Introduction to Physiology and Transport

1. Introduction to Physiology and Transport Ebaa M Alzayadneh, DDS, PhD e.alzayadneh@ju.edu Tortora, 13th edition

2. Office hours • Office is located 3rd floor of faculty of Medicine • For questions and explanations. • available 1-2 currently

3. Attendance rules • Please make sure not to exceed limit of allowed absence by UJ regulations either with or without medical or any unforeseen reasons. • The limit is 20% of lectures whatever the reason was. • Consequences of exceeding the limit is (prohibition of entering the final exam)

4. Syllabus University of Jordan Faculty of medicine Department of physiology and biochemistry Nursing physiology (0501105) three credit hours spring 2015-2016 Textbooks: 1. Principles of Anatomy and Physiology, 14th edition 2014 , by G.J. Tortora and B. Derrickson. No. of Topic (Tortora) 13thed14thed 2 Introduction, 8-12, 63-78 8-11, 61-73 Transport system 5 Excitable tissues 458-482 410-424 Action potential, 331-356 291-319 NM junction, Skeletal Muscle contraction & relaxation, 5 Body fluids and Blood. 1110-1118 661-683 728-751 1024-1030 8 Cardiovascular system 772-785 702-716 802-824737-752 1 Autonomic Nervous system 581-597523-541 3 Respiratory system 929-955854-876 4 Gastrointestinal system 974-977 893-896 981-1013899-932 3 Endocrine system 680-711 615-650 2 Reproductive system 1129-11671042-1074 3 Renal system 1065-1100991-1012 1024-1037 5 Central Nervous system 448-458 442-449 492-500460-469 512-554473-502 546-568 503-514 3 Special and Somatic senses 606-629572-606 635-670 Midterm Exam. 30%, Quiz 20% FINAL Exam 50%

5. Anatomy and Physiology Defined • Two branches of science that deal with body’s parts and function • Anatomy • The science of body structures and relationships • First studies by dissection (cutting apart) • Imaging techniques • Physiology • The science of body functions

6. Levels of Structural Organization

7. Levels of structural organization • Chemical level: Atoms (C, H, O, N, P, Ca, S), Molecules (DNA, H2O, Glucose) • Cellular level: Cells are the basic structural and functional unit of any organism • Tissue level: Groups of cells and surrounding materials that perform a certain function. • Organ level: composed of different types of tissues that have a recognizable shape and specific functions. • System level (organ-system level): consists of related organs with a common function. • Organismal level: All parts of the body

8. The Eleven Systems of The Human Body

9. The Eleven Systems of The Human Body

10. Basic Life Processes • Metabolism: Sum of all chemical processes in the body • Catabolism: Breakdown • Anabolism: build up • Responsiveness: ability to detect and respond to changes • Movement • Growth: hypertrophy(size) and proliferation(no.) • Differentiation: development of a cell from unspecialized (precursor,stem)to a specialized state.

11. Basic Life Processes • Reproduction: Formation of new cells for growth, repair or replacement or formation of a new individual

12. Homeostasis • A condition of equilibrium (balance) in the body’s internal environment. • Dynamic condition • Shift occur in a narrow range that is compatible with maintaining life. • Example • Blood glucose levels range between 70 and 110 mg of glucose/dL of blood • Whole body contributes to maintain the internal environment within normal limits

13. Homeostasis and Body Fluids • Maintaining the volume and composition of body fluids is important • Body fluids are defined as dilute, watery solutions containing dissolved chemicals inside or outside of the cell • Intracellular Fluid (ICF) • Fluid within cells • Extracellular Fluid (ECF) • Fluid outside cells • Interstitial fluid is ECF between cells and tissues

14. Interstitial Fluid and Body Function • Cellular function depends on the regulation of composition of interstitial fluid (Body’s internal environment) • Composition of interstitial fluid changes as substances move across capillary walls to: • provide nutrients (glucose, oxygen, ions) to tissue cells • remove waste (carbon dioxide) from tissue cells

15. Control of Homeostasis • Homeostasis is constantly being disrupted • Physical insults • Intense heat or lack of oxygen • Changes in the internal environment • Drop in blood glucose due to lack of food • Physiological stress • Demands of work or school • Disruptions • Mild and temporary (balance is quickly restored) • Intense and Prolonged (poisoning or severe infections) • REGULATING SYSTEMS: mainly nervous system and endocrine system

16. Feedback System (Loop) • Cycle of events • Body status is monitored and re-monitored • Each monitored variable is termed a controlled condition • Any change is called a stimulus • Three Basic components • Receptor, ex; nerve endings • Control center, ex; brain • Effector, ex; muscle

17. Feedback Systems • Receptor • Body structure that monitors changes in a controlled condition • Sends input to the control center • Nerve ending of the skin in response to temperature change

18. Feedback Systems • Control Center • Brain • Sets the range of values to be maintained • Evaluates input received from receptors and generates output command • Nerve impulses, hormones • Brain acts as a control center receiving nerve impulses from skin temperature receptors

