Nervous system I Flashcards
system is all about communication. It controls homeostasis by monitoring what is happening in the body and the outside environment, analyzing the information, and initiating a response if one is needed.
The Nervous
System
can be very long
(measuring a meter or more), as it
may start at the tip of your finger
and end at your spinal cord.
neuron
The more \_\_\_\_\_ the neuron has, the more information it can process. The dendrites branch to make multiple connections and form precise pathways
Dendrites
contains the
nucleus and organelles
for protein synthesis.
body
vesicles carry the neurotransmitter down the next part of the neuron (the axon) to the synaptic knob at the end.
Axonal transport
is only intermittently
covered with a myelin
sheath
Axon.
leaves the
neuron body at the axon
hillock, also called the
trigger zone.
Axon
They have multiple dendrites and an axon that may or may not have a collateral branch.
Multipolar neurons
This is the most
common type of neuron
in the brain and spinal
cord.
Multipolar neurons
Have one dendrite and one axon. They can be found in the nasal cavity, the retina of the eye, and the inner ear.
Bipolar neurons
They are sensory neurons in the body, located in areas such as the skin, organs, and other areas where bipolar neurons are not present.
Unipolar neurons
These cells form the
myelin in the CNS.
Oligodendrocytes
They produce
cerebrospinal fluid
(CSF).
Ependymal cells
Are the most numerous
neuroglia in the CNS.
Astrocytes
They have a somewhat
star-shaped
appearance and have
several functions.
Astrocytes
Form the myelin in the
PNS.
Schwann cells
Surround neuron cell
bodies in the ganglia of
the PNS.
Satellite cells
They help regulate the
chemical environment
of the neurons.
Satellite cells
are small macrophages in the CNS that look for cell damage, debris, and pathogens. If these items are found, it is the microglia’s responsibility to remove them.
Microglia
They constantly
wander through the
CNS as an important
line of defense.
Microglia
Form the bloodbrain barrier, regulate composition of CSF, and form scar tissue
Astrocytes
The brain and spinal
cord are covered by
Meninges
(“tough
mother”) - the most
superficial layer of the
meninges
Dura mater
(“spider-like mother”)
- deep to it is a very
delicate, web like layer.
Arachnoid mater
(“affectionate
mother”) - tight to the
brain and spinal cord.
Pia mater
Cerebrospinal Fluid
Is made by ependymal
cells lining cavities in
the brain called
ventricles.
Is made by ependymal
cells lining cavities in
the brain called
ventricles.
Cerebrospinal Fluid
is a clear, colorless fluid that circulates between the ventricles and the subarachnoid space to bathe the brain.
Cerebrospinal Fluid
A bed of capillaries
(small blood vessels),
called a
choroid plexus
Largest subdivision,
divided into two
hemispheres.
Cerebrum
Characterized by gyri
and sulci
Cerebrum
Contains premotor and
primary motor areas.
Frontal lobe
Motivation and aggression
are located here.
Frontal lobe
Contains Broca’s area for
language.
Frontal lobe
Sense of touch is located
here.
Parietal lobe
Higher-level processes for
math and problem solving
are also located here.
Parietal lobe
Sense of hearing is located
here.
Temporal lobe
Contains Wernicke’s area
for language.
Temporal lobe
Located deep to the
cerebrum.
Diencephalon
Switching station for
incoming sensory
messages.
Thalamus
Sends message to
appropriate lobe of the
cerebrum.
Thalamus
Monitoring station for
maintaining homeostasis.
Hypothalamus
Regulates temperature.
Hypothalamus
Performs autonomic and
endocrine functions.
Hypothalamus
Located in the cranial
cavity inferior to the
diencephalon and anterior
to the cerebellum.
Brainstem
Appears as a hook
Midbrain
Has colliculi for vision and
hearing.
Midbrain
Appears as a bulge
between the midbrain and
the cerebellum.
Pons
Serves as a bridge to the
cerebellum for efferent
motor messages.
Pons
Most inferior part of the
brainstem.
Medulla oblongata
Motor messages cross
sides at the pyramids.
