Ch. 1 Flashcards
Metabolism & Homeostasis
Metabolism- internal chemical change/how body consumes energy
Homeostasis- maintaining internal stability (temp/BP/body weight) [loss of homeostatic control causes illness & death] (PATHOphysiology-study of disease)
Negative Feedback
Body senses a change & activates a mechanism to REVERSE it; does not produce absolute constancy but fluctuates around a set point with narrow range (KEY mechanism for maintaining health)
Feedback Loop
- Person rises from bed
- Blood drains from upper to lower body causing HOMEOSTATIC IMBALANCE
- RECEPTOR- baroreceptors above heart respond to drop in BP
- INTEGRATED CONTROL CENTER- baroreceptors send signals to cardiac center in brain…
- EFFECTOR- heartbeat accelerates in response to cardiac center & carries out response to restore homeostasis
Positive Feedback
Self-amplifying cycle where a change in the body leads to a greater change in the SAME direction (sometimes a normal way of producing rapid change)
Ex/ childbirth contractions pushing fetus downward to stimulate cervix
**Positive feedback is MORE OFTEN a harmful process by bringing values away from set point
Ex/ Fevers triggered by infection raise metabolic rate but cannot produce heat faster than it can eliminate it
Body Planes (3)
- Sagittal Plane- cuts body into left to right
- Front (Coronal) Plane- cuts body into anterior & posterior
- Transverse (Horizontal) Plane- cuts body into superior & inferior
Levels Of Human Structure
- Organism
- Organ System-group of organs that carry out a function (11 systems)
- Organ- group of 2 or more tissues
- Tissue- group of similar cells (epithelial, connective, nervous, muscular)
- Cell- smallest unit of life
- Organelle- composed of molecules which are atoms
- Macromolecule- very large molecule
- Molecule- composed of 2 or more atoms united by covalent chemical bonds
- Atom- basic unit of a chemical element
Body Regions (2)
- Axial- Head, neck, trunk
>Trunk [thoracic region & abdomiopelvic] - Appendicular- Upper & lower limbs
- *Internal organs (viscera) are lined by SEROUS MEMBRANES
- *Open to the environment cavities are lined by MUCOUS MEMBRANES
ORGAN SYSTEMS FOR “PROTECTION-SUPPORT-MOVEMENT” [3]
- Integumentary (hair, skin, nails)- Protection, thermoregulation, water retention, vitamin D synthesis
- Skeletal (bones, cartilage, ligaments)- Support, movement, blood formation
- Muscular (skeletal muscles)- Movement, stability, communication, control of body openings & heat production
ORGAN SYSTEMS FOR “INTERNAL COMMUNICATION & INTEGRATION” [2]
- Nervous (brain, spinal cord, nerves & ganglia)- Rapid internal communication, motor control & sensation
- Endocrine (pituitary, thyroid, adrenal, testes/ovaries)- hormone production & internal chemical communication
ORGAN SYSTEMS FOR “FLUID TRANSPORT” [2]
- Circulatory (heart & blood vessels)- Distribution of oxygen, nutrients, wastes, hormones, electrolytes
- Lymphatic (lymph nodes, lymphatic vessels, thymus, spleen)- Recovery of excess tissue fluid, detection of pathogens and production of immune cells (WBC)
ORGAN SYSEMS FOR “INTAKE & OUTPUT” [3]
- Respiratory (nose, larynx/pharynx, lungs)- Absorption of oxygen & discharge of CO2, speech
- Urinary (kidneys, ureters, urethra)- Elimination of wastes, regulation of blood pressure & volume, control of fluids, stimulation of RBC formation
- Digestive (teeth, tongue, salivary glands, stomach)- Nutrient break down & absorption, metabolism of carbs/lipids/proteins
ORGAN SYSTEMS FOR “REPRODUCTION” [2]
- Male Reproductive (testes, penis, epididymis)- Production & delivery of sperm, secretes sex hormones
- Female Reproductive (ovaries, vagina, uterus)- Production of eggs, site of fertilization & fetal development
