Receptor and Its types

Receptors

Small electric shocks, chemical, mechanical, temperature and light stimuli excites the neuron fiber and cell bodies. The changes in the internal and external environment of the animal are detected by the receptors. Cells, neuron endings, or a receptor organ can be a receptor. Receptors are categories into following categories;

1.                       Chemoreceptors;

·         These are the receptors which receives the stimuli for smell, taste and for blood oxygen, CO₂, glucose, amino acids and fatty acids (these receptors are in the hypothalamus).

2.                       Mechanoreceptors;

·         These are receptors which receive the stimuli of pressure, hearing, touch and equilibrium.

·         Their receptors are free nerve endings, expended nerve endings and stray endings.

3.                       Photoreceptors;

·         Their receptors are called electromagnetic receptors. These receptors detect the stimuli of light for example rod and cone cells in the eyes.

4.                       Thermoreceptors;

·         Their receptors are free endings. These receptors receive the stimuli for warmth and cold.

5.                       Nociceptors;

·         Their receptors are undifferentiated endings which create the sensation of pain.