Question | Answer |
Feedback regulation and coordination with the nervous system are common in ___ signaling. | endocrine |
Diverse functions have evolved for many vertebrate ___. | hormones |
What is the endocrine system and what does it regulate? | - internal system of communication involving hormones, the ductless glands that secrete them, and the molecular receptors on/in target cells that respond to them
- functions with the nervous system to effect internal regulation and maintain homeostasis |
What is a simple endocrine pathway? | - endocrine cells respond directly to internal/environmental stimulus by secreting a particular hormone
- that travels in bloodstream to target cells, where it interacts with specific receptors
- signal transduction w/in target cells brings a response |
Why are insulin and glucagon considered to be an antagonistic hormone pair? | - because they have opposing effects
- their combined activity maintains homeostasis |
What do insulin and glucagon regulate? | blood glucose level |
What types of pathways and feedback are involved in the control of blood glucose? | two simple endocrine pathways and negative feedback loops (one to raise and one to lower blood glucose level) |
How is insulin doing its job of lowering blood glucose levels? | - the release of insulin (from beta cells of pancreas) triggers uptake of glucose from the blood into body cells, thus decreasing blood glucose level
- also, in the presence of insulin, the liver stores glucose as glycogen |
How is glucagon doing its job of raising blood glucose levels? | the release of glucagon (from alpha cells of pancreas) promotes the release of glucose into the blood from energy stores, such as liver glycogen, increasing the blood glucose level |
What causes diabetes mellitus? | - deficiency of insulin (not enough produced)
OR
- decreased response to insulin in target tissues (cells not responding) |
What happens with regard to glucose in individuals with diabetes mellitus? | blood glucose levels rise, but cells are unable to take up enough glucose to meet metabolic needs |
What can happen when fat becomes the main substrate for cellular respiration (like what happens in individuals with diabetes mellitus)? | - acidic metabolites formed during fat breakdown accumulate in the blood, threatening life by lowering blood pH and depleting sodium and potassium ions from the body
- (ketoacidosis) |
What happens in the kidneys of individuals with diabetes mellitus? | - the level of glucose in blood may exceed the capacity of the kidneys to reabsorb this nutrient
- excess is secreted via the urine, but that also brings along more water, resulting in excessive volumes of urine |
What kind of disease is type 1 diabetes (insulin-dependent diabetes)? What is happening in their body? What is the result? When does it show up? | - auto-immune disorder in which the immune system destroys the beta cells of the pancreas (basically, the person can't produce insulin, so glucose can't be taken into cells)
- inherited; appears during childhood
- treatment of insulin injected daily |
What is type 2 diabetes (non-insulin-dependent diabetes)? What is happening in their body? What is the result? When does it show up? | - a failure of target cells to respond normally to insulin (it's produced, but target cells fail to take up glucose from blood, so BGLs remain elevated)
- often results from lack of exercise and unhealthy diet; usually in 40s
- most common diabetes type |
The ___ plays a central role in integrating the endocrine and nervous systems. | hypothalamus |