1. Chapter 1 The Study of Body Function Remon Wahba, MD

2. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 1 Outline  Introduction to Physiology  Scientific Method  Homeostasis  Tissues:  Muscle Tissue  Nervous Tissue  Epithelial Tissue  Connective Tissue  Organs & Systems

3. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Human Physiology  Physiology:  Study of the function of the body  How the body works to Maintain Life  Cell & Tissue  Organs  Systems  Pathophysiology:  How physiological processes are altered in disease or injury 1-3

4. Scientific Method 1-4

5. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Scientific Method  Four Steps:  Observation  Hypothesis  Experiment  Conclusion  Theory  General statement explaining natural phenomena that is based on proven hypotheses (Experiments)

6. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Testing of Hypotheses  Involves:  Experimental & control groups  Quantitative measurements performed blindly  Analysis of data 1-6

7. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Using Scientific Method to Develop New Drugs When a new drug is suggested by experiments:  First step  Test Its effectiveness & toxicity in:  Tissue culture  Experimental animals  Rats  Mice 1-7

8. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Using Scientific Method to Develop New Drugs  Clinical Trials performed  Phase I Trials: Toxicity & metabolism tested in healthy human volunteers  Phase II Trials: Effectiveness & toxicity tested in target population  Phase III Trials: Widespread test of drug in diverse population  Phase IV Trials: Drug is tested for other uses 1-8

9. Homeostasis 1-9

10. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Homeostasis  Maintenance of the internal environment Constant  Dynamic Constancy  Around physiological set points  Failure of Homeostasis leads to illness or death  Maintained mainly by Negative Feedback Loops 1-10

11. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Homeostasis  Two Regulatory Mechanisms:  Intrinsic  Control is built-in the organ being regulated  Extrinsic  Control comes from outside of organ by  Nervous System  Nervous control of Body Temperature  Endocrine system  Hormonal control of Blood Glucose level 1-12

12. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Homeostasis

13. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Homeostasis  Negative Feed Back  The response opposes the stimulus  To counteract further changes and bring Homeostasis  Positive Feed Back  The response enhances the original stimulus  To speed up the change

14. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Negative Feedback Loops  Sensor:  Detects deviation from set point  Integrating center:  Determines response  Effector:  Produces response Fig 1.1 1-11

15. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Negative Feedback: The Control of Body Temperature Figure 1.5

16. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Negative Feedback: The Control of Blood Pressure

17. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Negative Feedback Hormonal Control of Blood Glucose Fig 1.6 1-13

18. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Positive Feedback Loops  Self-Amplifying change  The response enhances the original stimulus  Normal way of producing rapid changes  Occurs with childbirth, blood clotting, protein digestion, and generation of nerve signals

19. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Positive Feedback Loops “Childbirth”

20. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Positive Feedback Loops “Blood Clotting”

21. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Tissues

22. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Tissues  Tissues:  Groups of specialized cells organized to perform a limited number of functions  Histology = study of tissues

23. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Tissues  The Four primary types of tissue are:  Epithelial  Connective  Muscular  Nervous

24. Epithelial Tissue 1-14

25. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epithelial Tissue  Covers body surfaces & Lines body cavities  Separated from underlying tissue by Basement Membrane  Consists of cells that form:  Membranes  Glands  Does not contain Blood Vessels (Avascular)

26. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epithelial Tissue (cont)  Cells are Regularly Replaced  Cells are Tightly Joined together with small amount of matrix (intercellular substances)

27. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epithelial Tissue

28. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Classification of Epithelial tissue According to:  Number of Layers of Cells  Simple (one layer)  Stratified (more than one layer)  Shape of Apical Cells  Squamous epithelial cells are flattened  Cuboidal epithelial cells are cube-shaped  Columnar epithelial cells are taller than wide

29. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

30. Stratified Squamous Epithelial Tissue  Non-keratinized  Stratified Squamous consists of living cells  Mouth Cavity, Vagina…  Keratinized  Stratified Squamous has outer layer of dead cells contain water-resistant keratin  Skin.

31. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stratified Squamous Epithelial Tissue  Non-keratinized  Stratified Squamous consists of living cells  Mouth Cavity, Vagina…  Keratinized  Stratified Squamous has outer layer of dead cells contain water-resistant keratin  Skin.

32. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Keratinized Stratified Squamous Epithelial Tissue

33. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Simple Cuboidal Epithelium

34. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Simple Columnar Epithelium

35. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Pseudo-Stratified Columnar Epithelium

36. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stratified Columnar Epithelium

37. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Transitional Epithelium

38. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Exocrine Glands  Derived from epithelial cells  Secrete via ducts  Can be simple tubes or clusters called acini

39. Connective Tissue 1-30

40. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

41. Connective Tissue  Has lots of Extra cellular Material deposited in spaces between its cells  Includes  Connective Tissue Proper  Loose & Dense  Fluid Connective Tissue  Blood & Lymph  Supportive Connective Tissue  Cartilage & Bone

42. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Areolar Connective Tissue

43. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Adipose Connective Tissue  Specialized for fat synthesis, breakdown & storage Fig 1.18 1-33

44. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Adipose and Reticular Tissues Figure 4.11

45. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Dense Connective Tissue  Dense Fibrous Connective Tissue  packed with fibers of collagen  Two Types:  Dense Regular  As in Tendons  Dense Irregular  Capsules, Dermis

46. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Dense Regular Connective Tissue

47. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Dense Irregular Connective Tissue

48. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fluid Connective Tissue, Blood

49. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fluid Connective Tissue, Blood

50. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Supporting Connective Tissue (Cartilage)  Specialized for Support, Protection  Made of Chondrocytes & Elastic extracellular material  Serves as precursor for bone  Forms Articular Surfaces for Joints 1-34

51. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cartilage  Three Types:  Hyaline Cartilage  Elastic Cartilage  Fibro Cartilage

52. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hyaline Cartilage

53. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Elastic Cartilage

54. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fibrocartilage Figure 4.15d

55. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Supporting Connective Tissue (Bone)  Formed as concentric layers of calcified material  Contains 3 cell types:  Osteoblasts: bone-forming cells  Osteocytes: trapped, inactive osteoblasts  Osteoclasts: bone resorbing cells Fig 1.19 1-35

56. Muscle Tissue 1-23

57. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Muscle Tissue  Specialized for contraction  3 Types:  Skeletal  Cardiac  Smooth

58. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Skeletal Muscles  Striated  Voluntary  Attached to the skeleton  Muscle fibers:  Formed by fusion of Embryonic Myoblasts  Large & Multinucleated  Individually controlled  Lined-up in parallel to form bundles

59. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Skeletal Muscles

60. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cardiac Muscle  Striated; Involuntary; in the Heart only  Branched to form continuous fabric  Intercalated discs between cells provide mechanical & electrical interconnections  Fibers not individually controlled

61. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cardiac Muscle

62. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Smooth Muscle  Unstriated  Involuntary  Found in the walls of all Hollow Organs  Intestine, Blood Vessels..etc)  Controlled by ANS

63. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Smooth Muscle

64. Nervous Tissue 1-20

65. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nervous Tissue  Consists of:  Neurons  Supporting or glial cells (Neuroglia)  Neurons are specialized for conducting electrical signals  Have 3 basic components:  Cell body  Dendrites  Axon 1-21

66. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

67. Neurons  Cell body  Contains nucleus; is metabolic center  Dendrites:  Highly branched extensions off cell body  Receive inputs from other neurons  Conduct impulses to cell body  Axon:  Single, long extension off cell body  Conducts nerve impulses to other cells 1-22

68. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Neurons

69. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Supporting Cells  Supporting/Glial cells  Provide physical & functional support for neurons  Perform Phagocytosis  5X more abundant than neurons

70. Organs & Systems 1-36

71. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Organs & Systems  Organs:  Are anatomical & functional units made up of 2 or more primary tissues grouped together to perform a specific function  Systems:  Are groups of organs working together to perform certain function / functions to maintain Homeostasis

72. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stem Cells  Most cells in organs are highly specialized or differentiated  Many organs retain small populations of adult stem cells (Undifferentiated Cells)  Can become many cell types  E.g. bone marrow stem cells can give rise to all of the different blood cell types

73. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Skin  The Largest Organ  Has Three layers  Epidermis for protection  Dermis  Contains connective tissue, glands, blood vessels, nerve receptors  Hypodermis  Contains fatty (Adipose) tissue

74. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Skin

75. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Skin  Other structures:  Hair Follicles  Sweat Glands  Sebaceous Glands

76. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Body-Fluid Compartments  The Body has 2 Fluid Compartments:  Intracellular; inside the cells  Extracellular; outside the cells  Separated by cell’s outer membrane  Extracellular is composed of  Blood Plasma  The fluid component of blood  Interstitial fluid  Fluid in between body cells 1-39