Medulla oblongata
Contains centers to
regulate heart rate, blood
pressure, respiratory rate,
and blood vessel diameter.
Medulla oblongata
Groups of cell bodies
located throughout the
brainstem.
Reticular formation
Determines if sensory
messages will be
consciously perceived by
the cerebrum.
Reticular formation
Responsible for sleep-wake cycle.
Reticular formation
Receives input of body-part location.
Cerebellum
Uses that information in fine-tuning efferent motor messages to maintain coordination, balance, and smooth motions.
Cerebellum
is a solid cylindrical structure in the vertebral cavity that extends from the foramen magnum to the inferior margin of the first lumbar vertebra.
Spinal Cord
is a bundle of nerve roots
extends from L1 to S5 in the
vertebral cavity.
cauda equina
is the gray matter is in
the center of the cord and
arranged in an “H,”
Horns
Is a bundle of nerve fibers with an arrangement and connective tissues similar to those of the muscle fibers of a muscle.
Nerve
nerves connect
directly to the brain.
Cranial Nerves
Cranial nerve sensory for smell
Olfactory nerve
Cranial nerve Sensory for vision
Optic nerve
Motor for eye
movement
Oculomotor
nerve, Trochlear nerve, Abducens nerve
Sensory for pain, touch, and temperature for the eye and lower and upper jaws Motor for muscles for chewing
Trigeminal nerve
Sensory for taste
Motor for facial
expression
Facial nerve
Sensory for hearing
and equilibrium
Auditory
(vestibulocochlear)
nerve
Sensory for taste
Motor for
swallowing
Glossopharyngeal
nerve
Sensory and motor for organs in the thoracic and abdominal cavities Motor for larynx
Vagus nerve
Motor for the trapezius, sternocleidomastoid, and muscles of the larynx
Accessory nerve
Motor for the tongue
Hypoglossal
nerve
carry sensory and motor messages, so they are composed of both unipolar and multipolar neuron axons (bipolar neuron axons are found only in some cranial nerves).
spinal nerves
carries efferent messages. These messages go out primarily to thoracic and abdominal viscera as well as the smooth muscle of blood vessel walls.
Autonomic Nervous System
These messages are
involuntary, meaning they
are not under conscious
control.
Autonomic Nervous System
The autonomic nervous system is further
divided into two parts
the sympathetic
and parasympathetic divisions
carries
messages to prepare the body for
physical activity, sometimes
called fight or flight.
sympathetic division
carries messages for everyday body maintenance functions such as digestion and elimination of waste. It has a calming effect on the body. You might think of this as a rest-and-veg effect.
parasympathetic division
Local potentials start at a dendrite and travel toward the trigger zone. They are graded, decremental, and reversible, and may be excitatory or inhibitory.
Nerve Impulses
is an involuntary,
predictable motor
response to a stimulus
without conscious thought.
Reflexes
memory results from chemical changes in the neuron. This results in cellular changes, including the growth of dendrites and the formation of new connections.
Long-term memory
is the flow of electricity along an axon of a
neuron in one direction—from the trigger zone to the synaptic knob.
Action Potential
the dendrite of a neuron receiving the stimulus (a chemical, heat, light,
or mechanical disturbance)
Receptor
a neuron that has an action potential carrying the signal to the CNS
Afferent neuron (sensory):
either the brain or spinal cord, where the signal is received
from the afferent neuron and conducted to a motor neuron. This may or may not
require an interneuron.
Integrating center:
a neuron that has an action potential carrying a signal
away from the CNS.
Efferent neuron (motor)
the structure causing the effect. If this structure is skeletal muscle, it is
called a somatic reflex. If the effector is a gland or smooth muscle, it is called an
autonomic reflex.
Effector
Immediate memory lasts for a few seconds.
Immediate Memory
Short-term memory lasts a few seconds to a few hours.
Short-Term Memory
may last a lifetime and is not limited as
to the amount of information it can hold.
Long-Term Memory
This area is used to interpret incoming language by sorting out
what the incoming sounds are.
