Chapter 25 - **Neurological System Flashcards
Afferent
sensory
efferent
motor
Function of the meninges and CSF
protect the CNS
Cerebral Cortex
cerebrums outer layers of nerve cell bodies
Is the cerebral cortex grey or white matter?
grey - it lacks myelin
Myelin
white insulation on the axon that increases conduction velocity of nerve impulses
Cerebrum
centre for higher functions - thought, memory, reasoning, sensation, voluntary movement
Frontal Lobe
personality, behaviour, emotions, intellectual function
Precentral gyrus
initiates voluntary movement
Parietal Lobe
contains postcentral which is primary area of sensation
Occipital Lobe
visual reception
Temporal Lobe
auditory reception
Wernicke’s Area
speech comprehension - when damaged a person hears sound but it has no meaning
Broca’s Area
speech production - injury leads to inability to speak, person can still understand language
Basal Ganglia
bands of grey matter deep in the cerebrum that control automatic associated movements of the body
Thalamus
main relay station
Synapses
sites of contact between two neurons
Hypothalamus
major control centre - controls temp, HR, BP, sleep, pituitary gland, coordination of ANS and emotions
Cerebellum
-motor coordination and voluntary movements
-balance
-muscle tone
Midbrain
-most anterior part of brain stem
-merges with thalamus and hypothalamus
-contains motor neurons
Pons
ascending and descending fibre tracts
Medulla
-continuation of spinal cord
-autonomic centres (respiratory, cardiac, GI functions)
-nuclei for CN VIII-XII
-pyramidal decussation occurs here
Pyramidal Decussation
crossing of motor fibres
Crossed Representation
feature of nerve tracts - left cerebral cortex receives and controls the right side of the body and vice versa
Spinothalamic Tract
contains sensory fibres that transmit sensation of pain, temperature, crude or ligh touch
Posterior (Dorsal) Columns
conduct sensations of position, vibration, fine touch
Position (Proprioception)
sense of where your body parts are in relation to each other (without looking)
Vibration
ability to feel vibrating objects
Vibration
ability to feel vibrating objects
Stereognosis
finely localized touch, ability to identify objects without looking
Homonculus
“little man” responsible for sensation is particular body parts
Corticospinal Fibres
mediate voluntary movement, 10% don’t corss
Extrapyramidal Tracts
all the motor neurons originating in the motor cortex, basal ganglia, brain stem, spinal cord that are outside the pyramidal tract
Cerebellar System
coordinated movement, maintains equilibrium, posture
Upper Motor Neurons
complex of all the descending motor fibres that influence or modify lower motor neurons
Where are upper motor neurons located?
in the CNS
Examples of Upper Motor Neurons
-corticospinal
-corticobulbar
-extrapyramidal
Upper Motor Neuron Diseases
-cerebrovascular accident
-cerebral palsy
-multiple sclerosis
Lower Motor Neurons
located mostly in PNS - funnels neural signals and provides direct contact with muscles
Examples of Lower Motor Neurons
-cranial nerves
-spinal nerves
Examples of Lower Motor Neuron Diseases
-spinal cord lesions
-polio
-ALS
Deep Tendon Reflexes
myotatic - ie. knee jerk
Superficial Reflexes
ie. corneal reflex or abdominal reflex
Visceral Reflex
ie. pupillary response, accomodation
Pathological Reflexes
-abnormal
-ie. Babinski reflex
Name all 12 cranial nerves: (hint: oh, oh, oh to touch and feel very good velvet, such heaven!)
I - olfactory
II - optic
III - oculomotor
IV - trochlear
V- trigeminal
VI - abducens
VII - facial
VIII - vestibulocochlear
IX - glossopharyngeal
X - vagus
XI - spinal
XII - hypoglossal
What are the types of cranial nerves? (hint: some say marry money, but my brother says big brains matter most!)
