chapter 11

Identify the phases of an action potential. Select all that apply.

Afterpotential Repolarization Depolarization

Select the components of the central nervous system.

Brain and spinal cord

Which items are continuous with each other at the foramen magnum?

Brain and spinal cord

Identify the components of the peripheral nervous system. Select all that apply.

Ganglia Sensory receptors Nerves

_____ potentials are conducted in a decremental fashion, while ____ potentials are conducted with a constant magnitude.

Graded, action

_____ occurs when the inside of the plasma membrane becomes more negative, and ______ occurs when the inside of the plasma membrane becomes less negative.

Hyperpolarization, depolarization

Which of the following is NOT one of the phases of an action potential?

Hyperpotential

What is the name of the gaps found between segments of myelin along an axon?

Nodes of Ranvier

Identify the correct sequence of information in a chemical synapse.

Presynaptic terminal, synaptic cleft, postsynaptic membrane

Choose the neuroglial cell types found in the peripheral nervous system.

Satellite cells Schwann cells

List the components of the peripheral nervous system.

Sensory receptors and nerves

Neurons are classified by which of the following?

Structure and function

True or False: Inhibitory postsynaptic potentials (IPSPs) involve hyperpolarization of the plasma membrane.

T

True or False: The nervous system and the endocrine system are the major control systems of the body.

T

True or false: There is a significant difference in concentration between the intracellular concentration of sodium and the extracellular concentration of sodium.

T

As the strength of a stimulus increases, what will happen to action potentials?

They will be produced with increasing frequency.

The division of the nervous system that is responsible for processing, integrating, storing and responding to information is the nervous system.

central

The division of the nervous system that is the key decision maker of the body is the ______ nervous system.

central

The ______ are the two major subdivisions of the nervous system.

central and peripheral nervous systems

The two major subdivisions of the nervous system are the and the nervous systems.

central nervous system peripheral nervous system

Identify the type of synapse that includes a presynaptic cell, synaptic cleft, and postsynaptic cell.

chemical

Neurotransmitter receptors at the postsynaptic membrane act as - regu;lated ion

chemical

Neurotransmitter receptors at the postsynaptic membrane act as -regulated ion gates.ng stimulus strength results in an increase in the ______ of action potentials.

chemical

Synapses in which neurotransmitters are released are called ______ synapses.

chemical

Inhibitory postsynaptic potentials are due to the opening of ______ channels. Select all that apply.

chloride potassium

Inhibitory postsynaptic potentials are due to the opening of ______ channels.

chloride or potassium

Synapses in which gap junctions allow ions to diffuse quickly from cell to cell are called ______ synapses.

electrical

Gap junctions allow direct communication or ionic flow between adjacent cells for a(n) ______ synapse, while synapses that use neurotransmitters to signal from the presynaptic to postsynaptic cell are called _______ synapses.

electrical, chemical

A partial depolarization of a postsynaptic neuron or muscle cell in response to a neurotransmitter is a(n) ______ postsynaptic potential.

excitatory

Depolarization of a postsynaptic neuron in response to a neurotransmitter is called an postsynaptic potential.

excited

The entry of calcium into the synaptic knob triggers ______.

exocytosis of neurotransmitter

A hole which allows the brain and spinal cord to be continuous with one another is the .

foramen magnum

Increasing stimulus strength results in an increase in the ______ of action potentials.

frequency

Groups of nerve cell bodies located outside the central nervous system are called .

ganglia

The knotlike swelling in a nerve where neuron cell bodies are found is called a ______.

ganglion

Electrical synapses allow ions to diffuse quickly from cell to cell via ______.

gap junctions

A protein channel that opens or closes in response to a stimulus would be classified as a ______ channel.

gated

Some protein channels in a cellular membrane are able to open or close in response to stimuli; because of this characteristic, these channels are called ______ channels.

gated

The support cells of the nervous system are called _____.

glia cells

The cells that account for over half of the brain's weight and outnumber neurons by at least 10 times are called cells.

glial

There are several types of support cells within the nervous system. As a group, these support cells are called cells.

glial

Which cell type accounts for over half of the brain's weight and outnumbers neurons by 10 to 50 times?

glial cells

Hyperpolarization of a postsynaptic neuron in response to a neurotransmitter is called an postsynaptic potential.

inhibiting

An IPSP causes an ______ on its target membrane.

inhibitory postsynaptic potential

A hyperpolarizing local potential will make the neuron ______ likely to generate a nerve impulse.

less

Myelin has a high ______ concentration.

lipid

A depolarizing local potential will make the neuron ______ likely to generate a nerve impulse.

more

An excitatory local potential will make the neuron ______ likely to generate a nerve impulse.

more

When the resting membrane potential becomes more _____ the condition is referred to as hyperpolarization.

negative

What is the nature of the signal that propagates along neurons that ultimately regulates and coordinates the functions of the body?

