Do we need to know about the HPA axis?

[CossieG]

Title

[KingofDerp]

yes you do as its part of the biopsychosocial framework

[Damoz.G]

Yup, you do.

[adrihepburn]

It's separate to the biopsychosocial model however because there is limited content on the Mental Health AOS it is highly likely that this will be examined. Just remember it in the order of the letters :')

WHEN A THREAT IS PERCEIVED THE
H(hypothalamus is activated which stimulates the:)
P(pituitary glands to release the hormone ACTH into the bloodstream which activates the:)
A(adrenal glands to secrete adrenaline (epinephrine) and noradrenaline (norepinephrine) into the blood stream)
to ready the body's internal organs, muscles and glands to confront or flee from the threat.

NOTE: the adrenal glands also secrete cortisol (the hormone which increases metabolism and blood glucose levels to provide fuel to muscles) - too much release of this hormone (prolonged exposure to stress) is what weakens the immune system and is linked to psychosomatic illnesses.


the HPA axis is an allostatic system!!!

[spectroscopy]

lolwut teacher said we dont need to know it and it hasnt been on the ~12 different companies exams ive done?
i should study it now i suppose

[pi]

It's separate to the biopsychosocial model however because there is limited content on the Mental Health AOS it is highly likely that this will be examined. Just remember it in the order of the letters :')

WHEN A THREAT IS PERCEIVED THE
H(hypothalamus is activated which stimulates the:)
P(pituitary glands to release the hormone ACTH into the bloodstream which activates the:)
A(adrenal glands to secrete adrenaline (epinephrine) and noradrenaline (norepinephrine) into the blood stream)
to ready the body's internal organs, muscles and glands to confront or flee from the threat.

NOTE: the adrenal glands also secrete cortisol (the hormone which increases metabolism and blood glucose levels to provide fuel to muscles) - too much release of this hormone (prolonged exposure to stress) is what weakens the immune system and is linked to psychosomatic illnesses.

ACTH's "primary" function isn't to secrete catecholamines (adrenaline/noradrenaline - which come from the adrenal medulla), it is to secrete the glucocorticoid cortisol, and play a minor role in aldosterone secretion. If you know about the anatomy of the adrenal glands, it essentially has two parts: an outer cortex (that makes cortisol, aldosterone and androgens as you move from out to in) and an inner medulla (more of a neuronal area).

Not sure if this is taught in VCE, but the blood supply of the inner medulla is via that of the cortex, that is, that the blood supplies the cortex first before travelling to the medulla. Hence, many cortical products (eg. cortisol) pass in the medulla via this blood supply and the medulla is therefore essentially bathed in cortical products. These products (namely cortisol) promote adrenaline/noradrenaline secretion.

So it's not as simple as saying "Hypothalamus secretes CRH which causes the anterior pituitary to secrete ACTH which causes the adrenal glands to secrete adrenaline/noradrenaline (it might be fine to say this if you said "cortisol" instead of "adrenaline/noradrenaline"). Cortisol is not some thing that "also" happens, it's is the main product of the HPA axis which plays a further role in secretion of aldosterone and adrenaline/noradrenaline

edit: just realised this was a VCE board and not a uni board, might be too much detail >.> Oh well nothing like a bit of learning

[CossieG]

lolwut teacher said we dont need to know it and it hasnt been on the ~12 different companies exams ive done?
i should study it now i suppose

lol im in the exact same boat right now

[adrihepburn]

ACTH's primary function isn't to secrete catecholamines (adrenaline/noradrenaline - which come from the adrenal medulla), it is to secrete the glucocorticoid cortisol, and play a minor role in aldosterone secretion. If you know about the anatomy of the adrenal glands, it essentially has two parts: an outer cortex (that makes cortisol, aldosterone and androgens as you move from out to in) and an inner medulla (more of a neuronal area).

Not sure if this is taught in VCE, but the blood supply of the inner medulla is via that of the cortex, that is, that the blood supplies the cortex first before travelling to the medulla. Hence, many cortical products (eg. cortisol) pass in the medulla via this blood supply and the medulla is therefore essentially bathed in cortical products. These products (namely cortisol) promote adrenaline/noradrenaline secretion.

So it's not as simple as saying "Hypothalamus secretes CRH which causes the anterior pituitary to secrete ACTH which causes the adrenal glands to secrete adrenaline/noradrenaline (it might be fine to say this if you said "cortisol" instead of "adrenaline/noradrenaline"). Cortisol is not some thing that "also" happens, it's is the main product of the HPA axis which plays a further role in secretion of aldosterone and adrenaline/noradrenaline

Yes yes, all that you say is correct but in regards to its relation to stress, as a part of the study design only require knowledge on simplistic/basic arousal/stress responses ... what i wrote is as dot pointed in our text book.

[adrihepburn]

lol im in the exact same boat right now

it's been on the study design for 3 years but hasn't been examined yet, two of the assessors i've met with and discussed the HPA axis with both said it is very likely to be examined this year.

[Damoz.G]

For anyone with the Grivas Textbook (Purple Macmillan Text), its on Page 585-586

[pi]

Yes yes, all that you say is correct but in regards to its relation to stress, as a part of the study design only require knowledge on simplistic/basic arousal/stress responses ... what i wrote is as dot pointed in our text book.

Yeah kinda forgot this was a VCE board... I guess what you wrote might suffice for VCE

[spectroscopy]

For anyone with the Grivas Textbook (Purple Macmillan Text), its on Page 585-586

thanks mate

[CossieG]

it's been on the study design for 3 years but hasn't been examined yet, two of the assessors i've met with and discussed the HPA axis with both said it is very likely to be examined this year.

It's not mentioned explicitly though

[adrihepburn]

It's not mentioned explicitly though

It isn't but in unit 4 it isn't enough to say the "fight/flight response occurs when an individual is confronted with a stressor" as the sympathetic and parasympathetic nervous system are discussed in more detail in unit 3, so i guess that's where the ellaboration came from...
maybe have a look at this video just to familiarise yourself with it, we can't say which of our teachers was correct until tomorrow!



http://www.youtube.com/watch?v=y7VFD4718B4