Module 14 Nervous System Flashcards
Functions of the Nervous System:
- Sensory Input
- Motor Input
- Evaluation and Integration
- Homeostasis
- Mental Activity
EEG
electroencephalogram; record of the electrical activity of the brain
CNS
central nervous system; brain and spinal cord
PNS
peripheral nervous system; all neurons, nerves, ganglia, and plexuses outside the CNS; two divisions: sensory division- afferent nerves carry messages toward spinal cord and brain from sense organs, motor division- efferent nerves carry messages away from the spinal cord to muscles and organs
ANS
autonomic nervous system; aka visceral motor division; carries signals to glands and to cardiac and smooth muscle; involuntary; two divisions: sympathetic and parasympathetic
sympathetic division
arouses body for action and slows digestion so more available blood flow for other areas
parasympathetic division
calms the body, slowing down the heartbeat but stimulating digestion
neuron
nerve cells that receive stimuli and transmit impulses to other neurons or receptors in other organs; consists of a cell body, axons, and dendrites
dendrite
short, highly branched extensions that conduct impulses toward the cell body; the more dendrites the more impulses it can receive
axon
aka nerve fiber; carries impulses away from the cell body; constant diameter, but can range in length; covered in a myelin sheath (neurilemma) that enables impulses to travel faster
neurilemma
myelin sheath
neurotransmitters
stimulate or inhibit the receptor on a dendrite of another neuron or the cell of the muscle gland
examples of neurotransmitters:
- acetylcholine
- norepinephrine
- serotonin
- dopamine
- endorphins
plexus
group of nerves collected together
neuroglia
connective tissue cells that hold nervous tissue together; outnumber neurons 50:1
six types of neuroglia
In CNS: 1. astrocytes 2. oligodendrocytes 3. microglia 4. ependymal cells In PNS: 1. Neurolemmocytes (Schwann cells) 2. Satellite cells
blood-brain barrier
BBB; physical barrier between the capillaries that supply the CNS and most parts of the CNS;
Brain
3 major regions:
- cerebrum
- Brainstem
- cerebellum
cerebrum
80% of the brain and consists of 2 cerebral hemispheres; hemispheres connected by a bridge of nerve fibers called the corpus callosum
4 lobes of each hemisphere:
- frontal
- parietal
- temporal
- occipital
brainstem
includes: thalamus, pineal gland ,pons, fourth ventricle, and medulla oblongata (cardiac center, respiratory center, vasomotor center, and reticular formation)
cerebellum
most posterior area of the brain
gyrus
rounded elevation on the surface of the cerebral hemispheres
sulcus
groove on the surface of the cerebral hemispheres that separates gyri
CSF
cerebrospinal fluid; helps protect, cushion, and provide nutrition for the brain and spinal cord; inside ventricles
thalamus
receives all sensory impulses and channels them to the appropriate region of the cortex for interpretation;
hypothalamus
regulates: blood pressure, body temp, water and electrolyte balance, hunger and body weight, sleep and wakefulness, movement and secretions of the digestive tract
decussate
cross over like the arms of an X; thalamus decussates the impulses from the right side of the body to the left hemisphere and vice versa
cranial nerves
communicates between the brain and the rest of the body; 12 pairs
cauda equina
bundle of spinal nerves in the vertebral canal below the ending of the spinal cord
4 regions of the spinal cord:
- cervical
- thoracic
- lumbar
- sacral
meninges
3-layered covering of the brain a spinal cord; 3 layers:
- Dura mater
- Arachnoid mater
- Pia mater
arachnoid mater
weblike middle later of the three meninges; subarachnoid mater contains CSF
dura mater
hard, fibrous outer layer of the meninges
pia mater
delicate, inner layer of the meninges; attached to the surface of the brain and spinal cord; supplies nerves and blood vessels that nourish the outer cells of brain and spinal cord
dementia
symptoms not a disease; symptoms: short-term memory loss, inability to solve problems, confusion, inappropriate behavior (such as wandering), and impaired cognitive function
Alzheimer disease
most common form of dementia; affects 10% of the population over 65 and 50% over 85
vascular dementia
second most common form of dementia; due to lack of oxygen
delirium
sudden onset of disorientation, an inability to think clearly or pay attention; mental state not a disease
cognition
process of acquiring knowledge through thinking, learning, and memory
empathy
ability to place yourself into the feelings, emotions, and reactions of another person
sympathy
appreciation and concern for another person’s mental and emotional state
stroke
AKA cerebrovascular accident (CVA); occurs when blood supply to a part of the brain is suddenly interrupted and thus brain cells are deprived of oxygen so some die and others are left badly damaged
2 types of stroke:
- Ischemic strokes- 90% of all strokes caused by atherosclerosis, embolism, or microangiopathy
- hemorrhagic strokes (intracranial hemorrhage)- occurs when blood vessel in brain bursts or when a cerebral aneurysm or arteriovenous malformation (AVM) ruptures
hemiplegia
paralysis of one side of the body
hemiparesis
weakness of one side of the body
transient ischemic attacks
aka TIAs; short-term, small strokes with symptoms lasting less than 24 hours; most frequent cause is a small embolus
Cerebral palsy
CP; motor impairment resulting from brain damage in an infant or young child, regardless of cause or effect on child
spastic
pertaining to tight muscles that are resistant to being stretched; can become overactive when used and produce clonic movements
