nervous system Flashcards
Function of the nervous system?
- it receives messages from stimuli all over the body (sensory input)
- The brain interprets the messages (integration)
- The brain responds to the message and caries out activities inside and outside of the body (motor output)
- The brain is the seat of intellect, reasoning, and personality.
neuron (nerve cell)
the fundamental or structural unit of the nervous system. Neurons are found in the brain, spinal cord, and peripheral nerves. They are responsible for conducting electrical impulses throughout the body in response to an external or internal stimulus
sensory neurons
conduct electrical signals from the body to the bran and spinal cord. Also called Afferent neurons
motor neurons
receive electrical impulses from the brain and spinal cord and communicate these impulses to the body. also known as efferent, these carry messages to the muscles and glands
nerves
when many neurons from a bundle of fibers
3 parts of a neuron
- cell body
- dendrites
- axon
cell body
where the nucleus is
dendrites
nerve fibers which extend from the cell body and receive messages from other neurons
axon
single nerve fibers which are long and thin and carries impulses away from the cell body toward the axon terminal. Some are 1 ml others can be over 3 feet.
myelin sheath
many axons have a lipid covering
Functions of the myelin sheath
- speeds up the rate of impulse transmission
2. protects and insulates the axon
synapse
this contact point where one neuron communicates with another.
synaptic cleft
between nerve cells synapses is a microscopic spaces between them
neurotransmitters
special chemicals. located at the end of each axon, allow the nerve impulses to pass from one neuron to another. Can follow many diffrent routes.
frontal lobe
-emotions, personality, moality, intalect, reasoning, speech
parietal lobe
sensory, motor, pain, heat, touch
temporal lobe
hearing
occipital lobe
vision
Brain
a mass of tissue protected by membranes and the skull
cerebrum
largest and highest section of the brain. arranged in convolutions
convolutions
folds that help speed conduction of electrical impulses
cerebellum
-2nd largest portion of brain
responsible for muscle tone, equilibrium, walking and dancing
brainstem
midbrain, pons, medulla oblongata
PT
Physical therapy
OT
occupational tjherapy
ST
Speech therapy
-plegia
paralysis
epi
over, above,upon
quadri
4
cerebro
brain
rrhagic
bursting forth
trophy
growth
esthesia
sensation- feeling
lepsy
seizure
cranio
skull
algia
pain
meningo
meninges
encephalo
brain
phasia
speech
what is the brain
a mass of tissue protected by membranes and the skull
how much of your bllod is circulating through your brain at a time
20-25%
How are brain caprilaries diffrent from body capillaries
they are impermeable to many substances. this property of impermiability has been termed blood-brain barrier
what can pass through the barrier
water, glucose, amino acids, alchohol, fats, nichotine, respiratory gasses and anesthetics. some antibiotics and pain meds can go through
meninges
the membranes that cover and pprotect the brain and spinal cord
dura mater
the thick, tough outer layer.
arachnoid membrane
middle layer, weblike and delicate subarachnoid space-filled with cerebrospinal fluid
pia mater
the innermost layer- is closely attached to the brain and spinal cord and nourishes the nerve tisue
ventricles
4 holllow spaces that connect with each other and with th space under the arachnoid membrane. They are filled with cerebrospinal fluid (CSF) the circulates continuously
what is the 3 functions of cerebrospinal fluid
- it is a shock absorber to protect the brain and spinal cord
- carries nutrients to parts of the brain
- caries away metabolic products and wastes
what organs are involved in the central nervous system
brain and spinal cord
what is involved in the peripheral nervous system
12 cranial nerves, 31 spinal nerves
what are the 2 parts of the peripheral nervous system
somatic and autonomic nervous system
are somatic muscles voluntary
yes
are autonomic muscles voluntary
no- involuntary- heart and visceral
what are the 3 parts of the autonomic system
enteric, sympathetic, parasympathetic
enteric
controls all digestive functions
sympathetic
fight or flight Hr up, RR up, BP up digestive down
parasympathetic
rest and digest HR down RR down BP down Digestive up
peripheral nervous system
liaison between CNS and the rest of the body.
epilepsy
seizure disorder
- a brain disorder asscoiated with abnormal electrical impulses in neurons of the brain
causes of epilepsy
brain injury, brain trama, abnormal tissue (scaring), tumors, toxins, infections, or ideopathic, drug use
symptoms of epilepsy
loss of consciousness, convulsios, hypersalvation, loss of body functions
what to do for epilepsy
- remain calm and call 911
- help person to floor and onto their side
- move furniture so they do not hit anything
- place head on something soft.
cerebrovascular accident
- stroke or CVA
- occurs when the blood flow to the brain is impaired. This results in lack of oxygen to the brain and destruction of tissue
causes of stroke
hemorrhagic, ischemic
hemorrhagic
a vessel ruptures and causes bleeding into the brain (often due to high blood pressure or weakness in a vessel)
ischemic
an embolus (blood clot or fat) blocks a vessel. This causes cells to die because blood flow is blocked
symptoms of a stroke
changes in LOC, confusion, paralysis, dysphagia, aphasia, incontinence (inability to hold urine
WHat does fast stand for
F-ace drooping
A-rm weakness
S-peech difficulty
T-ime to call 911
multiple sclerosis
a chronic, progressive, disabling condition resulting from a degeneration of the myelin sheath in the centeral nervous system
impairments of multiple sclerosis
motor- difficulties with balance, gait (ability to walk), fatigue, coordination, movement, tremors, muscle spasms, dysphagia.
sensory- numbness, tingling, pain, loss of vision/ hearing
