Reflexes (U3) Flashcards
Reflex definition?
Basic defence mechanisms of the nervous system
Characteristics of a reflex?
Involuntary response to a stimulus
- Begins with sensory input
- Ends with motor response
- Unconscious
- Quick reaction to pain/damage
- Maintain balance
- Appropriate muscle tone
Reflex arc definition?
Pathway where reflex occurs
Two categories of reflexes?
Visceral (autonomic)
and somatic (skeletal)
Example of a visceral reflex?
- Ex. automatic production of saliva upon seeing/smelling food
Example of a somatic reflex?
- Ex. movement of a body part in the presence of pain
Four types of reflexes?
Deep tendon, superficial, visceral, pathological
What is a deep tendon reflex?
Patellar, knee jerk
What is a superficial reflex?
Abdominal
What is a visceral reflex?
Pupillary reflex to light and accomodation
What is a pathological reflex?
Babinski, extensor plantar reflex
What is a deep tendon response?
Each deep tendon reflex involving specific spinal segments, abnormal reflex helps locate pathologic lesion
Five reflex tests?
Bicep, tricep, brachioradialis, patellar, achilles
Bicep reflex test?
Support arm in yours with thumb over bicep, hold right arm with right hand and vice versa
- Normal: Biceps contract, lower arm move inward
Tricep reflex test?
Pull arm from patient’s body, forms right angle at shoulder with lower arm dangling right below elbow
- Normal: Lower arm extends at the elbow, swings away from body
Brachioradalis reflex test?
Strike area with reflex hamming anywhere in the vicinity
- Normal: Lower arm flex at elbow and pal of hand turns up (supinate)
Patellar reflex test?
Patient seated with feet dangling over edge of table
- Normal: Lower leg extends at knee
Achilles reflex test?
Foot forms right angle on lower leg and support it, strike tendon with hammer (see calf for muscle contraction)
- Normal: Causes foot to plantar reflex, moving into supporting hand
Four point scale for grading reflexes?
4+ very brisk, hyperactive with clonus
3+ brisker than average
2+ average, normal
1+ diminished, low normal
0 no response