olfactory - sensory
optic - sensory
oculomotor - motor
trigeminal - both
abducens - motor
facial - both
vestibulocochlear - sensory
glossopharyngeal - both
vagus - both
spinal - motor
hypoglossal - motor
Olfactory Nerve (I)
smell
Optic Nerve (II)
vision
Oculomotor Nerve (III)
MOTOR - extraocular movement, opening of eyelids
PARASYMPATHETIC - pupil constriction, lens shape
Trochlear Nerve (IV)
downward and inward movement of the eye
Trigeminal Nerve (V)
MOTOR - muscle of mastication
SENSORY - sensation of face, scalp, cornea, mucous membranes of mouth and nose
Abducens Nerve (VI)
lateral movement of the eye
Facial Nerve (VII)
MOTOR - facial muscles, closing of eyes, labial speech, closing mouth
SENSORY - taste on front 2/3 of tongue
Vestibulocochlear Nerve (VIII)
hearing and equilibrium
Glossopharyngeal Nerve (IX)
MOTOR - pharynx (phonation and swallowing)
SENSORY - taste on posterior 1/3 of tongue, gag reflex
PARASYMPATHETIC - parotid gland, carotid reflex
Vagus Nerve (X)
MOTOR - pharynx and larynx (talking and swallowing)
SENSORY - sensation from carotid body, carotid sinus, pharynx, viscera
PARASYMPATHETIC - carotid reflex
Spinal Nerve (XI)
trapezius and sternomastoid muscles
Hypoglossal Nerve (XII)
tongue movement
How many pairs of spinal nerves are there?
31
What type of nerves are spinal nerves?
mixed (sensory and motor)
Dermal Segmentation
the cutaneous distribution of the various spinal nerves
Dermatome
circumscribed skin area that is supplied mainly from on segment through a spinal nerve
What controls motor activity in newborns?
medulla and spinal cord
Do babies have myelinated neurons?
no
What order do infants neurons become myelinated in?
proximal to distal - head, neck, trunk, extremities
What order do infants gain motor control?
lifting head, lifting head and shoulders, rolling over, moving arm, using hands, walking
Hemorrhagic Stroke
occurs when a blood vessel in the brain ruptures and causes bleeding
Ischemic Stoke
blood clot blocks blood vessel in the brain
What are the most common stroke symptoms:
-sudden weakness in face, arms, or legs (esp. on one side of body)
-sudden confusion or dysphagia
-sudden trouble walking, dizziness, loss of balance
-sudden change in vision
-sudden severe headache
What are less common stroke symptoms?
-sudden N&V
-brief LOC + fainting
FAST acronym:
Face - drooping?
Arms - can raise both?
Speech - slurred?
Time - call 911 ASAP
Syncope
sudden loss of strength and a temporary loss of consciousness due to lack of blood flow or low BP
Paresis
weakness of voluntary movement
Dysmetria
inability to control ROM
Paraesthesia
an abnormal sensation such as burning or tingling
Dysphagia
difficulty swallowing
Dysarthria
difficulty forming words
Aphasia
difficulty with language comprehension or expression
Ansomnia
loss of smell from smoking, allergic rhinitis, cocaine
How do you test CN II?
-acuity
-confrontation
How do you assess CN III, IV, and VI?
-pupil size and accommodation
-cardinal positions
Nystagmus
back-and-forth oscillation of the eyes
How do you test CN V?
M - palpate temporal and masseter muscles while patient clenches teeth, try to separate jaws by pushing down on chin
S - close patients eyes and ask patient to say now when they feel cotton swab touch face
When do you not omit the corneal reflex test?
if the patient has abnormal facial sensation or abnormal facial movement
How do you test CN VII?
M - ask patient to smile, frown, close eyes tightly, lift eyebrows, puff cheeks
S - only test with facial nerve injury - taste test
How do you test CN VIII?
whispered voice test
How do you test CN IX and X?
M - pharyngeal “AHHH”, gag reflex
How do you test CN XI?
ask patient to rotate head against resistance and ask patient to shrug shoulders against resistance
How do you test CN XII?
ask patient to stick out tongue and ask patient to say “light, tight, dynamite”
How do you test cerebellar function?
gait (normal and heel-toe)
Ataxia
uncoordinated or unsteady gait
What is the Romberg Test?
ask patient to close eyes and hold a standing, stable position for 20s
What is a positive romberg signs?
loss of balance with eyes closed
Clonus
rapid, rhythmic contractions of the same muscle
What is Babinski’s signs?
splayed toes
