Neurotransmitters and receptor

Nervous system-Neurotransmitters and receptor

1. Human Anatomy and Physiology-II Nervous system (Neurotransmitters , Receptors) Mr N.JEGAN Associate Professor K.M.COLLEGE OF PHARMACY. MADURAI.

2. Content 1.Neurotransmitters 2. Receptors

3. Neurotransmitters

4. Neurotransmitters-Definition Neurotransmitter is a chemical substance that acts as a mediator for the transmission of nerve impulse from one neuron to another neuron through a synapse.

5. Neurotransmitters Target cell may be a neuron or some other kind of cell like a muscle or gland cell. Necessary for rapid communication in synapse. Neurotransmitters are packaged into synaptic vesicles - presynaptic side of a synapse .

6. PROPERTIES OF NEUROTRANSMITTERS 1) Synthesized in the presynaptic neuron 2) Localized to vesicles in the presynaptic neuron 3) Released from the presynaptic neuron under physiological condition

7. 4) Rapidly removed from the synaptic cleft by uptake or degradation 5) Presence of receptor on the post-synaptic neuron. 6) Binding to the receptor elicits a biological response

8. TYPES OF NEUROTRANSMITTERS

9. Action of Neurotransmitters Step-I Synthesis: Neurotransmitters are synthesized by the enzymatic transformation of precursors. Step-II Storage : They are packaged inside synaptic vesicles. Step-II Release: They are released from presynaptic terminal by exocytosis when calcium enters axon terminal during an action potential . It diffuse across the synaptic cleft to the postsynaptic membrane.

10. Step-IV Binding : They bind to receptor proteins. Step-IV Inactivation: The neurotransmitter is degraded either by being broken down enzymatically , or reused by active reuptake.

11. Receptor

12. Receptor-Definition Receptor is a protein molecule usually found embedded within the plasma membrane surface of a cell that receives chemical signals from outside the cell and when such chemical signals bind to a receptor, they cause some form of cellular/tissue response.

13. CLASSIFICATION OF RECEPTORS Generally, receptors are classified into two types: A. Exteroceptors B. Interoceptors

14. Exteroceptors Exteroceptors are the receptors, which give response to stimuli arising from outside the body. Exteroceptors are divided into three groups: 1.Cutaneous Receptors or Mechanoreceptors- situated in the skin, response to mechanical stimuli such as touch, pressure and pain 2. Chemoreceptors - Response to chemical stimuli e.g Taste 3. Telereceptors - Response to stimuli arising away from the body

15. INTEROCEPTORS Interoceptors are the receptors, which give response to stimuli arising from within the body. 1. Visceroceptors Receptors situated in the viscera are called visceroceptors. 2. Proprioceptors Proprioceptors are the receptors, which give response to change in the position of different parts of the body .

16. Functions of Receptor

17. Thank you