INTRODUCTION TO PHYSIOLOGY.ppppppppppptx

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1. INTRODUCTION TO MEICAL PHYSIOLOGY

2. Definition Physiology is study of the body processes/mechanisms and functions of all animals and plants in their normal state. an integrative science Figure 1-1: Levels of organization and the related fields of study

3. Definition- ct Physiology tells us how and why the bodies of living organisms work. It focuses on how and why body systems, organs , tissues, cells, and biomolecules work together to sustain life. It is the science of body normal functions It can be simply put as the study of the normal body functions It is worth noting that Structure and Function are intimately linked and thus Structure dictates the Function e.g. think of how the kidneys/skin of the following organisms dictate their functions so that the animals can survive well in their different habitats Abnormal body function is called pathophysiology as we are going to see in many diseases later. Environment and competition "naturally" select genes that give rise to Structures that have favorable Functions to improve the viability of each species e.g. a kangaroo in the desert, sea bass in salty ocean water  

4. Process/mechanism & Function Integrate both for complete picture! How do we breathe? How does blood flow? How do RBCs transport O 2 ? Why do we breathe? Why does blood flow? Why do RBC transport O 2 ? Distinguish between

5. Two views It has two views: Teleological vs Mechanistic views Teleological – the why, explains purpose of a physiological process Mechanistic – the how, explained in terms of cause and effect of physiological process Example: shivering Teleological - shivering elevates a low body temperature Mechanistic - when body temperature drops below normal, a reflex pathway causes involuntary oscillating skeletal muscle contractions which produce heat

6. LEVELS OF BODY ORGANIZATION Chemical Cellular Tissue Organs System Level Organismic Level A cell is the smallest functional unit of life. All living organisms are composed of one or more cells. Can you remember an example of unicellular and multicellular organisms ?

7. Chemical Level Organization Chemical Level - atomic and molecular level Chemical level Atoms, molecules, macromolecules Nucleic acids, Proteins, Carbohydrates, Lipids

8. Cellular Organization Cells are the smallest functional and structural unit of life They have basic and specialized functions Specialized function requires differentiation Review the various organelles in a cell and their functions Cells manifest the basic characteristics of living things- “MRS GREN” (movement, respiration, sensitivity, growth, reproduction, excretion, nutrition) Other characteristics- Homeostasis, adaptation, interaction Watch this video. GCSE Biology - Characteristics of Living Things (Organisms) #3 - Bing video

9. Tissue Level of Organization Tissue level Group of cells and the materials surrounding them that work together on one task Cells of similar shape and specialized function 4 basic tissue types: epithelium, muscle, connective tissue, and nerve Four major tissue types Muscle Specialized for contracting and generating tension Nervous Specialized in impulse production and transmission Connective Specialized for connecting and supporting Epithelial Specialized for surface lining and exchange From you cell biology and genetics what are The characteristics of the above tissues? The functions of the above tissues?

10. Organ level - consists of two or more types of primary tissues that function together to perform a particular function or functions Example: Stomach Inside of stomach lined with epithelial tissue Wall of stomach contains smooth muscle Nervous tissue in stomach controls muscle contraction and gland secretion Connective tissue binds all the above tissues together Organ Level Organization

11. System Level Organization Organs system level Composed of two or more organs that work to perform a common functions that is essential to survival Groups of organs that perform related functions and interact to accomplish a common activity essential to survival of the whole body Do not act in isolation from one another Human body has 11 systems

12. Body Systems

13. Body Systems

14. Body systems do not act in isolation from one another! Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings.

15. Homeostasis Called it ‘homeostasis’ (Greek, homeo = same; stasis = staying). Defined as maintenance of a relatively stable internal environment within and around the body E.g Temp.37 degrees C, pH 7.3-7.4 Other factors that are regulated? Does not mean that composition, temperature, and other characteristics are absolutely unchanging The structure and chemical reactions of living organisms are sensitive to the chemical and physical conditions within and around cells. Homeostasis is essential for survival and function of all cells Each cell contributes to maintenance of a relatively stable internal environment The internal environment is made up of the extra cellular fluid or ECF Cells that are isolated from the external environment can still exchange materials with the ECF

