1 / 27

By: Dr shahrokhi

By: Dr shahrokhi. CELL PHYSIOLOGY. CELL is the functional unit of the body - The body made of ~ 100 trillion plus cells, all surrounded by fluid, (extra-cellular fluid, ECF)

hanne
Télécharger la présentation

By: Dr shahrokhi

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. By: • Dr shahrokhi

  2. CELL PHYSIOLOGY CELL is the functional unit of the body - The body made of ~ 100 trillion plus cells, all surrounded by fluid, (extra-cellular fluid, ECF) PROTOPLASM - is the different substances that make-up the cell - Has 5 basic components; WATER, ELECTROLYTE, PROTEINS, LIPIDS, and CARBOHYDRATES.

  3. WATER: 60% to 75% ELECTROLYTES : important (inside the cell) are K+, Mg 2+, Phosphate, Bicarbonate, and small quantities of Na+, Cl- and Ca 2+ PROTEINS: - Constitutes ~ 10% -20% of cell mass. - 2 types; i) STRUCTURAL PROTEINS ii) GLOBULAR PROTEINS LIPIDS : most important are phospholipids and cholesterol which make-up ~2% of total cell mass • Phospholipids and cholesterol are mainly insoluble in water and are used to form cell membrane CARBOHYDRATE : structural role is limited. Major role is nutrition - especially in the form of dissolve glucose in the surrounding extra- cellular fluid.

  4. Composition of the human body Water: 60% Protein: 18% Fats: 18% Minerals: 4%

  5. Cytoplasm Components: • Cytosol – gel-like fluid • Storage substances • Cell organelles • Cytoskeleton – network of filaments and fibers

  6. The internal environment • The cell is surrounded by tissue fluid (Internal Environment). • The composition of the internal environment should remain constant within narrow limits.

  7. Homeostasis Maintaining constancy of internal environment. Dynamic constancy. Within a certain normal range. Regulatory mechanisms: Intrinsic: Within organ being regulated. Extrinsic: Outside of organ, such as nervous or hormonal systems.

  8. Negative Feedback Figure 1.5

  9. Positive Feedback • Actionof effectors amplifies the changes. • Is in same direction as change. • Examples: • Oxytocin (parturition). • Voltage gated Na+ channels(depolarization). • blood clotting

  10. Feed Forward Control When response has to occur rapidly, the brain uses a principle called feed forward control. Seen mainly in nervous system. Eg: Conditioned reflex Adaptive control.

  11. Body Water Content Infants have low body fat, low bone mass, and are 73% or more water Total water content declines throughout life Healthy males are about 60% water; healthy females are around 50% This difference reflects females’: Higher body fat Smaller amount of skeletal muscle In old age, only about 45% of body weight is water

  12. Major Compartments for Fluids INTRACELLULAR FLUID (ICF) EXTRACELLULAR FLUID (ECF) Interstitial fluid Transcellular fluid - cerebrospinal, pericardial , synovial

  13. Extracellular fluid: • It is the internal environment that immediately surround the units of life of the whole body • Intravascular: within the vascular system • Interstitial: lies between the cells • Transcellular : secreted by epithelial lining e.g., CSF, pleural fluid ,peritoneal fluid, joint fluid,…. • Large volumes are present in disease states, pleural effusion , ascites. • Large losses in diarrhea and vomiting leads to dehydration and electrolyte disturbances.

  14. Fluid Compartments Figure 26.1

  15. Electrolyte Composition of Body Fluids Figure 26.2

More Related