PCS EXAM 1 QUESTIONS AND ANSWERS
What is plasma? - Answers -liquid extra cellular non cellular parts of blood
What is serum? - Answers -Plasma with no clotting factors
What are the parts of a negative feedback system? - Answers -controlled variable
sensor
Controller (with set point and error signal)
Actuating signal
Effector
What is an error signal? - Answers -set point-controlled variable
What calculates error signal? - Answers -compator
What is a closed loop system? - Answers -when all information flows and all
components work properly
What is an open loop system? - Answers -where one component is damaged in
negative feedback
What is an agonist? - Answers -molecule that activates a receptor when it binds to it
What is an antagonist? - Answers -molecule that does not activate a receptor when it
binds to it
What is a GCPR? - Answers -G protein coupled receptor with 7TM
What is PTH? - Answers -hormone produced by parathyroid
What kind of hormone is PTH? - Answers -Protein (cannot diffuse)
What receives parathyroid? - Answers -PTHR, a GCPR
What is CASR, where is it found? - Answers -GCPR in PTH cells
Agonist Ca
What happens to PTH as calcium increases? - Answers -PTH down
What is 1,25(OH)2 D - Answers -A dihydroxylated vitamin D
What kind of molecule is 1,25(OH)2 D - Answers -Steroid (lipid soluble)
What is a VDR and where is it found? - Answers -Agonsit is 1,25(OH)2 D
, Nucleus of intestine cells
What happens when 1,25(OH)2 D binds to VDR? - Answers -Increase in absorption of
Ca++ from lumen of intestine to blood plasma
Describe the whole calcium pathway if Ca++ low? - Answers -Ca binds to CASR in
Parathyroid
PTH binds to PTHR in bone and kidney
Bone resporps Ca++ to plasma
Kidney reabsorbs Ca++ from kidney fluid into plasma
Kidney makes 125(OH)2D which leads to absorption of Ca++ from lumen to plasma
What is steady state? - Answers -when the error signal is near zero for a long time
What are the parts of a positive feedback? - Answers -output variable
sensor
amplifier(actuating signal)
effector
What is a plateau? - Answers -max value of the output variable that can be made by
the effector
What is a threshold? - Answers -a value that once passed goes to the plateau very fast
How are voltage gated Na+ channels an example of positive feedback? - Answers -
once it is above resting Na opens and Na goes into cell driving the membrane to Na
potential
What is oxytocin? - Answers -hormone released by axon cells in pituitary gland
What kind of hormone is Oxytocin? - Answers -protein hormone (not membrane
soluble)
What is OXTR and where is it located? - Answers -GCPR for oxytocin
Membrane of uterus
How does labor pathway work? - Answers -pressure in cervix/ute is felt by pressure
censors in cervix/ute which is interpeted by CNS which makes OXT which binds to
receptors in uterus increasing pressure
What is bult flow? - Answers -response of liquids, gases, or other in response to
differential pressure
What happens if both bulk flow pressures are equal? - Answers -no movement
What happens if PL>PR - Answers -Net movement to right
What is plasma? - Answers -liquid extra cellular non cellular parts of blood
What is serum? - Answers -Plasma with no clotting factors
What are the parts of a negative feedback system? - Answers -controlled variable
sensor
Controller (with set point and error signal)
Actuating signal
Effector
What is an error signal? - Answers -set point-controlled variable
What calculates error signal? - Answers -compator
What is a closed loop system? - Answers -when all information flows and all
components work properly
What is an open loop system? - Answers -where one component is damaged in
negative feedback
What is an agonist? - Answers -molecule that activates a receptor when it binds to it
What is an antagonist? - Answers -molecule that does not activate a receptor when it
binds to it
What is a GCPR? - Answers -G protein coupled receptor with 7TM
What is PTH? - Answers -hormone produced by parathyroid
What kind of hormone is PTH? - Answers -Protein (cannot diffuse)
What receives parathyroid? - Answers -PTHR, a GCPR
What is CASR, where is it found? - Answers -GCPR in PTH cells
Agonist Ca
What happens to PTH as calcium increases? - Answers -PTH down
What is 1,25(OH)2 D - Answers -A dihydroxylated vitamin D
What kind of molecule is 1,25(OH)2 D - Answers -Steroid (lipid soluble)
What is a VDR and where is it found? - Answers -Agonsit is 1,25(OH)2 D
, Nucleus of intestine cells
What happens when 1,25(OH)2 D binds to VDR? - Answers -Increase in absorption of
Ca++ from lumen of intestine to blood plasma
Describe the whole calcium pathway if Ca++ low? - Answers -Ca binds to CASR in
Parathyroid
PTH binds to PTHR in bone and kidney
Bone resporps Ca++ to plasma
Kidney reabsorbs Ca++ from kidney fluid into plasma
Kidney makes 125(OH)2D which leads to absorption of Ca++ from lumen to plasma
What is steady state? - Answers -when the error signal is near zero for a long time
What are the parts of a positive feedback? - Answers -output variable
sensor
amplifier(actuating signal)
effector
What is a plateau? - Answers -max value of the output variable that can be made by
the effector
What is a threshold? - Answers -a value that once passed goes to the plateau very fast
How are voltage gated Na+ channels an example of positive feedback? - Answers -
once it is above resting Na opens and Na goes into cell driving the membrane to Na
potential
What is oxytocin? - Answers -hormone released by axon cells in pituitary gland
What kind of hormone is Oxytocin? - Answers -protein hormone (not membrane
soluble)
What is OXTR and where is it located? - Answers -GCPR for oxytocin
Membrane of uterus
How does labor pathway work? - Answers -pressure in cervix/ute is felt by pressure
censors in cervix/ute which is interpeted by CNS which makes OXT which binds to
receptors in uterus increasing pressure
What is bult flow? - Answers -response of liquids, gases, or other in response to
differential pressure
What happens if both bulk flow pressures are equal? - Answers -no movement
What happens if PL>PR - Answers -Net movement to right
