BI204R      CHAP 1        Anatomy and Physiology

  1. Definitions

• Anatomy - science of body structures and relationships among structures                                                             many subdisciplines - gross anatomy, comparative anatomy, developmental anatomy, microscopic anatomy
• Physiology - science of body functions or how the body works                       many subdisciplines - renal physiology, neural physiology, cardiac physiology, cell physiology
• Levels of organization         1. atomic and chemical or molecular - atoms combine to form molecules with complex shapes - shape determines function       2. cellular - smallest living units in body are cells which contain organelles      3. tissue - group of cells working together to perform a specific function         4. organ - 2 or more tissues working in combination to perform several functions       5. organ system - organs are grouped into organ systems coordinating specific functions   the body has 11 organ systems    6. organism  - all systems work together to maintain life and health                                       organization at each level determines the characteristics and the functions at higher levels
• Organ systems -   1. integumentary system  - skin, hair, sweat glands, nails       2. nervous system - brain, spinal cord, peripheral nerves, sense organs      3. skeletal system - bones, cartilages, associated ligaments, bone marrow          4. endocrine system  -   pituitary gland, thyroid gland, pancreas, adrenal glands, gonads, endocrine tissue in other organs         5. muscular system - skeletal muscles, associated tendons and aponeuroses              6. cardiovascular system - heart, blood, blood vessels       7. lymphatic system - spleen, thymus,lymphatic vessels, lymph nodes, tonsils          8. urinary system - kidneys, ureters, urinary bladder, urethra             9. respiratory system - nasal cavities, sinuses, larynx, trachea, bronchi, lungs, alveoli          10. digestive system - teeth, tongue, pharynx, esophagus, stomach, small intestine, large intestine, liver, gallbladder, pancreas        11. reproductive system - A. male system - testes, epididymis, ductus deferens, seminal vesicles, prostate gland, penis, scrotum        B. female - ovaries, uterine tubes, uterus, vagina, labia, clitoris, mammary glands
• Characteristics of living things      1. organization - living things have discrete boundaries that separate it from the environment and maintain an internal environment     2. responsiveness - respond to changes in the environment        property also called irritability        allows organisms to be adaptable              3. growth and differentiation - organism grows larger by increasing number and size of cells and these cells become specialized to perform specific functions          4. reproduction - create new generations of similar organisms      5. movement - can be internal or external            6. metabolism and excretion - complex chemical reactions provide energy and allow synthesis of complex chemicals such as proteins       metabolism generates unneeded or potentially harmful waste products which are removed by excretion
• Autopsy - postmortem exam of the body and dissection of the internal organs to confirm or determine the cause of death
• Homeostasis - very important - condition of equilibrium in the body's internal environment produced by ceaseless interplay of all of the body's regulatory processes          1A. autoregulation - or intrinsic regulation occurs when activities within the cell, tissue organ ,etc. adjust to environmental change automatically       1B. extrinsic regulation - results from activities of endocrine or nervous systems                         nervous system directs rapid short termand very specific responses               endocrine system releases chemical hormones that affect specific tissues and organs slowly but effects can last for days or weeks                        2. regulatory mechanism consists of 3 parts     a. receptor - sensor sensitive to particular environmental change      b. control center - or integration center     receives and processes info from the receptor       c. effector - cell or organ that responds to commands of control center and whose activity opposes or enhances stimulus          opposes called negative feedback and enhances called positive feedback
• Negative feedback control mechanisms - variation outside the desired range triggers an automatic response that corrects the situation                             minimizes change keeping systems within narrow limits           most homeostatic regulatory mechanisms involve negative feedback                  body temperature, glucose levels, calcium ion levels in blood
• Positive feedback control mechanisms - initial stimulus produces response that enhances change in original conditions          blood clotting - each step enhances the effects of the previous steps until blood loss stops