Hormones and reproduction 6.6 30'

Hormones, homeostasis and reproduction

Learn about homeostasis, thermoregulation, control of blood glucose, diabetes, leptin, melatonin, male and female reproducive systems, the SRY gene, secondary sexual characteristics and the menstrual cycle.


Key words

Learn and test your biological vocabulary for 6.6 Hormones, homeostasis and reproduction using these flashards.

Clean sweep - quick revision through the whole topic 

Use the slideshow below to revise Hormones and Reproduction 6.6

Video tutorial

A short video tutorial is planned here.

Revision summary list for 6.6 Hormones and reproduction

  • Hormones travel in the blood more slowly than nerve impulses but are more widely distributed
    • Insulin and glucagon control blood glucose (cells in islets of pancreas)
    • Thyroxin regulates metabolic rate & partly controls body temperature. (thyroid gland)
    • Leptin acts on the hypothalamus of the brain to inhibit appetite (secreted by cells in adipose tissue)
    • Melatonin controls circadian rhythms (jet lag) (secreted by pineal gland.)

Hormones in human development & reproduction

  • The sry gene of the Y chromosomes causes embryonic gonads to develop as testes and then they secrete testosterone which causes pre-natal development of male genitalia. In puberty it causes, development of male secondary sexual characteristics and sperm production.
  • Estrogen and progesterone cause pre-natal development of female reproductive organs and in puberty the female secondary sexual characteristics.
  • In the menstrual cycle FSH, LH, estrogen and progesterone have roles in negative and positive feedback mechanisms.
  • IVF uses drugs to suspend the normal secretion of hormones, followed by the use of artificial doses of hormones to induce superovulation and establish a pregnancy.

Skills

  • Understand the causes and treatment of Type I and Type II diabetes.
  • Outline how tests using leptin on obese patients didn't reduce their obesity and give reasons why.
  • Understand how melatonin can be used to help alleviate jet lag.
  • Homeostasis of glucose
  • Annotate diagrams of the male and female reproductive systems with the names & function of structures.
  • State that scientific discoveries often follow developments in equipment, and illustrate this with the example that microscopes were not available for William Harvey’s investigation of sexual reproduction in deer so he failed to solve the mystery of sexual reproduction

Revision summary sheets

There is a lot to learn in this subsection so it is particularly useful to make revision summary sheets or mind maps.
These diagrams summarise the main sections of topic 6.6.
Test if you can draw something like these concept maps from memory.

Review questions

This is a self marking quiz containing questions covering the topic outlined above.
Try the questions to check your understanding.

1

Which answers best explains the difference between the speed of reaction of hormones compared to nerve impulses?

Hormones travel in the blood more slowly than nerve impulses but are more widely distributed

2
The hormone insulin lowers blood glucose. What is the name of the other hormone produced by the pancreas which helps to increase blood glucose levels?

Insulin and glucagon control blood glucose (they are both made in cells in islets of pancreas)

3

What is the function of the hormone thyroxine.

which regulates the body's metabolic rate & partly controls body temperature.

Thyroxin regulates metabolic rate & partly controls body temperature. ( it is made in the thyroid gland)

4

What is the role of the hormone Leptin?

Leptin acts on the hypothalamus of the brain to inhibit appetite (secreted by cells in adipose tissue)

5

What is the hormone which controls circadian rhythms called?

Melatonin controls circadian rhythms (It is secreted by pineal gland.)

6

What is the hormone which causes pre-natal development of male genetalia?

The sry gene of the Y chromosomes causes embryonic gonads to develop as testes

The testes secrete testosterone which causes pre-natal development of male genitalia.

Note: In puberty it causes, development of male secondary sexual characteristics and sperm production.

7

What is the role of estrogen and progesterone in a developing embryo?

Estrogen and progesterone cause pre-natal development of female reproductive organs

Note: in puberty the female secondary sexual characteristics.

8

The corpus luteum produces estrogen and progesterone which inhibit the production of LH and FSH causing the corpus luteum to degenerate.

Which of these terms best describes this example of feedback?

In the menstrual cycle FSH, LH, estrogen and progesterone have roles in negative and positive feedback mechanisms.

This is an example of negative feedback, as the result of the process reduces the stimulus of the process.
9
In terms of insulin, what is the difference between Type I diabetes and Type II diabetes?

In diabetes the glucose level of the blood is not controlled properly.

In type I the body cannot produce enough insulin.

In type II the body produces insulin but it doesn't have the effect of lowering blood glucose.

10
In the regulation of blood glucose insulin affects the liver and muscles lowering blood glucose concentration.
What is the name of the enzyme which raises blood glucose concentration?

Glucagon is the hormone which is released when blood glucose is too low.

It promotes the release of glucose into the blood, raising the blood concentration.

Total Score:

Revision fun activity

This is a little bit of fun, but still revision. Can you make the leader board?
If you can't see the content below, please click this link to Hormones and reproduction card match game