1. PowerPoint ® Lecture Slides prepared by Barbara Heard, Atlantic Cape Community College C H A P T E R © 2013 Pearson Education, Inc.© Annie Leibovitz/Contact Press Images 1 The Human Body: An Orientation:

2. © 2013 Pearson Education, Inc. Overview of Anatomy and Physiology Anatomy –Study of structure Subdivisions: –Gross or macroscopic (e.g., regional, systemic, and surface anatomy) –Microscopic (e.g., cytology and histology) –Developmental (e.g., embryology)

3. © 2013 Pearson Education, Inc. Overview of Anatomy and Physiology To study anatomy –Mastery of anatomical terminology –Observation –Manipulation –Palpation –Auscultation

4. © 2013 Pearson Education, Inc. Overview of Anatomy and Physiology Physiology –Study of the function of the body –Subdivisions based on organ systems (e.g., renal or cardiovascular physiology) –Often focuses on cellular and molecular level Body's abilities depend on chemical reactions in individual cells

5. © 2013 Pearson Education, Inc. Overview of Anatomy and Physiology To study physiology –Ability to focus at many levels (from systemic to cellular and molecular) –Study of basic physical principles (e.g., electrical currents, pressure, and movement) –Study of basic chemical principles

6. © 2013 Pearson Education, Inc. Principle of Complementarity Anatomy and physiology are inseparable –Function always reflects structure –What a structure can do depends on its specific form

7. © 2013 Pearson Education, Inc. Levels of Structural Organization Chemical –Atoms and molecules (chapter 2); and organelles (chapter 3) Cellular –Cells (chapter 3) Tissue –Groups of similar cells (chapter 4) Organ –Contains two or more types of tissues Organ System –Organs that work closely together Organismal –All organ systems

8. © 2013 Pearson Education, Inc. Necessary Life Functions Maintaining boundaries Movement Responsiveness Digestion Metabolism Dispose of wastes Reproduction Growth

9. © 2013 Pearson Education, Inc. Necessary Life Functions Maintaining boundaries between internal and external environments –Plasma membranes –Skin Movement (contractility) –Of body parts (skeletal muscle) –Of substances (cardiac and smooth muscle)

10. © 2013 Pearson Education, Inc. Necessary Life Functions Responsiveness –Ability to sense and respond to stimuli –Withdrawal reflex –Control of breathing rate Digestion –Breakdown of ingested foodstuffs –Absorption of simple molecules into blood

11. © 2013 Pearson Education, Inc. Necessary Life Functions Metabolism –All chemical reactions that occur in body cells –Catabolism and anabolism Excretion –Removal of wastes from metabolism and digestion –Urea, carbon dioxide, feces

12. © 2013 Pearson Education, Inc. Necessary Life Functions Reproduction –Cellular division for growth or repair –Production of offspring Growth –Increase in size of a body part or of organism

13. © 2013 Pearson Education, Inc. Interdependence of Body Cells Humans are multicellular –To function, must keep individual cells alive –All cells depend on organ systems to meet their survival needs All body functions spread among different organ systems Organ systems cooperate to maintain life –Note major organs and functions of the 11 organ systems (fig. 1.3)

14. © 2013 Pearson Education, Inc. Survival Needs Appropriate amounts necessary for life –Too little or too much harmful Nutrients Oxygen Water Normal body temperature Appropriate atmospheric pressure

15. © 2013 Pearson Education, Inc. Survival Needs Nutrients –Chemicals for energy and cell building –Carbohydrates, fats, proteins, minerals, vitamins Oxygen –Essential for energy release (ATP production)

16. © 2013 Pearson Education, Inc. Survival Needs Water –Most abundant chemical in body –Environment of chemical reactions –Fluid base for secretions and excretions Normal body temperature –37° C –Affects rate of chemical reactions Appropriate atmospheric pressure –For adequate breathing and gas exchange in lungs

17. © 2013 Pearson Education, Inc. Homeostasis –Maintenance of relatively stable internal conditions despite continuous changes in environment –A dynamic state of equilibrium –Maintained by contributions of all organ systems

18. © 2013 Pearson Education, Inc. Homeostatic Control Mechanisms Involve continuous monitoring and regulation of all factors that can change (variables) Communication necessary for monitoring and regulation –Functions of nervous and endocrine systems Nervous and endocrine systems accomplish communication via nerve impulses and hormones

19. © 2013 Pearson Education, Inc. Components of a Control Mechanism Receptor (sensor) –Monitors environment –Responds to stimuli (something that causes changes in controlled variables) Control center –Determines set point at which variable is maintained –Receives input from receptor –Determines appropriate response Effector –Receives output from control center –Provides the means to respond –Response either reduces (negative feedback) or enhances stimulus (positive feedback)

