Sugar Level in the Body

[bionewbie]

Hi, I was reading a chapter on homeostasis and I was wondering about how does the body regulate the sugar levels?

I heard from someone that the body could use up some glucose molecules by going through cellular respiration when there is too much glucose in the body and also it has something to do with glycogen and insulin. :shock: I was wondering if anyone could please explain to me the details of how the body does this. Thanks!

[Dr.Stein]

The regulation of blood glucose level in our body is controlled by antagonistic hormones: insulin and glucagon. Insulin will convert the excess blood glucose into glycogen (glycogenesis), vice versa glucagon will convert glycogen back into glucose when the blood glucose level is down (glycogenolysis). The normal level of blood glucose level for human is app. 65-110 mg/dL.

[victor]

Ah...I really get confuse with this.
Some of the books mentioned Glucagon and some other mentioned Noradrenaline.
The last thing that made me more confused is I found that Noradrenaline which acts vice-versa with insulin is mentioned again in the nerve system as a cerebrospinal fluid.....

[chemistry_freako]

Norepinephrine, known as noradrenaline outside the USA, is a catecholamine and a phenethylamine with chemical formula C8H11NO3. It is released from the adrenal glands as a hormone into the blood, but it is also a neurotransmitter in the nervous system where it is released from noradrenergic neurons during synaptic transmission. It is one of the 'stress hormones' and affects parts of the human brain where attention and impulsivity are controlled. Along with epinephrine this compound effects the fight-or-flight response, activating the sympathetic nervous system to directly increase heart rate, release energy from fat, and increase muscle readiness.

The host of physiological changes activated by a stressful event are unleashed in part by activation of a nucleus in the brain stem called the locus ceruleus. This nucleus is the origin of most norepinephrine pathways in the brain. Neurons using norepinephrine as their neurotransmitter project bilaterally from the locus ceruleus along distinct pathways to the cerebral cortex, limbic system, and the spinal cord, among other projections.

At synapses it acts on both alpha and beta adrenoreceptors.

There are two groups of mutually antagonistic metabolic hormones affecting blood glucose levels:

hyperglycemic hormones (such as glucagon, growth hormone, and adrenaline), which increase blood glucose
and one hypoglycemic hormone (insulin), which decreases blood glucose

http://en.wikipedia.org/wiki/Insulin

Glucagon helps maintain the level of glucose in the blood by binding to specific receptors on hepatocytes causing the liver to release glucose which is stored in the form of glycogen. As these stores become depleted, glucagon then encourages the liver to synthesize additional glucose by gluconeogenesis. This glucose is released into the bloodstream. Both of these mechanisms lead to glucose release by the liver preventing the development of hypoglycemia.

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[Dr.Stein]

Ah...I really get confuse with this.
Some of the books mentioned Glucagon and some other mentioned Noradrenaline.
The last thing that made me more confused is I found that Noradrenaline which acts vice-versa with insulin is mentioned again in the nerve system as a cerebrospinal fluid.....

You are one of 'victims' of bad high school education system in our country. I read your text book and they are... awawawawaaaa, a lot of mistakes I found I am not surprised if you are confused about this one. They put something wrong in your head. This one is just an example from many difference things between high school and university/college discussion. We here, in our faculty, are sad to realize this. We need to 'wash' our new students with old 'ideology' and put the new and correct one for them

[Poison]

That's why I hate high school bio books. They are complete rubbish.

[MrMistery]

Not all of them. Well, most of them yes. But if you wanna study something decent in high-school you should buy books written by college professors

[Dr.Stein]

In normal condition, to maintain homeostasis, the regulation of blood sugar (glucose) level is done by a pair of antagonistic hormones, insulin and glucagon. Both hormones are produced in pancreatic islets by beta cells and alpha cells, respectively. I have told you the process in my previous post.

There is another hormone (neurohormone) that acts similar to glucagon, epinephrin, produced buy medular part of adrenal gland. This helps to increase blood sugar level by glycogenolysis and/or glyconeogenesis not only from hepatic glycogen, but also from storage in muscles and adipose tissues. This process is not in normal condition, but under the stressful events, both physically or mentally. That's why this hormone is called as "stress hormone". This additional glucose will provide extra energy for the well-known term for epinephrin effect "fight or flight reaction".

As a neurohormone, epinephrin also works as neurotransmitter, this connects between our physical and mental condition. "If you think you are ill, you will ill. If you think you are healthy, you will be healthy" We study this relationship in PNI (psycho neuro immunology), that's veeery interesting

Norepinephrin is stated as a precursor of epinephrin. That's why in adrenal medulla the portion of norepinephrin is less than epinephrin, it is 20% and 80%, respectively.

[Poison]

Not all of them. Well, most of them yes. But if you wanna study something decent in high-school you should buy books written by college professors

Yes 'most of them' is a better definition.

[victor]

Ironically, my bio book that's used in my high school is written by a team that consisted 4 members. Two of them are Ph.D and the others are M.D. So?...for Dr.Stein, I think you know this book..it's published by ESIS Erlangga (the >400 pages one). Just see the 11th grade bio book.

So, the proper one is glucagon eh??ok, I'll change that (I have to defragment my brain then.. )

[Dr.Stein]

Yeah I know that book. My students complain too about that. I suggest them not to use that. Use international edition or get the latest information in the net. Period.

I have nothing to say about that book but.... ehm... err... aaaarrrggghh those Ph.D and M.D. thingy

[opuntia]

I have nothing to say about that book but.... ehm... err... aaaarrrggghh those Ph.D and M.D. thingy

Nothing about the book...but about the authors.....