Spinal nerves flash card

The spinal cord gives rise to 31 pairs of…
spinal nerves
The bulge in the spinal cord that gives off nerves to the upper limbs is called the…
cervical enlargement
The bulge in the spinal cord that gives off nerves to the lower limbs is called the…
lumbar enlargement
What is the groove that extends the length of the spinal cord posteriorly?
posterior median sulcus
In a spinal cord cross section, the posterior ____ of the gray matter resemble the upper wings of a butterfly.
The cell bodies of motor neurons are found in the ____ horns of the spinal cord?
What connects the gray matter on the left and right sides of the spinal cord?
gray commisure
What in the gray commisure of the spinal cord contains cerebrospinal fluid and is continuous with the ventricals of the brain?
central canal
The white matter of the spinal cord is divided into anterior, lateral, and posterior ____
The longitudinal bundles of nerve fibers within the spinal cord constitute major nerve pathways called ____
nerve tracts
Ascending tract to the brain to interpret touch, pressure, and body movements
fasciculus gracilis
Descending tract whose fibers conduct motor impulses to sweat glands and muscles to control tone
Descending tract whose fibers conduct motor impulses to skeletal muscles
Ascending tract to the cerebellum necessary for coordination of skeletal muscles
posterior spinocerebellar
Ascending tract to the brain to give rise to sensations of temperature and pain
lateral spinothalamic
Band of pia mater that anchors dura mater to cord
denticulate ligament
Channel through which venous blood flows
dural sinus
Outermost layer of meninges
dura mater
Follows irregular contours of spinal cord surface
pia mater
Contains cerebrospinal fluid
subarachnoid space
Thin, weblike middle membrane
arachnoid mater
Separates dura mater from bone of vertebra
epidural space
nerve ____ are routes followed by nerve impulses as they pass through the nervous system
interneurons in a withdrawal reflex are located in the…
central nervous system
____ are automatic subconscious responses to external or internal stimuli
effectors of reflex arc are glands and ____
a patellar reflex employs only ____ and ____ neurons
sensory, motor
the effector muscle of the patellar reflex is the ____
quadriceps femoris
the sensory stretch receptors (muscle spindles) of the patellar reflex are located in the ____ muscle
quadriceps femoris
the patellar reflex helps the body to maintain upright ____
the sensory receptors of a withdrawal reflex are located in the ____
____ muscles in the limbs are the effectors of a withdrawal reflex
the normal plantar reflec results in ____ of toes
stroking the sole of the foot in infants results in dorsiflexion and toes that spread apart, called the ____ reflex
what is the response of a patellar reflex?
extension of leg at knee
what is the response of a calcaneal reflex?
plantar extension of the foot
what is the response of a biceps reflex?
flexion of forearm or slight biceps twich
what is the response of a triceps reflex?
extension of forearm or slight triceps twitch
what is the response of a plantar reflex?
plantar extension of foot and flexion of toes
structure formed by the crossing-over of the optic nerves
optic chiasma
part of diencephalon that forms lower walls and floor of third ventricle
cone-shaped gland attached to upper posterior portion of diencephalon
pineal gland
connects cerebral hemispheres
corpus callosum
ridge on surface of cerebrum
gyrus (convolution)
separates frontal and parietal lobes
central sulcus
part of brainstem between diencephalon and pons
rounded bulge on underside of brainstem
part of brainstem continuous with the spinal cord
medulla oblongata
layer of dura mater that separates cerebellar hemispheres
falx cerebelli
cerebral lobe located deep within lateral sulcus
thin layer of gray matter on surface of cerebrum
cerebral cortex
regulates heart rate
equilibrium and hearing
stimulates superior oblique muscle of eye
sensory impulses from teeth and face
pupil constriction and eyelid opening
controls neck and shoulder movements
controls tongue movements
stimulates lateral rectus muscle of eye
taste, salivation, and secretion of tears
nervous tissue is made of…
neurons and neuroglial cells
neuron signals may be transmitted to another neuron or to an ____ that is either stimulated or inhibited by the signal
neurons are made up of…
cell membrane, cell body, nucleus, organelles, and processes
the cell bodies of neurons are usually filled with a dark staining material called ____, and are located within gray matter of the nervous system.
nissl substance
the three types of neurons are:
motor, sensory, and interneurons
neurons have only ___ axon(s)
depending on how many processes extend from the cell body, a neuron can be classified as:
multipolar, bipolar, unipolar
neuron cell bodies can be found in ____
gray matter
gray matter is located in
the central portion of the spinal cord, the cortex of the cerebrum and cerebellum, and in ganglia.
____ is made primarily of the processes of nerve cells
white matter
myelin is produced by ____ on peripheral nerve cell processes
schwann cells
myelin is produced by ____ on neuron cell processes within the central nervous system
bare regions of the axon where two regions of myelin come together are called
nodes of Ranvier
for every one neuron, there are ____ neurolgia
function of neurolgia
protection, nourishment, support
function of dendrites
receive input
function of axon
send out signals
what is an impulse (action potential)?
something received in the cell body and sent down an axon
function of the myelin sheath
facilitates the transmission of nerve impulses
what is the Central Nervous System (CNS) affiliated with?
brain and spine
what is the Peripheral Nervous System (PNS) affiliated with?
cranial and spinal nerves
what are the three general functions of the nervous system?
