Introduction to Anatomy and Physiology .

Introduction to anatomy and physiology

1. Chapter 1 Introduction to Human Anatomy and Physiology Clement Mwenje BScN , MU

2. ANATOMY AND PHYSIOLOGY Definition of terms Anatomy is the study of the structure (morphology) of the body and its parts. Physiology is the study of the functions of the anatomical parts The two disciplines are closely interrelated because the functional role of a part depends on how it is constructed.

3. Anatomical Terminology Relative Positions: 1. Terms of relative position are used to describe the location of a part relative to another part. They include: Superior vs Inferior Anterior vs Posterior Medial vs Lateral Proximal vs distal S uperficial (peripheral) vs deep.

4. Anatomical position The erect position of the body The face directed forward The arms at the side The palms of the hands facing forward Thumbs pointing laterally

5. Body Sections: 1. A sagittal section divides the body into right and left portions. 2. A transverse section divides the body into superior and inferior portions. It is often called a “ cross section ” . 3. A coronal section divides the body into anterior and posterior sections.

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7. Body Regions 1. The abdominal area can be divided into: four regions nine regions. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

8. Abdominopelvic Regions

9. -The epigastric region is located superior to the umbilical region (epi = above; gastri = stomach). -The hypogastric (pubic) region is located inferior to the umbilical region (hypo = below). -The right and left iliac , or inguinal, regions are located lateral to the hypogastric region (iliac = superior part of the hip bone). Terms used to refer to various body regions

10. -The right and left lumbar regions lie lateral to the umbilical region. -The right and left hypochondriac regions are lateral to the epigastric region (chondro = cartilage).

11. Levels of Organization of the human body:

12. 1. Atoms are the simplest level. 2. Two or more atoms comprise a molecule. 3. Macromolecules are large, biologically important molecules inside cells. 4. Organelles are aggregates of macromolecules used to carry out a specific function in the cell. 5. Cells are the basic living unit. 6. Tissues are groups of cells functioning together. 7. Groups of tissues form organs. 8. Groups of organs function together as organ systems. 9. Organ systems functioning together make up an organism. Levels of organization .

13. ORGANIZATION OF THE HUMAN BODY Major features of the human body include its cavities, membranes, and organ systems. Body Cavities: - The body can be divided into: - appendicular portion (upper and lower limbs) - axial portion (head, neck, and trunk ) - Major cavities includes a dorsal and a ventral cavity . - Organs within these cavities are called viscera.

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15. a. The dorsal cavity can be divided into the crania l cavity and vertebral canal. b. The ventral cavity is made up of a thoracic cavity and an abdominopelvic cavity, separated by the diaphragm. i . The mediastinum divides the thorax into right and left halves. ii. The abdominopelvic cavity can be divided into the abdominal cavity and the pelvic cavity. c. Smaller cavities within the head include the oral cavity, nasal cavity, orbital cavities, and middle ear cavities.

16. Thoracic and Abdominopelvic Serosal Membranes: 1. The thoracic cavity is lined with pleura ; the parietal pleura lines the cavities while the visceral pleura covers the lungs. A thin layer of serous fluid separates the two layers. 2. The heart is surrounded by pericardium . The visceral pericardium covers the heart and the parietal pericardium makes up an outer sac. Serous fluid separates the two layers. 3. Peritoneum lines the abdominopelvic cavity ; a parietal peritoneum lines the wall while visceral peritoneum covers the organs. *( serosa - A thin membrane lining the closed cavities of the body; has two layers with a space between that is filled with serous fluid)

17. Body systems: The human body has 11 systems 1-INTEGUMENTARY ORGANS Skin FUNCTIONS Cushions, protects deeper tissue Excretes salts & urea; senses pain, pressure Regulates body temp; synthesize vitamin D

18. 2-SKELETAL ORGANS Bones, cartilages, ligaments, joints FUNCTIONS Protects & supports body organs Body Framework muscle attachment & movement Hematopoiesis; Storage of minerals

19. 3- MUSCULAR ORGANS Skeletal muscle (attached to bone) FUNCTIONS Contraction & mobility (locomotion) Facial expression, posture Produce body heat

20. 4- NERVOUS ORGANS Brain, spinal cord, nerves, & sensory receptors FUNCTIONS Responds to external/internal stimuli via nerve impulses (electrical messages)

21. 5- ENDOCRINE ORGANS Pituitary, thyroid, parathyroids, adrenals, thymus, pancreas, pineal, ovaries, testes…..etc. FUNCTIONS Glands produce hormones that regulate growth, reproduction, metabolism,…. etc.

