1. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 1 Lecture Outline

2. Chapter 1 Outline  Introduction to Physiology  Scientific Method  Homeostasis  The Primary Tissues  Muscle Tissue  Nervous Tissue  Epithelial Tissue  Connective Tissue  Organs and Systems 1-2

3. Human Physiology  Physiology: study of how body works to maintain life  Pathophysiology: how physiological processes are altered in disease or injury 1-3

4. Scientific Method 1-4

5. Scientific Method  1. Form a testable hypothesis about observations  2. Conduct and analyze experiments to test hypothesis  3. Draw conclusions about whether or not results support hypothesis  4. Develop a theory  = general statement explaining natural phenomena that is based on proven hypotheses 1-5

6. Testing of Hypotheses  Involves:  Experimental and control groups  Quantitative measurements performed blindly  Analysis of data using statistics 1-6

7. Using Scientific Method to Develop New Drugs  When a new drug is suggested by experiments:  Its effectiveness and toxicity is tested first in tissue culture, rats, mice 1-7

8. Using Scientific Method to Develop New Drugs  If effective and safe, clinical trials performed  Phase I Trials: Toxicity and metabolism tested in healthy human volunteers  Phase II Trials: Effectiveness and toxicity tested in target population  Phase III Trials: Widespread test of drug in diverse population  Phase IV Trials: Drug is tested for other potential uses 1-8

9. Homeostasis 1-9

10. Homeostasis  Is maintenance of a state of dynamic constancy  In which conditions are stabilized above and below a physiological set point  By negative feedback loops 1-10

11. Negative Feedback Loops  Sensor: Detects deviation from set point  Integrating center: Determines response  Effector: Produces response 1-11

12. Homeostasis continued  Regulatory mechanisms:  Intrinsic control is built into organ being regulated 1-12

13. Homeostasis continued  Regulatory mechanisms:  Extrinsic control comes from outside of organ  E.g. body temperature is controlled by antagonistic effects of sweating and shivering 1-13

14. Homeostasis continued  Regulatory mechanisms:  Extrinsic control comes from outside of organ  E.g. hormones control blood glucose levels 1-14

15. Homeostasis continued  Regulatory mechanisms:  Positive feedback is rare because it amplifies changes  It is involved in producing blood clots  In females it is used to create the LH surge that causes ovulation  Positive feedback between the uterus and oxytocin secretion occurs during labor 1-15

16. Homeostasis continued  Regulatory mechanisms:  Negative feedback loops control blood pressure 1-16

17. Negative Feedback Hormonal Control of Blood Glucose 1-17

18. The Primary Tissues 1-18 (includes muscle, nervous, epithelial and connective tissues)

19. Muscle Tissue 1-19

20. Muscle Tissue  Specialized for contraction  3 types: skeletal, cardiac, smooth 1-20

21. Skeletal Muscle  Is striated; voluntary  Each fiber:  Forms by fusion of embryonic myoblasts  Allowing it to become large and multinucleated  Is individually controlled  Lines up in parallel with other fibers to form bundles 1-21

22. Cardiac Muscle  Myocardial celIs:  Are short, striated and involuntary  Are branched to form a continuous fabric  Have intercalated discs between cells that provide mechanical and electrical interconnections  Are not individually controlled 1-22

23. Smooth Muscle  Is not striated; is involuntary  Found in many organs, tissues  Controlled by ANS 1-23

24. Nervous Tissue 1-24

25. Nervous Tissue  Consists of neurons and supporting or glial cells  Neurons are specialized for conducting electrical signals  Have a cell body, dendrites and axon 1-25

26. Nervous Tissue continued  Cell body contains nucleus; is metabolic center  Dendrites: highly branched extensions off cell body  Receive inputs from other neurons  Axon: single, long extension off cell body  Conducts nerve impulses to other cells  Supporting/Glial cells provide physical and functional support for neurons  5X more abundant than neurons 1-26

27. Epithelial Tissue 1-27

28. Epithelial Tissue  Lines and covers body surfaces  Consists of cells that form membranes and glands  Regularly replaced  Squamous epithelial cells are flattened  Columnar epithelial cells are taller than wide  Cuboidal epithelial cells are cube-shaped 1-28

29. Epithelial Tissue continued 1-29

30. Epithelial Tissue continued  Simple membranes are one cell thick  Specialized for transport  Stratified has a number of layers  Specialized for protection 1-30

31. Epithelial Tissue continued  Non-keratinized stratified squamous consists of living cells  Keratinized stratified squamous has outer layer of dead cells  Cells contain water-resistant keratin 1-31

32. Epithelial Tissue continued  Cells are joined by junctional complexes, which increase strength and create barrier  Separated from underlying tissue by basement membrane 1-32

33. Exocrine Glands  Derived from epithelial cells  Secrete onto epithelium via ducts  Can be simple tubes or clusters called acini  Whose secretion is controlled by surrounding myoepithelial cells 1-33

34. Connective Tissue 1-34

35. Connective Tissue  Has lots of extracellular material deposited in space between its cells  Includes connective tissue proper, cartilage, bone and blood  Loose connective tissue consists of collagen (fibrous proteins) and tissue fluid  E.g. dermis of skin 1-35

36. Connective Tissue Proper  Dense regular connective tissue is packed with fibers of collagen  Can be regularly arranged as in tendons  Or irregularly oriented as in capsules, sheaths (Fig 1.16) 1-36

37. Connective Tissue - Adipose  Specialized for fat synthesis, breakdown and storage 1-37

38. Connective Tissue - Cartilage  Specialized for support, protection  Made of chondrocytes and elastic extracellular material  Serves as precursor for bone  Forms articular surfaces for joints 1-38

39. Connective Tissue - Bone  Formed as concentric layers of calcified material  Contains 3 cell types:  Osteoblasts: bone- forming cells  Osteocytes: trapped, inactive osteoblasts  Osteoclasts: the bone resorbing cells 1-39

40. Organs and Systems 1-40

41. Organs  Are anatomical and functional units made of two or more primary tissues  Systems are groups of organs working together to maintain homeostasis 1-41

42. Skin—The Largest Organ  Has an outer layer of protective cornified epidermis  Next layer is dermis, which contains connective tissue, glands, blood vessels, nerves  Inner layer is hypodermis, which contains fat 1-42

43. Stem Cells  Most cells in organs are highly specialized or differentiated  Many organs retain small populations of adult stem cells  These are less differentiated; can become many cell types  E.g. bone marrow stem cells can give rise to all of the different blood cell types 1-43

44. Stem Cells continued Hair follicle stem cells can form the hair shaft, root sheath, sebaceous glands and epidermis 1-44

45. Body-Fluid Compartments  Body has intracellular and extracellular compartments  Intracellular is inside cells  Extracellular is outside cells  Separated by cell’s plasma membrane  Extracellular is composed of blood plasma and interstitial fluid or tissue fluid 1-45