Introduction to the Human Body

Anatomy: study of structure (morphology) of body parts and how they are organized

Physiology: study of how the body functions

Levels of Structural Organization Chemical level (atoms) Some atoms essential to physiological function (C, H, O, N, Na, Ca, K)

2. Cellular level: basic structural and functional units of an organism

3. Tissue level: groups of similar specialized cells and surroundings that usually arise from a similar ancestor and perform certain special functions

4. Organ level: structures of definite form that are composed of two or more different tissues and have specific functions

5. System level: associations of organs that have a common function

6. Organism level: collection of structurally and functionally integrated systems

Organ System Overview Integumentary Skeletal Muscular Nervous Endocrine Cardiovascular Lymphatic Respiratory Digestive Urinary Reproductive

Maintaining Life Eight functions humans must perform to maintain life 1. Maintaining boundaries 2. Movement 3. Responsiveness/irritability 4. Digestion 5. Metabolism 6. Excretion 7. Reproduction 8. Growth

Survival Needs Nutrients: provide energy Oxygen: release energy from food Water: for reactions and transportation Heat: product of metabolic reactions Pressure: force (atmospheric pressure – breathing and exchange of oxygen depend upon it)

THE Right Brain vs Left Brain test THE Right Brain vs Left Brain test ... do you see the dancer turning clockwise or anti-clockwise? If clockwise, then you use more of the right side of the brain and vice versa. Most of us would see the dancer turning anti-clockwise though you can try to focus and change the direction; see if you can do it. LEFT BRAIN FUNCTIONS uses logic detail oriented facts rule words and language present and past math and science can comprehend knowing acknowledges order/pattern perception knows object name reality based forms strategies practical safe RIGHT BRAIN FUNCTIONS uses feeling "big picture" oriented imagination rules symbols and images present and future philosophy & religion can "get it" (i.e. meaning) believes appreciates spatial perception knows object function fantasy based presents possibilities impetuous risk taking

Maintaining Physiological Limits Homeostasis: Maintaining Physiological Limits condition in which the body’s internal environment remains within certain physiological limits or range regardless of external environment

Extracellular fluid (ECF) Outside body cells- must be maintained precisely for cells to survive Two types Filling the narrow spaces between cells of tissues- called interstitial, intercellular, or tissue fluid In blood vessels termed plasma, in lymphatic vessels termed lymph plasma interstitial lymph

Intracellular fluid (ICF) Fluid inside cells ICF (cytoplasm)

Homeostasis ECF is constantly in motion throughout the body - called the body’s “internal environment” Homeostatic requirements: Contains the optimum concentration of gases, nutrients, ions, and water Has optimal temperature Has optimal volume Demonstrated in body when needs are being adequately met Constantly monitored & controlled

Maintenance of homeostasis results in health; physiological imbalance may result in disease or death

Stress & Homeostasis Stress is any external or internal stimulus that creates an imbalance in the internal environment Homeostatic mechanisms attempt to counteract effects of stress to bring condition back to normal

Homeostatic Controls Regulated by nervous and endocrine systems- together or independently Nervous system detects body changes and sends nerve impulses to counteract stress- rapid changes Endocrine system secretes hormones- works more slowly

Feedback Systems (loops) cycle of events in which information about the status of a condition is continually monitored and fed back (reported) Receptor monitors & responds to changes in environment (stimuli) Control center determines level at which variable is to be maintaine Effector provides the means for the control center’s response (output) to the stimulus Feedback is negative (depressed) or positive (enhanced)

Negative Feedback Mechanisms Most homeostatic control mechanisms Net effect of response to stimulus is to shut off original stimulus or reduce its intensity (reverse it) Maintain conditions that need frequent monitoring and adjustment Examples: body temperature (hypothalamus), heart rate, blood pressure, breathing rate, blood levels of glucose, oxygen, carbon dioxide, minerals, water

Homeostasis of Blood Pressure Negative feedback stimulus (stress) rise in BP Impulses (output) Impulses (input) control receptors effector center Sensitive nerve cells in arteries The brain Heart or arterioles restoration response Heart rate decreases Arterioles dilate

Positive Feedback Mechanisms Enhances original stimulus Regulate conditions that do not occur often and do not require continual fine-tuning Potentially dangerous or stressful events that must be completed quickly Rare in body due to increasing the effect of the stimulus Examples: blood clotting & labor

Homeostasis of Labor Contractions stimulus (stress) Positive feedback Uterus stretched Impulses (output) Impulses (input) control effector receptors center Oxytocin released (hormone) Stretch-sensitive nerve cells in the cervix of the uterus hypothalmus uterus response Contractions more forceful Cycle stops with birth of baby (no more stretching)

Homeostatic Imbalance Disease: any change from a state of health, characterized by symptoms and signs Local disease- effects limited area or one part of body Systemic disease- effects either entire body or several parts With age, body organs become less efficient and internal conditions become less and less stable Increasing risk for illness and produce changes associated with age

Follow the movement of the rotating pink dot with your eyes and the dots will remain only one color, pink. But if you stare at the black + in the center, the moving dot will turn green.

Directional Terms (fig 1.1 page 15)

Regional Terms (fig 1.5 page 16)

Planes transverse sagittal coronal (frontal) (horizontal)

Body Cavities

Abdominopelvic Regions

Note Cards: At least 60 for full credit Note Cards: At least 60 for full credit. However, I suggest for study purposes that you do all you can!!! Body positions: slide 36-37 (3) Regional names: figure 1.5 page 16-17 (41) Directional terms: Table 1.1 page 15 (11) Planes and sections: page 17 in bold (5) Body cavities: figure 1.7, page 18-20 in bold (9) Any other vocabulary you do not understand in the chapter