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 and their relationship to one another.
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. Levels of Structural Organization
Smooth muscle cell
Molecules
Atoms
Smooth muscle tissue
Epithelial tissue
Connective tissue
Blood vessel (organ)
Cardio- vascular system
Cellular level Cells are made up of molecules
Tissue level Tissues consist of similar types of cells
Organ level Organs are made up of different types of tissues
Organ system level Organ systems consist of different organs that work together closely
Organismal level Human organisms are made up of many organ systems
Chemical level Atoms combine to form molecules
Figure 1.1

6. Levels of Structural Organization
Molecules
Atoms
Chemical level Atoms combine to form molecules
Figure 1.1, step 1

7. Levels of Structural Organization
Smooth muscle cell
Molecules
Atoms
Cellular level Cells are made up of molecules
Chemical level Atoms combine to form molecules
Figure 1.1, step 2

8. Levels of Structural Organization
Smooth muscle cell
Molecules
Atoms
Smooth muscle tissue
Cellular level Cells are made up of molecules
Tissue level Tissues consist of similar types of cells
Chemical level Atoms combine to form molecules
Figure 1.1, step 3

9. Levels of Structural Organization
Smooth muscle cell
Molecules
Atoms
Smooth muscle tissue
Epithelial tissue
Connective tissue
Blood vessel (organ)
Cellular level Cells are made up of molecules
Tissue level Tissues consist of similar types of cells
Organ level Organs are made up of different types of tissues
Chemical level Atoms combine to form molecules
Figure 1.1, step 4

10. Levels of Structural Organization
Smooth muscle cell
Molecules
Atoms
Smooth muscle tissue
Epithelial tissue
Connective tissue
Blood vessel (organ)
Cardio- vascular system
Cellular level Cells are made up of molecules
Tissue level Tissues consist of similar types of cells
Organ level Organs are made up of different types of tissues
Organ system level Organ systems consist of different organs that work together closely
Chemical level Atoms combine to form molecules
Figure 1.1, step 5

11. Levels of Structural Organization
Smooth muscle cell
Molecules
Atoms
Smooth muscle tissue
Epithelial tissue
Connective tissue
Blood vessel (organ)
Cardio- vascular system
Cellular level Cells are made up of molecules
Tissue level Tissues consist of similar types of cells
Organ level Organs are made up of different types of tissues
Organ system level Organ systems consist of different organs that work together closely
Organismal level Human organisms are made up of many organ systems
Chemical level Atoms combine to form molecules
Figure 1.1, step 6

12. Organ System Overview Integumentary Forms the external body covering
Protects deeper tissue from injury
Helps regulate body temperature
Location of cutaneous nerve receptors
Figure 1.2a

13. Organ System Overview Skeletal Protects and supports body organs
Provides muscle attachment for movement
Site of blood cell formation
Stores minerals
Figure 1.2b

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

15. Organ System Overview Nervous Fast-acting control system
Responds to internal and external change
Activates muscles and glands
Figure 1.2d

16. Organ System Overview Endocrine Secretes regulatory hormones Growth
Reproduction
Metabolism
Figure 1.2e

17. Organ System Overview Cardiovascular
Transports materials in body via blood pumped by heart
Oxygen
Carbon dioxide
Nutrients
Wastes
Figure 1.2f

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

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

20. Organ System Overview Digestive Breaks down food
Allows for nutrient absorption into blood
Eliminates indigestible material
Major function (large intestine) is to reclaim water
Figure 1.2i

21. Organ System Overview Urinary Eliminates nitrogenous wastes
Maintains acid-base balance of the blood
Regulates water and electrolytes
Figure 1.2j

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

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

24. Necessary Life Functions
Metabolism—chemical reactions within the body
Produces energy (ATP)
Makes body structures
Regulated by hormones secreted by the endocrine system
Excretion
Eliminates waste from metabolic reactions

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

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

27. Survival Needs Water 60–80% of body weight
Provides for metabolic reaction
Stable body temperature
Atmospheric pressure
Must be appropriate for exchange of oxygen and carbon dioxide in the lungs

28. Interrelationships Among Body Systems
Figure 1.3

29. 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

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

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

32. Variable (in homeostasis)
Input: Information sent along afferent pathway to
Control center
Output: Information sent along efferent pathway to activate
Receptor (sensor)
Effector
Change detected by receptor
Response of effector feeds back to influence magnitude of stimulus and returns variable to homeostasis
Stimulus: Produces change in variable
Imbalance
Variable (in homeostasis)
Imbalance
Figure 1.4

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

34. 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

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

36. Directional Terms
Table 1.1 (1 of 3)

37. Directional Terms
Table 1.1 (2 of 3)

38. Directional Terms
Table 1.1 (3 of 3)

39. Regional Terms
Anterior body landmarks
Figure 1.5a

40. Regional Terms
Posterior body landmarks
Figure 1.5b

41. 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

42. Body Planes and Sections
Figure 1.6

43. 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

44. Body Cavities
Figure 1.7

45. Abdominopelvic Quadrants
Figure 1.8a

46. Abdominopelvic Regions
Figure 1.8b

47. Abdominopelvic Major Organs
Figure 1.8c