General Physiology PDF

# General Physiology ## Presented By - Dr. Dalia El Agamy - Assistant Professor of Physiology ## Topics of physiology - General physiology - Autonomic nervous system - Blood - Cardiovascular system - Nerve & Muscle - Respiration - Gastrointestinal tract - Central Nervous System - Endocrine and...

# General Physiology ## Presented By - Dr. Dalia El Agamy - Assistant Professor of Physiology ## Topics of physiology - General physiology - Autonomic nervous system - Blood - Cardiovascular system - Nerve & Muscle - Respiration - Gastrointestinal tract - Central Nervous System - Endocrine and Reproduction - Metabolism - Renal and acid base balance - Special senses ## General Physiology General concepts and principles that are basic to the function of all systems in the body. ## Topics of General Physiology - Cell Physiology - Transport Across Cell membrane - Body Fluids and Electrolytes - Homeostasis ## Cell Physiology - Cells are the basic unit of life. ### Structure of the cell - The cell consists of a mass of protoplasm surrounded by cell membrane. - Cell Membrane - Protoplasm consists of: - Cytoplasm - Cell organelles - Nucleus A diagram of a cell is shown, with the following components labeled: - Secretory vesicle - Centrlole - Nucleolus - Nucleus - Agranular endoplasmic reticulum - Golgi Complex - Nuclear envelope - Mitochondrion - Lysosome - Chromatin - Plasma membrane - Microtubule - Granular endoplasmic reticulum - Cytoplasm (cytosol) - Ribosme ### Cell Membrane (Plasma Membrane) - It is a phospholipid bilayer structure in which proteins and cholesterol are embedded (fluid mosaic model). - Its thickness is 10 nanometers. - It is not solid. ### Functions of cell membrane: - It surrounds, holds the cell together and gives the cell its shape. - It's selectively permeable and controls the passage of materials into and out of the cell. Some molecules can move across the membrane while others cannot. - Yes: Non-charged molecules, H₂O - No: Macromolecules, Charged ions - It separates the cell's internal structures from the extracellular environment. - It participates in intracellular communication. - It contains receptors for chemical messengers which would activate or inhibit cellular functions. A diagram of a cell membrane showing a receptor protein receiving a signal is shown. ### Structure - **Lipids (41%)**: A diagram of a cell membrane is shown. Phospholipids are the main part of the membrane. - **Proteins (55%)** - **Carbohydrates (4%)** ### Membrane Phospholipid - **Phosphate Group-Polar** *(hydrophilic - seek water)* - **Fatty Acid Chains-Non Polar** *(hydrophobic - avoid water)*. A diagram showing a cell membrane with phospholipid heads that are hydrophilic and tails that are hydrophobic is shown. ### Membrane Lipids (41%) - **Phospholipids:** double layer of phospholipids [hydrophobic/hydrophilic parts (25%) - **Cholesterol (12%)** - **Glycolipids (4%)** ### Membrane Cholesterol - Responsible for toughness of cell membrane. - Solidity of cell membrane is directly proportional to cholesterol/phospholipid ratio. Changes in this ratio lead to abnormalities in cell function. ### Membrane Proteins - **Integral (internal or intrinsic) proteins:** - Span the membrane. - Transport protein - Structural channels or pores. - **Peripheral proteins (external or extrinsic):** - Embedded in one side. - Carrier protein. - Bind with substances to be transported. - E.g. hormone receptors and cell surface antigens. ### Functions of Proteins in the Cell Membrane - **Membrane receptors:** Bind to chemical messengers (e.g. hormones or chemical transmitters) which sends a message into the cell causing cellular reaction. A diagram of a cell membrane showing a receptor receiving a signal is shown. - **Membrane transport:** - **Passive channels:** for passage of ions and water. - **Active pumps:** for active transport of ions. A diagram showing a cell membrane with an active transport pump is shown. - **Membrane enzymes:** Carry out enzymatic reactions on the inner and outer surfaces of the membrane when a substrate binds to the active site. A diagram showing a cell membrane with enzymes is shown. - **Markers (antigens or Identity Protein):** Glycoproteins and glycolipids that serve as ID tags which give the cell the individual label of identity. A diagram showing a cell membrane with molecules carrying the identity tag is shown. - Immune system. - Identify blood and tissue type of an individual. - **Structural Protein:** Attach to cytoskeleton and/or the extracellular matrix to maintain cell shape, give the integrity of the cell membrane, and make it strong. - Attach to extracellular matrix and cytoskeleton filaments. A diagram showing a cell membrane with integral proteins connected to the cytoskeleton is shown. ### Membrane carbohydrates (4%) - Primarily attached to the outer surface of the cell membrane as: - **Glycoproteins (90%)** - **Glycolipids (10%)** ### Functions of carbohydrates in the Cell Membrane - Attach cells to each other. - Act as a receptor substance. - Some enter in the immune reaction. - Give most of the cells a negative surface charge, which affects the interaction of regulatory molecules with the membrane. # Thank You - An image of a golden fountain pen writing the word "Thank you" is shown.