1. Copyright © 2010 Pearson Education, Inc. Chapter 1 The Human Body: An Orientation Part A Shilla Chakrabarty, Ph.D.

2. Copyright © 2010 Pearson Education, Inc. Overview of Anatomy Anatomy- The Term: Derived from Ancient Greek word anatemnein, where ana means separate, apart from; and temnein means to cut up, cut open Anatomy : The study and structure of body parts and their relationship to each other

3. Copyright © 2010 Pearson Education, Inc. Gross Anatomy Of The Human Brain Brain Of A Deceased Person Brain Of A Living Person

4. Copyright © 2010 Pearson Education, Inc. Subdivisions Of Anatomy  Gross or macroscopic (e.g., regional, surface, and systemic anatomy)  Microscopic (e.g., cytology and histology)

5. Copyright © 2010 Pearson Education, Inc. Overview of Anatomy Essential tools for the study of anatomy: Mastery of anatomical terminology Observation (Macroscopic and microscopic) Manipulation (Latin Manipulare: to work with hands) Palpation (Latin Palpare: to stroke) Auscultation (Latin Auscultare: to listen)

6. Copyright © 2010 Pearson Education, Inc. Overview of Physiology Physiology – The Term: Derived from Ancient Greek physis which means nature or origin, and logia which means study of Physiology: The study of function at many levels  Subdivisions are based on organ systems (e.g., renal or cardiovascular physiology)

7. Copyright © 2010 Pearson Education, Inc. Overview of Physiology Essential tools for the study of physiology: Ability to focus at many levels (from systemic to cellular and molecular) Basic physical principles (e.g., electrical currents, pressure, and movement) Basic chemical principles

8. Copyright © 2010 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

9. Copyright © 2010 Pearson Education, Inc. Levels of Structural Organization Chemical: atoms and molecules (Chapter 2) Cellular: cells and their organelles (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

10. Copyright © 2010 Pearson Education, Inc. Cardiovascular system Organelle Molecule Atoms Chemical level Atoms combine to form molecules. Cellular level Cells are made up of molecules. Tissue level Tissues consist of similar types of cells. Organ level Organs are made up of different types of tissues. Organ system level Organ systems consist of different organs that work together closely. Organismal level The human organism is made up of many organ systems. Smooth muscle cell Smooth muscle tissue Connective tissue Blood vessel (organ) Heart Blood vessels Epithelial tissue Smooth muscle tissue 1 2 3 4 5 6 Levels of Structural Organization

11. Copyright © 2010 Pearson Education, Inc. Overview of Organ Systems There are 11 organ systems with different functions, as shown in the following slides NOTE: In this course we will learn about five organ systems and their functions: - The Integumentary System: Function - Protection -The Skeletal System: Function - Support -The Muscular System: Function - Movement -The Nervous System: Function – Integration and Coordination -The Endocrine system: Function – Integration and Coordination

12. Copyright © 2010 Pearson Education, Inc. Figure 1.3a Nails Skin Hair  Forms the external body covering, and protects deeper tissues from injury.  Synthesizes vitamin D, and houses cutaneous (pain, pressure, etc.) receptors and sweat and oil glands. Organ Systems: The Integumentary System

13. Copyright © 2010 Pearson Education, Inc. Figure 1.3b Bones Joint  Protects and supports body organs, and provides a framework the muscles use to cause movement.  Blood cells are formed within bones.  Bones store minerals. Organ Systems: The Skeletal System

14. Copyright © 2010 Pearson Education, Inc. Figure 1.3c Skeletal muscles  Allows manipulation of the environment, locomotion, and facial expression.  Maintains posture, and produces heat. Organ Systems: The Muscular System

15. Copyright © 2010 Pearson Education, Inc. Figure 1.3d Brain Nerves Spinal cord  As the fast-acting control system of the body, it responds to internal and external changes by activating appropriate muscles and glands. Organ Systems: The Nervous System

