What are Receptors?-Binding and Classification

A receptor is a molecule or cell that recognizes and binds to specific molecules called ligands. Ligand binding triggers a cellular response such as activation, inhibition, or signal transduction.

The human body has receptors for hormones, neurotransmitters, drugs, toxins, and other chemicals. These receptors allow cells to communicate with each other and respond to external stimuli.

Receptors are proteins located on the surface of the cells. They allow the cells to communicate with each other. When a receptor senses something foreign, it sends out signals to alert the rest of the cell. This allows the cell to respond appropriately.

Receptors play an important role in regulating our physiology. They are also involved in disease processes such as cancer, diabetes, and cardiovascular diseases.

Receptor Binding

Receptor binding is the process where a ligand (a molecule) binds to its specific receptor (another molecule). This interaction between two molecules triggers a biological response. For example, insulin binds to a cell surface receptor called the insulin receptor. The insulin receptor then activates intracellular signaling pathways that cause changes in gene expression.

The nervous system which helps in coordination is composed of three elements: Receptors, neurons, and effectors.

The cells or organs which detect changes in the external and environment of the animal are called receptors.” Electric shocks, mech chemical, light and temperature stimuli can excite neuron fibers and cell body receptor may be a cell, or neuron ending or a receptor organ.

Classification Of Receptors

Receptors are classified as follows:

Chemoreceptors

Chemoreceptors are used for smell and taste. They detect CO2 oxygen, blood glucose, amino acids, and fatty acids (receptors hypothalamus).

Mechanoreceptors

These receptors detect stimuli of touch (free nerve end expanded tip ending stray endings). They also detect pressure and hearing equilibrium.

Photoreceptors (Electromagnetic Receptors)

Photoreceptors detect stimulus of light. For example rods and cones cells of the eyes.

Thermoreceptors

They show response to cold and warm environments. 5. Nociceptors (Undifferentiated endings): They produce the sensation of pain.

Mechanical receptors of internal organs:

There are many receptors that re to the mechanical conditions of the internal organs. Examples are the receptor’s stomach wall. They produce hunger.

Stretch Receptors

Stretch receptors are present in the carotid and aortic artery tetrapods. They have important roles in the regulation of blood pressure. endings with similar properties are found in the bronchial vessels of fishes.

Read about Skin Structure of Fishes

Modalities Of Sensation

Each principal type of sensation that we can experience pain, touch, sight, and sound is called modalities of sensation. We can experience these different modalities of sensation. But nerve fibers transmit only similar impulses. Different nerve fibers t different modalities of sensation by following method:

Each nerve tract terminates at a specific point in the CNS nervous system). This point determines the type of sensation. So touch stimulates sensation.