Question | Answer |
Cerebral cortex | • higher functioning, thought, memory, reasoning, sensation, voluntary movement |
• frontal lobe | personality, behaviour, emotions, intellectual function |
• parietal lobe | : postcentral gyrus is primary center for sensation |
• occipital lobe | visual receptor center |
• temporal lobe | behind ear, has primry auditory reception center with functions of hearing, taste, and smell |
• Wernicke’s Area | in temporal lobe, associated with language comprehension. |
• Receptive aphasia | person hears sound, but it has no meaning, like hearing a foreign language. Results with damage to Wernicke’s area |
• Broca’s Area | : in frontal lobe, mediates motor speech |
• Expressive aphasia | person cannot talk, but can understand language and knows what he or she wants to say but produces garbled sound |
o Basal Ganglia | form the subcortical associated motor system (extrapyramidal system). Coordinate movement and control, automatic associated movements of body |
o Thalamus | relay station where sensory pathways of spinal cord, cerebellum, and brainstem form synapses on their way to cerebral cortex |
o Hypothalamus | respiratory center, temperature control, appetite, sex drive, heart rate, BP, sleep center, anteriro and posterior pituitary gland regulator, coordinator of autonomic nervous sytem activity and stress response |
o Cerebellum | motor coordination of voluntary movements, equilibrium, muscle tone |
o Brainstem | midbrain, pons, medulla |
midbrain | merges into thalamus and hypothalamus |
• Pons | 2 respiratory centers, ascending and descending motor tacts |
• Medulla | continuation of spinal cord in brain, vital autonomic centers (respiration, heart, GI), nuclei for CN VIII-XII |
- Spinal Cord | medulla to lumbar vertebrae L1-L2. Highway for ascending and descending fiber tracts that connect brain with spinal nerves. Mediates reflexes |
sensory pathways (2) | Spinothalamic Tract and Posterior/Dorsal Columns |
Spinothalamic Tract | sensation travels in peripheral nerve, then through the dorsal root of spinal cord.they synapse with 2nd sensory neuron that crosses to opposite side and ascends up cord to thalamus. Fibers synapse with 3rd sensory neuron which carries msg to cortex |
Spinothalamic Tract- types of sensations | pain, temperature, crude/light touch |
posterior/dorsal columns | fibers enter dorsal root and go up same side of spinal cord to brainstem. At medulla, they synapse with 2nd sensory neuron and cross. They travel to thalamus, synapse, and proceed to cortex |
posterior/dorsal column- types of sensation | proprioception, vibrations, finely localized touch (stereognosis) |
proprioception | without looking, you know where your body parts are in space and in relation to each other |
finely localized touch (stereognosis) | you can feel familiar objects by touch without looking |
Motor pathways | pyramidal, extrapyramidal, cerebellar |
upper motor neurons | complex of all descending motor fibers that can influence or modify the lower motor neurons, located mostly in CNS |
lower motor neurons | located mostly in PNS, nerve fiber extends to muscles, final direct contact with muscles (ex. cranial nerves and spinal nerves) |
sensory neurons | afferent to CNS |
motor neurons | efferent from CNS to muscles, glands, autonomic messages to organs and vessels |
nerve | bundle of fibers outside CNS, carry input to CNS via sensory afferent fibers and deliver output via efferent fibers |
reflex arc | involuntary movements, operating below level of conscious control, permit quick reaction to potentially painful stimuli. |
deep tendon reflexes | myotactic (e.g. knee jerk) |
superficial reflexes | corneal reflexes, abdominal reflex |
visceral reflexes | pupillary reflex and accommodation |
pathologic reflexes | abnormal, e.g. babinski plantar reflex |
where do CN I and II extend from? | extend from cerebrum |
where do CN III-XIII extend from? | extend from brainstem |
vagus nerve | travels to heart, respiratory muscles, stomach, and gall bladder (parasympathetic innervation) |
cranial nerves | enter and exit the brain rather than spinal cord, supply primarily head and neck (except vagus nerve) |
spinal nerves | 31 pairs of spinal nerves, arise from length of spinal cord and supply the rest of the body, named for region of spine from which they exit |
# cervical spinal nerves | 8 |
# thoracic spinal nerves | 12 |
# lumbar spinal nerves | 5 |
# sacral spinal nerves | 5 |
# coccygeal spinal nerves | 1 |
dermal segmentation | cutaneous distribution of various spinal nerves |
dermatomes | circumscribed skin area that is supplied mainly from one spinal cord segment through a particular spinal nerve (can overlap) |
