Physiology Lec (1) PDF

Introduction to human physiology BY DR /Madeha Baraka lecturer of Physiology Benisuef University What is physiology?  Human physiology is concerned with the way the human body works. It is the study of the functions of organs, system...

Introduction to human physiology BY DR /Madeha Baraka lecturer of Physiology Benisuef University What is physiology?  Human physiology is concerned with the way the human body works. It is the study of the functions of organs, systems&the way these functions are integrated.  Homeostasis Keeping the conditions in the internal environment(extracellular fluid) constant ( ex:O2,food materials,CO2,Waste products ,Temperature ,PH).  Total body water "TBW" = 60% total body weight:  compartments: 1. Intracellular fluid "ICF" :2/3 = 40% 2. Extracellular fluid "ECF":1/3 = 20%: a) Intra vascular fluid (plasma) "IVF" 5% b) interstitial fluid (bathing cells) "ISF" 15%  COMPOSITION OF BODY FLUIDS CATIONS (mmol/l) Plasma Interstitial Intracellular Na 142 139 14 K 4.2 4.0 140 Ca 1.3 1.2 0 Mg 0.8 0.7 20 ANIONS (mmol/l) Cl 108 108 4.0 HCO3 24.0 28.3 10 Protein 1.2 0.2 4.0 HPO4 2.0 2.0 11  CELL MEMBRANE Membranes: Structurally define cells, nucleus, and organelles. Thin, elastic,semipermeable,dynamic,7.5-10 nanometer thick. – Phospholipids- 25%:amphipathic,bilayer, important for the flexibility& selective permeability. – Cholesterol-13%:hydrophobic embedded in phospholipid bilayer, gives toughness to the membrane. – Other lipids:4%. – Carbohydrates-3%:glycolipids, glycoprotein, recognition sites in cell differentiation&immune response,attaching cells together. – Proteins-55%:Integral,peripheral.  Phsopholipids are amphipathic Phospholipids are polar, having hydrophobic "tails" made of lipids, and hydrophilc "head" groups Diffusion Through the Plasma Membrane  Now…What are the functions of cell membrane proteins ??? - Enzymes - Channels -Identity proteins -Carriers -Intercellular - Receptors connections. Types of channels Nongated(leak) Gated -Ligand gated - Voltage gated Types of carriers Bindin junction Gap junction