16. Homeostasis Homeostasis is essential for survival of cells in that : • Cells need homeostasis for their own survival and for performing specialized function essential to survival of the whole body. • Cells need a constant supply of nutrient and oxygen and ongoing elimination of acid-forming carbon dioxide, to generate energy needed to power life sustaining cellular activities as follows: Food + Oxygen = Carbondioxide + water + Energy

17. Maintenance of Homeostasis Nervous system Controls and coordinates bodily activities that require rapid responses Detects and initiates reactions to changes in external environment Endocrine system Secreting glands of endocrine regulate activities that require duration rather than speed Controls concentration of nutrients and, by adjusting kidney function, controls internal environment’s volume and electrolyte composition

18. Role of Body Systems in Homeostasis

19. Homeostasis Factors homeostatically regulated include Concentration of nutrient molecules Concentration of water, salt, and other electrolytes Concentration of waste products Concentration of O 2 = 100mmHg and CO 2 = 40 mmHg pH = 7.35 Blood volume 4-6 L osmolality, and pressure 120/80 Temperature = 37 o C

20. Control of Homeostasis Homeostasis is continually being disrupted by External stimuli heat, cold, lack of oxygen, pathogens, toxins Internal stimuli Body temperature Blood pressure Concentration of water, glucose, salts, oxygen, etc. Physical and psychological distresses Disruptions can be mild to severe If homeostasis is not maintained, illness and death may result

21. Control of Homeostasis

22. Body fluids Body cells are in contained in watery internal environment through which life-sustaining exchanges are made Extracellular fluid (ECF) - Fluid environment in which the cells live (fluid outside the cells) Two components: Plasma Interstitial fluid Intracellular fluid (ICF) - Fluid contained within all body cells

23. Homeostasis

24. Cells, the fundamental units of life, exchange nutrients and wastes with their surroundings: The intracellular fluid is “conditioned by”… the interstitial fluid, which is “conditioned by” … the plasma, which is “conditioned by” … the organ systems it passes through. Balancing the Internal and External Environment ICF ISF plasma organs external environment internal environment

25. COMPOSITION OF THE BODY At an average, 60% of the body weight of young adult male is water. The remaining is composed of minerals, fat and proteins. The human body contains organic compounds such as lipids, proteins, carbohydrates and nucleic acids.

26. COMPOSITION OF THE BODY The lipids are important forms of storage fuel in addition to providing insulation of the body as a whole or essential component in the structure of plasma membranes, myelin and other membranes. Carbohydrates serve as a lesser form of fuel storage (400-500 gms). Proteins serve as the structural basis for all enzymes, contractile muscle proteins, connective tissue, such as collagen and elastin and in addition as a fuel (about 15%), or precursor for carbohydrate in the process of gluconeogenesis. Ingested glucose is converted to glycogen and stored in the liver, muscle and adipose tissue.

27. Elements in the Human Body Element Body weight % Hydrogen, H 9.5 Carbon, C 18.5 Nitrogen, N 3.3 Oxygen, O 65.0 Sodium, Na 0.2 Magnesium, Mg 0.1 Phosphorus, P 1.0 Sulfur, S 0.3 Chlorine, Cl 0.2 Potassium 0.4 Calcium 1.5

28. Our Bodies Require Energy What is energy? Energy is the capacity to do work, this puts matter into motion 1. Potential energy - energy stored in a structure water stored in a lake uphill chemical bonds of glucose molecule 2. Kinetic energy - energy in an object in motion water in a stream - allows mill to grind corn broken glucose bonds -> ATP -> muscles work

