Ch. 14 Flashcards
True or false: The human central nervous system consists of the brain, spinal cord, and nerves.
False
The nerves of the human body make up the ______.
peripheral nervous system
The central nervous system functions to receive
input, _____ perform integration, and generate
_____ output.
sensory. motor
What are all parts of the nervous system
Brain, Spinal cord
Based on function, the three basic types of neurons are sensory neurons, interneurons, and
__________ neurons.
motor
Which type of neuron lies entirely within the central nervous system?
Interneuron
The general tissue type that includes cells called neurons and neuroglia is
______ tissue.
nervous
Receptors that detect changes in the environment are called _______ receptors.
sensory
In nervous tissue, cells called
________ support and nourish the cells called ________ that transmit nerve impulses.
neuroglia, neurons
In the CNS, cells called
_____ form myelin; in the PNS,myelin is formed by _______ cells.
oligodendrocytes, schwann
All neurons have three parts: an axon, a cell body, and _____
dendrites
Which class of neurons takes nerve signals to the central nervous system?
sensory
A nerve is a bundle of axon or nerve _____
fibers
Which type of receptor would respond to changes in the environment?
sensory
Which type of cell forms myelin sheaths in the peripheral nervous system?
Schwann cell
A sensory neuron has a cell body located along its very long _____
axon
What are three parts of a neuron
Dendrite, Axon, Cell body
Areas along an axon where there is no myelin sheath are called
______ of Ranvier.
nodes
A bundle of long axons outside of the central nervous system is called a(n) ______.
nerve
The central nervous system disorder that results from an autoimmune destruction of myelin is called
_____ sclerosis.
multiple
In the peripheral nervous system, Schwann cells wrap their membranes around the _____ of neurons to form myelin sheaths.
axons
In the CNS, gray matter is gray because it contains no ______.
myelin
Multiple sclerosis is an autoimmune disorder of the nervous system resulting from the breakdown of ______.
myelin
The prick of a sharp pin would be the
______ that starts an action potential on a pain neuron.
stimulus
Areas of the CNS where the axons are myelinated are called _______ matter.
white
The voltage that will result in an action potential is called the _____.
threshold
When a neuron is not transmitting an impulse, the energy resulting from the level of membrane polarization is called ______.
the resting potential
Increasing the strength of a stimulus does not change the strength of the action potential, however it may
_____.
cause more action potentials to occur in a given period
Which part of a neuron conducts an action potential?
Axon
Which term refers to an event that activates a neuron and begins an action potential?
Stimulus
The rapid movement of potassium ions out of a neuron during an action potential causes ______ of the cell membrane.
repolarization
Once an impulse has passed down a neuron, it is then unable to conduct another impulse for a short period of time. This is referred to as ______.
the refractory period
The region where a neuron transmitting an impulse comes in close proximity to a receiving neuron is the ______.
synapse
Conduction along an unmyelinated axon ______.
is slower than conduction on a myelinated axon
Conduction of an impulse along a myelinated axon is termed ______ conduction.
saltatory
What is the function of a neuron membrane’s refractory period?
It prevents an action potential from traveling in the wrong direction.
The best definition of an axon terminal is ______.
the small swelling at the tip of an axon branch
The location where an axon terminal of one neuron comes into close proximity with a dendrite or cell body of a second neuron is called a(n)
_________.
synapse
Which enzyme breaks down acetylcholine at the synapse?
Acetylcholinesterase
A chemical released by a sending neuron, which diffuses across the synaptic cleft to bind to the membrane of a receiving neuron, is called a ________.
neurotransmitter
Which neurotransmitter excites skeletal muscle but inhibits cardiac muscle?
Acetylcholine
The small swelling at the end of an axon, which lies close to the dendrite or cell body of another neuron, is the axon _________.
terminal
Whereas an inhibitory signal opens ______ gates of a neuron cell membrane, an excitatory signal opens _____ gates of a neuron.
potassium; sodium
In some synapses, the receiving membrane contains ______ that rapidly inactivates the neurotransmitter, preventing the continuous stimulation or inhibition of the receiving membrane.
ENZYMES
If a neuron receives more inhibitory signals than excitatory signals, an impulse will not be sent due to ______.
integration
A viral or bacterial infection of the protective membranes around the brain and spinal cord is called ______.
meningitis
Whereas an inhibitory signal causes a neuron to be ______ threshold, an excitatory signal causes a neuron to be _____ threshold.
further from; closer to
The fluid that cushions and protects the organs of the central nervous system is called ______.
cerebrospinal fluid
The protective membranes that surround the brain and spinal cord are called the ______.
meninges
Which disorder occurs as a result of excess accumulation of cerebrospinal fluid?
Hydrocephalus
In the CNS, which type of nervous tissue contains cell bodies and short nonmyelinated nerve fibers?
Gray matter
The myelinated axons that run together in bundles in the CNS are called ______.
tracts
True or false: In the spinal cord, the gray matter is more internal and the white matter is more external
true
Quadriplegia results from damage to the spinal cord at a region that is ______ damage that would cause paraplegia.
higher than
The structure that provides a means of communication between the brain and peripheral nerves is the _________.
spinal cord
How many ventricles does the human brain have?
4
If the spinal cord is completely severed in the thoracic region, what is the most likely outcome?
Paraplegia
The neurons that control an action where impulses from sensory axons travel through the spinal cord and back to an effector (muscle or gland) constitute a reflex ______.
arc
Which of these is the largest portion of the human brain, receives sensory input, and regulates voluntary motor output?
Cerebrum
The human brain is comprise of the cerebrum, diencephalon, brain stem and
_________.
cerebellum
Which lobe of the cerebrum controls movement and higher reasoning?
frontal
