1. Chapter 1 Orientation of the Body

2. Science and Society
Science involves logical inquiry based on experimentation (Figure 1-1)
Hypothesis—idea or principle to be tested in experiments
Experiment—series of tests of a hypothesis; a controlled experiment eliminates biases or outside influences

3. Science and Society
Theory—a hypothesis that has been proven by experiments to have a high degree of confidence
Law—a theory that has an unusually high level of confidence
The process of science is active and changing as new experiments add new knowledge

4. Science and Society
Science is affected by culture and culture is affected by society

5. Anatomy and Physiology
Anatomy and physiology are branches of biology concerned with the form and functions of the body
Anatomy—science of the structure of an organism and the relationship of its parts

6. Anatomy and Physiology
Gross anatomy—study of the body and its parts using only the naked eye (Figure 1-2)
Microscopic anatomy—study of body parts using a microscope
Cytology—study of cells
Histology—study of tissues

7. Anatomy and Physiology
Developmental anatomy—study of human growth and development
Pathological anatomy—study of diseased body structures
Systemic anatomy—study of the body by systems

8. Anatomy and Physiology
Physiology—science of the functions of organisms; subdivisions named according to
Organism involved—human or plant physiology
Organizational level—molecular or cellular physiology
Systemic function—respiratory, neurovascular, or cardiovascular physiology

9. Language of Science and Medicine
Scientific terms are often based on Latin or Greek word parts
Terminology tool is provided in pull-out section near the front of this textbook

10. Language of Science and Medicine
Terminologia anatomica
Official list of anatomical terms
Terms listed in Latin, English, and by number
Avoids use of eponyms (terms based on a person’s name)
Physiology terms do not have an official list but follow the same principles as Terminologia Anatomica

11. Characteristics of Life
A single criterion may be adequate to describe life, as in following examples:
Autopoiesis—living organisms are self-organized and self-maintaining
Cell theory—if it is made of one or more cells, it is alive

12. Characteristics of Life
Characteristics of life considered most important in humans:
Responsiveness
Conductivity
Growth
Respiration
Digestion
Absorption
Secretion
Excretion
Circulation
Reproduction

13. Characteristics of Life
Metabolism—sum total of all physical and chemical reactions occurring in the living body

14. Levels of Organization (Figure 1-3)
Chemical level—basis for life
Organization of chemical structures separates living material from nonliving material
Organization of atoms, molecules, and macromolecules results in living matter—a gel called cytoplasm

15. Levels of Organization
Organelle level
Chemical structures organized to form organelles that perform individual functions
It is the functions of the organelles that allow the cell to live
Dozens of organelles have been identified, including the following:
Mitochondria
Golgi apparatus
Endoplasmic reticulum

16. Levels of Organization
Cellular level
Cells—smallest and most numerous units that possess and exhibit characteristics of life
Cell—nucleus surrounded by cytoplasm within a limiting membrane
Cells differentiate to perform unique functions

17. Levels of Organization
Tissue level
Tissue—an organization of similar cells specialized to perform a certain function
Tissue cells surrounded by nonliving matrix
Four major tissue types:
Epithelial tissue
Connective tissue
Muscle tissue
Nervous tissue

18. Levels of Organization
Organ level
Organ—organization of several different kinds of tissues to perform a special function
Organs represent discrete and functionally complex operational units
Each organ has a unique size, shape, appearance, and placement in the body

19. Levels of Organization
System level
Systems—most complex organizational units of the body
System level involves varying numbers and kinds of organs arranged to perform complex functions (Table 1-1):
Support and movement
Communication, control, and integration
Transportation and defense
Respiration, nutrition, and excretion
Reproduction and development

20. Levels of Organization
Organism level
The living human organism is greater than the sum of its parts
All of the components interact to allow the human to survive and flourish

21. Anatomical Position (Figure 1-4)
Reference position
Body erect with arms at sides and palms forward
Head and feet pointing forward

22. Anatomical Position (Figure 1-4)
Bilateral symmetry is a term meaning that right and left sides of body are mirror images
Bilateral symmetry confers balanced proportions
Remarkable correspondence of size and shape between body parts on opposite sides of the body
Ipsilateral structures are on the same side of the body in anatomical position
Contralateral structures are on opposite sides of the body in anatomical position

23. Body Cavities (Figure 1-5; Table 1-2)
Ventral body cavity
Thoracic cavity
Right and left pleural cavities
Mediastinum
Abdominopelvic cavity
Abdominal cavity
Pelvic cavity

24. Body Cavities
Dorsal body cavity
Cranial cavity
Spinal cavity

25. Body Regions (Figure 1-6; Table 1-3)
Axial subdivision
Head
Neck
Torso, or trunk, and its subdivisions

26. Body Regions Appendicular subdivision Upper extremity and subdivisions
Lower extremity and subdivisions

27. Body Regions Abdominal regions (Figure 1-11)
Right hypochondriac region
Epigastric region
Left hypochondriac region
Right lumbar region
Umbilical region
Left lumbar region
Right iliac (inguinal) region
Hypogastric region
Left iliac (inguinal) region

