HOMEOSTASIS Flashcards
Homeostasis
process of keeping the environment inside the body fairly constant
steady state with dynamic equilibrium
What does homeostasis regulate?
core body temp
blood pressure
O2 + CO2 blood conc.
metabolic waste
glucose conc.
pH + fluid conc.
Feedback system
circular system in which body responds to a change/stimulus
response alters original stimulus + provides feedback
Stimulus
change in environment that causes system to operate
Receptor
detects change
Modulator
Control centre responsible for processing info received from receptor + sends to effector by medulla/hyp.
Effector
Carries out response counteracting/enhancing effect of stimulus
Homeostatic mechanisms
Controlled by nervous + endocrine
systems detect when body begins to deviate from balanced state
Nervous- messages to appropriate organs so change counteracted
Endocrine- hormones secreted into blood
Negative feedback
Response of homeostatic mechanisms that has effect of reducing/eliminating stimulus that caused it
Dynamic equilibrium
Systems fluctuate around a normal level/set point with tolerance limits
Tolerance limits
upper + lower limits between which levels fluctuate
dysfunctions occur if levels exceeded
Positive feedback
response to stimulus which reinforces/intensifies it
Cellular respiration
O2 + glucose = CO2 + H2O + energy
Islets of Langerhans hormones
Alpha- glucagon
Beta- insulin
Glucogen + BGL
glycogenolysis
gluconeogenesis