Sensory Input, Integration, and Motor Output
function of sensory receptors
receive information, detect changes in the body
what are the two divisions of motor neurons?
somatic and autonomic
are somatic nerves voluntary or involuntary?
are autonomic nerves voluntary or involuntary?
sensory (afferent) neurons conduct impulses in which direction?
interneurons (association neurons) conduct impulses in which direction?
other neurons
motor (efferent) neurons conduct impulses in which direction?
function of astrocytes
protect, nourish, support, ‘adhesiveness’
function of oligodendrocytes
produce myelin in the CNS
what color are myelinated oligodendrocytes?
what color are unmyelinated oligodendrocytes?
function of microglia
kill bacteria, destroy debris
functino of ependyma
form thin membranes, fill in gaps or spaces
function of satellite cells
nourish, protect, support
the neuron conducting an impulse to the synapse is the sender, or ____
presynaptic neuron
the neuron receiving input at the synapse is the ____
postsynaptic neuron
neurotransmitters are released by ____
neurotransmitters bind to receptors on the ____ of a postsynaptic cell
motor output is the conduction of signals from the ____ to the ____
CNS, effector cells such as muscles
signals are conducted by ____, which are bundles of ____ wrapped in connective tissue
nerves, neurons
sensory and motor neurons are collectively called the…
peripheral nervous system (PNS)
what are the four main parts of a neuron?
cell body, dendrites, axon, synaptic terminals
the site of contact between a synaptic terminal of a neuron and a target, such as another neuron, a muscle cell, or a gland, is called a…
what are the cells that lie on each side of a synapse?
pre-synaptic and post-synaptic cells
the simplest type of nerve circuit is termed a….
reflex arc
what is the minimum number of neurons that can make up a “reflex arc”, and what kind of neurons would these neurons be?
2, at least one sensory and at least one motor
what are “interneurons”?
neurons within the CNS
interneurons are constantly active. what does this activity provide the context for?
interpreting sensory input and giving a response
ganglia and nuclei are collections of ____. How do they differ from one another?
cell bodies of neurons, ganglia are found in the PNS and nuclei are found in the brain
supporting cells, called ____, are essential for the structural integrity of the nervous system and normal function of neurons
which neuroglia (glial cells) provide structural and metabolic support for neurons?
what structure, or membrane, do these neuroglial cells also form?
blood-brain barrier
what cells form the insulating sheaths around axons in the PNS and the CNS?
Schwann cells outside CNS, oligodendrocytes inside CNS
all cells have an electrical charge difference across their plasma membrane called the…
membrane potential
what creates membrane potential?
the different concentration of ions across the cell membrane
the membrane potential of an unstimulated neuron is called the…
resting membrane potential
in a resting neuron, the plasma membrane separates ions on the inside of the cell from those on the outside. there is a net ____ charge on the inside of the membrane. this creates a voltage across the membrane of ____mV that is called the ____
negative, 70, resting potential
in a resting neuron, would the concentration of potassium ions be higher inside or outside the cell?
how do ions move across the cell membrane?
through ion pumps or diffusion through channels
when a stimulus is strong enough that the membrane depolarizes to the threshold, gates open on many channels, allowing ____ ions to rush into the cell. this sudden depolarization is called a ____
sodium, membrane potential
all cells have a membrane potential; however, only certain cells such as ____ and ____ have the ability to generate large changes in their membrane potential. These cells are called ____
neurons, muscle cells, excitable
what types of ion channels are present in the cell membrane? how are these channels opened?
ungated are always open, and gated are opened by chemicals or by threshold voltage
if a sufficiently strong stimulus causes depolarization to reach “threshold potential” it triggers a different type of response called an ____
action potential
in a neuron, an action potential can only be generated in the ____
the action potential is a non-graded, all or non-event; meaning…
The action potential is a non-graded, all or non event; meaning magnitude of the action potential is independent of the strength of the depolarizing stimulus that produced it, providing the stimulus reached threshold depolarization level.
which two types of voltage-gated ion channels contribute to the action potential?
Na+ first, K+ second
the ____, not their amplitude, codes for stimulus intensity in the nervous system
number of action potentials per second
what two factors affect the speed at which an action potential travels down an axon?
diameter of axon, and the presence of myelin
what is a synapse?
all junctions that control communication between a neuron and another cell
name the two general types of synapses?
electrical and chemical
one important function of the chemical synapse is to allow…
nerve impulses to travel in only one direction
the “motor division” of the PNS is divided into two functional divisions, called the ____ and ____ nervous systems
the somatic nervous system carries signals to ____
the autonomic nervous system carries signals to ____
cardiac and smooth muscle and glands
the somatic nervous system carries signals to ____
skeletal muscle
the autonomic nervous system consists of two divisions that act on body organs with ____
opposite effects
the sympathetic division causes a(n)…
activation of fight or flight
the parasympathetic division causes a(n)…
calming effect