AN INTRODUCTION TO THE HUMAN BODYA. ANATOMY AND PHYSIOLOGY DEFINEDAnatomy (from the Greek “anatome” = to cut up, dissect)What do you mean when you speak of the anatomy of the body?You are referring to the study of structures and the relationships between structures.Physiology (from the Greek “physis” = nature)What do you mean when you speak of the physiology of the body?You are referring to the functions of the body parts.These two cannot be wholly separated?Why not?Structure usually determines function and, in turn, the function of a body part usually influences its size, shape, and overall health.B. LEVELS OF STRUCTURAL ORGANIZATIONWhat are the six levels of structural organization of the human body? What comprises each level?1. chemical level – lowest level; includes all atoms and molecules essential for maintaining life2. cellular level – cells are the basic structural and functional units of life; formed from molecules and atoms3. tissue level – tissues are groups of similar cell types and the extracellular matrix around them; cells work for a common function4. organ level – organs are comprised of two or more different tissues;each organ has a specific function and shape5. system level – consists of an association of related organs that have a common function6. organismic level – highest level; all body parts are functioning together to comprise the individualC. LIFE PROCESSESAll living forms carry on certain processes that distinguish them from nonliving things.1Can you list the six important life processes of humans?metabolismresponsiveness (excitability, irritability)movementgrowthdifferentiationreproductionWhat is metabolism?Metabolism is the sum of all chemical processes in the body.Metabolism can be broken down into two processes that contribute to the whole. Name them.Catabolism – breaking-down processes that provide energy by breaking large molecules into their components partsAnabolism – building up processes that use energy and raw materials to build and maintain the body’s structural and functional componentsWhat is responsiveness (excitability, irritability)Responsiveness is the ability to detect and respond to changes in the external and internal environments.What roles do the nervous and endocrine systems have in this process?The nervous and endocrine systems detect changes in the environment, then integrate and interpret those changes.What roles do the muscles and glands have in this process?Muscular and glandular tissues respond to input from the nervous and endocrine systems to elicit changes in the body to counteract changes in the environment.What is movement and what does it include?Movement includes motion of the whole body, individual organs, tissues, cells, or even organelles within cells.2What is growth and in what two ways can it occur?Growth refers to an increase in size and complexity of an individual. It canoccur as:(1) an increase in the number and size of cells and as(2) an increase in the amount of extracellular matrix betweencells, pushing the cells farther apart.What is differentiation?Differentiation is the process a cell undergoes as it moves developmentally from an unspecialized stage to a more specialized one.What is reproduction?Reproduction refers either to the formation of new cells for growth, repair, or replacement (mitosis), or to the production of a new individual (sexual).D. ANATOMICAL POSITIONWhat is the anatomical position?The subject stands upright facing the observer, with feet flat on the floor, arms at the sides, palms and eyes facing forward.E. DIRECTIONAL TERMSWhy do we use directional terms?Directional terms are used to discuss body parts in relation to one another.What are the five most commonly used directional term pairs?superior versus inferioranterior (ventral) versus posterior (dorsal)medial versus lateralproximal versus distalsuperficial versus deepF. PLANES AND SECTIONSWhat is a plane and how does it compare to a section?A plane is an imaginary flat surface that passes through the body. A section is a two-dimensional surface resulting from a cut made through thethree-dimensional structure along one of planes described below.3Can you list the four major planes of the body?A sagittal plane is a vertical plane that divides a structure into right and leftsides.A frontal (coronal) plane divides the body or part into anterior (front) and posterior (back).A transverse (horizontal or cross) plane divides the body or part into superior (top) and inferior (bottom) parts.An oblique plane passes through the body or part at an angle between thetransverse plane and the others.What are the five sections you can make through the body or a body part?midsagittal, parasagittal, transverse, frontal, obliqueG. BODY CAVITIESWhat is a body cavity?Body cavities are confined spaces within the body that separate internal organs and serve to protect, separate, and support the organs. There are two, dorsal and ventral.Name the subdivisions of the dorsal cavity?cranial cavity contains the brainvertebral (spinal) cavity contains the spinal cordName the subdivisions of the ventral body cavity?thoracic cavity contains the pleural cavities (lungs)mediastinumanteriormiddle (pericardial cavity)posteriorabdominopelvicHow is the ventral body cavity divided?The abdominopelvic cavity is separated from the thoracic cavity by the muscular diaphragm.An imaginary plane lying across the bony pelvis separates the abdomen and pelvis.4H. HOMEOSTASISHomeostasis: maintaining physiological limits(Greek “homoi-“ = same, “stasis” = standing stillDefine the term homeostasis.A condition in which the body’s internal environment remains within certainphysiological limitsWhat three conditions must be maintained at all times to ensure that a cell remains in homeostasis?1. optimum levels of gases, ions, nutrients, water2. optimum temperature3. optimum pressureWhy must the fluid bathing body cells by precisely maintained?For the cells of the body to live, the composition of their surrounding fluids must be precisely maintained at all times, since this is the fluid with which they exchange materials.Define extracellular fluid and its two major components?Extracellular fluid (ECF) is that fluid outside of cells:1. Interstitial fluid (intercellular or tissue fluid) is that fluid filling the narrow spaces between the cells.2. Plasma is the fluid components of the bloodWhat is intracellular fluid?Intracellular fluid is the fluid