AOS 4 sac Flashcards
what is homeostasis
the (relatively) constant physiological state of the body despite changes (fluctuations) in the external environment
what are the most important systems involved in homeostasis
nervous system and endocrine system
what is the endocrine system
system of ductless glands that produce hormones and release them directly into the bloodstream
are exocrine glands considered part of the endocrine system. If no why not
no, they do not produce hormones so aren’t considered part of the system
What are the two types of stimulus response models
open stimulus-response model and closed homeostatic stimulus-response model
what are the 5 components of the stimulus response models
stimulus, receptor, control center, effector, response
what happens in the stimulus stage
a change, either increase or decrease, in the level of an internal variable
what happens is the receptor
the structure detects the change and send signals to the control centre
what is the control centre
the structure (central nervous system) that evaluates the change against the set point for that variable and sends signals to the effector about the correction needed
what is the effector
the structure that adjusts its output to make the required correction
what happens in the response stage
the corrective action is taken
what are the two types of feedback
negative and positive
what happens in negative feedback
maintains the body’s internal environment at a relatively steady state
what happens in positive feedback
amplify (increase) a response in order to achieve a particular result (pooping, birth)
what is the term for how body temperature is regulated
thermoregulation
what is thermoregulation controlled by?
hypothalamus
what is the hypothalamus
a region of the brain that has thermoreceptors that monitor the core temperature
what does the hypothalamus do to maintain homeostasis
it registers change in the temperature and then it coordinates nervous and hormonal responses to counteract the changes and restore homeostasis
what happens in the stimulus stage of decreased body temperatures
the body temperature decreases below normal ranges (set point ranges)
what happens in the receptor stage of decreased body temperatures
the decrease in temperature is detected in the thermoreceptors in the skin, organs and hypothalamus