Nervous System Part 1 Flashcards
two major parts of NS
CNS (Central Nervous System) & PNS (Peripheral Nervous System)
The CNS contains
Brain and spinal cord
The PNS contains
Cranial nerves and spinal nerves
basic structural and functional unit of the nervous system
Neuron
Neuron is composed of
cell body, dendrites, axon
core section of the neuron
cell body
part of neuron composed of protein and fatty substances
myelin sheath
gaps formed between the myelin sheath
Nodes of Ranvier
cell that surrounds neurons
Schwann cells
transmits information away from the cell body to adjacent neurons
Axon
clue: A = away
transmits information towards the cell body to adjacent neurons which receive information from axon terminals
Dendrites
20% body weight, 1400g in young adult, 1200g in elderly
Brain
Three main section of the brain
Cerebrum, cerebellum, brain stem
Part of brain responsible for reasoning, problem solving; judgment, thinking; 80% of brain
Cerebrum
Part of brain responsible for transmission of information from one side of the brain to the other; connects the two hemispheres of the brain
Corpus callosum
Part of brain responsible for memory, sensation, and pain impulses pass through this section; relay station for all sensation except smell
Thalamus
body’s smart control coordinating center; regulates pituitary gland, hunger, thermoregulation
Hypothalamus
maintains balance, posture, coordination
Cerebellum
The brainstem consists of the ______________, _______________, and _____________
Midbrain, pons, medulla oblongata
topmost part of the brainstem
Midbrain
center for auditory and visual reflexes
Midbrain
where cranial nerves III and IV originates
Midbrain
coordinates facial movements, hearing and balance
Pons
where cranial nerves V and VIII originates
Pons
where cranial nerves IX and XII originates
Medulla oblongata
terminal part of brain stem
medulla oblongata
Reflex centers for respiration, blood pressure, heart rate, coughing, vomiting, swallowing, and sneezing
medulla oblongata
Four lobes of cerebral hemisphere
frontal lobe, parietal lobe, occipital lobe, temporal lobe
concentration, abstract thought, information storage and motor function, decision-making and movement and recognition of smell
frontal lobe
Located in the frontal lobe. Motor control of speech
Broca’s area
Damage to Broca’s area. The inability to produce language (despite being able to understand language)
Expressive aphasia
involved in interpreting pain and touch in the body
parietal lobe
identify objects and understand spatial relationships— essential to a person’s awareness of body position in space, size and shape discrimination, and right-left orientation
parietal lobe
responsible for visual interpretation (vision)
occipital lobe
damage to occipital lobe that leads to inability of the person to read
Alexia
involved in auditory reception, speech/language; plays a role in memory of sound and music.
Temporal lobe
Located in the temporal lobe. Primarily involved in speech comprehension. It is the center for language development
Wernicke’s area
damage to Wernicke’s area
Receptive aphasia
fibrous connective tissues that cover the brain and spinal cord, provide protection, support, and nourishment.
Meninges
outermost layer; covers the brain and the spinal cord. It is tough, thick, inelastic, fibrous, and gray
Dura mater
middle membrane; an extremely thin, delicate membrane that closely resembles a spider web
Arachnoid mater
has cerebrospinal fluid (CSF) in the space below arachnoid mater
Subarachnoid space
fingerlike projections that absorb CSF into the venous system
Subarachnoid villi
innermost, thin, transparent layer that hugs the brain closely and extends into every fold of the brain’s surface
Pia mater
clear, colorless watery fluid that flows in and around the brain and spinal cord
CSF
produces CSF
choroid plexus
amount of CSF produced per day
approx 500ml/day
normal CSF pressure
70-180 mmHg
normal CSF glucose
50-80 mg/dL
normal CSF protein
20-50 mg/dl
normal CSF specific gravity
1.007
length of spinal cord
45 cm or 18 in
thickness of spinal cord
a finger
Spinal cord pathway for sensory (afferent)
clue: A = akyat
Ascending pathway
Spinal cord pathway for motor (efferent)
clue: E = exit
Descending pathway
Patient feels pain if neck is flexed forward
Nuchal rigidity
When patient is placed in supine, pain is felt upon straightening a flexed leg
Kernig’s sign
When neck is flexed forward, knee flexion follows
Brudzinki’s Sign
prolonged arching of back, with head and heels bent backward, and meningeal irritation
Opisthotonus
Inward flexion of upper and lower extremities
Decortication
Deconjugate movement of eyes
Doll’s eye sign
CSF leakage from ears
Otorrhea
CSF leakage from nose
Rhinorrhea
increased CSF leads to
Hydrocephalus, cerebral edema, increased ICP
Decreased glucose, and increased protein leads to
Meningitis/infection
Increased specific gravity leads to what?
FVD, DHN, Decreased CVP
Definitive test for meningitis
Lumbar tap
Patient’s position for lumbar tap
knee-chest, fetal position, side-lying, sitting/leaning forward
Patient should be flat on bed for ________ post lumbar tap to prevent spinal headache
6-8h
Cloudy CSF indicates
infection
Reddish or bloody CSF indicates
Subarachnoid hemorrhage
Trace the production of CSF from the choroid plexus to the subarachnoid space
Choroid plexus - lateral ventricle - 3rd ventricle - cerebral aqueduct - 4th ventricle - subarachnoid space
pH of CSF
slightly alkaline (7.30-7.36)