Levels of Organization, Homeostasis, Feedback Loops

levels of organization

chemical, cellular, tissue, organs, organ system, organismal

chemical level

group of atoms form molecules e.g. macromolecules

cellular level

group of molecules form cells e.g. muscle cell, skin cell

tissue level

group of cells with similar functions form tissues e.g. muscle, epithelium

organs level

two or more tissues that work together to complete a task form organs e.g. heart, liver

organ system level

group of organs that work together to complete a task e.g. cardiovascular, skeletal

organismal level

all structures working together to make up an organism e.g. humans, cats

homeostasis definition

process of maintaining stable conditions within your body’s internal environment

set point definition

range of internal conditions that is considered normal / equilibrium

components of internal environment

intracellular fluid and extracellular fluid

intracellular fluid

fluid within cells, 2/3 of body fluids

extracellular fluid

interstitial fluid (all fluid between cells) and plasma (blood)

homeostatic control system components

stimulus, receptor, control center, effector

stimulus in homeostasis

something that causes a change from what is considered normal

receptor in homeostasis

something that detects a specific change e.g. protein

control center in homeostasis

receptor sends information here, which is then given to the effector

effector in homeostasis

carries out a change to return to homeostatic level

negative feedback loop definition

response that counters the initial change, stops when conditions return to normal

positive feedback loop

response that enhances the initial change, stops when action needed to be done is completed