29. Forms of Energy Chemical energy – is the energy in chemical bonds e.g. ATP (adenosine triphosphate) - which stores energy in the body Electrical energy - energy of separated charges e.g. Battery - + pole and - pole separate charge also the nervous impulse run just like a battery Mechanical energy - energy of matter in motion e.g. a bowling ball transfers energy to move pins also muscle contraction. Electromagnetic energy - energy traveling in waves (light, X-rays, UV rays) e.g. electromagnetic spectrum - visible light, UV light, radio waves, X-rays

30. Our Bodies Require Energy Examples: Car Engine vs. Human Body a. Car Engine - gasoline used to run motor to move car: Chemical Energy (in gasoline) --->changes to mechanical energy in the motor that produces motion (20%) + heat (79%) + sound (1%) Human Body - food used to move body, digest, think, etc. Chemical Energy (food/glucose) --> physiological functions (80%) + heat (20%) Our bodies convert energy from one form to another

31. ORGANIZATION OF MATTER (ATOMS - ELEMENTS)   Atom is the smallest component of an element having the chemical properties of the element.   It cannot be broken by any chemical means.   A typical atom consists of a nucleus of protons and neutrons with electrons orbiting this nucleus. Examples of Atoms: hydrogen, carbon-14, zinc, A substance can be an atom and an isotope or ion at the same time

32. 3 Particles found in an Atom Proton - has a positive charge and this what defines element Electron - has a negative charge and this determines element bonding properties Neutron -has a neutral charge and this what defines isotopes

33. Structure of Atoms (AKA elements) Some Terminology: Atomic Number Atomic mass Ion Isotope Fig 2-3 Fig 2.1

34. -The number of protons gives us what is called atomic number (unique for each element) -The number of protons + the number of neutrons = give us atomic mass -Isotopes belong to the same element but different is the number of neutrons they contain  

35. An isotope A substance can be an atom and an isotope or ion at the same time  An isotope is an Atom with the same number of protons , but differing numbers of neutrons . Isotopes are different forms of a single element . Examples of Isotopes: Carbon 12 and Carbon 14 are isotopes of carbon , one with 6 neutrons and one with 8 neutrons (both with 6 protons).

36. Most common Much rarer Isotopes = Atoms of an element that have different numbers of neutrons. Same Atomic Number, variable Atomic Mass Heavy water = ?

37. Some isotopes are unstable: R adioisotopes 3 types of radiation:  radiation – protons and neutrons (If protons are emitted, the element changes!)  radiation - electrons  radiation: high energy waves, not particles More stable atom of same element

38. Nuclear Medicine: use of radioisotopes in diagnosis & treatment of disease. 127 I is “normal” iodine 131 I has 4 extra neutrons Medical Imaging ? Treatment?  and  radiation

39. Importance of Electrons in Physiology Ion formation = gain or loss of electrons Bond formation between atoms  molecules Energy capture & transfer Free radical formation Ions are often called electrolytes!

40. Types of Chemical Bonds 1. Ionic Bond : one atom donates electron(s) to another Example: Sodium Chloride (table salt) Na + Cl­ - 2. Covalent Bond : two atoms share one/more electrons Example: Methane (CH 4 ), Carbon Dioxide (C0 2 ), and Ammonia (NH 3 ) 3. Hydrogen Bond : weak attraction between H atoms and O, N, and Fl. Causes surface tension in water. 4. Van der Waal’s forces : weak attractions between nuclei of atoms

41. Ionic Bonding Fig 2-4

42. If two electrons are shared, that is a “double bond.” Covalent bond: Water The electrons are shared equally

43. Polar covalent molecule Non-polar covalent molecules Consequence: ions and polar molecules dissolve well in water

44. Hydrogen bonds = weak attraction between H and nearby O, N or F. Critical for protein structure Hydrogen bonding of H 2 O leads to important characteristics: Liquid at RT Universal solvent for polar molecules Temp. buffer / frozen water less dense Capillary action Surface tension

45. Important Ions in Physiology

46. Element = Building block of matter Contains only atoms with same # of protons In human: 11 major essential elements COH NSPMgKCaFe + trace elements Organic Chemistry = Chemistry of Carbon Some scientists say that the human body is “a walking periodic table”, since in contains a variety of chemicals found in our environment.

