Intro to Anatomy Physiology

1. Chapter 1 Intro to Anatomy & Physiology

2. Studying the Human Body Anatomy � study of internal and external structures of the body & the physical relationships among body parts (how a muscle attaches to the skeleton) Physiology � study of how living organisms perform their vital functions (how a muscle contracts) Relationship � they are closely related. Anatomical information provides clues about functions, and physiological mechanisms can be explained only in terms of the underlying anatomy.

3. Studying the Human Body 100 Keys � page 5 All physiological functions are performed by specific anatomical structures. These functions follow the same physical and mechanical principles that can be seen in the world at large. Examples: cars, planes, computers

4. Studying the Human Body Anatomy Gross Anatomy � (macroscopic) involves examination of relatively large structures that can be seen with the unaided eye. Surface, regional, systemic, developmental, and clinical anatomy Microscopic Anatomy � deals with structures that cannot be seen without magnification. Cytology and histology

5. Studying the Human Body Gross Anatomy Surface � study of general form & superficial markings Regional � focuses on the anatomical organization of specific areas of the body (head, neck) Systemic � study of the structure of organ systems (groups of organs that function together � ex. Skeletal, muscular) Developmental � describes the changes in form that occur between conception & physical maturity Clinical � includes many subspecialties important in clinical practice (medical anatomy, surgical anatomy)

6. Studying the Human Body Microscopic Anatomy Cytology � analysis of the internal structure of individual cells Histology � examination of tissues (groups of specialized cells that work together to perform specific functions). Tissues combine to form organs (liver, heart)

7. Studying the Human Body Physiology Cell physiology � study of the functions of cells Special physiology � study of physiology of specific organs (cardiac physiology � study of heart function) Systemic physiology � all aspects of the functioning of specific organ systems (cardiovascular, respiratory) Pathological physiology � study of the effects of diseases on organ or system functions

8. Levels of Organization Chemical Level � atoms Cellular Level � organelles (components of cells) Tissue Level � group of cells working together (heart muscle) Organ Level � two or more tissues working together Organ System Level � interaction of organs (heart, blood, blood vessels = cardiovascular system) Organism Level � highest level of organization; all organ systems working together

9. Levels of Organization The cells, tissues, organs, and organ systems of the body coexist in a relatively small shared environment To survive, every organisms must maintain homeostasis Homeostasis � refers to the existence of a stable internal environment (homeo � unchanging; stasis � standing)

10. Levels of Organization 100 Keys � page 8 The body can be divided into 11 organ systems, but all work together and the boundaries between them are not absolute Integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, & reproductive

11. Homeostasis Homeostasis is vital to organisms; failure to maintain homeostasis soon leads to illness or even death Homeostatic regulation is the adjustment of physiological systems to preserve homeostasis Autoregulation � (intrinsic) occurs when a cell, tissue, organ, or organ system adjusts its activities automatically Extrinsic � results from the activities of the nervous or endocrine systems (adjust many systems simultaneously)

12. Homeostasis Mechanism Receptor � sensor that is sensitive to a particular environmental change Control Center � receives and processes the information supplied by the receptor, and which sends out commands Effector � a cell or organ that responds to the commands of the control center and whose activity either opposes or enhances the stimulus Example � thermostat (figure 1-3, page 12)

13. Homeostasis 100 Keys � page 11 Physiological systems work together to maintain a stable internal environment, the condition of homeostasis. In doing so they monitor and adjust the volume and composition of body fluids, and keep body temperature within normal limits

14. Homeostasis Role of Negative Feedback Occurs on most homeostatic regulatory mechanisms Example is the control of body temperature which occurs in the hypothalamus in the brain Figure 1-4, page 13

15. Homeostasis Role of Positive Feedback Where an initial stimulus produces a response that exaggerates the change in the original condition Rarely happens Typically found when a potentially dangerous or stressful process must be completed quickly before homeostasis can be restored Example � loss of blood from a severe cut can lower blood pressure and reduce efficiency of the heart. Blood loss causes blood clotting (figure 1-5, page 14) Example � disease � illness due to organ system malfunction from an infection or injury or genetic abnormality

16. Homeostasis State of Equilibrium � exists when opposing processes or forces are in balance Table 1-1, page 15 The Roles of Organ Systems in Homeostatic Regulation Body temperature Body fluid composition Body fluid volume Waste product concentration Blood pressure

17. Homeostasis 100 Keys � page 14 A state of equilibrium exists when opposing processes are in balance. When homeostasis is threatened, physiological systems attempt to restore a state of equilibrium within normal homeostatic limits. If they cannot do so, internal conditions become increasingly abnormal, and survival becomes uncertain.

18. Frames of Reference Anatomy uses a special language Latin and Greek Superficial anatomy Sectional anatomy Body cavities

19. Frames of Reference Superficial anatomy � anatomical landmarks, regions, and directions Anatomical landmarks � figure 1-6, page 16 Anatomical position � hands are at the side with palms facing forward and feet are together. Anterior view � front (ventral) Posterior view � back (dorsal) Supine � person lying down face up Prone � person lying down when face is down

20. Frames of Reference Superficial anatomy (continued) Anatomical regions � table 1-2, page 17 � regions of the human body (cephalon � cephalic region, etc) Two methods Adbominopelvic quadrants � formed by a pair of imaginary perpendicular lines (RLQ, RUQ, LLQ, LUQ) � figure 1-7, pg17 Abdominopelvic regions � more precise terms (RHR, RLR, RIR, LHR, LLR, LIR) � figure 1-7, pg17

21. Frames of Reference Superficial anatomy (continued) Anatomical directions � figure 1-8, page 18 and table 1-3, pg19 Anterior � or ventral � front Posterior � or dorsal � back Lateral � side Left and right always refer to the left and right sides of the subject, not the observer

22. Frames of Reference Sectional Anatomy Planes and sections: a plane is an axis; a section is a single slice of one the planes Transverse plane� lies at right angles to the long axis of the body Frontal plane � parallel to the long axis of the body, extends from side to side Sagittal plane � parallel to the long axis of the body, extends from front to back Table 1-4, page 20

23. Frames of Reference Body Cavities � many vital organs are suspended in internal chambers called body cavities � figure 1-10, page 21 Two essential functions: Protect delicate organs from accidental shocks and cushion them from the thumps and bumps that occur when we walk, jump, or run Permit significant changes in the size and shape of internal organs

24. Frames of Reference Body Cavities continued Thoracic Cavity � contains the lungs and heart Divided into the left and right pleural cavities, separated by the mediastinum (which includes the heart � pericardial cavity) Mediastinum consists of a mass of connective tissue that surrounds, stabilizes, and supports the esophagus, trachea, and thymus, as well as the major blood vessels that begin or end at the heart

25. Frames of Reference Body Cavities continued Abdominopelvic Cavity � extends from the diaphragm to the pelvis Subdivided into a superior abdominal cavity and an inferior pelvic cavity Abdominal cavity � include liver, stomach, spleen, small intestine, and most of the large intestine Pelvic cavity � include lower (distal) large intestine, urinary bladder, and various reproductive organs