Chapter One Introduction to Anatomy and Physiology

Relationship Between Anatomy and Physiology Anatomy: study of the structure and shape of the body and their relationship to one another Physiology: study of how the body and its parts work or function STRUCTURE DETERMINES FUNCTION

Anatomy can be divided into gross and microscopic: – Forms of Gross Anatomy Surface anatomy – study of superficial marking Regional anatomy – study of specific area Systemic anatomy – study of system Developmental anatomy – study changes from conception to physical maturity. – Microscopic anatomy includes two major subdivisions Cytology – study of cell Histology – study of tissue The Specialties of Anatomy

Comparative Anatomy All vertebrates share a basic pattern of organization, most noticeable during embryology.

Physiology is the study of the normal function of cell, tissue, organs, systems and organisms Physiology can be divided into the following specialties: – Cell physiology – study of cell – Special physiology - study of specific organ – Systemic physiology – study of system – Pathological physiology – study of the effect of disease on cell, tissue, organ and system. The Specialties of Physiology

Levels of Organization

Organ Systems

20 Characteristics of Life 1.Responsiveness a.permits an organism to sense, monitor, and respond to changes in its external environment b. highly developed in nerve and muscle cells 2.Conductivity a. capacity of living cells and tissues to selectively transmit or propagate a wave of excitation from one point to another within the body b. highly developed in nerve and muscle cells 3.Growth a. normal increase in size or number of cells b. produces an increase in size (person, organ, part) c. little change in the shape 4.Respiration a. Involves processes in absorption, transport, utilization, or exchange of respiratory gases between an organism and its environment b. Internal vs. external 5.Digestion a. Complex food products are broken down into simpler substances that can be absorbed and used by organism 6.Absorption a. Movement of digested nutrients through the wall of the digestive tube and into body fluids for transport to cells

21 Characteristics of Life 7.Secretion a. Production and delivery of specialized substances (digestive juices, hormones) for diverse body functions 8.Excretion a. Removal of wastes produced during body functions (breakdown and use of nutrients in the cell) 9.Circulation a. Movement of body fluids and many other substances (nutrients, hormones, waste products) from one body area to another 10.Reproduction a. Formation of new individual and new cells (cell division) b. Permits growth, wound repair, and replacement of dead/aging cells Metabolism – describes the various processes by which life is made possible - breakdown of nutrients - produce energy - transform one material into another - required to make complex cpds out of simple cpds

How can you remember the list? I am walking to McDonalds (movement) I stop at the traffic light (response) My body is growing (growth) I am breathing air (respiration) My body absorbs the hamburger (absorption) The hamburger circulates in my body (circulation) The hamburger is changed to things my body needs (assimilation) Eventually, I go to the bathroom (excretion) Someday I may reproduce (reproduction)

23 Anatomical Position/Bilateral Symmetry Anatomical Position – erect; palms, head and feet forward Bilateral Symmetry – right and left sides are mirror images

General Organization Axial= Head, neck, trunk Appendicular= Arms and legs

Regional Terms Anterior: front Posterior: back

Directional Terms

27 Directional Terms Superior – toward the head Inferior – toward the feet Anterior/ventral – front Posterior /dorsal– back Medial – toward the midline Lateral – toward the side/away from midline Proximal – toward or nearest the trunk or point of origin Distal – away from or farthest from trunk or point of origin Superficial – nearest the surface Deep – farther away from surface

28 Body Planes Sagittal – lengthwise, front to back, divides body into left and right sides, * Midsagittal (sagittal section in middle) Coronal/Frontal – lengthwise, side to side, divides body into anterior and posterior portions; frontal plane Transverse – crosswise, divides body or parts into upper and lower parts; horizontal plane

Body cavities are internal chambers holding vital organs – Cavities protect vital organs – Cavities allow organs to change in shape and size Two body cavities – Dorsal body cavity (back side) includes the cranial cavity and the spinal cavity – Ventral body cavity (front side) includes the thoracic cavity (chest) and the abdominopelvic (stomach and lower abdomen) cavity Body Cavities

31 Abdominopelvic Regions 4 Quadrants Doctors divide torso into quadrants to describe the site of pain and/or locate internal pathology (tumor) 1. Right upper quadrant (RUQ) 2. Left upper quadrant (LUQ) 3. Right lower quadrant (RLQ) 4. Left lower quadrant (LLQ)

32 Abdominal Regions Superficial Organs 1.Right hypochondriac – right lobe of liver, gallbladder 2. Epigastric – right and left lobes of liver, stomach 1.Left hypochondriac – stomach, large intestine 2. Right lumbar – large and small intestine 5. Umbilical – transverse colon, small intestine 6. Left lumbar – small intestine, colon 7.Right iliac – cecum, small intestine 8.Hypogastric – small intestine, bladder, appendix 9. Left iliac – colon, small intestine

Homeostasis Homeostasis is a stable internal environment Every organism must maintain homeostasis for survival Homeostatic regulation is responsible for keeping internal environment within certain limits. Internal environment (ie. body temp, pH, glucose level) External environment (ie. Weather, fluid surrounding cells)

Two general points: Autoregulation or intrinsic regulation – results when cell, organ or system adjusts its activity automatically. Extrinsic regulation - results from activity of nervous system or endocrine system

A homeostatic regulatory mechanism consist of : – A receptor – senses an environmental change or stimuli. – A control center –processes information supplied by receptor and generates a response (command) – An effector – an organ or cell that responds to the command of control center. A variation outside the desired range triggers an automatic response to correct the situation – Negative feedback Homeostatic regulation involves

Afferent= approaches Efferent= exits

Negative Feedback: The Control of Body Temperature Negative feedback: system is shut off

In positive feedback an initial stimulus produces a response that enhances the change in the original condition. For instance: Damage to blood vessel wall will cause release of chemicals. Chemicals will trigger blood clotting Clotting process increases release of chemicals More chemicals means accelerated clotting Accelerated clotting means more chemicals Positive Feedback: Blood Clotting Positive feedback: reaction continues at a faster rate

39 Negative Feedback Inhibitor Oppose change by creating response opposite in direction of initial disturbance change – temperature drop response – heat production initial disturbance – temp fall below normal set point Stabilize physiological variables Maintain constant internal environment Ex: goosebumps, sweating Positive Feedback Stimulatory Amplifies/reinforces change which can be harmful and disastrous Cause instability and disrupt homeostasis (continuous temp increase) Ex: sneezing, birth of baby, immune response to infection, blood clot