Transcript Ch 1 ppt
Chapter 1 Human Body Orientation Anatomy • Study of structure – Types • Gross Anatomy: the study of large body structures visible to the naked eye such as the heart or lungs • Microscopic Anatomy: the study of structures too small to be seen without a microscope such as tissues and cells • Developmental Anatomy: the study of structural changes that occur in the body throughout the lifespan Physiology • The study of the function of the body – Types • Renal Physiology: kidney function and urine production • Neurophysiology: nervous system • Cardiovascular Physiology: heart and blood vessels Structure determines Function • How a cell looks determines what the cell does. (ex. Long dendrites on a nerve cell allows it to send signals quickly) • How an organ looks determines how well it functions. Levels of Structural Organization • 1. chemical level (atoms & molecules) • 2. cellular level (cells & organelles) • 3. tissue level (groups of similar cells that have a common function) • 4. organ level (discrete structures composed of at least two tissue types) • 5. organ system (organs work together to accomplish a common purpose) • 6. organismal level (the sum total of all structural levels) Necessary Life Functions • 1. maintaining boundaries: internal boundaries remain distinct from external environment • 2. movement: activities of the muscular system, etc. • 3. responsiveness: the ability to sense changes (stimuli) and respond to them • 4. digestion: breaking down food to simple molecules • 5. metabolism: chemical reactions in the body • 6. excretion: removing wastes • 7. reproduction: cellular or organismal • 8. growth: increase in the size of cells, body parts, or the organism itself Survival Needs • 1. nutrients: contain the chemical substances used for energy and cell building • 2. oxygen: allows cellular respiration to occur • 3. water: accounts for 60-80% of body weight, needed for chemical reactions • 4. normal body temperature: maintains metabolic reactions • 5. atmospheric pressure: needed for proper breathing and gas exchange in the lungs Homeostasis • The ability to maintain a stable internal environment • Every organ system plays a role in maintaining the constancy of the internal environment Negative Feedback • The output shuts off the original stimulus or reduces its intensity (prevents sudden severe changes in the body) • These mechanisms cause the variable to change in a direction opposite to that of the initial change • Ex. Body temperature and blood volume Positive Feedback • The response enhances the original stimulus so that the activity is accelerated • The change that occurs is in the same direction as the initial disturbance • Ex. Oxytocin: intensifies labor contractions Response to Environment • Nervous system – electrochemical – Afferent pathway – (arriving) receptor stimuli to control center – Efferent pathway – (exiting) control center • Ex. hot stove and hand • Endocrine system – hormones • Ex. insulin and glucose Orientation and Direction • • • • • • • • • • Cranial Caudal Ventral Dorsal Superior Inferior Medial Lateral Proximal Distal Body Planes and Sections • Sagittal: divides body into right and left • Median: sagittal along the midline • Frontal (coronal): divides body into anterior and posterior • Transverse: horizontal; divides body into superior and inferior parts • Dorsal Body Cavities – Cranial & vertebral • Ventral – Thoracic • Pleural cavities – houses lungs • Mediastinum – houses heart, trachea, esophagus – Abdominal -- Pelvic Membranes of Body Cavities • Serous membranes – Covering on organs • Parietal serosa: lines the cavity walls • Visceral serosa: covers the organs • Serous fluid: lubricating fluid • Peritonitis- inflammation of the membrane lining of the abdominal cavity Abdominopelvic Quadrants Other Body Cavities • • • • • 1. oral and digestive 2. nasal 3. orbital 4. middle ear 5. synovial 11 Systems • • • • • • • • • • • Cardiovascular Skeletal Integumentary Lymphatic Urinary Muscular Digestive Respiratory Reproductive Nervous Endocrine