Intercellular signalling pathways

intercellular pathways and their types

1. INTERCELLULAR SIGNALLING PATHWAYS Presented by: Manju Jakhar Rollno.20PPC008

2. What is cell signaling All cells receive and respond to signals their surroundings Communication between cells.

3. INTERCELLULAR SIGNALING Intercellular signals can travel all throughout the body. This allows certain glands within the body to produce signals which take action on many different tissue across the body.

4. TYPES OF INTERCELLULAR Contact-dependent( juxtracrine ) When the signal molecule remains bound to the cell that produced it and therefore, will only influence cells that directly contact it, then this type of intercellular signaling is known as contact dependent signaling. This type of signaling is very important in the development of multicellular organism ans in the immune system.

5. Paracrine Cells that are near one another communicate through the release of chemical messengers ( ligands that can diffuse through the space b etween the cells).This type of signaling in which cells communication over relatively sort distances, is known as paracrine signaling. Paracrine signaling depends on local mediators that are released into the extracellular space and act on neighboring cells.

6. c. Synaptic Synaptic signaling is unique example of paracrine signaling in which nerve cells transmit signal with the help of synapse. Synapse is the junction between two nerve cells where signal transmission occurs.

7. Endocrine This is a type of communication occuring between distant cells and mediated by hormones. The hormones are released by endocrine cells of the body. Signaling molecules(hormones) travel through the body and act upon particular target cells. They cause slow but long lasting responses.

8. Autocrine In autocrine signaling, cells respond to substances that they themselves release. Many growth factors act in this fashion and cultured cells often secrete growth factors that stimulate their own growth and proliferation. This type of signaling is particularly common in tumor cells, many of which overproduce and release growth factors that stimulate inappropriate, unregulated proliferation of themselves as well as adjacent non-tumor cells; this process may lead to formation of tumor mass. Important during embryonic development. Blood platelates secretes eicosanoids to influence their own activity.