athetoid
pertaining to difficulty in controlling and coordinating movements, leading to involuntary writing movements in constant motion
ataxic
pertaining to a poor sense of balance and depth perception, leading to a staggering walk and unsteady hands
epilepsy
chronic disorder in which clusters of neurons in the brain discharge their electrical signals in an abnormal rhythm; this disturbed electrical activity (a seizure) can cause strange sensations and behavior, convulsions, and loss of consciousness
partial seizure
occur when epileptic activity is in one area of the brain only
absence seizures
aka “petit mal”; most common in ages 4-14; child stares vacantly for less than 10 seconds; recovery is quick
tonic-clonic seizures
aka “grand mal”; person experiences LOC, breathing stops, muscles stiffen, jaw clenches; this “tonic” phase lasts 30-60 seconds; followed by “clonic” phase in which they whole body shakes with a series of violent, rhythmic jerking of the limbs.; last for 1-3 minutes and then consciousness returns
LOC
loss of consciousness
febrile seizures
triggered by a high fever in kids aged 6 months - 5 years
status epilepticus
continuous seizure lasting more than 10 minutes or 3 recurrent seizures without the person regaining consciousness between
cataplexy
sudden loss of muscle tone with brief paralysis; happens with narcolepsy
brain tumors
most often secondary tumors that have metastasized from cancers in the lung, breast, skin, or kidney
cephalalgia
headaches
chorea
involuntary, irregular spasms of limb and facial muscles
Creutzfeldt-Jakob disease
progressive incurable neurological disease that is thought to be caused by an abnormal infectious protein called a prion
traumatic brain injury
TBI; over 1mil people seen per year for blows to the head; 50k-100k will have prolonged problems
coup
injury to the brain occurring directly under the skull at the point of impact
contrecoup
injury to the brain occurring at the point opposite to the original point of contact
contusion
bruising of a tissue including the brain
concussion
mild head injury; feel dazed or have a period of confusion or even lose consciousness; repeated concussions have a cumulative effect
ADL
activities of daily living
subdural hematoma
bleeding into the subdural space outside the brain; associated with closed head injuries and bleeding from broken veins, ex. roller-coasted rides
epidural hematoma
pooling of blood in the epidural space outside the brain; associated with fracture skull and bleeding from an artery that lies in the meninges
meningitis
inflammation of the meninges covering the brain and spinal cord
meningioma
tumor originating in the arachnoid cells of the meninges, most commonly overlying the cerebral hemispheres
Bell palsy
disorder of the 7th cranial nerve (facial), causing a sudden onset of weakness or paralysis of facial muscles on one side of the face
hematoma
collection of blood that has escaped from the blood vessels into tissue
demyelination
destruction of an area of ht myelin sheath, can occur in the PNS caused by inflammation, B12 deficiency, poisons, and some medication
Guilllain-Barre syndrome
disorder of the peripheral nerves in which the body makes antibodies against myelin, leading to loss of nerve conduction, muscle weakness, and paresthesia (changes in sensation)
multiple sclerosis
MS; most common demyelination disorder; chronic, progressive disorder; thought to be autoimmune; onset 18-35 years and is more common in women
encephalitis
inflammation of brain cells and tissues
cervical spondylosis
disorder in which the discs and vertebrae in the neck degenerate, narrow the spinal canal, and compress the spinal cord and/or nerve roots
poliomyelitis
polio; acute infectious disease, occurring mostly in children; destroys motor neurons; progressive muscle paralysis
amyotrophic
pertaining to muscular atrophy
myel-
spinal cord
spondylosis
degenerative arthritis of the spine
neuropathy
used here as any disorder affecting one or more peripheral nerves
carpal tunnel syndrome
median nerve at the writs is compressed between the wrist bones and a strong overlying ligament; numbness, pain, tingling of the thumb side of the hand
shingles and chicken pox
infection of the peripheral nerves
myasthenia gravis
immune system produces antibodies that attack the acetylcholine receptors on the muscle cells; symptoms: drooping eyelids, weak eye muscles, causing double vision, difficulty talking and swallowing
spinal tap
aka lumbar puncture (LP); needle inserted through the skin, back muscles, spinal ligaments, epidural space, dura mater, and arachnoid mater into the subarachnoid space to aspirate CSF
3 types of CVA’s (strokes)
- ischemic
- intracerebral
- subarachnoid
kinesi/o
movement
lept/o
thin, slender
lex/o
word, phrase
radicul/o
nerve root
sten/o
strength
thec/o
sheath
ton/o
tension
-asthenia
weakness, debility
-esthesia
feeling
-lepsy
seizure
-paresis
partial paralysis
-phasia
speech
-plegia
paralysis
-taxia
coordination
pachy-
thick
ot/o
ear
salping/o
tubes (eustachian)
staped/o
stapes
ambly/o
dull, dim
choroid/o
choroid
dacry/o
tear, lacrimal apparatus
dacryocysto/o
lacrimal sac
glauc/o
gray
goni/o
angle
presby/o
old age
vitr/o
vitreous body of the eye
-opia, -opsia
vision
-tropia
turning
-acusia, -cusis
hearing
cerebrovascular disease
process that involves any functional abnormality of the cerebrum that is caused by disorders of the blood vessels in the brain; most commonly associated with a stroke
seizure
any medical condition characterized by sudden changes in behavior or consciousness as a result of uncontrolled electrical activity in the brain
epilepsy
chronic or recurring seizure disorders/activity
