Cell Membrane Physiology - Part 1 PDF

CHAPTER 3 CELL MEMBRANE PHYSIOLOGY - ACTION POTENTIAL 3.1. Cell Membrane Structure 3.2. Membrane Transport 3.3. Membrane Potential 3.4. Action Potential Human Anatomy and Physiology I HUAP 210 Objectives You will be able to: 1. Describe the structure and function of the cell membrane, incl...

CHAPTER 3 CELL MEMBRANE PHYSIOLOGY - ACTION POTENTIAL 3.1. Cell Membrane Structure 3.2. Membrane Transport 3.3. Membrane Potential 3.4. Action Potential Human Anatomy and Physiology I HUAP 210 Objectives You will be able to: 1. Describe the structure and function of the cell membrane, including its regulation of materials into and out of the cell 2. Recognize the significant of membrane potential. 3. Describe the function of ion channels and sodium/potassium pump in maintaining membrane potential. 4. Describe the stages of action potential and explain the threshold potential. 5. Identify the characteristics of action potential. 6. Describe the conduction of action potential along nerve fibers. Human Anatomy and Physiology I HUAP 210 Cell Membrane Structure Section 3.1 Cell Membrane Cell membrane of the cell is a semi-permeable phospholipid bilayer containing many different molecular components, including proteins and cholesterol, some with carbohydrate groups attached. Phospholipid Bilayer consists of two adjacent sheets of phospholipids, arranged tail to tail. The polar heads contact the fluids. Human Anatomy and Physiology I HUAP 210 Phospholipid Structure Phospholipid molecule consists of: Polar phosphate “head” - hydrophilic, having an affinity for water; capable of interacting with water molecules. Non-polar lipid “tail” - hydrophobic, lacking affinity for water, and tending to repel water molecules. Human Anatomy and Physiology I HUAP 210  Cell Membrane Functions Isolation of the cytoplasm from the external body fluids Identification Communication - Action Potential Regulation of solute exchange through the membrane Human Anatomy and Physiology I HUAP 210 Membrane Transport Section 3.2 Cell Membrane Transport Passive Transport - It is the movement of solutes down their concentration gradient without energy (ATP). Active Transport – It is the movement of solutes up their concentration gradient requiring energy (ATP). Human Anatomy and Physiology I HUAP 210 Passive Transport Simple diffusion: small, non-polar molecules (O2 and CO2). Facilitated diffusion: big (Glucose) and polar (ions) molecules. Osmosis: water molecules. Human Anatomy and Physiology I HUAP 210 Active Transport Primary Active transport: Sodium/Potassium Pump. Secondary Active Transport (Coupled): Glucose active transport. Bulk Transport: Phagocytosis, Exocytosis and Pinocytosis (Macromolecules). Human Anatomy and Physiology I HUAP 210