28. Body Regions Abdominopelvic quadrants (Figure 1-8)
Right upper quadrant
Left upper quadrant
Right lower quadrant
Left lower quadrant

29. Terms Used in Describing Body Structure
Directional terms (Figure 1-9)
Superior
Inferior
Anterior (ventral)
Posterior (dorsal)
Medial
Lateral
Proximal
Distal
Superficial
Deep

30. Terms Used in Describing Body Structure
Terms related to organs
Lumen (luminal)
Central
Peripheral
Medullary (medulla)
Cortical (cortex)
Apical (apex)
Basal (base)
Many directional terms are listed inside the front cover of the book

31. Body Planes and Sections (Figures 1-9 and 1-10)
Planes are lines of orientation along which cuts or sections can be made to divide the body, or a body part, into smaller pieces

32. Body Planes and Sections (Figures 1-9 and 1-10)
There are three major planes, which lie at right angles to each other:
Sagittal plane runs front to back so that sections through this plane divide body (or body part) into right and left sides
If section divides body (or part) into symmetrical right and left halves, the plane is called midsagittal or median sagittal
Frontal (coronal) plane runs lengthwise (side to side) and divides body (or part) into anterior and posterior portions
Transverse (horizontal) plane is a “crosswise” plane—it divides body (or part) into upper and lower parts

33. Interaction of Structure and Function
Complementarity of structure and function is an important and unifying concept in the study of anatomy and physiology
Anatomical structures often seem “designed” to perform specific functions because of their unique size, shape, form, or body location
Understanding the interaction of structure and function assists in integration of otherwise isolated factual information

34. Body Type and Disease (Figure 1-11)
Somatotype—category of body build or physique
Endomorph—heavy, rounded physique with accumulation of fat
“Apple-shaped” endomorph has more accumulation of fat in the waist than hip
Waist-to-hip ratio >0.9 for women and >1.0 for men
Higher risk for health problems than “pear shape”
“Pear-shaped” endomorph has more accumulation of fat in hips than in waist

35. Body Type and Disease (Figure 1-11)
Mesomorph—muscular physique
Ectomorph—thin, often fragile physique with little fat

36. Homeostasis (Figure 1-14)
Term homeostasis coined by the American physiologist Walter B. Cannon
Homeostasis is the term used to describe the relatively constant states maintained by the body—internal environment around body cells remains constant

37. Homeostasis (Figure 1-14)
Body adjusts important variables from a normal “set point” in an acceptable or normal range
Examples of homeostasis:
Temperature regulation
Regulation of blood carbon dioxide level
Regulation of blood glucose level

38. Homeostatic Control Mechanisms
Devices for maintaining or restoring homeostasis by self-regulation through feedback control loops
Basic components of control mechanisms
Sensor mechanism—specific sensors detect and react to any changes from normal
Integrating, or control, center—information is analyzed and integrated, and then, if needed, a specific action is initiated
Effector mechanism—effectors directly influence controlled physiological variables
Feedback—process of information about a variable constantly flowing back from the sensor to the integrator

39. Homeostatic Control Mechanisms
Negative feedback control systems
Are inhibitory
Stabilize physiological variables
Produce an action that is opposite to the change that activated the system
Are responsible for maintaining homeostasis
Are much more common than positive feedback control systems

40. Homeostatic Control Mechanisms
Positive feedback control systems
Are stimulatory
Amplify or reinforce the change that is occurring
Tend to produce destabilizing effects and disrupt homeostasis
Bring specific body functions to swift completion
Feed-forward occurs when information flows ahead to another process or feedback loop to trigger a change in anticipation of an event that will follow

41. Homeostatic Control Mechanisms
Levels of control (Figure 1-15)
Intracellular control
Regulation within cells
Genes or enzymes can regulate cell processes
Intrinsic control (autoregulation)
Regulation within tissues or organs
May involve chemical signals
May involve other “built-in” mechanisms
Extrinsic control
Regulation from organ to organ
May involve nerve signals
May involve endocrine signals (hormones)

42. Cycle of Life: Life Span Considerations
Structure and function of body undergo changes over the early years (developmental processes) and late years (aging processes)
Infancy and old age are periods of time when the body functions least well

43. Cycle of Life: Life Span Considerations
Young adulthood is period of greatest homeostatic efficiency
Atrophy—term to describe the wasting effects of advancing age

44. 1-6

45. back
1-1

46. 1-2

47. 1-3

48. 1-4

49. 1-5

50. 1-8

51. 1-9

52. 1-10