Lecture - 5 DR . ZAHOOR ALI SHAIKH. SENSORY SYSTEM 1. PAIN 2. Somatosensory cortex. PAIN. It is mainly a protective mechanism of the body, to bring conscious awareness of the fact that tissue damage is occurring. Response may be Motor – e.g. withdrawal
- Recptor-- Polymodal
Characteristics of C fibers
Ans. persons ability to interpret the quality of pain & precise location of pain will be affected.
Ans. Paleospinothalamic (chronic slow pain) pathway sends information to reticular formation and thalamic nuclei which are part of brain activating / alerting system, therefore it may explain why chronic pain syndrome causes difficulty in sleep.
SITE OF ACTION
By release of Endorphin.
(Brodmann area 1,2,3) – post central gyrus parietal lobe.
(Brodmann area no. 40) in the wall of sylvian fissure which separate temporal lobe from frontal & parietal lobes.
1. Somasthetic [touch, pain, temperature, pressure]
2. Properioception [awareness of body position]
SOMATOSENSORY CORTEX [CONT]
receptor is decreased
(When many peripheral nerves are affected)
All forms of sensations are impaired in distal parts of limbs (Glove & stocking anesthesia)
Site of Lesion