a&p chapter 11
Select the components of the central nervous system.
Brain & spinal cord
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
Which items are continuous with each other at the foramen magnum?
Brain & spinal cord
Which organs make up the central nervous system?
Brain and spinal cord
True or false: Neurons consist of a cell body, a single dendrite and multiple axons.
False
True or false: Summation of all incoming signals occurs at the axon terminus of a neuron.
False
A group of related nerve cell bodies is located outside of the central nervous system. It is called a _____.
Ganglia
Groups of nerve cell bodies located outside the central nervous system are called _____.
Ganglia
Identify the components of the peripheral nervous system. Select all that apply.
Ganglia Sensory receptors Nerves
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
Myelin has a high ______ concentration.
Lipid
True or false: There is a significant difference in concentration between the intracellular concentration of sodium and the extracellular concentration of sodium.
True
The gaps found between Schwann cells forming the myelin are referred to as the _____ of _____.
nodes of ranvier
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
Within a chemical synapse, the receptors _____.
Bind to very specific ligands
Entry of ______ ions into the synaptic knob triggers exocytosis of neurotransmitters.
Calcium
Correctly pair the parts of a neuron with the correct description.
Cell body~ enlarged portion of a neuron that contains the nucleus and other organelles Axon~ process of a neuron that transmits action potentials away from the cell body Dendrite~ process of a neuron that receives stimuli and and generates local potentials Nissl body~ rough endoplasmic reticulum of a neuron responsible for protein synthesis Collaterals~ branches of an axon
The division of the nervous system that is the key decision maker of the body is the ______ nervous system.
Central
The two major subdivisions of the nervous system are the _____ and the _____ nervous systems.
Central & peripheral
Match each division of the nervous system with the correct description.
Central Nervous System~ consists of brain and spinal cord Peripheral Nervous System~ consists of sensory receptors, nerves, ganglia and plexuses Autonomic Nervous System~ consists of the sympathetic and parasympathetic divisions Somatic Nervous System~ division of the efferent division that is mostly under voluntary control Afferent Division~ also referred to as the sensory division of the PNS Efferent Division~ also referred to as the motor division of the PNS Enteric Nervous System~ independent sub division that controls the digestive tract
Correctly match each division of the nervous system with its description.
Central Nervous System~ processes information, initiates responses and integrates mental processes Peripheral Nervous System~ detects stimuli and transmits information to and receives information from the CNS Autonomic Nervous System~ transmits information to cardiac muscle, smooth muscle and glands. Somatic Nervous System~ transmits information to skeletal muscle Afferent Division~ transmits information from receptors to the CNS Efferent Division~ transmits information from the CNS to muscles and glands Enteric Nervous System~ tract Independent sub-division that controls the digestive tract
The brain and spinal cord are the two components of the ______.
Central 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 _____ -regulated ion gates.
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
Match the neuronal pathways and circuits with the correct definition.
Convergent pathway~ a pathway where several neurons synapse with a smaller number of neurons Divergent pathway~ a pathway where a small number of neurons synapse with a larger number of neurons Oscillating circuit~ neurons arranged in a circular fashion that are repeatedly stimulated to produce action potentials
Match the neuronal pathways and circuits with the correct function.
Convergent pathway~ pathways that allow different parts of the nervous system to affect the activity of a neuron Divergent pathway~ pathways that allow one part of the nervous system to affect more than one part of the nervous system. Reverberating circuit~ 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
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
Match the type of synapse with the correct description.
Electrical synapse~ a gap junction that allows an ionic current to flow between adjacent cells Chemical synapse~ a synapse where one cell releases a neurotransmitter to communicate with another cell
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.
Excitatory
The entry of calcium into the synaptic knob triggers ______.
Exocytosis of neurotransmitter
True or false: When a neurotransmitter binds to a receptor on a postsynaptic membrane, a depolarization will always occur.
False
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
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
Supporting cells such as oligodendrocytes and ependymal cells are examples of ______ cells.
Glia
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
Which cell type accounts for over half of the brain's weight and outnumbers neurons by 10 to 50 times?
Glial cells
_____ potentials are conducted in a decremental fashion, while ____ potentials are conducted with a constant magnitude.
Graded & action
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.
Inhibitory postsynaptic potentials involve ______ of the plasma membrane.
Hyperpolarization
_____ 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
An IPSP causes an ______ on its target membrane.
Inhibitory postsynaptic potential
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.
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
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
Select the item that is NOT a component of a neuron.
Myelin
When the resting membrane potential becomes more _____ the condition is referred to as hyperpolarization.
Negative
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
Select all of the cell types that are components of the nervous system.
Neurons Glial cells
The general types of cells that make up the nervous system are _____ and _____ cells.
Neurons & glia
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
What is the name of the gaps found between segments of myelin along an axon?
Nodes of Ranvier
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
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
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
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 & nerves
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
Correctly match the parts of a neuron with the correct description.
Soma~ also known as the cell body Nissl body~ rough endoplasmic reticulum of a neuron responsible for protein synthesis Collaterals~ branches of an axon Presynaptic terminal~ enlarged end of axon containing vesicles filled with neurotransmitters Axoplasm~ cytoplasm of an axon
Which term best describes the concentration gradients for sodium and potassium on an excitable cell?
Steep
Identify all of the bases for neuron classification.
Structure & function
Neurons are classified by which of the following?
Structure and function
The intracellular fluid is considered to be electrically neutral because ______.
There are the same number of positively and negatively charged ions.
As the strength of a stimulus increases, what will happen to action potentials?
They will be produced with increasing frequency.
Within a neuron, summation of all incoming signals occurs at the ______.
Trigger zone
True or False: Inhibitory postsynaptic potentials (IPSPs) involve hyperpolarization of the plasma membrane.
True