Flashcards in Physiology of Nervous System Deck (90)
______ pathways carry SENORY impulses _____ the CNS.
_______ pathways carry MOTOR impulses _____ the CNS.
efferent; away from
What do motor impulses target?
effector organs - skeletal, cardiac, smooth muscle; glands
What are the divisions of PNS?
somatic: motor/sensory of voluntary motor control of skeletal muscle
autonomic: motor/sensory of involuntary muscles (sympathetic & parasympathetic)
Degeneration of peripheral nerve fiber (axon and myelin) that has been severed from its cell body (nutrition center)
Occurs at DISTAL portion of severed axon
PROXIMAL end of injury site sprouts new terminal 1-2 wks after injury, hopefully connecting with Schwann cell pathway and grow approx 1 mm/day
Where is Wallerian regeneration restricted to in nervous system? Why?
Regeneration limited to PNS
Very limited in CNS d/t scar formation after injury and different nature of myelin production by oligodendrocytes
intension vs resting tremor
intension occurs with movement or following commands
resting occurs at rest when not thinking about it
quick, irregular, involuntary, but relatively coordinated movement face, limbs, trunk
distal muscle postural fixation disorder; slower than chorea, writhing, sinuous, abnormal hand posture, slowly fluctuating grimaces
proximal muscle postural fixation; wild flinging movement of limbs - usually unilateral
- inability to recognize and interpret objects, people, sounds, or smells despite intact primary sense organs
- ex: inability to identify a sound despite intact hearing; inability to identify a coin placed in hand; inability to recognize familiar faces
- damage to occipital & parietal lobe
paucity of movement
condition in which an ordinarily painless stimulus is experienced as being painful (ex. the pant leg touching the thigh is described as uncomfortable)
Lack of self-awareness; unaware they have a problem or disability
Ex: schizophrenic who doesn't take meds because “there is nothing wrong with me” or hemiplegic who finds excuses (other than paralysis) for not using paralyzed arm
part of “brain death exam” where patient taken off the ventilator for a certain amount of time
- Verifies lack of responsiveness to increased carbon dioxide (paCO2 > 60 mm Hg) in the presence of respiratory acidosis (pH < 7.3)
inability to formulate or understand language
expressive vs receptive aphasia
expressive: damage to Broca's; have understanding but can't produce speech
receptive: damage to Wernicke's; speak without understanding; "word salad"
impaired planning/sequencing of movement that is not due to weakness, incoordination, or sensory loss. Although the movements cannot be performed for a specific situation, they may be performed under other circumstances (e.g., inability to lift feet off the floor when attempting to walk but preserved ability to perform bicycling movements of the legs while lying in bed)
sudden palmar flapping movement of the hands at the wrists; indicative of hepatic encephalopathy
Lack of coordination of movement usually due to disease of cerebellum or damage to sensory pathways
slowed movement typically due to dysfunction of the basal ganglia and related structures
progressive destruction and deformity of bone and soft tissue at weight bearing joints due to severe sensory or autonomic neuropathy.
CNS disorder characterized by cerebellar elongation and protrusion through the foramen magnum into cervical spinal cord. Places these individuals at risk with extension of the head on the neck
spring-like resistance to passive extension at elbow or flexion at knee that increases up to a certain length and force before suddenly relaxing as the Golgi tendon organ is activated; sign of spasticity
ratchet movement due to superimposition of tremor on rigidity
inability to pronounce or articulate words d/t disorder of vocal apparatus (lips, tongue, larynx)
pain or discomfort in response to stimuli (e.g. touch) that would not be expected
spontaneous firing of axon resulting in visible twitch of all muscle fibers that it controls; indicates denervation
weakness on one side of body