It is electrical.

What effect will a neurotransmitter have on the postsynaptic membrane?

It may produce a depolarization or a hyperpolarization.

Identify all of the bases for neuron classification.

Function Structure

1.Electrical synapse 2.Chemical synapse

1. A gap junction that allows an ionic current to flow between adjacent cells 2.A synapse where one cell releases a neurotransmitter to communicate with another cell

1. Central nervous system 2. peripheral nervous system 3. somatic Nervous System 4. Afferent Division 5. Efferent Division 6. Enteric Nervous system

1.Consists of the brain and spinal cord 2.Consists of sensory receptors, nerves, ganglia and plexuses. 3.Consists of the sympathetic and parasympathetic divisions 4.Also referred to as the sensory division of the PNS 5Also referred to as the motor division of the PNS 6.Independent sub-division that controls the digestive tract

1. cell body 2. Axon 3. Dendrite 4. Nissl body 5. collaterals

1.Enlarged portion of a neuron that contains the nucleus and other organelles 2.Process of a neuron that transmits action potentials away from the cell body 3.Process of a neuron that receives stimuli and and generates local potentials 4.Rough endoplasmic reticulum of a neuron responsible for protein synthesis 5.Branches of an axon

Differentiate graded potentials and action potentials. Select all that apply.

1.Graded potentials are conducted in a decremental fashion and action potentials are conducted with a constant magnitude. 2.The magnitude of graded potentials is variable and action potentials are all-or-none.

True or false: Neurons consist of a cell body, a single dendrite and multiple axons.

F

True or false: Summation of all incoming signals occurs at the axon terminus of a neuron.

F

True or false: When a neurotransmitter binds to a receptor on a postsynaptic membrane, a depolarization will always occur.

F

An inhibitory local potential will make the neuron ______ likely to generate a nerve impulse.

Less

Identify the two functional sub-divisions of the peripheral nervous system.

Motor division Sensory division

Select the item that is NOT a component of a neuron.

Myelin

Excitatory postsynaptic potentials are due to the entry of the electrolyte through gated ion channels in the postsynaptic membrane.

Na+

Select all of the cell types that are components of the nervous system.

Neurons Glial cells

Entry of ______ ions into the synaptic knob triggers exocytosis of neurotransmitters.

calcium

A period of time when a cell cannot respond again to an electrical stimulus is the __ refractory period.

absolute

After a nerve cell responds to a stimulus, the period of time when the cell cannot respond again, regardless of the strength of stimulus, is called the refractory period.

absolute

The electrical signals that are propagated along axons, regulating and coordinating body activities, are known as _____.

action potentials

The nervous system transfers information from one part of the body to another by using _____.

action potentials

Traveling waves of excitation moving down an axon are referred to as ______.

action potentials

Glands, smooth muscles, and cardiac muscles are innervated by the ______ division of the motor nervous system.

autonomic

The division of the motor nervous system that is under involuntary control and innervates glands, smooth muscle, and cardiac muscle is the ______ division.

autonomic

The intracellular fluid has essentially the same number of positive and negative charges and is therefore electrically .

balanced

Within a chemical synapse, the receptors _____.

bind to very specific ligands

The central nervous system consists of the , which is found within the skull, and the , which is found within the vertebral column.

brain spinal cord

The two major control systems in the body are the ______ system and the ______ system.

nervous, endocrine

A cell that receives stimuli and transmits action potentials to other nerve cells or effector organs is a(n) .

neuron

The structural unit of the nervous system that consists of a cell body, dendrites, and an axon is the ______.

neuron

The general types of cells that make up the nervous system are and cells.

neurons glial

Ligand-gated ion channels bind ______ that have diffused across a synaptic cleft.

neurotransmitters

The gaps found between Schwann cells forming the myelin are referred to as the of .

nodes ranvier

All of the nervous tissue outside the central nervous system is categorized as belonging to the ______ nervous system.

peripheral

Schwann cells and satellite cells are examples of neuroglial cells in the ______ nervous system.

peripheral

The sensory and motor divisions are the two functional sub-divisions of the ______ nervous system.

peripheral

The subdivision of the nervous system that is responsible for detecting stimuli in and around the body and sending that information to the central nervous system is the ______.

peripheral nervous system

Myelin has a high lipid content because it is formed of ______.

plasma membranes

During an EPSP, an influx of ______ occurs.

sodium

Which term best describes the concentration gradients for sodium and potassium on an excitable cell?

steep

The intracellular fluid is considered to be electrically neutral because ______.

there are the same number of positively and negatively charged ions.

Within a neuron, summation of all incoming signals occurs at the ______.

trigger zone