The Human Body: An Orientation

1. The Human Body: An Orientation

2. The Human Body—An Orientation Anatomy • Study of the structure and shape of the body and its parts Physiology • Study of how the body and its parts work or function

3. Anatomy—Levels of Study • Gross anatomy • Large structures • Easily observable Figure 14.1

4. Anatomy—Levels of Study • Microscopic Anatomy • Very small structures • Can only be viewed with a microscope Figure 14.4c–d

5. Smooth muscle cell Molecules Cellular levelCells are made up of molecules Atoms Chemical levelAtoms combine toform molecules Smoothmuscletissue Tissue levelTissues consist ofsimilar types of cells Epithelialtissue Smoothmuscletissue Bloodvessel(organ) Organismal levelHuman organismsare made up of manyorgan systems Cardio-vascularsystem Connectivetissue Organ levelOrgans are made upof different typesof tissues Organ system levelOrgan systems consist of differentorgans that work together closely Levels of Structural Organization Figure 1.1

6. Organ System Overview • Integumentary • Forms the external bodycovering • Protects deeper tissue frominjury • Helps regulate body temperature • Location of cutaneousnerve receptors Figure 1.2a

7. Organ System Overview • Skeletal • Protects and supportsbody organs • Provides muscleattachment for movement • Site of blood cellformation • Stores minerals Figure 1.2b

8. Organ System Overview • Muscular • Produces movement • Maintains posture • Produces heat Figure 1.2c

9. Organ System Overview • Nervous • Fast-acting controlsystem • Responds to internal andexternal change • Activates muscles andglands Figure 1.2d

10. Organ System Overview • Endocrine • Secretes regulatoryhormones • Growth • Reproduction • Metabolism Figure 1.2e

11. Organ System Overview • Cardiovascular • Transports materials in bodyvia blood pumped by heart • Oxygen • Carbon dioxide • Nutrients • Wastes Figure 1.2f

12. Organ System Overview • Lymphatic • Returns fluids to blood vessels • Cleanses the blood • Involved in immunity Figure 1.2g

13. Organ System Overview • Respiratory • Keeps blood supplied with oxygen • Removes carbon dioxide Figure 1.2h

14. Organ System Overview • Digestive • Breaks down food • Allows for nutrient absorption into blood • Eliminates indigestible material Figure 1.2i

15. Organ System Overview • Urinary • Eliminates nitrogenous wastes • Maintains acid-base balance • Regulates water and electrolytes Figure 1.2j

16. Organ System Overview • Reproductive • Produces offspring Figure 1.2k–l

17. Necessary Life Functions • Maintain boundaries • Movement • Locomotion • Movement of substances • Responsiveness • Ability to sense changes and react • Digestion • Break-down and absorption of nutrients

18. Necessary Life Functions • Metabolism—chemical reactions within the body • Produces energy • Makes body structures • Excretion • Eliminates waste from metabolic reactions

19. Necessary Life Functions • Reproduction • Produces future generation • Growth • Increases cell size and number of cells

20. Survival Needs • Nutrients • Chemicals for energy and cell building • Includes carbohydrates, proteins, lipids, vitamins, and minerals • Oxygen • Required for chemical reactions

21. Survival Needs • Water • 60–80% of body weight ????? • Provides for metabolic reaction ???? • Stable body temperature • Atmospheric pressure • Must be appropriate • Properties of water??? c & a gs lds Hsh hhv

22. Interrelationships Among Body Systems Figure 1.3

23. Homeostasis • Homeostasis—maintenance of a stable internal environment • A dynamic state of equilibrium • Homeostasis is necessary for normal body functioning and to sustain life • Homeostatic imbalance • A disturbance in homeostasis resulting in disease

24. Input:Informationsent alongafferentpathway to Controlcenter Output:Information sentalong efferentpathway to activate Effector Receptor (sensor) Changedetectedby receptor Response ofeffector feedsback toinfluencemagnitude ofstimulus andreturns variableto homeostasis Stimulus:Produceschangein variable Imbalance Variable(in homeostasis) Imbalance Figure 1.4, step 5

25. Maintaining Homeostasis • The body communicates through neural and hormonal control systems • Receptor • Responds to changes in the environment (stimuli) • Sends information to control center

26. Maintaining Homeostasis • Control center • Determines set point • Analyzes information • Determines appropriate response • Effector • Provides a means for response to the stimulus

27. Feedback Mechanisms • Negative feedback • Includes most homeostatic control mechanisms • Shuts off the original stimulus, or reduces its intensity • Works like a household thermostat

28. Feedback Mechanisms • Positive feedback • Increases the original stimulus to push the variable farther • In the body this only occurs in blood clotting and during the birth of a baby

29. The Language of Anatomy • Special terminology is used to prevent misunderstanding • Exact terms are used for • Position • Direction • Regions • Structures

30. Regional Terms • Anterior body landmarks Figure 1.5a

31. Regional Terms • Posterior body landmarks Figure 1.5b

32. Directional Terms Table 1.1 (1 of 3)

33. Directional Terms Table 1.1 (2 of 3)

34. Directional Terms Table 1.1 (3 of 3)

35. Body Planes and Sections • A sagittal section divides the body (or organ) into left and right parts • A median, or midsagittal, section divides the body (or organ) into equal left and right parts • A frontal section divides the body (or organ) into anterior and posterior parts • A transverse, or cross, section divides the body (or organ) into superior and inferior parts

36. Body Planes and Sections Figure 1.6

37. Body Cavities • Dorsal body cavity • Cranial cavity houses the brain • Spinal cavity houses the spinal cord • Ventral body cavity • Thoracic cavity houses heart, lungs and others • Abdominopelvic cavity houses digestive system and most urinary system organs

38. Body Cavities Figure 1.7

39. Abdominopelvic Quadrants Figure 1.8a

40. Abdominopelvic Major Organs Figure 1.8c