20. © 2013 Pearson Education, Inc. Negative Feedback Most feedback mechanisms in body Response reduces or shuts off original stimulus –Variable changes in opposite direction of initial change Examples –Regulation of body temperature (a nervous system mechanism) –Regulation of blood glucose by insulin (an endocrine system mechanism)

21. © 2013 Pearson Education, Inc. Negative Feedback: Regulation of Blood Glucose by Insulin Receptors sense increased blood glucose (blood sugar) Pancreas (control center) secretes insulin into the blood Insulin causes body cells (effectors) to absorb more glucose, which decreases blood glucose levels

22. © 2013 Pearson Education, Inc. Positive Feedback Response enhances or exaggerates original stimulus May exhibit a cascade or amplifying effect Usually controls infrequent events that do not require continuous adjustment –Enhancement of labor contractions by oxytocin (chapter 28) –Platelet plug formation and blood clotting

23. © 2013 Pearson Education, Inc. Homeostatic Imbalance Disturbance of homeostasis – Increases risk of disease – Contributes to changes associated with aging Control systems less efficient – If negative feedback mechanisms overwhelmed Destructive positive feedback mechanisms may take over (e.g., heart failure)

24. © 2013 Pearson Education, Inc. Anatomical Position Standard anatomical body position –Body erect –Feet slightly apart –Palms facing forward Thumbs point away from body Always use directional terms as if body is in anatomical position Right and left refer to body being viewed, not those of observer

25. © 2013 Pearson Education, Inc. Regional Terms Two major divisions of body –Axial Head, neck, and trunk –Appendicular Limbs Regional terms designate specific areas within body divisions

26. © 2013 Pearson Education, Inc. Anatomical Variability Humans differ externally and internally –90% of all structures present in body match description in textbook –Nerve or blood vessel may be out of place –Small muscle may be missing Extreme variations inconsistent with life

27. © 2013 Pearson Education, Inc. Body Planes and Sections Body plane –Flat surface along which body or structure may be cut for anatomical study Sections –Cuts or sections made along a body plane

28. © 2013 Pearson Education, Inc. Body Planes Three most common –Lie at right angles to each other –Sagittal plane –Frontal (coronal) plane –Transverse (horizontal) plane

29. © 2013 Pearson Education, Inc. Sagittal Plane Sagittal plane –Divides body vertically into right and left parts –Produces a sagittal section if cut along this plane –Midsagittal (median) plane Lies on midline –Parasagittal plane Not on midline

30. © 2013 Pearson Education, Inc. Body Planes Frontal (coronal) plane –Divides body vertically into anterior and posterior parts –Produces a frontal or coronal section Transverse (horizontal) plane –Divides body horizontally (90° to vertical plane) into superior and inferior parts –Produces a cross section Oblique section –Result of cuts at angle other than 90° to vertical plane

31. © 2013 Pearson Education, Inc. Body Cavities Two sets of internal body cavities –Closed to environment Provide different degrees of protection to organs Dorsal body cavity Ventral body cavity

32. © 2013 Pearson Education, Inc. Dorsal Body Cavity Protects nervous system Two subdivisions: –Cranial cavity Encases brain –Vertebral cavity Encases spinal cord

33. © 2013 Pearson Education, Inc. Ventral Body Cavity Houses internal organs (viscera) Two subdivisions (separated by diaphragm) –Thoracic cavity –Abdominopelvic cavity

34. © 2013 Pearson Education, Inc. Ventral Body Cavity Thoracic cavity subdivisions –Two pleural cavities Each surrounds a lung –Mediastinum Contains pericardial cavity Surrounds thoracic organs –Pericardial cavity Encloses heart

35. © 2013 Pearson Education, Inc. Ventral Body Cavity Abdominopelvic cavity subdivisions –Abdominal cavity Contains stomach, intestines, spleen, and liver –Pelvic cavity Contains urinary bladder, reproductive organs, and rectum

36. © 2013 Pearson Education, Inc. Membranes in Ventral Body Cavity Serous membrane or serosa –Thin, double-layered membranes Parietal serosa lines internal body cavity walls Visceral serosa covers internal organs (viscera) –Layers separated by slit-like cavity filled with serous fluid Fluid secreted by both layers of membrane

37. © 2013 Pearson Education, Inc. Serous Membranes Named for specific cavity and organs with which associated Each has parietal and visceral layers Pericardium –Heart Pleurae –Lungs Peritoneum –Abdominopelvic cavity

38. © 2013 Pearson Education, Inc. Abdominopelvic Quadrants Divisions used primarily by medical personnel

39. © 2013 Pearson Education, Inc. Abdominopelvic Regions Nine divisions used primarily by anatomists

40. © 2013 Pearson Education, Inc. Other Body Cavities Exposed to environment –Oral and digestive cavities –Nasal cavity –Orbital cavities –Middle ear cavities Not exposed to environment –Synovial cavities