Anatomy and Physiology Chapter 7
Subdivision of the motor division responsible for controlling involuntary events
Autonomic Nervous System (ANS)
Brain and Spinal Cord
Central Nervous System
Integrating and Command Centers
Central Nervous System
Structural nervous system subdivision that consists of the brain and spinal cord
Central Nervous System (CNS)
Which of the stimuli in this experiment would be considered a threshold stimulus?
Stimulus 2
What cells of the nervous system are responsible for anchoring neurons to their blood vessels and controlling the extracellular fluid concentrations of potassium and neurotransmitters?
astrocytes
What is the most abundant glial cell in the central nervous system (CNS)?
astrocytes
The Schwann cell forms a myelin sheath around the ________.
axon
The part of the neuron that typically conducts nerve impulses away from the cell body is the ________.
axon
The term central nervous system refers to the ________.
brain and spinal cord
Which ion causes neurotransmitter vesicles to fuse with the axon's membrane during the conduction of a nerve impulse from one neuron to the next?
calcium
Ganglia are collections of ________.
cell bodies
The nervous system is structurally subdivided into two systems: ________ nervous system and ________ nervous system.
central, peripheral
The major role of the interneuron (association neuron) is to ________.
connect motor and sensory neurons in their pathways
What part of a neuron receives signals and sends a message to the cell body?
dendrite
The neuron processes that normally receive incoming stimuli are called ________.
dendrites
Unmyelinated nerve fibers are known as ________.
gray matter
When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron,
ion channels in the plasma membrane of the receiving neuron open.
The two major functional properties of neurons are ________.
irritability and conductivity
The gaps between Schwann cells are indicated by ________.
label H
Which of these is a deep pressure receptor?
lamellar corpuscle
Impulse conduction is fastest in neurons that are ________.
myelinated
Support cells in the central nervous system are collectively called ________.
neuroglia
A molecule that carries information across a synaptic cleft is a
neurotransmitter
The gaps between Schwann cells found at regular intervals in peripheral system neurons are called ________.
nodes of Ranvier
Which of these neuroglial cells forms the myelin sheath in the central nervous system?
oligodendrocytes
Cranial and Spinal Nerves
peripheral nervous system
communication lines with body
peripheral nervous system
During the resting state, a neuron is ________.
polarized with more sodium ions outside the cell and more potassium ions inside the cell
Sensory receptors located in muscles and tendons are termed ________.
proprioceptors
Which of the following is the correct sequence in a typical reflex arc?
receptor, sensory neuron, integration center, motor neuron, effector
Which of these lists the components of a reflex arc in the correct sequence?
receptor; afferent neuron; control center; efferent neuron; effector
Nerve impulse transmissions occurring along myelinated neurons are called ________.
saltatory conduction
An action potential is caused by an influx of these ions into the cell ________.
sodium
Which division of the peripheral nervous system activates skeletal muscles?
somatic nervous system
Fibers that carry information from the skin, joints, and skeletal muscles to the central nervous system are ________.
somatic sensory
The gap between two communicating neurons is termed ________.
synaptic cleft
The small space between the sending neuron and the receiving neuron is the
synaptic cleft
Neurons either conduct action potentials along the length of their axons, or they remain at rest. This statement best describes ________.
the all or none response
If a signal from a sending neuron makes the receiving neuron more negative inside,
the receiving neuron is less likely to generate an action potential.
When calcium ions enter the synaptic terminal,
they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.
Bundles of nerve fibers (neuron processes) running through the CNS are called ________, whereas in the PNS they are called ________.
tracts, nerves
Myelinated fibers (tracts) form ________ matter while unmyelinated fibers form ________ matter.
white, gray
At which membrane potential, given the graphs shown, do a sufficient number of the voltage-gated Na+ channels start to open?
-60 mV
What is the resting membrane potential of the neuron used in the experiment?
-80 mV
Which one of the following is the correct sequence of events that correlates to the sequence of events of a nerve impulse? 1. the membrane becomes depolarized 2. sodium channels open and sodium ions diffuse inward 3. the membrane becomes repolarized 4. potassium channels open and potassium ions diffuse outward while sodium is actively transported out of the cell
2,1,4,3
________ connect sensory and motor neurons in neural pathways and their cell bodies are typically located in the central nervous system.
Interneurons (association neurons)
Why is white matter "white"?
It contains a high concentration of myelin.
The neural processes that convey incoming messages toward the cell body are indicated by ________.
Label A
The axon is indicated by ________.
Label B
The axon terminals are indicated by ________.
Label C
The metabolic center of the neuron is indicated by ________.
Label D
The nucleus of the neuron is indicated by ________.
Label E
Functional nervous system division that carries information from the central nervous system toward effectors
Motor (efferent) Division
Structural nervous system subdivision that consists of spinal nerves and cranial nerves
Peripheral Nervous System (PNS)
________ cells form the myelin sheaths around nerve fibers in the PNS.
Schwann
Functional nervous system subdivision that carries information toward the central nervous system from receptors
Sensory (afferent) division
What is the first event of an action potential?
Sodium gates open and the membrane depolarizes.
The substance that is released at axonal endings to propagate a nervous impulse is called ________.
a neurotransmitter