Understanding Human Anatomy and Physiology: Key Concepts and Functions

1. Chapter 1Organization of the Body Slide

2. Anatomy and Physiology • Anatomy and physiology are branches of biology concerned with the form and functions of the body • Anatomy - study of the structure of an organism and the relationship of its parts • Physiology – is the science that deals with the functions of the living organism and its parts. Slide

3. 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 Slide

4. 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 Slide

5. 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 Slide

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

7. Characteristics of Life • Responsiveness – permits an organism to sense, monitor and respond to changes in its external environment • Example: withdrawing from a painful stimulus, i.e. pinprick… • Conductivity – capacity of living cells and tissues to selectively transmit a wave of excitation from one point to another • Nerve impulse conduction Slide

8. Characteristics of Life • Growth – result of a normal increase in the size or number of cells • Hypertrophy or Hyperplasia • Respiration – processes that result in the absorption, transport, utilization, or exchange of respiratory gases • O2/CO2 exchange in the lungs Slide

9. Characteristics of Life • Digestion – process by which complex foods are broken down into simpler substances that can be absorbed by the bodies cells • Catabolism • Absorption – movement of digested nutrients through the wall of the digestive tract into the bodies fluids • Small bowel and nutrient absorption Slide

10. Characteristics of Life • Secretion – production and delivery of specialized substances • Digestive juices or hormones • Excretion – removal of waste products produced during the bodies functions • CO2 exhaled Slide

11. Characteristics of Life • Circulation – movement of body fluids and many other substances from one place in the body to another • O2 to the bodies cells • Reproduction – formation of new cells or a new individual • Mitosis Slide

12. Characteristics of Life • Metabolism – the sum total of all physical and chemical reactions occurring in the living body Slide

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14. Levels of Organization (Figure 1-3) • Chemical level—basis for life • Organization of chemical structures separates living material from nonliving material • Combinations of atoms form molecules • Combinations of molecules and atoms form macromolecules results in living matter • The complex relationship between these form a gel called cytoplasm • The essential material to human life Slide

15. Levels of Organization • Organelle level • Chemical structures organize to form organelles that perform individual functions • 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 Slide

16. Levels of Organization • Cellular level • Cells are the smallest and most numerous units that possess and exhibit characteristics of life • A cells nucleus is surrounded by cytoplasm within a limiting membrane • Cells differentiate to perform unique functions Slide

17. Levels of Organization • Tissue level • Tissue consist of an organization of similar cells specialized to perform a certain function • Tissue cells are surrounded by nonliving matrix and are the fabric of the body • Four major tissue types: • Epithelial tissue • Connective tissue • Muscle tissue • Nervous tissue Slide

18. Levels of Organization • Organ level • An organ is several different kinds of tissues that combine 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 Slide

19. Levels of Organization • System level • System – the most complex organizational unit of the body • The system level involves varying numbers and kinds of organs arranged to perform complex functions (Table 1-1): • Outer protection • Support and movement • Communication, control, and integration • Transportation and defense • Respiration, nutrition, and excretion • Reproduction and development Slide

20. Levels of Organization • Organism level • The living human organism is greater than the sum of its parts • All of the components (chemical – system) work together to allow the human to survive and flourish Slide

21. Anatomical Position (Figure 1-4) • Reference position for A&P and Positioning • Body erect or standing, with arms at sides, palms turned forward, and the head and feet pointing forward Slide

22. Anatomical Position Slide

23. 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 • There is 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 Slide

24. 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 Slide

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26. Body Cavities • Dorsal body cavity • Cranial cavity • Spinal cavity Slide

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

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30. Body Regions • Abdominal regions (Figure 1-7) • 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 Slide

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

33. Terms Used in Describing Body Structure • Superior – towards the head • Inferior – towards the feet • Anterior – front • Posterior – back • Medial – toward the midline • Lateral – away from the midline Slide

34. Terms Used in Describing Body Structure • Proximal – toward the nearest point of attachment or the trunk of the body • Distal – away or furthest from the point of attachment or trunk • Superficial – nearer the surface • Deep – farther from the surface Slide

35. 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 Slide

36. 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 Slide

37. 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 • If section divides the body into equal anterior or posterior portions, the plane is called midcoronal • Transverse (horizontal) plane is a “crosswise” plane—it divides body (or part) into upper and lower parts Slide

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40. 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 bodies internal environment • The body maintains homeostasis through feedback systems Slide

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42. Homeostasis (Figure 1-14) • Examples of homeostasis: • Temperature regulation • Regulation of blood carbon dioxide level • Regulation of blood glucose level • Body adjusts important variables from a normal “set point” in to get the body back into an acceptable or normal range (blood pressure) Slide

43. Homeostatic Control Mechanisms • A homeostatic control mechanism is a device for maintaining or restoring homeostasis by self-regulation through feedback control loops • The basic components of control mechanisms: • Sensory mechanism (receptor) – are specific sensors that detect and react to any changes from normal • Nerve • Integrating, or control, center – where information is analyzed and integrated, and then, if needed, a specific action is initiated • CNS or Thyroid • Effector mechanism—effectors directly influence controlled physiological variables • Muscle or gland • Feedback system - processes information about a variable constantly sends information back from the sensor to the integrator (control) Slide

44. Feedback System Example Slide

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46. Homeostatic Control Mechanisms • Negative feedback control system – reverses a change in a controlled condition • 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 • Example: Body Temperature Control or Blood Pressure Slide

47. Homeostatic Control Mechanisms • Positive feedback control system – the effector produces a physiological responses that reinforces the initial change in the controlled condition • 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 • Example: Childbirth, Clotting, Immune Response, or Sneeze Slide

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49. 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) Slide

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