Chapter 1 - The Human Body: An Orientation

Transcription

1 Chapter 1 - The Human Body: An Orientation A. Terminology I. AN OVERVIEW OF ANATOMY AND PHYSIOLOGY 1. Anatomy: To Cut. No analyzing involved. - where things are, how connect to each other - Gross vs. microscopic 2. Physiology : Study of nature - how things work. Most = chemistry. 3. Relationship Between Anatomy and Physiology - form = function A. From Atoms to Organisms II. LEVELS OF STRUCTURAL ORGANIZATION Chemical Level: atoms form molecules Cellular Level: some molecules (carbon-based)_join to form cells Tissue Level: groups of cells with similar function Organ Level: structure with more than 2 tissue types. Does an important job for the body. * don t confuse organ with visceral organs! Organ System Level: group of organs cooperating to do a job. 11 in human body. Digestion, etc. Organismal Level: individual B. Organ System Overview 1. Integumentary System - external covering (skin). - perspiration: control body temperature. - receptors: info on outside world. Temperature, pressure, pain.

2 2. Skeletal System - bones, cartilage ligaments & joints. - supports, movement (locomotion), protection (thoracis, skull, vertebrae), hematopoeisis. 3. Muscular System - contract = shorten. Skeletal, cardiac, smooth. 4. Nervous System - fast control (on/off). - CNS (brain, sp. cord), PNS (nerves & receptors) - take sensory info (energy change, inside or outside), messages (impulses) are sent via electrical signals called Acton Potentials (or APs) to CNS to make decision. CNS then send to an effector (muscle, gland or another nerve) 5. Endocrine System - glands that secrete hormone, slow control - pituitary, thyroid, parathyroid, adrenals, thymus, pancreas, pineal, gonads - not connected, but release into general fluids of the body. 6. Cardiovascular System -heart, blood, vessels carry Oxygen& nutrients to tissues & wastes to removal sites (CO2 to lungs, nitrogenous wastes to kidneys). - heart = pump for blood - vessels contain blood - blood also is water reservoir, control ph (acidity), and immunity (protect against infection from viruses, bacteria and parasites). 7. Lymphatic System - return fluid leaked out of cardiovascular, and immunity 8. Respiratory System - bring in/remove gases 9. Digestive System - tube running through body that breaks down and delivers nutrients. 10. Urinary System - excretion. Nitrogenous wastes are soluble in water. Urine = urea + water + other ions not needed. 11. Reproductive System - produce offspring.

3 III. MAINTAINING LIFE A. Survival Needs 1. Nutrients (food) - chemicals used for building/repairing. Glucose is main energy molecule. - use building block molecules to build macromolecules. 2. Oxygen (gas) - oxidize glucose. Cellular respiration. O2 + glucose = ATP + CO2 + water 3. W ater % of body weight. Fluid for metabolism, because it is such a good medium for chemical reactions. - Hydrolysis = breaking down with water. - Dehydration synthesis = building with water. 4. Body Temperature 37 0 C, 98 0 F. Too high = proteins break down, too low = chemical reactions (metabolism...see later) go too slow. 5. Atmospheric Pressure - breathing depends on pressure. B. Necessary Life Functions 1. Maintaining Boundaries - inside vs. outside, cells have a membrane, body has integument. - Keep water & nutrients inside, infections outside. 2. Movement - find food, water, mates. Muscles & skeleton. 3. Responsiveness - detect changes (stimuli), and react. 4. Metabolism - Everything in body is a chemical reaction. Building up & breaking down. - Metabolism = all chemical reactions, breaking down (catabolism) & building up (anabolism). See section on water later. - hormones control metabolism. 5. Digestion - break down nutrients, because must be small to bring into body. Also, build what you need. 6. Excretion - removing solid wastes, especially those from protein metabolism and extra electrolytes.

4 7. Reproduction - reproducing offspring. Organismal level and cellular level (mitosis of cells). 8. Growth & repair - increase # cells of tissues. Done via mitosis of cells. C. HOMEOSTASIS: ( unchanging or same state ): Internal Balance - environment changes, but body levels must stay within narrow range of temperature, ph, fluid levels and nutrient levels to maintain metabolism. Homeostatic Control Mechanisms (p. 10) Variable - factor or event that will change. Receptor - detection. Afferent pathway Control Center - determines set point Efferent pathway Effector Homeostatic Imbalance - negative feedback loops - lower change. Increase in reaction to a decrease, or vis-a-versa. * hypothalamus of brain controls temperature. Muscles = effectors. - positive feedback loops - increase change. * labor contractions. Baby gets big, baby pushes on uterus, receptors in uterine wall detect it, impulse to brain, pituitary release oxytocin, causes uterus to contract.

5 IV. THE LANGUAGE OF ANATOMY W e leatned these in lab, but will also be using them in lecture: Correct Anatomical Position Directional Terms Superior Inferior Anterior (Ventral) Posterior (Dorsal) Medial Lateral Intermediate Proximal Distal Superficial Deep Regional Terms Anterior Body Landmarks Abdominal Antecubital Axillary Brachial Buccal Carpal Cervical Digital Femoral Inguinal Nasal Oral Orbital Patellar Peroneal Pubic Sternal Tarsal Thoracic Umbilical Posterior Body Landmarks Cephalic Deltoid Gluteal Lumbar Occipital Popliteal Scapular Sural Vertebral Body Planes and Sections Sagittal Frontal Transverse Body Cavities Dorsal Body Cavity Cranial Cavity Spinal Cavity Ventral Body Cavity Thoracic Cavity Abdominopelvic Cavity Pelvic Cavity