Homeostasis Flashcards
Homeostasis
The process by which a relatively stable internal environment is maintained within an organism, despite external changes.
TENDENCY TO MAINTAIN EQUILIBRIUM
Allostasis
Extends the concept of homeostasis. It refers to the process by which the body achieves stability through change, adapting to both predictable and unpredictable stressors.
THE PROCESSES OF HOMEOSTASIS
Drive states
Drive states are motivational states that propel organisms to fulfill their basic needs, such as hunger, thirst, and the need for shelter and safety.
Endothermy
Generate their own heat
Ectothermy
Get their heat from the environment
Diffusion
Passive movement from an area of higher concentration to an area of lower concentration
Osmosis
Specific type of diffusion where the movement of solvent molecules (often water) through a semi-permeable membrane from a region of lower solute concentration to a region of higher solute concentration.
Osmotic thirst
Thirst occurs when the extracellular fluid becomes to salty Eg. Respiration and urination, high salt intake
Hyovolemic thirst
Thirst is due to a reduction in the volume of extracellular fluid
Eg. Large cut, vomiting
Basal metabolism
the energy used for heat production, maintenance of membrane potentials, and life sustaining processes. Uses the majority of our energy.
Insulin for apetite
Lowering an animal’s blood insulin level does cause it to become hungry and eat a large meal, and injecting some insulin causes the animal to eat much less
Set zone
The tolerance of a system
Intracellular compartment
The fluid part of the body contained within cells
Extracellular compartment
The fluid in the space outside of the cells
Osmotic pressure
The force that pulls or pushes water across the membrane
Baroreceptors
Detect a drop in pressure in the blood vessels and heart
Angiotensin II (AII)
Increases blood pressure by constricting blood vessels
Fluid regulation chart
Chart
Glycogen
Is glucose stored in the liver and muscles for the short term
Glucagon
Converts glycogen back into glucose
Diabetes mellitus
Results from failure of insulin to induce glucose absorption
Type 1 diabetes
Pancreas stops producing insulin
Type 2 diabetes
Caused by greatly reduced tissue sensitivity to insulin
Phases of insulin release at mealtime
Cephalic phase- Brain says release when seeing, etc. food
Digestive phase- Released when food enters the digestive tract
Absorptive phase- Glucodetectors signal the pancreas to release more
