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. 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

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

6. Organ System Overview 2. Skeletal System Functions:
Protects and supports body organs
Provides muscle attachment for movement
Site of blood cell formation
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 and external changes
Activates muscles and glands
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 body via 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. 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

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
Scan and insert Answer Key that corresponds to blank sheet
Figure 1.5a

33. Regional Terms: Posterior View
Figure 1.5b

34. Regional Terms: Posterior View
Scan and insert Answer Key that corresponds to blank sheet
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