ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: Stick on March 23, 2013, 02:37:12 pm
-
What are the two sensors and what are the two effectors? :)
-
The sensors are the alpha and beta cells in the pancreas (part of the islets of Langerhans). The effectors are primarily liver and muscle cells
-
Nature of Biology didn't explicitly state this and yet they go and ask a question on it. >_< Thanks for the help, Scooby. :)
-
Nature of Biology didn't explicitly state this and yet they go and ask a question on it. >_< Thanks for the help, Scooby. :)
Yeah, that's alright :)
This is pretty much the only homeostatic mechanism you'll go through in VCE Bio where there's no "control centre" either
-
I thought that the two sensors were the islet of Langerhans cells and a glucometer and the two effectors were the alpha/beta cells and an insulin pump.
-
Things external to the body that it can't control can't be part of a biological homeostatic loop
-
I thought that alpha and beta cells in the pancreas would be effectors? When blood glucose level is not within the narrow ranges maintained by homeostasis, wouldn't that cause alpha cells to produce glucagon to increase blood glucose level or beta cells to produce insulin to lower blood glucose level.. Are you sure that is right??
-
I thought that alpha and beta cells in the pancreas would be effectors? When blood glucose level is not within the narrow ranges maintained by homeostasis, wouldn't that cause alpha cells to produce glucagon to increase blood glucose level or beta cells to produce insulin to lower blood glucose level.. Are you sure that is right??
Yeah, that's right.
In response to decreased blood glucose concentration, alpha cells increase their secretion of glucagon and beta cells decrease their secretion of insulin. In response to increased blood glucose concentration, beta cells increase their secretion of insulin and alpha cells decrease their secretion of glucagon
However, it isn't these alpha and beta cells that are actually bringing about a change in blood glucose concentration. They are merely detecting changes in blood glucose concentration and altering their release of glucagon or insulin. They aren't directly modifying blood glucose concentration. They are producing the hormones that will cause other cells in the body to modify blood glucose concentration
The cells that that these hormones act on are the effectors because they are actually changing the concentration of glucose in the blood. Liver cells will break glycogen down into glucose (glycogenolysis) and release this into the bloodstream in response to glucagon, increasing blood glucose concentration. Liver and muscle cells will increase their uptake of glucose from the bloodstream in response to insulin, decreasing blood glucose concentration
Other types of cells in the body respond to insulin, but liver and muscle cells show the greatest response
-
Yeah, that's right.
In response to decreased blood glucose concentration, alpha cells increase their secretion of glucagon and beta cells decrease their secretion of insulin. In response to increased blood glucose concentration, beta cells increase their secretion of insulin and alpha cells decrease their secretion of glucagon
However, it isn't these alpha and beta cells that are actually bringing about a change in blood glucose concentration. They are merely detecting changes in blood glucose concentration and altering their release of glucagon or insulin. They aren't directly modifying blood glucose concentration. They are producing the hormones that will cause other cells in the body to modify blood glucose concentration
The cells that that these hormones act on are the effectors because they are actually changing the concentration of glucose in the blood. Liver cells will break glycogen down into glucose (glycogenolysis) and release this into the bloodstream in response to glucagon, increasing blood glucose concentration. Liver and muscle cells will increase their uptake of glucose from the bloodstream in response to insulin, decreasing blood glucose concentration
Other types of cells in the body respond to insulin, but liver and muscle cells show the greatest response
Yeah that makes sense - so ultimately, it isn't like glucagon directly increases blood glucose concentration, but it is a chemical messenger that actually informs the muscle/liver cells where glycogen is stored to break it down in hydrolysis to glucose, which enters the bloodstream and increases blood glucose levels.
Sensors: alpha/beta cells of the pancreas
Effectors: muscle/liver cells.
Thanks so much :)
-
Yeah that makes sense - so ultimately, it isn't like glucagon directly increases blood glucose concentration, but it is a chemical messenger that actually informs the muscle/liver cells where glycogen is stored to break it down in hydrolysis to glucose, which enters the bloodstream and increases blood glucose levels.
Sensors: alpha/beta cells of the pancreas
Effectors: muscle/liver cells.
Thanks so much :)
Yup, that's exactly right :)