47. Major Essential elements in the human body include:  Carbon C: Component of all in organic materials in the body Hydrogen H: Component of proteins, carbohydrates and fats Oxygen O: Component of proteins, carbohydrates and fats Nitrogen N: Component of proteins Calcium n C: Bones, teeth, muscle and nerve action, blood clotting Phosphorus P: Bones and Teeth, DNA, RNA, ATP. Important in energy transfer

48. Major Essential elements-ct Potassium K: Osmotic balance; cell voltage, muscle and nerve action Sulfur S: Component of proteins (cysteine) and other organic molecules Sodium Na: Osmotic balance; cell voltage, muscle and nerve action Magnesium Mg: Co-factor for many enzymes Iron Fe: Hemoglobin and many enzymes

49. Trace Elements (Less than 1 % of body weight altogether) Chlorine Cl: Osmotic balance; cell voltage, muscle and nerve action Copper Cu : Co-factor of many enzymes Zinc Zn : Co-factor of many enzymes Manganese Mn: Co-factor of many enzymes Cobalt Co: Co-factor of many enzymes and vitamin B 12 Chromium Cr: Co-factor of many enzymes and potentiates Insulin

50. Trace Elements-ct Selenium Se : Required for normal liver function Molybdenum Mo: Co-factor of many enzymes Flourine F : Teeth and bones Tin Sn : Promotes growth (unknown mechanism) Silicon Si: Growth, bone mineralization, connective tissue synthesis Vanadium V: Promotes growth and reproduction

51. CHEMICAL REACTIONS Synthesis or Anabolism Smaller molecules form larger molecule This type of reaction requires energy Examples A + B  AB (anabolic process) Amino acid 1 + amino acid 2 + ..........  peptide (protein) Sugar 1 + sugar 2 + sugar 3 + ............  polysaccharide (glycogen)  

52. CHEMICAL REACTIONS-ct 2. Decomposition or Catabolism: Larger molecule broken down into smaller molecules This type of reaction requires energy Examples AB  A + B (catabolic process) Glycogen ---> glucose + glucose + glucose +...........

53. CHEMICAL REACTIONS-ct 3. Displacement - one part is exchanged Examples AB + C  A + BC Glucose + adenosine-P- P-P (ATP)  glucose-P + adenosine-P-P (ADP)  

54. Factors affecting the Rates of Chemical Reactions Size of reactants species (smaller means faster Temperature (speeds up the particles) Concentration (more likely to come together) 4. Catalysts (enzymes ) - make reacting more convenient

55. Body Molecules Chemical compounds are generally divided into two categories. In the first category are the inorganic compounds that are composed of relatively small molecules bonded ionically. In the second category fall the organic compounds that mainly consist of carbon and hydrogen and build up the human body. Certain salts (NaCl, CaCl), which are inorganic compounds, exist in the human body as dissolved in water. Inorganic vs Organic Compounds

56. More than 62% of our body is water. The percentage depends on the age of the human being- in children this percentage is higher than in an adult’s body. Our daily consumption of water is approximately 2.7 L. This amount of water may come from a variety of sources: food, metabolism, drinking, and etc. H2O regulates homeostasis and the body is not able to function properly without it. Water

57. Any substance that releases hydrogen positive ions (when it is dissolved in water) is called an acid. Any substance that releases hydroxyl negative ions is called a base. An ionic substance that contains a negative ion other than OH- or O2- is called a salt. When acid reacts with base, the products are salt and water. This process is called neutralization. Acids, Bases, and Salts

58. The numerical scale that measures acidity or alkalinity is called a pH scale. It is a number between 0 to 14. the pH of water is 7. It is considered to be neutral. Any substance having a pH higher than 7 is considered to be acidic and any substance having a pH lower than 7 is considered to be basic. in order homeostasis to be maintained in the human body, body fluids (including blood) need to have a relatively constant pH. pH