19. Feedback Systems • Effector • Receives output from the control center • Produces a response or effect that changes the controlled condition • Found in nearly every organ or tissue • Body temperature drops the brain sends and impulse to the skeletal muscles to contract • Shivering to generate heat

20. Negative and Positive Feedback systems • The response feeds back information to the control center to change controlled condition: • Negative Feedback systems • Reverses a change in a controlled condition (Occurs more often) • Regulation of blood pressure (force exerted by blood as it presses again the walls of the blood vessels) • Positive Feedback systems • Strengthen or reinforce a change in one of the body’s controlled conditions (not very often) • Normal child birth

21. Negative Feedback: Regulation of Blood Pressure Good thing • External or internal stimulus increase BP • Baroreceptors (pressure sensitive receptors) • Detect higher BP • Send nerve impulses to brain for interpretation • Response sent via nerve impulse sent to heart and blood vessels • BP drops and homeostasis is restored • Drop in BP negates the original stimulus

22. Positive Feedback Systems: Normal Childbirth Good thing • Uterine contractions pushes baby to cervix • Stretch-sensitive receptors in cervix send impulse to brain • Oxytocin is released into the blood • Contractions are enhanced and so Oxytocin release and baby pushes farther down the uterus • Cycle continues to the birth of the baby (no stretching)

23. Positive Feedback: Blood Loss Bad thing • Normal conditions, heart pumps blood under pressure to body cells (oxygen and nutrients) • Severe blood loss • Blood pressure drops • Cells receive less oxygen and function less efficiently • If blood loss continues • Heart cells become weaker • Heart pumping decrease • BP continues to fall more • May lead to death

24. Homeostatic Imbalances • Normal equilibrium of body processes are disrupted • Moderate imbalance • Disorder: any abnormality of structure and function • Disease: specific term for an illness with recognizable signs and symptoms • Signs are objective changes such as a fever, swelling or high blood pressure • Symptoms are subjective changes such as headache • Severe imbalance • Death

25. Cells and homeostasis Cell structure: 1. Plasma membrane • forms the cell’s outer boundary • separates the cell’s internal environment from the outside environment • lipid bilayer: Glycerol head (hydrophilic backbone) and fatty acid (hydrophobic tail) • is a selective barrier: • lipid soluble substances cross the lipid bilayer • water soluble substances only cross through channels • plays a role in cellular communication

26. Cell structure: 2. Cytoplasm - all the cellular contents between the plasma membrane and the nucleus - cytosol - the fluid portion, mostly water - organelles - subcellular structures having characteristic shapes and specific functions

27. Fig. 3.1 Generalized Body Cell

28. Cell Structure 3. Nucleus - large organelle that contains DNA - contains chromosomes,each of which consists of a single molecule of DNA and associated proteins - a chromosome contains thousands of hereditary units called genes

29. Plasma Membrane • Flexible yet sturdy barrier • The fluid mosaic model - the arrangement of molecules within the membrane resembles a sea of lipids containing many types of proteins • The lipids act as a barrier to certain substances • The proteins act as “gatekeepers” to certain molecules and ions

30. Structure of a Membrane • Consists of a lipid bilayer - made up of phospholipids, cholesterol and glycolipids • Integral proteins – firmly embedded and extended into or through the lipid bilayer • Transmembrane proteins - most integral proteins, span the entire lipid bilayer • Peripheral proteins – more loosely attached to the inner or outer surface of the membrane, do not extend through it

31. Structure of the Plasma Membrane

32. Structure of aMembrane • Glycoproteins - membrane proteins with a carbohydrate group attached that protrudes into the extracellular fluid • Glycocalyx - the “sugary coating” surrounding the membrane made up of the carbohydrate portions of the glycolipids and glycoproteins; functions: • Signature • Adherence • protection • attracts fluid

33. Functions of Membrane Proteins • Integral proteins are Ion channels Transporters - selectively move polar or ionic substances through the membrane Receptors - for cellular recognition; a ligand is a molecule that binds with a receptor Enzymes - catalyze chemical reactions Linkers Mechanical activities and division • Membrane glycoprotein and glycolipids often are: Cell-identity markers, ex. ABO blood type • Peripheral proteins: support the plasma membrane

34. Fig 3.03 Tortora

35. Membrane Permeability • The cell is either permeable or impermeable to certain substances • The lipid bilayer is permeable to oxygen, carbon dioxide and steroids, slightly permeable to water and urea (small uncharged), but impermeable to glucose ( large polar uncharged). • Transmembrane proteins act as channels and transporters to assist the entrance of certain substances, for example, glucose and ions. Very selective • Macromolecules such as proteins only pass by endocytosis and exocytosis.