16. Copyright © 2010 Pearson Education, Inc. Figure 1.3e Pineal gland Pituitary gland Thyroid gland Thymus Adrenal gland Pancreas Testis Ovary  Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells. Organ Systems: The Endocrine System

17. Copyright © 2010 Pearson Education, Inc. Figure 1.3f Heart Blood vessels  Blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes, etc.  The heart pumps blood. Organ Systems: The Cardiovascular System

18. Copyright © 2010 Pearson Education, Inc. Figure 1.3g Lymphatic vessels Red bone marrow Thoracic duct Thymus Spleen Lymph nodes  Picks up fluid leaked from blood vessels and returns it to blood.  Disposes of debris in the lymphatic stream.  Houses white blood cells (lymphocytes) involved in immunity.  The immune response mounts the attack against foreign substances within the body. Organ Systems: The Lymphatic/Immunity System

19. Copyright © 2010 Pearson Education, Inc. Figure 1.3h Nasal cavity Bronchus Pharynx Larynx Trachea Lung  Keeps blood constantly supplied with oxygen and removes carbon dioxide.  The gaseous exchanges occur through the walls of the air sacs of the lungs. Organ Systems: The Respiratory System

20. Copyright © 2010 Pearson Education, Inc. Figure 1.3i Liver Oral cavity Esophagus Large intestine Stomach Small intestine Rectum Anus  Breaks down food into absorbable units that enter the blood for distribution to body cells.  Indigestible foodstuffs are eliminated as feces. Organ Systems: The Digestive System

21. Copyright © 2010 Pearson Education, Inc. Figure 1.3j Kidney Ureter Urinary bladder Urethra  Eliminates nitrogenous wastes from the body.  Regulates water, electrolyte and acid-base balance of the blood. Organ Systems: The Urinary System

22. Copyright © 2010 Pearson Education, Inc.  Overall function is production of offspring.  Testes produce sperm and male sex hormone. Male ducts and glands aid in delivery of sperm to the female reproductive tract.  Ovaries produce eggs and female sex hormones. The remaining female structures serve as sites for fertilization and development of the fetus. Mammary glands of female breasts produce milk to nourish the newborn. Figure 1.3k-l Prostate gland Ductus deferens Penis Testis Scrotum Ovary Uterine tube Mammary glands (in breasts) Uterus Vagina (k) Male Reproductive System (l) Female Reproductive System Organ Systems: The Reproductive System

23. Copyright © 2010 Pearson Education, Inc. Figure 1.2 Digestive system Takes in nutrients, breaks them down, and eliminates unabsorbed matter (feces) Respiratory system Takes in oxygen and eliminates carbon dioxide Food O2O2 CO 2 Cardiovascular system Via the blood, distributes oxygen and nutrients to all body cells and delivers wastes and carbon dioxide to disposal organs Interstitial fluid Nutrients Urinary system Eliminates nitrogenous wastes and excess ions Nutrients and wastes pass between blood and cells via the interstitial fluid Integumentary system Protects the body as a whole from the external environment Blood Heart Feces Urine CO 2 O2O2 Organ Systems Interrelationships All cells depend on organ systems to meet their survival needs Organ systems work cooperatively to perform necessary life functions

24. Copyright © 2010 Pearson Education, Inc. Necessary Life Functions 1.Maintaining boundaries between internal and external environments Plasma membranes Skin 2.Movement (contractility) Of body parts (skeletal muscle) Of substances (cardiac and smooth muscle)

25. Copyright © 2010 Pearson Education, Inc. Necessary Life Functions 3.Responsiveness: The ability to sense and respond to stimuli Withdrawal reflex Control of breathing rate 4.Digestion Breakdown of ingested foodstuffs Absorption of simple molecules into blood

26. Copyright © 2010 Pearson Education, Inc. Necessary Life Functions 5.Metabolism: All chemical reactions that occur in body cells Catabolism and anabolism 6.Excretion: The removal of wastes from metabolism and digestion Urea, carbon dioxide, feces

