Cell - signalling, Communication, Junctions
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Cell signaling allows for communication between cells and is crucial for many biological processes. It works through signal molecules that transmit information from one cell to another through direct contact, over short distances through paracrine signaling, or over long distances through endocrine signaling like hormones. Errors in cell signaling can lead to diseases like cancer and diabetes. The main steps involve signal molecules binding to receptors on the target cell surface, which activates intracellular signaling pathways to ultimately change gene expression. Different types of cell junctions like tight junctions, adherens junctions, and desmosomes help regulate cell-cell communication and maintain tissue structure.
Cell - signalling, Communication, Junctions
- 2. Presented by Rushendran. R Assistant Professor Cell Signalling
- 3. Cell-cell signaling involves the transmission of a signal from a sending cell to a receiving cell. However, not all sending and receiving cells are next-door . Signal reaches a cell phone to facilitate communication in essentially the same manner that two-way radios communicate via a signal transmitter and a signal receiver. When you're talking on a cell phone, it converts your voice into a signal that is transmitted via radio waves to the nearest cell tower.
- 4. Why is cell Signalling important Cell Signaling is an important facet of biological life. It allows cells to perceive and respond to the extracellular environment allowing development, growth, immunity, etc. Additionally, errors in cell signaling may result in cancer growth, diabetes.
- 5. Cell signaling is the fundamental process by which specific information is transferred from the cell surface to the cytosol and ultimately to the nucleus, leading to changes in gene expression.
- 8. Steps of Cell Signalling
- 10. Types of cell signalling Direct signalling Paracrine signalling Autocrine signalling Endocrine signalling
- 11. Endocrine Signalling The signaling molecule s (hormones) are secreted by specialized endocrine c ells and carried through the circulation to act on target cells at distant body sites. Eg: Hormones
- 12. Insulin is a hormone produced by the β cells in the pancreas and is secreted into the bloodstream, from where it can act on many different cells, even those located far from the pancreas.
- 14. Example
- 15. Paracrine signaling is a form of cell signaling or cell-to-cell communication in which a cell produces a signal to induce changes in nearby cells, altering the behaviour of those cells. Paracrine Signalling Paracrine signals is the chemical transmitted from nerve to muscle that causes the muscle to contract.
- 16. Neuron Signalling Ach, NA, Adrenaline, Dopamine etc.
- 18. Thank You
- 19. CELL JUNCTION Cell junctions are a class of cellular structures consisting of multiprotein complexes that provide contact or adhesion between neighboring cells or between a cell and the extracellular matrix in animals. They also maintain the paracellular barrier of epithelia and control paracellular transport
- 20. Tight Junction Tight junctions, also known as occluding junctions or zonulae occludentes (singular, zonula occludens) are multiprotein junctional complexes whose general function is to prevent leakage of transported solutes and water and seals the paracellular pathway
- 21. Tight junctions are often found at epithelial cells, which are cells that line the surface of the body and line body cavities Tight junctions form the continuous intercellular barrier between epithelial cells, which is required to separate tissue spaces and regulate selective movement of solutes across the epithelium Functions
- 22. Gap junctions are a specialized intercellular connection between a multitude of animal cell-types. They directly connect the cytoplasm of two cells, which allows various molecules, ions and electrical impulses to directly pass through a regulated gate between cells.
- 23. Gap junctions are found in many places throughout the body. This includes epithelia, which are the coverings of body surfaces, as well as nerves, cardiac (heart) muscle, and smooth muscle (such as that of the intestines). Their primary role is to coordinate the activity of adjacent cells.
- 24. Adherens junctions are protein complexes that occur at cell–cell junctions in epithelial and endothelial tissues, usually more basal than tight junctions. An adherens junction is defined as a cell junction whose cytoplasmic face is linked to the actin cytoskeleton. The Adherens junction performs multiple functions including initiation and stabilization of cell-cell adhesion, regulation of the actin cytoskeleton, intracellular signaling and transcriptional regulation.
- 25. Desmosomes are intercellular junctions that provide strong adhesion between cells. Because they also link intracellularly to the intermediate filament cytoskeleton they form the adhesive bonds in a network that gives mechanical strength to tissues.
- 26. Hemidesmosomes are very small stud-like structures found in keratinocytes of the epidermis of skin that attach to the extracellular matrix. Hemidesmosomes are found in epithelial cells connecting the basal epithelial cells to the lamina lucida, which is part of the basal lamina Intermediate filaments
- 27. Thank YouHave a nice time…