36. Gradients Across Plasma Membrane • Concentration gradient: Difference in the concentration of a chemical from one place to another ( Na and O2 outside, K and CO2 inside) • Electrical gradient: Difference in electrical charges between two compartments. (Membrane Potential) • Both help substances move across the plasma membrane down their Chemical or electrical gradient to reach equilibrium. (Electrochemical gradient)

37. Diffusion • Passive process due to particles kinetic energy • Move down the concentration gradient( high to low) • Factors affecting Diffusion rate: • Steepness of conc. Gradient (directly) • Temperature (directly) • Mass of diffusing substance (indirectly) • Surface area (directly) • Diffusion distance (indirectly)

38. Diffusion • Through the lipid bilayer : fast • O2, CO2, N • Fatty acids • Steroids • Fat soluble vitamins (A,E,D,K) • Small alcohol and ammonia • H2O and Urea (slightly) • Through membrane ion channels: slower due to surface area. • mostly; K, Cl • Na, Ca • gated channels: open/close

39. Passive vs. Active Transport • Passive processes - substances move across cell membranes without the input of any energy; use the kinetic energy of individual molecules or ion • Active processes - a cell uses energy, primarily from the breakdown of ATP, to move a substance across the membrane, i.e., against a concentration gradient

40. Passive: Simple Diffusion, Channel-mediated Facilitated Diffusion, and Carrier-mediated Facilitated Diffusion High Low Transport maximum-saturation

41. Channel-mediated Facilitated Diffusion of Potassium ions through a Gated K + Channel

42. Extracellular fluid Extracellular fluid Extracellular fluid Plasma membrane Plasma membrane Plasma membrane Cytosol Cytosol Cytosol Glucose transporter Glucose transporter Glucose transporter Glucose Glucose Glucose 1 1 1 Glucose gradient Glucose gradient Glucose gradient 2 2 3 Glucose Carrier-mediated Facilitated Diffusion of Glucose across a Plasma Membrane

43. Extracellular fluid Extracellular fluid Extracellular fluid Na+ gradient Na+ gradient Na+ gradient 3 Na+ expelled 3 Na+ expelled 3 Na+ expelled 2K+ 2K+ Na+/K+ ATPase Na+/K+ ATPase Na+/K+ ATPase P P P 3 Na+ 3 Na+ 3 Na+ Cytosol Cytosol Cytosol K+ gradient K+ gradient K+ gradient ATP ATP ATP 2 K+ imported 1 1 1 2 2 2 3 3 4 P P ADP ADP ADP Active Transport Solutes are transported across plasma membranes with the use of energy, from an area of lower concentration to an area of higher Concentration Sodium-potassium pump Extracellular fluid Na+ gradient Na+/K+ ATPase 3 Na+ Cytosol K+ gradient 1

44. Osmosis • Net movement of water through a selectively permeable membrane from an area of high concentration of water (lower concentration of solutes) to one of lower concentration of water • Water can pass through plasma membrane in 2 ways: • through lipid bilayer by simple diffusion • through aquaporins, integral membrane proteins

45. This Membrane is impermeable to the solute Fig 3.6

46. Osmosis, Hydrostatic pressure and Osmotic pressure • Hydrostatic pressure: Pressure exerted by a liquid • Osmotic pressure: Due to impermeable solute particles (high conc.)

47. Tonicity and its effect on RBCS Shrink Lysis, explode

48. Clinical Application on solutions tonicity • Intravenous solutions: • Normally: Isotonic ( Saline 0.9% NaCl) and (Dextrose 5%) • Cerebral edema: hypertonic solution are useful • Dehydration: hypotonic solutions

49. Transport in Vesicles • Vesicle- a small spherical sac formed by budding off from a membrane • Endocytosis - materials move into a cell in a vesicle formed from the plasma membrane three types: receptor-mediated endocytosis phagocytosis bulk-phase endocytosis (pinocytosis) • Exocytosis - vesicles fuse with the plasma membrane, releasing their contents into the extracellular fluid • Transcytosis - a combination of endocytosis and exocytosis

50. 1 1 1 1 1 1 Binding Binding Binding Binding Binding Binding Receptor-LDL complex Receptor-LDL complex Receptor-LDL complex Receptor-LDL complex Receptor-LDL complex Receptor-LDL complex Plasma membrane Plasma membrane Plasma membrane Plasma membrane Plasma membrane Plasma membrane LDL particle LDL particle LDL particle LDL particle LDL particle LDL particle Receptor Receptor Receptor Receptor Receptor Receptor Invaginated plasma membrane Invaginated plasma membrane Invaginated plasma membrane Invaginated plasma membrane Invaginated plasma membrane Invaginated plasma membrane Clathrin-coated pit Clathrin-coated pit Clathrin-coated pit Clathrin-coated pit Clathrin-coated pit Clathrin-coated pit 2 2 2 2 2 Vesicle formation Vesicle formation Vesicle formation Vesicle formation Vesicle formation Clathrin-coated vesicle Clathrin-coated vesicle Clathrin-coated vesicle Clathrin-coated vesicle Clathrin-coated vesicle 3 3 3 3 Uncoating Uncoating Uncoating Uncoating Transport vesicle Transport vesicle Uncoated vesicle Uncoated vesicle Uncoated vesicle Uncoated vesicle 4 4 4 Fusion with endosome Fusion with endosome Fusion with endosome 5 5 Recycling of receptors to plasma membrane Recycling of receptors to plasma membrane Endosome Endosome Endosome 6 Degradation in lysosome Transport vesicle Transport vesicle Transport vesicle Digestive enzymes Lysosome Receptor-Mediated Endocytosis