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Tuesday, May 25, 2010

The Hypothalamus and its releasing hormones



Before i begin with the topic let me share what my friend and i had talked before we eat lunch it has something to do with brains and when we talk of brains the word imagination is just 15 meters away right?
while walking to the canteen...

Me: My brain is like a stomach that has intestines around it when i'm hungry .
Friend: why?
Me: because i starve, i think eating delicious food and when you eat in your imagination the food will only go on your brain not in your stomach.
Friend: Your just hungry!, a perfect example of the brain is the heart.
Me: Why?
Friend: because when i imagine me and my crush are together i feel so inlove!
Me: Your pretty much hungry.

Hypothalamus: Part of the brain that sends information from the rest of the body and regulates most of the body's endocrine system, it acts a link between the endocrine system and the nervous system, just like the door in our library as we enter, it functions automatically by monitoring and regulating the nervous system as well as the body's homeostasis (proper metabolism) through eating (love it), drinking, temperature control (for those hot headed),sexual drives (please don't drink and DRIVE),pleasure and pain, fight or flight reactions.

It also directs hormones release by the anterior pituitary gland, so what else i did not mention? The secretion of hormones released by anterior pituitary gland is controlled by the hypothalamus, it will then now releases a hormone which allows the anterior pituitary gland to secrete its own hormone messenger , this is carried to the blood to its target's endocrine gland which is stimulated to release its hormone into the blood. The circulating target gland hormone goes back to the hypothalamus and anterior pituitary gland to inhibit their activity, this allows a balanced activity of the hypothalamus and the anterior pituitary gland and also the target gland.

Hormones secreted by the hypothalamus

TRH ( Thyrotropin releasing hormone )

This stimulates the production of TSH ( thyroid stimulating hormone) and PRL ( prolactin )
from the anterior pituitary gland.

GnRH (Gonadotrophin releasing hormone)

This hormone is increased when puberty starts. This hormones helps in the sexual development for normal sexual function of both males and females.
Primary Effect: Increase in FSH (follicle stimulating hormone) and LH (luteinizing hormone)
Secondary effect: Female - increase in FSH = Estrogen and Progesterone UP.
Male - increase LH = testosterone UP.
GHRH ( Growth Hormone Releasing Hormone)

As the name indicates it stimulates cells in the anterior pituitary to secrete growth hormone.

CRH ( Corticotropin releasing hormone)

Aids in the release of adrenocorticotropic hormone, it is secreted by the placenta and helps in the determination of duration of pregnancy, it has also a function on keeping the T cells of the mother from preventing attack to the fetus.

for better explanation please refer to this site's:

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/H/Hypothalamus.html

Wednesday, May 12, 2010

Definitions



Endocrinology - It is the study of endocrine system, this endocrine system is composed of glands in different parts of the body as you can see on the picture above. The primary function of endocrine glands is to release hormones, the function of this so called hormones is to control reproduction, metabolism,growth and development in short to maintain homeostasis (normal body function).

So imagine life without hormones? let's just say for example you don't have any insulin hormone,when insulin is absent, glucose in the blood is not taken up by body cells, glucose is a body sugar and having too much of it the blood (diabetes) causes a lot of health problems in the eyes,nerves,kidneys which can lead to blindness,dialysis, or even in much worst case scenario is amputation, ouch!.


Toxicology - Study of harmful toxic effects o substances/chemicals, also called as the science of poisons.Toxicology has many aspects like food toxicology,environmental toxicology and clinical toxicology.But eventhough it looks like politics that has many groups and divisions, it has only one goal.That is to give proper information and understanding of how chemicals can bring adverse effects on living organisms.

Drug Testing - Program created by the law to solve widespread problem of drug abuse and its consequences.When you take in anything inside from the food that you eat, drinks and drugs. The body will break down all of them into smaller particles and they will be digested and eventually go out of the body, but not the drugs, its metabolites can remain in the body for long period of time.