Chapter 1: The Human Body An Orientation

Science as a Process: 1.) Observations & Previous Experiments 2.) Propose hypothesis (educated guess) 3.) Design experiment (w/experimental & control group) 4.) Collect data & analyze it - data is biased - redesign experiment - not - continue 5.) Refine hypothesis - broad to specific 6.) Repeat experiment - (100s of times) - results are not consistent - new hypothesis - results are - accept as theory - could become a law

Anatomy - the study of the structure of an organism & the relationship of its parts - learn through dissection - subdivisions are: a.) gross anatomy b.) microscopic c.) developmental d.) pathological e.) systemic Physiology - the study of the functions of living organisms & their parts - subdivided into: a.) type of organism involved b.) organizational level studied c.) systemic function being studied

Characteristics of Life: Responsiveness Conductivity Growth Respiration Digestion Absorption Secretion Excretion Circulation Reproduction

***These 10 characteristics maintain metabolism ***Other criteria have been used to determine life on other planets such as the presence of ATP (adenosine triphosphate)

Levels of Organization 1.) Chemical Level - atoms molecules macromolecules cytoplasm 2.) Organelle Level - structures made of molecules organized to perform a specific function 3.) Cellular Level - smallest “living” unit of structure & function in the body - made of many organelles 4.) Tissue Level - organization of many similar cells that act together to perform a common function 5.) Organ Level - group of several different kinds of tissues arranged to perform a special function - each organ has a unique shape, size, appearance & placement in the body - “Form Fits Function” 6.) System Level - organization of varying # & kinds of organs arranged to perform complex functions 7.) Organism Level - any living entity considered as a whole - contains the characteristics of life

Anatomical Position The body is in an erect or standing posture w/ the arms at the sides & palms turned forward - head & feet also turned forward Humans are bilaterally symmetrical - rht & left sides of the body are mirror images of each other only 1 plane can divide the body terms: –ipsilateral - on the same side –contralateral - on opposite sides

Body Cavities - 2 major cavities I. Ventral Cavity - made of: A. Thoracic Cavity (chest) 1.) left & rht pleural cavity - lungs 2.) mediastinum - heart, trachea, bronchi, esophagus, thymus, blood & lymph vessels, lymph nodes, nerves

Is this person in the anatomical position? Justify your answer in 3 or more ways.

B. Abdominopelvic Cavity (stomach & groin) 1.) Abdominal Cavity - liver, gall bladder, stomach, pancreas, intestines, spleen, kidneys, ureters 2.) Pelvic Cavity - bladder, certain repro. organs, part of large intestines

***The thoracic & abdominal cavities are separated by a white band called the diaphragm, used for breathing

II. Dorsal Cavity - made of: A.) Cranial Cavity - brain B.) Spinal Cavity - spinal cord

***Membranes that line or cover body cavities are: a.) parietal - actual wall of the body cavity or the lining membranes that cover its surface b.) visceral - thin membranes that cover organs w/in a cavity

Body Regions - 2 of them A. Axial - consists of the head, neck, torso (trunk) B. Appendicular - consists of the upper & lower extremities - each portion is then divided further

Directional Terms 1.) LeftvsRight (subject’s)(subject’s) 2.) DorsalvsVentral (vertebral side)(belly side) 3.) CaudadvsCephalad (toward tail)(toward head) 4.) MedullaryvsCortical (inner region)(outer region) 5.) SuperiorvsInferior (toward head; upper;(toward feet; above)lower; below)

6.) AnteriorvsPosterior (front; in front of;(back; in back ventral)of; dorsal) 7.) MedialvsLateral (toward body’s midline)(toward side of body; away from midline) 8.) ProximalvsDistal (toward or nearest trunk(away from or or pt of origin)farthest from trunk or pt of origin)

9.) SuperficialvsDeep (nearer the surface)(farther away from surface) 10.) SupinevsProne (lying face upward)(lying face downward)

Body Planes & Sections 1.) Sagittal - lengthwise plane runing from front to back - divides the body into left & rht sides - divided into 2 equal halves - midsagittal plane 2.) Coronal (Frontal) - lengthwise plane running from side to side - divides the body into anterior & posterior (front & back) portions 3.) Transverse (Horizontal) - crosswise plane - divides the body into upper & lower portions

Abdominopelvic Regions

4 Quadrants

****Body planes are used in medical imaging like radiography, CT Scans, MRIs & ultrasonography

Body Types - Somatotypes 1.) Endomorphs - heavy, rounded physique charac. by large accumulations of fat in trunk & thighs - 2 types a.) apple shaped - higher health risk such as heart disease, stroke, hypertension, diabetes, breast cancer b.) pear shaped ***Determined by waist-to-hip ratio 2.) Mesomorph - muscular 3.) Ectomorph - thin, fragile physique charac. by little body fat

Homeostatic Control Mechanisms: - have at least 3 components a.) receptor – the sensor b.) control center – deter the set point at which a variable is to be maintained, analyzes the received info, & deter the appropriate response c.) effector – how the control center responds to the stimuli - feedback - feedback can be either: a.) negative feedback – effect either shuts off or decreases the stimuli’s intensity – mostly used in the body – ex) body temperature b.) positive feedback – effect enhances the stimuli’s intensity – rare – ex) blood clotting & giving birth

Feed Forward – info may flow ahead to another process to trigger a change in anticipation of an event that will follow – ex.) digestion

Fake!!!!