Homeostasis Flashcards
what is homeostasis?
state of equilibrium regarding internal conditions
What are external perturbations?
in regards to homeostasis, its anything like environmental temperatured changes
_________ and _______ are related to homeostasis
physiological and psychological
Positive feedback does what to change?
strengthens the change
negative feedback does what to change?
reverses the change
What is a variable
a controlled conditions that needs to be regulated
what is a stimulus
the movement of a system away from the set point
What does the detector/receptor do?
detect changes in the controlled variable from its set point
what does the detector/receptor do in simple terms?
measure things
What does the control center do?
figures out what to do when stimulus is detected; initiates response
Control center will send _____ to ______ to fix the change
Control center will send response to out put effector to fix the change
control centre sends messages via _____, _______, _____
nerve, hormone, chemical
IS the signal sent out by the control centre the effector?
NOPE
What does the effector do?
move variable back to normal by depriving/taking away stimulus and terminating feedback loop
List three reasons why there might not be enough O2?
Lungs cant get enough O2 from air, heart cant move enough blood around, blood vessels blocked
what is atherosclerosis
arteries have plaque
______ -> _________ -> ________ -> ________
detector/receptor, control centre, effector, response
what does the effector do in simple terms?
creates a response to the change
What is the detector in blood glucose regulation?
pancreas
what does the detector in blood glucose regulation do?
pancreas tastes blood and detects high glucose
what is the control center in blood glucose regulation
pancrease
what does the control center in blood glucose regulation do?
release insulin (signal) which tells cells + liver to remove glucose
What are the effectors of blood glucose regulation?
liver and body cells
what do the effectors of blood glucose regulation do?
liver takes glucose and makes glycogen, adipocytes take glucose and put into fat cells
What is the normal blood sugar level?
4.5mmol/L
What is the normal temperature range?
36-40 degrees
42-44 what happens to brain?
brain cant handle temp and makes permanent lesions you cant recover from
at what temp do you get arrthymia?
26 degrees
what temp does you heart stop pumpin
26 degrees
What happens at 26 degrees?
you heart stops pumpin and you cant warm up -> arrthymia
youre not dead unless youre _____ + _______
warm and dead
What are the detectors in temp regulation?
skin receptors and hypothalamus
What is the control center in temp regulation when temp decreases?
neurosecretory cells in hypothalmus, preoptic area, heat promoting area, and thrytropes in anterior pituitary gland
How does the control center send signals to the effectors?
via nerve impulses and TSH
What are the effectors in temp regulation of decreased temp
vasoconstriction, adrenal medulla, skeletal muscles, and thyroid glands
What does vasoconstriction do as the effector of temp regulation when its cold?
decrease heat loss through skin
what does adrenal medulla do as the effector of temp regulation when its cold?
releases hormones that increase cellular metabolism
what does skeletal muscle do as the effector of temp regulation when its cold?
shiver
what does thyroid gland do as the effector of temp regulation when its cold?
release thyroid hormones, increase metabolic rates
What is the control center in temp regulation when temp increases?
nuclei in the hypothalamus
What are the effectors in temp regulation of increased temp
blood vessels dilate and sweat glands activate
What are the five requirements of a feedback loop?
variable, stimulus, detector, control center, effector
What is the main thing a positive feedback loop requires
a distinct event
Positive feedback is when the change in variable …
stimulates more change in variable
What are five examples of a positive feedback
blood clotting, action potential, ovulation, orgasm, uterine contractions
_________ feedback is found with ______ feedback
positive feedback is found with in negative feedback
How does positive feedback loop terminate?
w/some distinct event which deprives feedback system of input
Pathology can also result from _________ feedback
positive
Example of pathology that results from ________ feedback?
positive; epileptic seizure
What is the stimulus in lactation?
suckling on break
What are the detectors in lactation?
touch receptors on breast that sense pressure
What is the control center in lactation
hypothalamus, which sends signals to posterior pituitary to release oxytocin
In lactation, where is oxytocin released into?
pituitary portal circulation
What does the oxytocin do?
Oxytocin causes the myoeptihelium of breast to contract and let milk down
What is the effector in lactation?
breast
What is the variable in lactation?
milk flow
What is the variable in blood clotting?
blood flow
What is the inital stimulus in blood clotting?
broken blood vessels with exposed binding sites on BV wall for platelets
What is the secondary stimulus in blood clotting?
platelets
What are the detectors in blood clotting?
platelet receptors which detect broken blood vessels
what are the binding sites on broken blood vessels termed?
collagen
what do the exposed broken blood vessel binding sites attract?
platelets
What are the control centers of blood clotting?
activated platelets; become activated when they bind to BV
How do activated platelets attract more platelets?
release thromboxane and adenosine diphosphate
What are the effectors of blood clotting?
the platelets which beging to make up the clot
What stimulates anticlotting chemicals?
clotting chemicals
What are anticlotting chemicals?
prostacylin and prostaglandin
What is the problem with a massive wound
lots of collagen, therefore lots of platlets binding, therefore lots of blood clots causing person to bleed otu
Person with massive wound needs what?
lots of platelets
WHat is hypertension
high blood pressure
What is a sign?
objective measure of change
What is a symptom
subjective measure of change
What is a disorder
abnormality of structure/function
What is a disease?
illness characterized by recognizable set of signs and symptoms