59. When a strong acid or base appears in the human organism, it may be destructive for the human cells. Substances called buffers (combinations of weak acids or weak bases and their respective salts in a solution) help the body fluids to resist changes in pH and to maintain the balance in the organism. Buffers

60. Carbohydrates are the major source of energy for most cells. They can be broken down in the cells in order energy to be released. Composition: carbon, hydrogen, and oxygen in a ratio twice as much hydrogen as oxygen (example: CH2O, but they can be more complex). Carbohydrates

61. Monosaccharides (comes from Greek ) are the simplest type of carbohydrates. They are the building blocks of more complex sugars and cannot be broken down by hydrolysis. Disaccharides (Di means 2) are the two monosaccharides bounded together. They all have the same chemical formula but differ in structure. (example: glucose, fructose). The third type of carbohydrates are polysaccharides (poly means many). Polysaccharide chains (called polymers) may contain hundreds and thousands of monosaccharides. Their general formula is (C6H10O5)n, n-the number of glucose units in the molecule. Kinds of Carbohydrates

62. Fats are molecules that are rich in energy and are a source of food reserve and long-term fuel. They are stored in the organism in the form of neutral fats or triglyceride. Each fat molecule is composed of glycerol and fatty acids. Two types of fatty acids exist: saturated fatty acids (solids at room temperature) unsaturated fatty acids – oils (liquid at room temperature) Fats

63. These are fatty compounds containing alcohol, fatty acids, and a phosphate group (PO43-), often linked with a nitrogen containing group. Fatty acid Fatty acid glycerol phosphate alcohol Every phospholipid has a hydrophilic head and non-polar tails. This is important, for phospholipids build cell membranes and they are all arranged with the water-loving heads on one side and the tails- on the other. Phospholipids

64. These are fat-soluble compounds composed of four bonded carbon rings, consisting of 17 carbons. Examples: cholesterol, male and female sex hormones, etc.) Steroid hormones help regulate certain phases of metabolism in the body such as puberty, menopause, etc. Steroids

65. These organic compounds compose most of the tissues of the body. They contain carbon, hydrogen, oxygen, nitrogen (sometimes sulfur), phosphorus, and iron. Proteins form enzymes that control chemical activity (during the break-down of food molecules in the stomach), protect us against diseases in the form of antibodies, carry oxygen throughout the body, make up some of the hormones, express genetic information, and serve as indicators. enzyme A B enzyme A B enzyme A+B Proteins

66. R H H H C N O O C a Amino acids are the basic building units of proteins. They always contain an amino group (NH2) at one end of the molecule and a carboxyl group at the other. An amino acid contains one variable component. They may occur in different chemical combinations. They simplest amino acid is the glycine. It has only one hydrogen atom. We know only 22 amino acids in the living organisms. However, their large variety of combinations can create more than 50000 proteins in the organism. Amino Acids

67. Nucleic acids are very large and complex molecules. They carry the body’s hereditary messages and regulate the synthesis of proteins. The building blocks of NA are called nucleotides. In 1869, the Swiss physician Friedrich Miescher first isolated them from the nuclei of human pus cells. There are two types of nucleic acids: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nucleic Acids

68. May be present in either the nucleus or the cytoplasm actually, there are three types - messenger R(mRNA) carries genetic information from DNA - transfer RNA (tRNA) is involved in amino-acid activation during protein synthesis - ribosomal RNA(rRNA) is involved in ribosome structure. Makes up the chromosomes within the cell’s nucleus holds the genetic code controls heredity Determines which proteins will be synthesized in a cell and thus controls the cell’s activity RNA DNA DNA and RNA

69. The energy that is produced from chemical reactions in body is stored in a small organic molecule called ATP(adenosine triphosphate). When energy is needed, ATP is broken down through hydrolysis and releases the necessary energy. ATP  ADP(adenosine triphosphate) + Pi(inorganic phosphate) + Energy ATP