22. 6- CIRCULATORY ORGANS Heart, blood vessels & blood FUNCTIONS Carries O 2, nutrients, hormones, & other substances to and from tissue cells White blood cells protect against bacteria, toxins, tumors

23. 7- LYMPHATIC ORGANS Lymphatic vessels, lymph nodes, spleen, tonsils FUNCTIONS Assists the circulatory system by returning leaked fluid back to blood vessels Involved in immunity

24. 8- RESPIRATORY ORGANS Nasal cavity, pharynx, larynx, trachea, bronchi, & lungs FUNCTIONS Keeps blood supplied with O 2 & removes CO 2 Carries out gas exchanges through air sacs in lungs

25. 9- DIGESTIVE ORGANS Oral cavity, esophagus, stomach, small intestine, large intestine, rectum, anus (liver & pancreas) FUNCTIONS Breaks down food into absorbable units that enter the blood; while indigestible food is eliminated as feces

26. 10- URINARY (EXCRETORY) ORGANS Kidney, ureter, urinary bladder, urethra FUNCTIONS Eliminates nitrogenous waste from the body (urea & uric acid) Regulates water, electrolytes, & acid-base balance of the blood

27. 11- REPRODUCTIVE ORGANS Male Seminal vesicles, prostate, penis, vas deferens, testis, scrotum Female Ovaries, mammary glands, uterus, vagina, uterine tube FUNCTIONS Primary function for both sexes is to produce offspring Male – testes produce sperm & male sex hormones Female – ovaries produce eggs & female sex hormones; mammary glands for nourishment

28. HOMEOSTASIS Is the body’s ability to maintain relatively stable internal conditions even though the outside environment is continuously changing The literal translation of homeostasis is “unchanging,”( homeo= the same, stasis = standing still which is not true).

29. In general, the body is in homeostasis when its needs are adequately met and it is functioning well. Homeostatic control mechanisms are TWO: Negative feedback mechanisms Positive feedback mechanisms

30. Negative Feedback Mechanisms Most homeostatic control mechanisms are negative feedback mechanisms. NEGATIVE FEEDBACK MECHANISMS push a system back to its original equilibrium position E.g. Imagine you are out walking in the country. As you walk, the sun rises higher in the sky and the air temperature increases. Your body senses that your internal temperature is rising above 370C and you start to sweat, which reduces your body temperature by evaporating water from your skin, returning your temperature to normal

31. Positive feedback mechanisms POSITIVE FEEDBACK MECHANISMS – push a system to a new state of equilibrium E.g., Imagine you are lost on a high snowy mountain. When your body senses that it is cooling below 37 C, various mechanisms such as shivering help to raise your internal temperature again,

32. Chapter 2 Chemical Basis of Life

33. Introduction: A. Chemistry deals with the composition of substances and how they change. B. A knowledge of chemistry is necessary for the understanding of physiology because of the importance of chemicals in body processes.

34. Structure of Matter: A. Elements and Atoms: Living organisms require about 20 elements, of which oxygen, carbon, hydrogen, and nitrogen are most abundant. Elements are composed of atoms; atoms of different elements vary in size and in how they interact. B. Atomic Structure: 1. An atom consists of a nucleus containing protons and neutrons , with electrons in orbit around the nucleus in shells.

35. C. Bonding of Atoms: 1. Atoms form bonds by gaining, losing, or sharing electrons. 2. Electrons are found in shells around the nucleus. a. The first energy shell holds two electrons; the other energy shells each hold eight electrons when on the outside.

36. D. Types of chemical bonds Covalent bonds - are formed when atoms share electrons to become stable with filled outer shells. Ionic bonds - A chemical bond in which one atom loses an electron to form a positive ion and the other atom gains an electron to form a negative ion Hydrogen bonds - A chemical bond that occurs when hydrogen forms a covalent bond with another atom e.g with Oxygen in H2O

37. Formation of a Covalent Bond in the O2 molecule.

38. Formation of ionic bond in the NaCl molecule

39. E. Formulas: 1. A molecular formula represents the numbers and types of atoms in a molecule. 2. Various representations, called structural formulas, can be used to illustrate molecules.

