Lab 16 practical physiology Assist. Lec.
Suha Talal Abd
Second class
Examination of Motor Function
Examination of motor function include:
1- Size of muscle.
2- State of muscle tone.
3- Muscular Power.
4- Co-ordination of movement.
5- Reflexes.
Reflexes: is an involuntary movement in response to a stimulus by action of
muscle or glands through nerves. It considered as basic defense
mechanisms of the nervous system.
A reflex arc: defines the pathway by which a reflex travels, from the stimulus to
sensory neuron to motor neuron to reflex muscle movement.
The reflex arc typically consists of five components
1. The receptor at the end of a sensory neuron reacts to a stimulus.
2. The sensory (afferent) neuron conducts nerve impulses towards the central
nervous system (CNS).
3. The integration center consists of one or more synapses in the CNS.
4. A motor (efferent) neuron conducts a nerve impulse from the integration center
to an effector.
5. An effector responds to the efferent impulses by contracting (if the effector is a
muscle fiber) or secreting a product (if the effector is a gland).
Four Types of Reflexes:
(Deep tendon ( Patellar or knee jerk-1
2-Superficial ( Corneal, abdominal, Plantar , Cremastric reflex).
(Visceral ( Pupillary reflex to light and accommodation-3
4-Pathologic( Babinski , Extensor plantar reflex )
Reflex is evaluated according to:
1) amount (size, magnitude) of motor response.
2) latency (time to elicit motor response).
1- Deep reflexes (The receptors are in the tendons and muscles) which include:
a- Knee reflex.
b- Ankle reflex.
c- Biceps reflex.
d- Triceps reflex.
e- Jaw jerk.
2- Superficial reflexes which include (The receptors are in the skin and
mucous membrane)
a- Abdominal reflex.
b- Planter reflex.
1- Deep reflexes
Knee - Jerk:
By tapping the tendon between patella and tibia with a rubber - covered patellar.
Hammer, the monosynaptic reflex causes the muscle to contract; extends the knee.
So kicks the foot forward. (The subject should be sitting).
Ankle reflex:
The subject should lie on his back, the leg to be examined
is slightly flexed; tap the Achilles tendon with hammer, the
response is a contraction of the muscles with plantar
flexion of the foot.
The Biceps jerk:
Flex the elbow of the subject and support it on your left hand; now put the thumb of your
left hand firmly over the elbow, and at the same time slightly supinates.
The Triceps jerk:
Flex the elbow of your subject; now tap the triceps tendon just proximal to its insertion,
the normal response.
2- Superficial reflexes
Abdominal reflex:
By a key or wooden stick scratch on abdominal wall outside to midline normally, there is
contraction of muscle and movement of umbilicus.
Planter reflex:
Scratch the outer bode of sole with a key normally, the big toe goes down ward flexion
and Adduction of all other toes.
Examination of sensory:
1- Test for touch sensation: stimulation of tactile receptors in skin or in
tissues’; immediately beneath the skin.
2- Pain.
3- Temperature.
4- Position sense.
