. A sensory System It is a system which gives information about sensory stimuli through skin and the body adjusts its responses through the motor system.. Components of Sensory System. ReceptorsPeripheral nervesSpinal cordTractsThalamusThalamocortical projectionSomatosensory cortex. . Recep
2. A sensory System
It is a system which gives information about sensory stimuli through skin and the body adjusts its responses through the motor system.
3. Components of Sensory System Receptors
20. Transduction (receptor potential) It is a change in membrane potential of a receptor.
1) Mechanical deformation of receptor membrane.
2) Application of chemical which binds to the receptor.
3) Change in temperature.
4) Application of electromagnetic energy.
These lead to the opening of selective channels and depolarization of receptor membrane.
21. Generator Potential (Receptor Potential) Non propagated depolarizing potential.
It is produced in un-myelinated nerve terminal.
22. Depolarization of receptor membrane leads to local circuit which initiates action potential at the first node of Ranvier on the nerve attached to the receptor.
46. Sensory Pathways
47. DORSAL COLUMN PATHWAY
CARRIES FINE TOUCH, POSITION, PRESSURE, VIBRATION, TWO POINT DESRIMINATION stereognosis
AFFERENT SENSORY FIBERS Aß TYPE.
VERY FAST VELOCITY 30 – 70 m/s
3 NEURON SYSTEM
(SEE THE DIAGRAM) ANTEROLATERAL PATHWAY
CARRIES PAIN & TEMPRATURE (lat. Sp.Th)
CRUDE TOUCH & PRESSURE ( VENT, Sp. Th)
AFFERENT SENSORY FIBERS Ad (MYELINATED) FAST PAIN
C FIBERS( UNMYELINATED) SLOW PAIN
RELATIVELY SLOW VELOCITY Ad – 6 – 30 m/s. C – 0.5 – 2 m/s.
3 NEURON SYSTEM
(SEE THE DIAGRAM)
49. Spinal Tracts