1: Life Functions/Survival Needs Flashcards
Maintaining boundaries
Separation between internal and external environments must exist
Plasma membranes
Separation between cells
Movement
Muscular system allows movement, either of body parts via skeletal muscles or of substances via cardiac muscle and smooth muscle (blood, digestion, etc)
Contractility
Movement at the cellular level
Responsiveness
Ability to sense and respond to stimuli (withdrawal reflex, breathing rate, etc)
Digestion
Breakdown of ingested foodstuffs, followed by absorption of simple molecules into blood
Metabolism
All chemical reactions that occur in body cells
Catabolism
Breakdown of molecules
Anabolism
Synthesis of molecules
Excretion
Removal of waste from metabolism and digestion (urea, carbon dioxide, feces)
Reproduction
Division of cells for growth or repair, or production of offspring
Growth
Increase of size in a body part or organism
Nutrients
Chemicals for energy and cell building
Carbohydrates
Main source of energy
Protein
Needed for cell building and chemistry
Fats/lipids
Long-term energy storage
Minerals and vitamins
Involved in chemical reactions and used for structural purposes
Oxygen
Essential for release of energy from foods
Water
Most abundant chemical in the body, provides liquid environment required for chemical reactions. Fluid base for secretions and excretions
Normal body temperature
If body temp falls above or below 37C, chemical reaction rates are affected
Atmospheric pressure
Needed for adequate breathing and gas exchange in lungs
Homeostasis
Maintenance of relatively stable internal conditions despite environmental changes
Receptor
Sensor that monitors environment and responds to stimuli
Control center
Determines set point that variables are maintained at, receives input from receptor, determines response
Effector
Receives output from control center, provides means to respond, reduces or enhances stimulus
Negative feedback
Most-used feedback mechanism in body, response reduces or shuts off stimulus
Positive feedback
Response enhances or exaggerates stimulus