Healthcare

The biceps reflex

bowo84 — Fri, 26 Feb 2010 13:11:20 +0000

The forearm is placed halfway between flexion and extension and slightly pronated (the biceps being also a supinator) and the thumb or finger on the tendon. A blow on the digit results in flexion of the forearm. The reflex arc is by way of the musculocutaneous nerve and the fifth and sixth cervical segments. The triceps reflex. The forearm is held by the examiner, partly flexed at the elbow and the tendon struck just above the olecranon process. Extension’s of the forearm results. Reflex arc: radial nerve and the sixth and seventh cervical segments. The radials (Brachioradial) reflex. With the elbow partly flexed the hand is placed half way between pronation and supination and the styloid process of the radius tapped.

The result is some supination and flexion at the elbow (the brachioradialis being a flexor). Occasionally there is also flexion of the wrist and fingers. Reflex arc: radial nerve and seventh and eight cervical segments. What is known as inversion of the radial reflex occurs in a lesion of the spinal cord affecting the fifth and sixth cervical segments. On tapping the radial bone the finger flexion reflex is elicited not supination or flexion at the elbow (Walshe, Babinski).

The ulnar pronator reflexes. The hand is held in a position similar to that for eliciting the radial reflex and the styloid process of the ulna tapped. The result is pronation of the hand. Reflex arc: median nerve and eight cervical and first dorsal segments.

The patellar quadriceps reflex’s or knee. The leg is flexed at the knee joint to about 120 degree. The quadriceps tendon is tapped just below the patella. Result: extension at the knee visible and palpable contraction of the quadriceps and occasionally ipsilateral or crossed adduction of the thigh. The last is known as the patella adductor reflex. Reflex arc: femoral nerve and the second, third, and fourth lumbar segments. Loss of the knee jerk used to known as Westphal’s sign.

The biceps reflex is a post from: Healthcare

Pathologic reflexes

bowo84 — Sat, 13 Feb 2010 13:07:39 +0000

The Babinski toe sign is found in lesion of the pyramidal tract (although dorsiflextion of the big toe may occur spontaneously in extra-pyramidal disease) and is obtained by scratching with a pin upward and inward the outer side of the sole of the foot. If positive, there is fanning plantar flexion of the lesser toes and dorsiflexion (extension) of the big toe. Often in severe lesions there is simultaneous dorsiflexion at the ankle, flexion at the knee and hip, and contraction of the tensor fasciae femoris. The Babinski sign is a pathologic exaggeration of the flexor reflex, namely a defense reflex. It is possible that is a release phenomenon that is when the pyramidal tract is impaired the extra-pyramidal influence causes dorsal extension of the toe. Fulton has shown that the Babinski sign is absent after section of the pyramidal tract in the lower apes, but is elicited in the higher anthropoids. Utilizing the mechanism of the tonic neck reflexes, Walshe showed that the Babinski sign could be accentuated if the head is rotated with the occiput to the paralyzed side, and inhibited if it is turned the other way. The same extension of the toe in pyramidal tract disease may be obtained by various stimulations of the foot and leg, such as:

The Oppenheim maneuver’s (stroking downward the median side of the tibia).

Gordon (Compression of the calf muscle).

Schaefer (Pinching the tendo Achilles) sign.

The Rossolimo sign consists of plantar flexion of the toes on tapping the balls of the toes of flipping the toes upward. We are dealing here (Fulton) with a tendon and not a skin reflex.

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Infants grasp reflex

bowo84 — Fri, 22 Jan 2010 13:02:35 +0000

The grasp reflex is significant of frontal lobe lesions. It is regarded as a release phenomenon and occurs normally in infants below one year of age. The grasp reflex probably is the result of tonic innervation’s, due to stretch, hence is proprioceptive in nature. Fulton has shown that the grasp reflex is an integral part of the body righting reflex mechanism and varies with the position of the body in space parallel with the righting reflexes. In the bilateral motor promoter ablated (thalamic) animal, the grasp reflex is elicited in the upper, most flexed limb and not in the extended limbs on the side on which the animal lies. The grasp movement is elicited by stroking the palms and the finger which result in closure of the hand on the stimulating object. Probably the promoter region, Broadmen are 6 of the frontal lobe has to do with this reflex. Both grasping and groping occur in patients who are not stupor us though the first may be elicited in more dulled individuals, but it is a question whether there is a groping reflex. Barraquer, Brain and Curran have described a similar foot grasp reflex.

The mass reflex described by Rid-dock may be elicited by stimuli below the level of the lesion in severe injury or complete interruptions of the spinal cord. It consists of the flexion reflex, contraction of the abdominal wall, automatic evacuation of the bladder and sweating of the skin below the level of the lesion.

The oculocardiac reflexes. Pressure on the eye balls normally causes slowing of the pulse rate by about eight to ten beats. The reflex arc is by way of the trigemius (afferent) to the automatic vagus center in the bulb and by way of the vagus to the heart. The reflex is diminished or absent in sympathicotonics and exaggerated in vagotonics.

Infants grasp reflex is a post from: Healthcare