PHIS 206 lecture

biology

study of living things (study of life)

physiology

study of things being alive (study of what stops happening when you die)

experimental, not observational

experimentation necessary to explain what was observed

levels of complexity

chemical, cellular, tissue, organ, body (organ) system, organism

tissue

groups of different types of cells performing a specialized tasks (muscle tissue, nervous tissue, epithelial tissue, connective tissue)

digestive system

processes food for use by the body and removes wastes from the undigested food

urinary system

controls water balance in the body and removes wastes from blood and excretes them

lymphatic system

returns fluid to blood and defends against pathogens

respiratory system

removes carbon dioxide from the body and delivers oxygen to blood

male reproductive system

produces sex hormones and gametes and delivers gametes to female

female reproductive system

produces sex hormones and gametes, supports embryo/fetus until birth, and produces milk for infant

muscular system

enables movement (with skeletal system) and helps maintain body temperature

nervous system

detects and processes sensory information and activates bodily responses

integumentary system

encloses internal body structures and site of many sensory receptors

skeletal system

supports the body and enables movement (with muscular system)

endocrine system

secretes hormones and regulates bodily processes

cardiovascular system

delivers oxygen and nutrients to tissues and equalizes temperature in the body

ICF

intracellular fluid (contained within cells)

ECF

extracellular fluid (fluid outside of cells)

ISF or IF

bathes cells directly (component of ECF)

plasma

circulates fuel and wastes to restore composition of ISF (component of ECF)

process of homeostasis

cells survive and thrive only when ECF is compatible.

chemical and physical state of this environment must be maintained within ranges compatible with cellular function.

maintenance of ECF makes demands upon the entire organism.

conditions to be alive

maintained conditions, organism must interact with environment (further interaction endangers conditions)

maintain homeostasis

detect and transmit information (sensor)

combine info with other data to make a plan for adjustments (integrator/control)

make adjustments (via effector) that restore og conditions

negative feedback

opposes a change in the system by driving the variable in the other direction

as the issue begins to improve, need for action finishes (negative feedback is inherently stable)

positive feedback

not inherently stable by design

increases in stimulus

eventually will abruptly change the conditions (cycle will “break” after exceeding a level)

amplifies change until the system undergoes a watershed (irreversible transition to a new state)