Wernicke’s Area
This area is used to find the words for outgoing language.
Broca’s Area
A procedure used to collect and analyze cerebrospinal
fluid (CSF) surrounding the brain and spinal cord
Lumbar puncture (spinal tap)
A procedure that assesses the conduction of nerve
impulses along peripheral nerves by using electrodes
to stimulate the nerve while reading the conduction
of the impulse as it reaches its end point
Nerve conduction study (NCS)
commonly called a stroke,
happens when part of the
brain dies due to a lack of
blood supply.
Cerebrovascular accident (CVA)
is a progressive,
irreversible disease of the
brain that is characterized
by dementia.
Alzheimer’s disease
is a genetic disease that
destroys brain cells
responsible for movement
and coordination.
Huntington’s disease
is a degenerative disorder of the brain characterized by tremors and slow, uncoordinated movements.
Parkinson’s disease
is a disease characterized
by demyelination of the
axon
Multiple sclerosis (MS)
is the loss of muscle function due to an interruption in the pathway between the brain and muscles.
Paralysis
is a condition resulting in
the buildup of excess
cerebrospinal fluid in the
brain.
Hydrocephalus
is a condition that is characterized by recurring seizures caused by a misfiring of electrical signals in the brain.
Epilepsy
is characterized by a group of symptoms that occur following an injury to the brain in children before the age of 5 years old.
Cerebral palsy
cell bodies and
unmyelinated fibers
Gray matter
unmyelinated fibers
White matter
clusters of cell bodies
within the white matter of the
central nervous system
Nuclei
collections of cell
bodies outside the central
nervous system.
Ganglia
Carry impulses from the
sensory receptors
Sensory (afferent) neurons
Carry impulses from the
central nervous system
Motor (efferent) neurons
characterized by a series of grooves
and folds
Cerebrum
Grooves are called
sulci (sulcus)
Folds called
gyri (gyrus)
its
purpose is to give extra surface
area.
gyri
separates
the cerebrum into right and left
hemisphere
Longitudinal fissure
a white librous band; deep to the fissure and keeps the right and left hemispheres connected; allows the left and right hemisphere to communicate.
Corpus callosumis
superficial part of the cerebrum; composed of gray matter; where most of the brain's dendrites and cell bodies are located; it is where conscious thought and voluntary actions arise.
Cortex
is a serious inflammation of
the meninges caused by viruses or
bacteria often acquired through a
respiratory, throat or ear infection.
Meningitis
is a test that can be
done to look for the presence of a
pathogen in the cerebrospinal fluid (CSF)
Lumbar puncture
carry
messages to the brain
Axons in ascending columns
carry
messages away from the brain
Axons in descending columns
is the connective tissue
surrounding an axon of an individual
neuron
Endoneurium
are bundled to form a nerve,
which is surrounded by epineurium
Fascicles
cause blood
vessels to the heart and skeletal muscles
to dilate to increase blood flow
Efferent Messages
the flow of electricity begun by stimulating the dendrite of a neuron. It starts with the opening of an NA+ channel on the membrane of a dendrite.
Local potential
a stimulus
depolarizes the neuron’s
membrane
Depolarization
- Smooth muscle regulation
- Heart and blood pressure
regulation - Regulation of glands
- Digestive system regulation
Autonomic reflexes
Activation of skeletal muscles
Somatic reflexes
is any language deficit
resulting from damage to either
Wernicke’s or Broca’s area.
APHASIA
TYPES OF PARALYSIS which affects only
one arm or leg
Monoplegia
TYPES OF PARALYSIS which affects one
arm and one leg on the same side
of the body
Hemiplegia
TYPES OF PARALYSIS which affects booth
of the legs
Paraplegia
TYPES OF PARALYSIS which affects both of the arms
and both of the legs.
Quadriplegia or tetraplegia
develops at the time of birth or at some point afterward, which can affect individuals of all ages and may be caused by injury or disease
Acquired hydrocephalus
s present at birth and maybe caused by either events or influences that occur during fetal development, or genetic abnormalities
Congenital hydrocephalus
