1. The Human Body: An Orientation

2. Overview of Anatomy and Physiology
Anatomy – the study of the structure of body parts and their relationships to one another
How is it constructed?

3. Physiology
Physiology – the study of the function of the body’s structural machinery or organ systems
How does it work?

4. Levels of Structural Organization
Chemical – atoms combined to form molecules
Cellular – cells are made of molecules
Tissue – consists of similar types of cells

5. Organ – made up of different types of tissues
Organ system – consists of different organs that work closely together
Organismal – made up of the organ systems

6. Levels of Structural Organization
Smooth muscle cell
Molecules
Cellular level Cells are made up of molecules 2
Atoms 1
Chemical level Atoms combine to form molecules
Smooth muscle tissue
Heart 3
Tissue level Tissues consist of similar types of cells
Cardiovascular system
Blood vessels
Epithelial tissue
Smooth muscle tissue
Blood vessel (organ) 6
Organismal level The human organism is made up of many organ systems
Connective tissue 4
Organ level Organs are made up of different types of tissues 5
Organ system level Organ systems consist of different organs that work together closely
Figure 1.1

7. Orientation
Orientation is the position of something relative to some point.
The human body is oriented into
Directions
Landmarks
Planes
Cavities
Quadrants
Regions
Systems

8. Directional Terms
Superior or cranial toward the head end of the body; upper (example, the hand is part of the superior extremity). Inferior or caudal away from the head; lower (example, the foot is part of the inferior extremity).

9. Anterior or ventral front (example, the kneecap is located on the anterior side of the leg).
Posterior or dorsal back (example, the shoulder blades are located on the posterior side of the body).

10. Medial toward the midline of the body (example, the middle toe is located at the medial side of the foot).
Lateral away from the midline of the body (example, the little toe is located at the lateral side of the foot).

11. Proximal toward or nearest the trunk or the point of origin of a part (example, the proximal end of the femur joins with the pelvic bone).
Distal away from or farthest from the trunk or the point or origin of a part (example, the hand is located at the distal end of the forearm).

12. Superficial toward the surface Deep away from the surface
Cephalad
toward the head
Caudal
toward the tailbone

13. Figure 1.9

14. Anatomical Landmarks See page 4 for anterior and posterior landmarks.
Record those landmarks on the handout provided.

16. Body Cavities Body cavities are internal chambers holding vital organs
Cavities protect vital organs
Cavities allow organs to change in shape and size

17. Two body cavities
Dorsal body cavity includes the cranial cavity and the spinal cavity
Ventral body cavity includes the thoracic cavity and the abdominopelvic cavity

19. Abdominopelvic Cavity
The abdominopelvic cavity is lined by the peritoneum
The abdominal cavity extends from the diaphragm to the superior margins of the pelvis
liver, stomach, spleen and most of the large intestine

20. Abdominopelvic Cavity
The pelvic cavity is bordered by the pelvis, with a floor of muscle
reproductive organs, urinary bladder and the final portion of the large intestine

21. Abdominopelvic Regions

22. Prefixes, Suffixes, and Roots
epi- upon, above
hypo – below
gastric – stomach
iliac – superior part of the hip bone
chondro – cartilage
lumbus – loin
umbilicus - navel
Decipher the following words:
Hypochondriac
Epigastric
Hypogastric

23. Body Systems See the handout that describes the 11 body systems.
Learn the function and organs found in each system.

24. Organ Systems Interrelationships
Organ systems work together to carry necessary life functions.
For example
Digestive and respiratory systems, in contact with the external environment, take in nutrients and oxygen

25. Necessary Life Functions
Maintaining boundaries – the internal environment remains distinct from the external
Cellular level – accomplished by plasma membranes
Organismal level – accomplished by the skin

26. Movement – locomotion, propulsion (peristalsis), and contractility
Responsiveness – ability to sense changes in the environment and respond to them
Digestion – breakdown of ingested foodstuffs

27. Metabolism – all the chemical reactions that occur in the body
Excretion – removal of wastes from the body
Reproduction – cellular and organismal levels
Cellular – an original cell divides and produces two identical daughter cells
Organismal – sperm and egg unite to make a whole new person

28. Growth – increase in size of a body part or of the organism

29. Homeostasis
Homeostasis is the ability to maintain a relatively stable internal environment in an ever-changing outside world
The internal environment of the body is in a dynamic state of equilibrium

30. The nervous system and the endocrine system work together to maintain homeostasis.

31. Homeostatic Control Mechanisms
The variable produces a change in the body
The three interdependent components of control mechanisms are:

32. Receptor – monitors the environments and responds to changes (stimuli)
Control center – determines the set point at which the variable is maintained
Effector – provides the means to respond to the stimulus

33. Homeostatic Control Mechanisms3
Input: Information sent along afferent pathway to 4
Output: Information sent along efferent pathway to
Control center
Effector
Receptor (sensor) 2
Change detected by receptor 5
Response of effector feeds back to influence magnitude of stimulus and returns variable to homeostasis
Stimulus: Produces change in variable 1
Imbalance
Variable (in homeostasis)
Imbalance
Figure 1.4

34. Negative Feedback
In negative feedback systems, the output shuts off the original stimulus
Example: Regulation of blood glucose levels

35. Negative Feedback
Figure 1.5

36. Positive Feedback
In positive feedback systems, the output enhances or exaggerates the original stimulus
Example: Regulation of blood clotting
Figure 1.6

37. Homeostatic Imbalance
Disturbance of homeostasis or the body’s normal equilibrium
Overwhelming of negative feedback mechanisms allowing destructive positive feedback mechanisms to take over