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 • Ex. Heart beating • Ex. Nerve sending electrical impulse

3. Anatomy—Levels of Study • Gross anatomy • Large structures • Easily observable • Microscopic Anatomy • Very small structures • Can only be viewed with a microscope Figure 14.1

4. 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

5. Organ System Overview 1. Integumentary System (skin) Functions: • Forms the external body covering • Protects deeper tissue frominjury • Helps regulate body temperature • Location of cutaneousnerve receptors Figure 1.2a

6. Organ System Overview 2. Skeletal System Functions: • Protects and supportsbody organs • Provides muscleattachment for movement • Site of blood cellformation • Stores minerals Figure 1.2b

7. Organ System Overview 3. Muscular Functions: • Produces movement • Maintains posture • Produces heat Figure 1.2c

8. Organ System Overview 4. Nervous • Fast-acting control system Functions: • Responds to internal andexternal changes • Activates muscles andglands Figure 1.2d

9. Organ System Overview 5. Endocrine • Secretes hormones Functions: Regulation of • Growth • Reproduction • Metabolism Figure 1.2e

10. Organ System Overview 6. Cardiovascular Function: • Transports materials in bodyvia blood pumped by heart • Oxygen • Carbon dioxide • Nutrients • Wastes Figure 1.2f

11. Organ System Overview 7. Lymphatic Functions: • Returns fluid to blood vessels • Cleanses the blood • Involved in immunity Figure 1.2g

12. Organ System Overview 8. Respiratory Functions: • Keeps blood supplied with oxygen • Removes carbon dioxide Figure 1.2h

13. Organ System Overview 9. Digestive Functions: • Breaks down food • Allows for nutrient absorption into blood • Eliminates indigestible material (feces) Figure 1.2i

14. Organ System Overview 10. Urinary Functions: • Eliminates nitrogenous wastes (ex. Urea) • Maintains acid-base balance • Regulates water and electrolytes Figure 1.2j

15. Organ System Overview 11. Reproductive Function: • Produce offspring Males - produce sperm in testes Females - produce eggs in ovaries - serve as site of fertilization & fetal development Figure 1.2k–l

16. Necessary Life Functions • Maintain boundaries • Separation of internal from external environment • Movement • Locomotion • Movement of substances • Responsiveness • Ability to sense changes and react • Digestion • Break-down and absorption of nutrients

17. Necessary Life Functions (con’t) • Metabolism • chemical reactions within the body • Produces energy • Makes body structures • Excretion • Eliminates waste from metabolic reactions • Reproduction • Produces future generation • Growth • Increases cell size and number of cells

18. Survival Needs • Nutrients • Chemicals for energy and cell building • Includes carbohydrates, proteins, lipids, vitamins, and minerals • Oxygen • Required for chemical reactions • Makes up 20% of the air we breathe

19. Survival Needs • Water • 60–80% of body weight • Necessary for metabolic reactions • Stable body temperature • 37 degrees C or 98 degrees F • Atmospheric pressure • Must be appropriate level to allow for gas exchange

20. Interrelationships Among Body Systems Figure 1.3

21. Homeostasis • Homeostasis: • maintenance of a stable internal environment despite continuous changes • dynamic equilibrium • necessary for normal body functioning and to sustain life • Homeostatic imbalance • A disturbance in homeostasis resulting in disease or illness

22. 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

23. Maintaining Homeostasis Homeostatic Control Mechanisms • neural and hormonal control systems (Nervous & Endocrine Systems) • Receptor • Responds to changes in the environment (stimuli) • Sends information to control center

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

25. Feedback Mechanisms • Negative feedback • Can shut off the original stimulus or reduce its intensity as well as turn on or increase its intensity • Ex. a household thermostat, most hormones

26. Feedback Mechanisms • Positive feedback • Can ONLY increase the original stimulus to push the variable farther • Ex. blood clotting and childbirth

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

28. Directional Terms

29. Directional Terms (con’t)

30. Directional Terms (con’t) Table 1.1 (3 of 3)

31. Regional Terms: Anterior View Figure 1.5a

32. Regional Terms: Anterior View Figure 1.5a

33. Regional Terms: Posterior View Figure 1.5b

34. Regional Terms: Posterior View Figure 1.5b

35. Body Planes and Sections • A sagittal or parasagittal 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, or coronal section divides the body (or organ) into anterior (front) and posterior (back) parts • A transverse, or cross, section divides the body (or organ) into superior (upper) and inferior (lower) parts • An oblique section divides the body (or organ) diagonally

36. Body Planes and Sections Figure 1.6

37. Body Cavities • Dorsal body cavity • Cranial cavity- brain • Spinal cavity- spinal cord • Ventral body cavity • Thoracic cavity- heart & lungs • Abdominal cavity- most digestive organs • Pelvic cavity- most urinary system organs

38. Abdominopelvic Quadrants Abdominopelvic Regions Figure 1.8a Figure 1.8b