40. F. Chemical Reactions: 1. A chemical reaction occurs as bonds are formed or broken between atoms, ions, or molecules. 2. Those changed by the reaction are the reactants ; those formed are the products . 3. Two or more atoms or molecules can be joined during synthesis . 4. Larger molecules can be broken into smaller ones in decomposition reactions. 5. Reversible reactions are symbolized by using two arrows. 6. Catalysts influence the rates of chemical reactions. E.g H2O + CO2 HCO3- +H+

41. WATER Water constities 50% to 70% o the human body weight Properties of water Solvency - ability to dissolve other chemicals (universal solvent) Adhesion - water adheres to body tissues and forms a lubricating film on membranes such as pleura and pericardium Cohesion - due to hydrogen bonds. Cohesion of water is especially evident when water hangs in drops from a leaky object Chemical reactivity- ability to participate in chemical reactions Thermal stability- ability of water to stabilize the internal temperature of the body

42. pH pH (potential of hydrogen) is a numeric scale used to specify the acidity or basicity of an aqueous solution. The pH scale 1-3 : strong acid e.g gastric acid, sulphuric acid 4-6 : weak acid e.g carbonic acid, acetic acid 7 : Neutral e.g pure water, blood 8-10: weak base e.g Ammonia 11-14 : strong base e.g sodium hydroxide

43. G. Acids and Bases: 1. Substances that release ions in water are called electrolytes . E.g sodium and potassium and hydrogen ions 2. Electrolytes that release hydrogen ions in water are called acids . 3. Electrolytes that release ions that combine with hydrogen ions in water are called bases .

44. 4. The concentrations of H+ & OH- in the body is very important to physiology. 5. pH represents the concentration of hydrogen ions [H + ] in solution.

45. Chemical Constituents of Cells: Compounds that contain both hydrogen and carbon are called organic, the others are inorganic

46. A. Inorganic chemistry Inorganic Substances 1. Water a. Water is the most abundant compound in living things and makes up two-thirds of the weight of adults. b. Water is an important solvent; most metabolic reactions occur in water.

47. Inorganic Substances 2. Oxygen - Oxygen is needed to release energy from nutrients - Used to drive the cell's metabolism. 3. Carbon Dioxide Carbon dioxide is released as a waste product during energy-releasing metabolic reactions.

48. Inorganic Substances 4. Inorganic Salts a. Inorganic salts are the sources of ions of sodium, chloride, potassium, calcium, magnesium, phosphate, carbonate, bicarbonate, and sulfate. b. These electrolytes play important roles in many of the body's metabolic processes.

49. B. Organic chemistry Organic Substances: Carbohydrates a. Carbohydrates provide energy for cellular activities and are composed of carbon, hydrogen, and oxygen. b. Carbohydrates are made from monosaccharides (simple sugars); disaccharides are two monosaccharides joined together; complex carbohydrates (polysaccharides ), such as starch, are built of many sugars.

50. 2. Lipids: a. Lipids are insoluble in water and include fats, phospholipids, and steroids. b. Fats supply energy, are composed of oxygen, carbon, and hydrogen, and are built from glycerol and three fatty acids.

51. 2. Lipids: Phospholipids contain glycerol, two fatty acids, and a phosphate group, and are important in cell structures. d. Steroids are complex ring structures, and include cholesterol, which is used to synthesize the sex hormones.

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53. 3. Proteins: a. Proteins have a great variety of functions in the body---as structural materials, as energy sources, as certain hormones, as receptors on cell membranes, as antibodies, and as enzymes to catalyze metabolic reactions.

54. 3. Proteins: b. Proteins contain C, O, H, and nitrogen atoms; some also contain sulfur. c. Building blocks of proteins are the amino acids , each of which has a carboxyl group, an amino group and a side chain called the R group.

55. 3. Proteins: d. Proteins have complex shapes held together by hydrogen bonds. e. Protein shapes, which determine how proteins function, can be altered (denatured) by pH, temperature, radiation, or chemicals.

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57. 4. Nucleic Acids : a. Nucleic acids form genes and take part protein synthesis. b. They contain carbon, hydrogen, oxygen, nitrogen, and phosphorus, which are bound into building blocks called nucleotides.

58. 4. Nucleic Acids : c. Nucleic acids are of two major types: DNA (with deoxyribose ) and RNA (with ribose). d. RNA (ribonucleic acid) functions in protein synthesis; while DNA (deoxyribonucleic acid) stores the molecular code in genes.  

59. END Qns ?