NERVOUS SYSTEM Flashcards
anything that can cause excitation or activation
stimulus
a wave of excitation transmitted through nervous
tissues (along neuron connections)
impulse
an automatic and involuntary response to change
reflex
is the primary functional cell of the nervous system. This
cell is highly excitable, which results in the rapid transmission of information
neuron
cell body
soma
are neuronal
processes that transmit electrical signals toward the cell body
dendrites
a neuronal process responsible in conducting electrical signals away from the
cell body
axon
conduct signals from receptors to the central nervous
system (CNS)
sensory
or afferent neurons
conduct signals from the CNS to effector organs such as muscles and glands
motor or efferent neurons
conduct signals from one neuron to another, and are
mainly confined to the CNS
interneurons or
association neurons
having only one process
unipolar neurons
having
one dendrite and one axon, and these are common in sensory system
bipolar neurons
are sensory neurons having their single dendrite and
axon fused resulting to a single process appearance
pseudounipolar neurons
having a number of dendrites and a single axon
multipolar
neurons
Supporting cells of the nervous system
neuroglia
are cells of the CNS that form the myelin
sheaths that surround axon of neurons
Oligodendrocytes
are cells of the CNS that regulate extracellular brain
fluid composition and promote tight junctions to form the bloodbrain barrier.
Astrocytes
are specialized macrophages of the CNS responsible in
removing damage neurons and infections.
Microglia
CNS cells that line the brain ventricles and
spinal cord central canal, and also help in forming choroid
plexuses that secrete cerebrospinal fluid (CSF).
Ependymal cells
peripheral nervous system (PNS) cells that
surround neuron cell bodies in ganglia (singular: ganglion; clusters
of neural bodies outside the CNS), and provide support and
nutrients.
Satellite cells
are cells of the PNS that are
wrap around portion of one axon to form myelin sheath.
Schwann cells or neurolemmocytes
- composed of the brain
and spinal cord - controls most of the functions of the body and mind
central nervous system (CNS)
composed of sensory neurons and motor
neurons, which are further divided based on their physiologic functions
peripheral nervous system (PNS)
receives and processes
sensory information, initiates responses, stores memories, and generates
thoughts and emotions
brain
is responsible in conducting
signals to and from the brain, and controls reflex activities.
spinal cord
The CNS is
covered by a connective tissue called
meninges
the thick
outermost layer composed of dense irregular connective tissue
dura mater or pachymeninx
the middle layer with thin filaments creating a weblike appearance
arachnoid
the innermost layer that directly covers the surface of the
brain
pia mater
is used to describe the combination
of pia mater and arachnoid
leptomeninx
the largest
part, that can be divided into several lobes
cerebrum
- located at the
back of the brainstem - functions in
coordination of muscle movements, maintaining posture, and balance
cerebellum
- connects the cerebral
hemispheres (right and left) with the spinal cord - functions as relay center, connecting the cerebrum and
cerebellum to the spinal cord for involuntary movements such as swallowing,
breathing, heartbeat, body temperature, digestion, and wake and sleep
cycles
brainstem
The surface of the cerebrum
in domestic mammals is increased by numerous foldings to form convex
ridges which are separated by furrows
gyri (gyrus: singular) & fissures or sulci (sulcus: singular)
for judgement,
foresight, and voluntary movement
frontal lobe
for comprehension of
language
parietal lobe
as the primary visual area
occipital lobe
for intellectual and emotional functions
temporal lobe
5 parts of spinal cord
- cervical part
- thoracic part
- lumbar part
- sacral part
- caudal or coccygeal part
the inner part, has letter H
appearance and composed mainly of nerve cell bodies
gray matter/substance
superficial part, composed predominantly of nerve fibers.
white
matter/substance
that controls voluntary movements
somatic nervous system
that controls involuntary movement
autonomic nervous system
for “fight or flight”
sympathetic division
for “rest and digest”
parasympathetic division
controls body temperature, reproductive
functions, eating, sleeping, and the display of
emotions.
forebrain
associated with vision, hearing, motor
control, sleep/wake, arousal (alertness), and
temperature regulation.
midbrain
controls functions outside conscious
control, such as breathing and blood flow.
hindbrain
are pairs of nerves that connect the brain to the
different parts of the head, neck, and trunk, providing motor and sensory supply
cranial nerves
cranial nerves
sensory type for smell
I - olfactory
cranial nerves
sensory type for vision
II - optic
cranial nerves
motor type for eye movement (3)
III - oculomotor
IV - trochlear
VI - abducens
cranial nerves
both sensory and motor type for facial touch, temperature, and pain
V - trigeminal
cranial nerves
both sensory and motor type for chewing, saliva production, and taste buds
VII - facial
cranial nerves
sensory type for maintaining equilibrium and hearing
VIII - vestibulocochlear
cranial nerves
both sensory and motor type for throat and tongue movement and swallowing
IX - glossopharyngeal
cranial nerves
both sensory and motor type for heart and lung signals
X - vagus
cranial nerves
motor type for neck muscle motor functions
XI - accessory
cranial nerves
motor type for tongue, chewing movement, and speech
XII - hypoglossal