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. Levels of Structural Organization
Figure 1.1

4. Organ System Overview Integumentary Forms the external body covering
Protects deeper tissue from injury
Synthesizes vitamin D
Location of cutaneous nerve receptors
Figure 1.2a

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

6. Organ System Overview Muscular Allows locomotion Maintains posture
Produces heat
Figure 1.2c

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

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

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

10. Organ System Overview Lymphatic Returns fluids to blood vessels
Disposes of debris
Involved in immunity
Figure 1.2g

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

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

13. Organ System Overview Urinary Eliminates nitrogenous wastes
Maintains acid – base balance
Regulates water and electrolytes
Figure 1.2j

15. Overview of Homeostasis
Figure 1.4

16. Homeostatic Control Mechanisms
Communication within the body is essential for homeostasis and is accomplished chiefly by the Nervous and Endocrine systems.
They use electrical signals delivered by nerves or blood borne hormones as information carriers.

17. Maintaining Homeostasis
Regardless of the factor or event that is being regulated (the Variable), all homeostatic control mechanisms have at least 3 components…..
Receptor
Sensor that monitors and responds to changes in the environment (stimuli)

18. Maintaining Homeostasis
2. Control center
The sensor responds to stimuli by sending information to control center
Information flows from the receptor to the control center via an afferent pathway.
(afferent pathway approaches Control Center)
Determines the set point at which the variable is to be maintained
Analyzes information that is received and then determines appropriate response

19. Maintaining Homeostasis
3. Effector
Provides a means for the Control Center’s response to the stimulus
Information flows from the control center to the effector via an efferent pathway.
(efferent exits the control center)

20. Feedback Mechanisms Negative feedback
Includes most homeostatic control mechanisms
The net effect is to Shut Off the original stimulus, or to reduce its intensity
Negative feedback systems include: Body temp, Heart Rate, Blood Pressure, O2, CO2 and Glucose levels
Works like a household thermostat

21. Feedback Mechanisms Negative feedback (cont.)
Works like a household thermostat
They tend to shut off or reduce the intensity of the stimulus
Example: Heart rate and Blood Pressure

22. Feedback Mechanisms Positive feedback
Positive feed back systems are rare in the body!
Increases the original stimulus to push the variable farther
They tend to have explosive effects
In the body this only occurs when blood clots and giving birth

24. The Language of Anatomy
Special terminology is used to prevent misunderstanding
Exact terms are used for: Position, Direction, Regions, & Structures
It is always assumed that the body is in a “standard” position called the Anatomical Position.

25. Anatomical Position
The body is assumed to be standing, the feet together, the arms to the side, and the head and eyes and palms of the hands facing forwards.

26. Body Landmarks
Anterior
Figure 1.5a

27. Body Landmarks
Posterior
Figure 1.5b

29. Orientation and Directional Terms
Table 1.1

30. Orientation and Directional Terms
Table 1.1 (cont)

31. Orientation and Directional Terms
Distal
Superficial (external)
Deep (internal)
Table 1.1 (cont)

33. Body Planes
Figure 1.6

34. Body Cavities
Figure 1.7

35. Abdominopelvic Quadrants
Figure 1.8a

36. Abdominopelvic Regions
Figure 1.8b

37. Abdominopelvic Major Organs
Figure 1.8c