Nervous system Flashcards
These neurons have usually have one axon and several dendrites
motor neurons
transmits signals a long distance from the neuron to the area to be activated
axon
axon is covered with a insulating fatty layer called a
myelin sheath
are short and unsheathed part of the neuron
Dendrites
Motor neurons cause
muscle contractions
control secretions from glands and organs
These neurons do not have true dendrites. They are attached to sensory receptors and transmit impulses to the central nervous system
Sensory neurons
Sensory neurons are attached to
sensory receptor
NERVE RECEPTORS > __________ NEURONS > _______NEURONS > _________NEURONS
Sensory, Inter-, Motor
are located entirely within the central nervous system. They intercept the
impulses from the sensory neurons and transmit the signals to the motor neurons.
Interneurons
, only found on peripheral nerves which can regenerate
Schwann cells
a fatty layer of insulation on some
nerve fibers
Myelin sheath
These nerves conduct impulses to the central nervous system
AFFERENT nerves
These nerves conduct impulses to the muscles, organs, and glands.
EFFERENT nerves
A bundle of nerve fibers is simply called a
nerve
Nerve impulses are transmitted via branches called
synapses
The synapses are __________… hooking dendrites and axons from one neuron to another.
connectors
The number of synapses
influences
transmission
the central nervous system receive impulses, process the information, and respond with the appropriate action
brain and spinal cord
_____ _________ of the brain and spinal cord consists of unsheathed nerve fibers (cannot be regenerated if damaged) in the cortex or surface layer
Gray matter
Gray matter of the brain and spinal cord consists of unsheathed nerve fibers n the
cortex or surface layer
makes up the internal structure, and consists of myelinated nerve fibers.
white matter
The brain and spinal cord are
enclosed by 3 membranes,
collectively known as the
meninges
the outside membrane is the
dura mater
the middle membrane is the
arachnoid
the inside membrane is the
pia mater
governs all sensory and motor
activity which includes sensory perception, emotions, consciousness, memory, and voluntary movements
cerebrum
cerebrum Taking up of the _____ brain’s weight
7/8
The cerebrum is divided into the l______ & _____hemispheres
left and right
cortex is arranged in bulging folds, each one called a
gyrus
the furrows, each one called a
sulcus
The surface of the brain is called the
Cortex
The cortex is also divided into 4 lobes that correspond to the overlying bones of the skull:
Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
This lobe specializes in motor activity,
personality, and speech
Frontal lobe
This lobe is where s where language, temperature, pressure, touch are interpreted;
Parietal lobe
This lobe contains centers for hearing, smell, and language input
Temporal lobe
This lobe specializes in vision
Occipital lobe
the second largest part of the brain which contains nerve fibers that connect it to every part of the central
nervous system.
cerebellum
This part of the brain coordinates voluntary and involuntary patterns of movements. It also adjusts muscles to automatically maintain posture
cerebellum
refers to the thalamus, epithalamus
and hypothalamus.
diencephalon
the relay center for all sensory impulses except olfactory (sense of smell) and motor areas of the cortex.
thalamus
regulates behavior and emotional expression, body temperature,
and many metabolic activities
hypothalamus
hypothalamus is Attached to the ____________ ______, it also controls
hormonal secretions of this gland.
pituitary gland
brainstem consists of 3 structures:
gray matter of the midbrain
white matter of the pons
medulla oblongata
control visual reflexes and sense of hearing
gray matter of the midbrain
plays a role in regulating visceral (internal organ) control.
white matter of the pons
connects the rest of the brain to the spinal cord. It regulates breathing, swallowing, coughing, sneezing, vomiting, heartbeat, and blood pressure.
medulla oblongata
The spinal cord has ____ segments
31
__ cervical segments to the vertebrae; ____ thoracic segments
___ lumbar segments
___ sacral segments
__ coccygeal segment.
8
12
5
5
1
The 44 cm long spinal cord is shorter than the ________ ________
spinal column
At each segment of the spinal cord, left and right pairs of sensory and motor nerves branch out and connect to the
Peripheral NS
A colorless fluid is produced in the ventricles of the brain; it surrounds the brain and spinal cord which cushions the brain and cord from
shocks that could cause injury
Cerebrospinal fluid
Cerebrospinal fluid is maintained at a level around ____-___ cup.
1/2 - 2/3
The network of nerves branching out
throughout the body from the brain and spinal cord is called the
peripheral nervous system.
there are _____ pairs of cranial nerves that attach to the brain:
12
This cranial nerve carries sensory input for smell
olfactory nerve
This cranial nerve carries sensory input for vision
optic nerve
This cranial nerve controls muscles
of the eye and eyelid
oculomotor nerve
This cranial nerve controls the eyeball
trochlear nerve
This cranial nerve controls the face, nose, mouth, forehead, top of head, and jaw.
trigeminal nerve
This cranial nerve controls muscles of the face and scalp, and part of the tongue for sense of taste.
facial nerve
This cranial nerve provides sensory
input for hearing and equilibrium.
auditory or cochlear nerve
This cranial nerve controls saliva, swallowing, and taste.
glossopharyngeal nerve
This cranial nerve is the longest cranial nerve, extending to and controlling the heart, lungs, stomach, and intestines.
vagus nerve
This cranial nerve permits movement of the head and shoulders.
accessory nerve
This cranial nerve controls the muscles of the tongue.
hypoglassal nerve