Page 83 - Biology_Form_3

Biology for Secondary Schools

Endocrine Position Hormone produced Role of the hormone Effects of Effect of excess
gland deficiency production
Hydrocortisone Controls metabolism of Less glycogen is More glycogen
carbohydrates, lipids and stored in the liver stored in the liver
proteins and muscles and muscles
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Aldosterone Promotes retention of The kidneys excrete There will be
sodium chloride and too much sodium, little secretion of
bicarbonate ions chloride and sodium, chloride
bicarbonate ions and bicarbonate ions

Gonads Ovaries: Oestrogen Promote the growth Failure of growth Premature
(ovaries Pelvic region and development of and development of development of
and testes) reproductive organs reproductive organs reproductive organs
in females and the in females and the and secondary sexual
development of female development of characteristics in
secondary sexual female secondary
characteristics sexual characteristics females
Progesterone Inhibits ovulation and May cause Irregular menstrual
prepare the uterus for miscarriage cycle/ Periods
embryo implantation by May affect pregnancy
making its lining thicker and reduce libido
and more vascularised
Testes: Androgen Promotes the growth Failure of growth Premature
Scrotum and development of and development of development of
reproductive organs in reproductive organs reproductive organs
males and development of and also failure and secondary sexual
male sexual characteristics. to develop male characteristics in
Testosterone Promote spermatogenesis secondary sexual males
and development of characteristics
male secondary sexual
characteristics Poor sperm
production
Differences between nervous and 4. Transmission of information in
hormonal coordination nervous coordination is of electrical
1. Nervous coordination is quick and nature while hormonal coordination
the response is immediate while is of a chemical nature.
hormonal coordination is slow and 5. Nervous coordination controls
the response takes much longer. activities which require fast response

2. Nervous coordination involves while hormonal coordination control
specialised cells while hormonal slow or long term activities such as
coordination does not require growth and sexual development.
specialised cells. 6. The origin of message in nervous

3. Nervous coordination uses nerve coordination involves receptors and
cells for conducting nerve impulses brain while in hormonal coordination
while hormonal coordination needs it involves endocrine glands.
bloodstream to transport hormones
to different parts of the body.

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