27. Copyright © 2010 Pearson Education, Inc. Necessary Life Functions 7.Reproduction Cellular division for growth or repair Production of offspring 8.Growth: Increase in size of a body part or of organism

28. Copyright © 2010 Pearson Education, Inc. Survival Needs 1.Nutrients Chemicals for energy and cell building Carbohydrates, fats, proteins, minerals, vitamins 2.Oxygen Essential for energy release (ATP production)

29. Copyright © 2010 Pearson Education, Inc. Survival Needs 3.Water Most abundant chemical in the body Site of chemical reactions 4.Normal body temperature Affects rate of chemical reactions 5.Appropriate atmospheric pressure For adequate breathing and gas exchange in the lungs

30. Copyright © 2010 Pearson Education, Inc. Homeostasis And Homeostatic Control Mechanisms Homeostasis is: Maintenance of a relatively stable internal environment despite continuous outside changes A dynamic state of equilibrium Homeostatic Control Mechanisms Involve continuous monitoring and regulation of many factors (variables) Nervous and endocrine systems accomplish the communication via nerve impulses and hormones

31. Copyright © 2010 Pearson Education, Inc. Stimulus produces change in variable. Receptor detects change. Input: Information sent along afferent pathway to control center. Output: Information sent along efferent pathway to effector. Response of effector feeds back to reduce the effect of stimulus and returns variable to homeostatic level. ReceptorEffector Control Center BALANCE Afferent pathway Efferent pathway IMBALANCE 1 2 3 4 5 Figure 1.4 Components of a Control Mechanism

32. Copyright © 2010 Pearson Education, Inc. Components of a Control Mechanism 1.Receptor (sensor) Monitors the environment Responds to stimuli (changes in controlled variables) 2.Control center Determines the set point at which the variable is maintained Receives input from receptor Determines appropriate response 3.Effector Receives output from control center Provides the means to respond Response acts to reduce or enhance the stimulus (negative and positive feedback, respectively)

33. Copyright © 2010 Pearson Education, Inc. Negative Feedback The response reduces or shuts off the original stimulus Examples: Regulation of body temperature (a nervous mechanism) Regulation of blood sugar by pancreatic insulin Regulation of blood sugar

34. Copyright © 2010 Pearson Education, Inc. Figure 1.5 Sweat glands activated Shivering begins Stimulus Body temperature rises BALANCE Information sent along the afferent pathway to control center Information sent along the afferent pathway to control center Afferent pathway Afferent pathway Efferent pathway Efferent pathway Information sent along the efferent pathway to effectors Information sent along the efferent pathway to effectors Stimulus Body temperature falls Receptors Temperature-sensitive cells in skin and brain Receptors Temperature-sensitive cells in skin and brain Effectors Sweat glands Effectors Skeletal muscles Control Center (thermoregulatory center in brain) Control Center (thermoregulatory center in brain) Response Evaporation of sweat Body temperature falls; stimulus ends Response Body temperature rises; stimulus ends Negative Feedback: Regulation of Body Temperature

35. Copyright © 2010 Pearson Education, Inc. Positive Feedback The response enhances or exaggerates the original stimulus May exhibit a cascade or amplifying effect Usually controls infrequent events e.g.: Enhancement of milk production by oxytocin Platelet plug formation and blood clotting

36. Copyright © 2010 Pearson Education, Inc. Feedback cycle ends when plug is formed. Positive feedback cycle is initiated. Positive feedback loop Break or tear occurs in blood vessel wall. Platelets adhere to site and release chemicals. Released chemicals attract more platelets. Platelet plug forms. 1 2 3 4 Figure 1.6 Positive Feedback: Platelet Plug Formation

37. Copyright © 2010 Pearson Education, Inc. Homeostatic Imbalance Disturbance of homeostasis Increases risk of disease Contributes to changes associated with aging May allow destructive positive feedback mechanisms to take over (e.g., heart failure) Cardiovascular Homeostatic Imbalance