue

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

Schwann cell

The release of a neurotransmitter is an example of which physiological property exhibited by a neuron?

Secretion

Which terms refers to the part of the PNS that carries signals from various receptors to the CNS?

Sensory division

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

Which are names for the cell body of a neuron?

Soma Neurosoma

What is the primary function of the myelin sheath?

To increase the speed of signal conduction in the axon

True or false: Unmyelinated nerve fibers (axons) in the PNS are enveloped in Schwann cells.

True

Which type of neuron has one single process that branches like a T into a peripheral fiber and a central fiber?

Unipolar

Which process of a neuron is specialized for rapid conduction of nerve signals to structures relatively far away from the neuron cell body?

axon

A neuron with one axon and one dendrite is structurally classified as a ________ neuron.

bipolar

The brain and spinal cord are components of the ______ nervous system, while the nerves and ganglia are components of the ______ nervous system. Multiple choice question.

central, peripheral

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

dendrites

____ are the processes of a neuron that usually receive signals from other neurons.

dendrites

_____ are the processes of a neuron that usually receive signals from other neurons.

dendrites

Two organ systems are dedicated to internal coordination, communication between the other systems, and maintaining the overall homeostasis of the body. They are the ______ system, which communicates by means of hormones, and the ______ system which sends quick electrical and chemical messages from cell to cell.

endocrine nervous

The glial cells that line cavities of the brain and spinal cord and secrete and circulate cerebrospinal fluid are ______.

ependymal cells

The plural form of ganglion is ______.

ganglia

The myelin sheath is composed mostly of which of the following?

lipids

What are the effectors of motor neurons?

muscles and glands

In the CNS, myelin is produced by glial cells called _____

oligodendrocytes

In the CNS, myelin is produced by glial cells called ______

oligodendrocytes

Afferent neurons are ______ neurons.

sensory

The sensory division of the PNS is further subdivided into the ______ sensory division, which carries signals from receptors in the skin, muscles, bones, and joints, and the ______ sensory division, which carries signals from organs of the thoracic and abdominal cavities.

somatic, visceral

Which division inhibits digestion?

sympathetic

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

sympathetic, parasympathetic

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

synaptic knob

At its distal end, an axon has an extensive complex of fine branches called a(n) ______.

terminal arborization

Neurons with a single process extending from the soma, such as the neurons that carry sensory signals to the spinal cord, are classified structurally as ______ neurons.

unipolar

An axon lacking a myelin sheath is said to be ______.

unmyelinated