all about motor unit...through its physiological aspects

1. BY SHRAVAN TV
ROLL - 21

2. IT IS A FUNCTIONAL UNIT OF SKELETAL MUSCLE.
IT CONSISTS OF A NEURON AND THE MUSCLE IT INNERVATES

4.  SPINAL CORD – IT HELPS IN SENDING IMPULSES TO THE MOTOR
NEURON FOR A CONTRACTION.
 MOTOR NEURON – IT CARRIES THE IMPULSE TO THE MUSCLE FOR
CONTRACTION.
 NEUROMUSCULAR JUNCTION (MOTOR END PLATE) – IT TRANSMITS THE
IMPULSE FROM NEURON TO MUSCLE.
 MUSCLE FIBERS – THEY SENSE THE IMPULSE AND LEAD TO
CONTRACTION.

6.  Process by which more and more motor units are put into action are called as
recruitment of motor unit
 When a weak signal is sent from the spinal cord, smaller motor units get
stimulated and as the signal gets stronger, longer and longer motor units get
stimulated.
 In the movements where precision is required around two or three muscle fibers
will be innervated by one neuron.
 In the movements where precision is not required, one neuron will supply to an
average of around 100 muscle fibers.
 IN PLACES LIKE PHARYNX THERE ARE ONLY TWO TO THREE MUSCLE
FIBRES PER NEURON.
CAN ANY ONE GUESS THE EXAMPLES OF PRECISE MOVEMENT AND
NON-PRECISE MOVEMENT??

7.  RULE
I WILL CALL OUT TWO ROLL NUMBERS AT A TIME, ONE PERSON SHOULD
SAY THE NAME OF THE PART, OTHER PERSON WILL SAY THE FUNCTION
OF THAT PART !!

10.  TEXTBOOK OF PHYSIOLOGY BY K.SEMBULINGAM AND PREMA
SEMBULINGAM
 GUYTON AND HALL TEXTBOOK OF MEDICAL PHYSIOLOGY