2. B.6.1 OUTLINE THE
PRODUCTION AND
FUNCTION OF HORMONES IN
THE BODY
3. • What is hormone?
– Hormones are chemical messenger that are
produced by the body’s endocrine glands (many
of which are controlled by the pituitary gland
which in turn, is controlled by the hypothalamus)
– Released directly via bloodstream to target organ
– Perform a variety of different function and vary
greatly in their chemical composition
– Generally have a negative feedback mechanism
whereby a high level of the hormone inhibits its
own production.
4. • Examples of hormone:
– ADH (controls body water content)
– Aldosterone (a steroid which regulates the Na and
K balance in the blood)
– Adrenalin
– Thyroxine
– Insulin
– Sex hormone (male and female)
5. ADRENALIN
• Produced in the adrenal gland.
• A stimulant, closely related to the
amphetamine drugs.
• Released in times of excitement and causes a
rapid dilation of the pupils and airways,
increases the rate of heartbeat and the rate
of release of sugar into the bloodstream.
• Sometimes known as the ‘flight or fight’
hormone.
8. THYROXINE
• Produced in the thyroid gland (located in the
neck)
• Contains iodine.
• Lack of iodine can cause the thyroid gland to
swell. (goitre)
• Thyroxin regulates the body’s metabolism
• Low levels of thyroxin cause hypothyroidism,
characterized by lethargy as well as sensitivity to
cold and a dry skin.
• Overactive thyroid gland causes hyperthyroidism
with the symptoms of anxiety, weight loss,
intolerance to heat, and protruding eyes.
11. INSULIN
• A protein containing fifty-one amino acid residues
• Formed in the pancreas and regulates blood sugar
levels
• Low level of insulin or absence of it can cause
hyperglycemia (high blood sugar) and results in thirst,
weight loss, lethargy and circulation problems.
• Long term sufferers of diabetes can suffer blindness,
kidney failure, and need limbs to be amputated due to
poor circulation.
• Thus, it is treated by reducing sugar intake and taking
daily insulin injections.
• Too much insulin can cause hypoglycemia (low blood
sugar), where the blood sugar level falls resulting in
dizziness and fainting.
14. SEX HORMONE
• The sex hormones are all steroids.
• Steroids contain a characteristic four-ring
structure
• The basic building block for the other steroids
is cholesterol formed in the liver and found in
all tissues, the blood, brain, and spinal cord.
15. MALE SEX HORMONE
• Comprise mainly testosterone and
androsterone
• Produced in the testes
• They are anabolic – encouraging tissue,
muscle, and bone growth – and androgenic –
conferring the male sexual characteristics.
17. FEMALE SEX HORMONE
• Structurally very similar to male sex
hormones, except for the small changes in the
functional groups attached to the steroid
framework
• They are produced in the ovaries from
puberty until menopause
• The two main female sex hormones are
oestradiol and progesterone
• They are responsible for sexual development
and the menstrual and reproductive cycles in
women.
21. Cholesterol structure
• The basic building block
for the other steroids is
cholesterol.
• It has a chain of alkanes
on one ring
• and a C-OH group
(hydroxyl group) on the
last ring
• Consist of four carbon
rings :
– Three cyclohexane
– 1 cyclopentane
• Cholesterol is primarily
hydrophobic, with only
one hydroxyl group.
22. Testosterone
• C-OH group (hydroxyl
group) on the first, ring
C=O (carbonyl group)
on the last
• The sex hormones have
carbonyl groups and
hydroxyl groups which
make the molecule
partly hydrophilic on
both ends.
23. Progesterone
• Carbonyl group (ring
C=O) attached to a
methyl group on the
first ring, carbonyl
group (ring c=O) on the
last ring