Somatic Nervous System: | fibers innervate skeletal (voluntary muscles) |
Autonomic Nervous System | fibers innervate smooth muscles, cardiac muscles, glands (involuntry, unconscious acitivty) |
CN I | Olfactory Nerve
- present familiar smell with eyes closed |
CN II | Optic nerve
- visual acuity test
- opthalmoscope/fundoscopy |
CN III | Oculomotor
- EOMs (w/IV and VI) |
CN IV | Trochlear
-EOMs |
CN V | Trigeminal
- motor: palpate TMJ
-sensory: cotton ball |
CN VI | abducens
- EOMs |
CN VII | Facial
- motor: smile, frowm, close eyes, lift eyebrows, show teeth, puff checks
-sensory: taste |
CN VIII | vestibulococchlear
- whisper test |
CN IX and CN X | glossopharyngeal and vagus nerve
- motor: pharynx curtains and uvula rises
-sensory: taste posterior 2/3 of tongue |
CN XI | spinal accessory; rotate head against resistance, shrug shoulders against resistance |
CN XII | hypoglossal; tongue movement, light/tight/dynamite |
Muscle exam | size, strength, tone, involuntary movements |
gait | observe as person walks 10-20 feet, turns and returns to starting point; normally gait is smooth, rhythmic, and effortless; opposing arm swing in coordinated; person turns smoothly |
o Romberg Test | ask person to stand up with feet together and arms at sides. When stable position, ask person to close eyes and to hold position for about 20 seconds |
thumbs to finger test | tests fine motor skills |
finger to nose test | ask person to close eyes and stretch out arms. Then ask to touch tip of nose with each index finger and alternate hands --> coordination |
heel to shin test | ask patient in supine position to place heel on opposite knee and run it down shin to ankle |
graphesthesia | ability to read a number by having it traced on skin |
o two point discrimination | ability to distinguish separation of 2 simultaneous pin points on skin |
o extinction | simultaneously touch both sides of body at same point; normally, both sensations are felt |
o point location | touch skin and withdraw stimulus promptly; ask person to put finger where you touched |
reflex grade 4 | very brisk, hyperactive with clonus, indicative of disease |
reflex grade 3 | brisker than average, may indicate disease |
reflex grade 2 | average, normal |
reflex grade 1 | diminished, low normal, or occurs with reinforcement |
reflex grade 0 | no response |
superficial (cutaneous) reflexes | sensory receptors in skin rather than in muscles; motor responseis localized muscle contraction (abdominal reflex) |
upper abdominal reflex (spinal nerves) | T8-T10 |
lower abdominal reflex (spinal nerves) | T10-T12 |
performing the abdominal reflex test | o move from each corner toward midline at both upper and lower abdominal levels
o normal response is ipsilateral contraction of abdominal muscle with observed deviation of umbilicus toward stroke |
- plantar reflex (spinal nerves) | L4-S2 |
Babinski Reflex | fanning of toes, present at birth to 1 year old |
- Paralysis | decrease or loss of motor power due to problem with motor nerve or muscle fibers |
- Fasciculations | rapid, continuous twitching of resting muscle or part of muscle |
- Tic | involuntary, compulsive repetitive twitching of a muscle group |
- Myoclonus | rapid, sudden jerk or a series of jerks at fairly regular intervals |
- tremor | involuntary contraction of opposing muscle groups |
- rest tremor | when muscles are quiet and supported against gravity; coarse and slow (3-6 per sec), partly or completely disappears with voluntary movement |
intention tremor | : worse with voluntary movement as in reaching toward a visually guided target |
- chorea | sudden, rapid, jerky purposeless movements of limbs, trunk, or face. Occurs at irregular intervals, not rhythmic or repetitive, more convulsive than a tic |
- athetosis | slow, twisting, writhing, continuous movement, resembling a snake or worm. Involves distal part of limb more than proximal part. Occurs with cerebral palsy. |
- Periphral neuropathy | loss of sensation involves all modalities; loss most severe distally at feet and hands |
- Individual nerves or roots | decrease or loss of all sensroy modalities; corresponds to distribution of involved nerve |
- Complete transection of spinal cord: | complete loss of all sensory modalities below level of lesion; associated with motor paralysis and loss of sphincter control |
- Cortex (sensory loss) | loss of discrimination on cotnralateral side; loss of graphesthesia, stereognosis, recognition of shapes and weights, finger finding |
Glascow Coma Scale | eye opening, verbal response, motor response
- fully alert = 15
-<7 = coma |