-The involuntary,automatic and immediate response of our body against external stimuli called reflex action.
-Reflex action do not require thought or decision.
-More than 200 reflex action are known in human body.
-Marshal discovered reflex action in 1833.
-Reflex action do not require will of the organism.eg-knee-jerk reflex,coughing etc.
-Knee-jerk reflex:-When the patellar tendon is hit by a small hammer,the quadriceps muscle initiate a stritch reflex which causes the lower leg to move foreward.
-Reflex Pathway:-This pathway include afferent neuron and efferent neuron in a series.
-Reflex Arc:-The entire impulse circuit of a reflex response is known as reflex arc.
Facts about Coma
Coma is a prolonged period of unconsciousness. Unconsciousness is the lack of appreciation of (or reaction to) a stimulus. Coma differs from sleep in that one cannot be aroused from a coma.
Coma involves two different concepts:
1.) Reactivity: Reactivity refers to the innate (or inborn) functions of the brain, i.e., the telereceptors (eyes and ears), the nociceptors (responses to pain), the arousal reaction (wakefulness) and the orienting response (turning one's head toward the source of sound or movement). We could also refer to these as reflexive movements.
2.) Perceptivity: Perceptivity refers to the responses of the nervous system to stimuli, which have been learned or acquired, i.e., language, communication skills, individual methods of movement such as gestures, etc. Perceptivity also refers to less complex learned or acquired reactions such as flinching when threatened. We can also think of these as conscious movements.
