A&P 1 LearnSmart Homework Chapter 11

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

Calcium

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

Excitatory postsynaptic potential

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

Not true

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

Sensory receptors Ganglia Nerves

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

absolute

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

Place the events of an electrical synapse in chronological order

1) An action potential occurs within the membrane of an initial cell 2) A local current is generated 3) The local current flows through a gap junction 4) This stimulates the production of an action potential in an adjacent cell.

Electrical synapse Chemical synapse

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

Convergent pathway Divergent pathway Oscillating circuit

A pathway where several neurons synapse with a smaller number of neurons A pathway where a small number of neurons synapse with a larger number of neurons Neurons arranged in a circular fashion that are repeatedly stimulated to produce action potentials

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

Place the events of an electrical synapse in chronological order, starting with the first at the top.

An action potential occurs within the membrane of an initial cell, a local current is generated, the local current flows through gap juntion, this stimulates the production an adjacent cell

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

Blank 1: brain Blank 2: spinal Blank 3: cord

The two major subdivisions of the nervous system are the () and () of the nervous system

Blank 1: central or CNS Blank 2: peripheral or PNS

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

Blank 1: foramen Blank 2: magnum

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

Blank 1: neurons Blank 2: neuroglia, glial, supportive, nonneural, or glia

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

Brain and spinal cord

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

Chemical

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

Chloride Potassium

Central Nervous System Peripheral Nervous System Autonomic Nervous System Somatic Nervous System Afferent Division Efferent Division Enteric Nervous System

Consists of the brain and spinal cord Consists of sensory receptors, nerves, ganglia and plexuses. Consists of the sympathetic and parasympathetic divisions Division of the efferent division that is mostly under voluntary control Also referred to as the sensory division of the PNS Also referred to as the motor division of the PNS Independent sub-division that controls the digestive tract

Convergent pathway Divergent pathway Reverberating circuit

Convergent pathway Convergent pathway answer drop zone Pathways that allow different parts of the nervous system to affect the activity of a neuron. correct toggle button unavailable Pathways that allow different parts of the nervous system to affect the activity of a neuron. Divergent pathway Divergent pathway answer drop zone Pathways that allow one part of the nervous system to affect more than one part of the nervous system. correct toggle button unavailable Pathways that allow one part of the nervous system to affect more than one part of the nervous system. Reverberating circuit Reverberating circuit answer drop zone Important in functions that are periodically active such as the sleep/wake cycle and respiration. correct toggle button unavailable Important in functions that are periodically active such as the sleep/wake cycle and respiration.

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

Depolarization Repolarization Afterpotential

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

False

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

Glial cells

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

Glial cells

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

Glial cells Neurons

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

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

_____ 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

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

Inhibitory

What effect will a neurotransmitter have on the postsynaptic membrane?

It may produce a depolarization or a hyperpolarization.

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

Myelin

The general class of cells in the nervous system that protect nerve cells and help in their functioning are called

Neuroglia cells

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

Nodes of R

Describe characteristics of receptors at the synapses. Select all that apply.

Only specific molecules are able to bind to the receptors They are ligand activated receptors

Convergent pathway Divergent pathway Reverberating circuit

Pathways that allow different parts of the nervous system to affect the activity of a neuron. Pathways that allow one part of the nervous system to affect more than one part of the nervous system. Important in functions that are periodically active such as the sleep/wake cycle and respiration.

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

Peripheral

Central Nervous System Peripheral Nervous System Autonomic Nervous System Somatic Nervous System Afferent Division Efferent Division Enteric Nervous System

Processes information, initiates responses and integrates mental processes Detects stimuli and transmits information to and receives information from the CNS Transmits information to cardiac muscle, smooth muscle and glands. Transmits information to skeletal muscle Transmits information from receptors to the CNS Transmits information from the CNS to muscles and glands Independent sub-division that controls the digestive tract

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

Ranvier

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

Satellite cells Schwann cells

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

Sensory division Motor division

List the components of the peripheral nervous system.

Sensory receptors and nerves

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

Spinal cord Nerves Sensory receptors Brain

Neurons are classified by which of the following?

Structure and function

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

They will be produced with increasing frequency.

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

action potentials

Place the events of a chemical synapse in chronological order, starting with the first at the top.

an action potentialreaches the presynaptic terminal, voltage gated Ca++ channels open, Ca++ diffuses into the presynaptic terminal, neurotransmitter are released into the synapticcleft, neurotransmitter bind to receptors on the postsynaptic membrane, depolarization or Hyperpolarization of the postsynaptic membrane occurs

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

Within a chemical synapse, the receptors _____.

bind to very specific ligands

Which organs make up the central nervous system?

brain and spinal cord

The division of the nervous system that is responsible for processing, integrating, storing and responding to information is the (Blank) 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 spinal cord and brain comprise the

central, nervous system.

Synapses in which neurotransmitters are released are called ______ synapses.

chemical

Neurotransmitter receptors at the postsynaptic membrane act as

chemical regulated. ion gates

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

chloride or potassium

Local currents flow through gap junctions between adjacent cells in a(n)

electrical

Local currents flow through gap junctions between adjacent cells in a(n) _____ synapse.

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

The entry of calcium into the synaptic knob triggers ______.

exocytosis of neurotransmitter

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

false

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

frequency

A group of related nerve cell bodies are outside of the central nervous system. The group is called a _____.

ganglia

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

ganglion

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 cells that are general support cells for neurone in the brain and spinal cord are ______ cells.

glial

An IPSP causes an ______ on its target membrane.

inhibitory postsynaptic potential

Potassium has a much higher concentration in the _____ fluid than in the _____ fluid.

intracellular, extracellular

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

less

An inhibitory 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

The brain, nerves, and sensory receptors are all part of the ______ system.

nervous

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

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

neurotransmitters

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

neutral

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 subdivision of the nervous system that consists of nerve tissue external to the central nervous system is the (Blank), Incorrect Unavailable nervous system.

peripheral

The ion that is in a higher concentration in the intracellular fluid compared to the extracellular fluid is

potassium, K, or K+

Identify the correct sequence of information in a chemical synapse.

presynaptic terminal, synaptic cleft, postsynaptic membrane

During an EPSP, an influx of ______ occurs.

sodium

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

sodium

Identify all of the bases for neuron classification.

structure and function

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

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

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

tis electrical.

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

trigger zone