chapter 7 quiz part 1

Select all that are true of oligodendrocytes.

- They are glial cells found in the CNS - They can form myelin around several axons simultaneously - They help form a myelin sheath around CNS axons

Place the following structures in the order that an electrical impulse would travel beginning with the postsynaptic membrane.

1. Dendrites 2. Soma 3. Axon hillocks 4. Neurofibril nodes 5. synaptic knob

Fill in the blanks with the terms provided. Not all terms will be used.

A synapse is the specific location where a neuron is functionally connected to either another neuron or an effector. There are two types of synapses in the human body: chemical synapses and electrical synapses. Most synapses within the nervous system are chemical synapses.

Which glial cell is star-like in shape and helps form the blood-brain barrier?

Astrocytes

Select all that are common features of most neurons.

Axon Dendrite Soma

Match the subdivision of the nervous system with its components.

Consists of the brain and spinal cord Central nervous system Includes cranial nerves, spinal nerves, and ganglia Peripheral nervous system

Nerve growth factors that stimulate outgrowth of severed axons are secreted by

Neurolemmocytes

What type of cells produce the myelin sheath in the central nervous system (CNS)?

Oligodendrocytes

____ are large cells that unsheathed many different axons.

Oligodendrocytes

Myelin sheaths mainly consist of which part of the glial cells that form them?

Plasma membranes

Check all that are a function of the nervous system.

Processing and evaluating information Collecting information Responding to information

Fill in the blanks with the terms provided.

Pumps move substances against a concentration gradient, a process that requires energy. Channels instead provide the means to move a substance with a concentration gradient. Neurons contain the following major types of channels: • Channels that are always open, allowing continuous diffusion of a specific ion from a region of high concentration to a region of low concentration are leak channels. • Channels that are normally closed that open in response to the binding of a neurotransmitter are chemically gated channels. When open, they allow a specific ion to diffuse across the plasma membrane. • Channels that are normally closed, but open in response to changes in electrical charge across the plasma membrane are voltage-gated channels. When open, they allow a specific ion to diffuse across the membrane.

Place these neurons into the proper classification group.

Structural Classification -Multipolar neuron -Bipolar neuron -Unipolar neuron Functional Classification -Sensory neuron -Motor neuron - interneuron neuron -afferent neuron -efferent neuron -association neuron

Check all that are factors that increase the chance of a damaged axon being able to regenerate.

The damaged axon is in the PNS. Some neurilemma remains. The distance between the site of the damaged axon and the effector organ is relatively short.

The nervous system serves as the body's primary ____________ and control system. It provides a rapid means of ____________ and regulating body functions through electrical activity transmitted along specialized nervous system cells called ____________ to accomplish the following: • Collect information. Specialized nervous system structures called ____________ monitor changes in both the internal and external environment called ____________ . • Process and evaluate information. After processing ____________ input, the brain and spinal cord determine what response, if any, is required. • Initiate response to information. The brain and spinal cord initiate a response as ____________ output via nerves to ____________ . These structures include all three types of muscle tissue and glands.

The nervous system serves as the body's primary communication and control system. It provides a rapid means of integrating and regulating body functions through electrical activity transmitted along specialized nervous system cells called neurons to accomplish the following: • Collect information. Specialized nervous system structures called receptors monitor changes in both the internal and external environment called stimuli. • Process and evaluate information. After processing sensory input, the brain and spinal cord determine what response, if any, is required. • Initiate response to information. The brain and spinal cord initiate a response as motor output via nerves to effectors. These structures include all three types of muscle tissue and glands.

Pain receptors in the skin send signals to the CNS for processing. These pain receptors are an example of ____________ neurons.

afferent

Whereas a nerve is a bundle of __________ within the peripheral nervous system, a ganglion is a cluster of ___________ within the ___________ nervous system.

axons; cell bodies; peripheral

Ependymal cells help produce

cerebrospinal fluid

When a neurotransmitter binds a protein channel, it opens and lets sodium diffuse down its concentration gradient. This is an example of a

chemically gated sodium channel.

Neurons that carry signals from the CNS to skeletal muscle for contraction would be classified as _____________ neurons.

efferent

Which glial cell acts as a phagocyte?

microglial cell

The vagus nerve contains afferent and efferent neurons; therefore it is an example of a(n) __________ nerve.

mixed

Neurolemmocytes produce myelin in the _____ nervous system.

peripheral

PNS axons are vulnerable to cuts, crushing injuries, and other types of trauma. However, a damaged ____________ can regenerate if the ____________ remains intact and a critical amount of ____________ remains. The success of peripheral nervous system axon regeneration depends upon two primary factors: (1) the amount of ____________ and (2) the ____________ between the site of the damaged axon and the ____________ . The possibility of repair is ____________ with an increase in either of these two factors.

PNS axons are vulnerable to cuts, crushing injuries, and other types of trauma. However, a damaged axon can regenerate if the cell body remains intact and a critical amount of neurilemma remains. The success of peripheral nervous system axon regeneration depends upon two primary factors: (1) the amount of damage and (2) the distance between the site of the damaged axon and the effector organ. The possibility of repair is decreased with an increase in either of these two factors. Neurolemmocytes play an active role in regeneration

Select all the appropriate classifications for a nerve that sends sensory information from the eye to the brain.

Sensory cranial

Fill in the blanks with the terms provided. Not all terms will be used.

The peripheral nervous system is further subdivided into an afferent (sensory) division and an efferent (motor) division. The afferent or sensory division transmits impulses from peripheral organs to the CNS. The efferent or motor division transmits impulses from the CNS out to the peripheral organs. The motor division is separated further into a somatic motor division and a(n) autonomic motor division. Autonomic refers to the controls we are not aware of, like smooth muscle, cardiac muscles, and glands.

Fill in the blanks with the terms provided. Not all terms will be used.

The structural classification of nerves is based upon the CNS component from which the nerve extends. Cranial nerves extend from the brain, and spinal nerves extend from the spinal cord. The functional classification of nerves is based upon whether a nerve contains sensory neurons or motor neurons. Sensory nerves contain only sensory neurons that relay information to the CNS, and motor nerves contain primarily motor neurons that relay information from the CNS. In contrast, mixed nerves contain both sensory and motor neurons.

A typical synapse in the CNS consists of a presynaptic neuron and a postsynaptic neuron, separated by a narrow space called the

synaptic cleft.

The fundamental physiological properties that enable nerve cells to communicate with other cells are

the ability to respond to environmental changes. the ability to produce electrical signals that are quickly conducted to other cells at distant locations. the ability to secrete a chemical that will stimulate the next cell when an electrical signal reaches the end of an axon.