1. Topic 6.6 – Hormones, homeostasis and reproduction
Essential Idea: Hormones are used when signals need to be widely distributed.

2. The Endocrine System Key endocrine glands:
A stimulus is received and processed.
Hormones are secreted directly into the blood.
They are carried to the target tissues (the place of intended action).
The action of the hormone changes the condition of the tissue.
This change in monitored through feedback.
Most hormonal change results in negative feedback.
Key endocrine glands:
Endocrine glands from:

3. The Endocrine System Key endocrine glands:
A stimulus is received and processed.
Hormones are secreted directly into the blood.
They are carried to the target tissues (the place of intended action).
The action of the hormone changes the condition of the tissue.
This change in monitored through feedback.
Most hormonal change results in negative feedback.
Key endocrine glands:
Pineal gland
Pituitary gland
Thyroid gland
Thymus
Adrenal gland
Pancreas
Ovary (female)
Testes (male)
Endocrine glands from:

4. Hormones in IB Biology Insulin Glucagon Thyroxin Leptin Ghrelin
Melatonin
Testosterone
Estrogen
Progesterone
Follicle-Stimulating Hormone
Luteinizing Hormone

5. Hormones in IB Biology Insulin – turns glucose into glycogen
Glucagon – turns glycogen into glucose
Thyroxin – regulates metabolic rate and body
temperature
Leptin – inhibits appetite
Ghrelin – promotes appetite
Melatonin – controls circadian rhythm
Testosterone – forms secondary sexual characteristic in males
Estrogen – causes secondary sexual characteristic in females
Progesterone – see above
Follicle-Stimulating Hormone – causes release of follicle during menstruation
Luteinizing Hormone – causes the development of endometrium during menstruation
Key
Pancreatic Hormones
Thyroid Hormone
Adipose Tissue Hormone
Pineal Gland Hormone
Testes Hormones
Ovarian/Pituitary Hormones

7. A simple diabetes animation

11. Diabetes Research Activity
Use the following websites to gather data on the prevalence of diabetes worldwide:
Then use this data to evaluate the following statement:
77% of people worldwide with diabetes are in low or middle income countries.
Suggest a hypothesis as to whether this statement is true, and search through the data to see if you can derive a correlation.
Design a one page report on this topic, detailing the information that you found and whether it supports or refutes .

14. Your Task: To design and record the most efficient negative feedback loop model of a hormone in a small group using only the space equivalent to one desktop.
Steps you must include (for example): Digestion of starch by mouth
Digestion of sugar by stomach/small intestine
Assimilation of sugar into blood stream
Pancreas stimulating release of insulin
Cells receiving insulin from pancreas
Cells then up-taking glucose from blood stream
Particles you should make sure to include:
Glucose
Starch
Beta Cells
Record your pathway using Vine and post it under #profbiohl2.
(upon a certain concentration of glucose being reached)
= Awesome!

15. Application: Causes of jet lag and the use of melatonin to alleviate it.
How many of you guys have experienced the following symptoms when travelling over 3 time zones?
Hard to sleep?
Falling asleep at the wrong time?
Insomnia?
GOOD NEWS! – This is simply a natural phenomenon, known as Jet Lag.
Naturally recovering works a bit differently depending on which direction you are travelling:
East – takes approx. 2/3 the number of time zones in days Travelling West – takes approximately ½ the number of time zones in days
Or!!! You can simply take melatonin supplements at the time you want to fall asleep on the days before and after travelling. It works to stimulate your circadian rhythm back to normal.
This can eliminate travelling sleep issues.

16. Humans have 23 pairs of chromosomes in diploid somatic cells (n=2).
A gene on the Y chromosome causes embryonic gonads to develop as testes and secrete testosterone.
Humans have 23 pairs of chromosomes in diploid somatic cells (n=2).
22 pairs of these are autosomes, which are homologous pairs.
One pair is the sex chromosomes.
XX gives the female gender, XY gives male.
Karyotype of a human male, showing X and Y chromosomes:
SRY
The X chromosome is much larger than the Y.
X carries many genes in the non-homologous region which are not present on Y.
The presence and expression of the SRY gene on Y leads to male development.
Chromosome images from Wikipedia:
3.4 Theoretical Genetics

17. Skill: Annotate diagrams of the male and female reproductive system to show the names of their structures and function

18. Reproduction (Core)
Image: Ovum, from Gray’s Anatomy

19. Application: William Harvey’s investigation of sexual reproduction in deer.
Historical Perspective of Sexual Reproduction
One of the earliest theories as to how animals reproduce sexually was the 'soil and seed' theory proposed by Aristotle
According to this theory, the male produces a ‘seed' which forms an ‘egg' when mixed with menstrual blood (the ‘soil’)
The ‘egg’ then develops into a fetus inside the mother according to the information contained within the male 'seed’ alone
Debunking the ’Soil and Seed’ Theory 
The ‘soil and seed’ theory was a popular doctrine for hundreds of years before it was eventually debunked by William Harvey
William Harvey studied the sexual organs of female deer after mating in an effort to identify the developing embryo
He was unable to detect a growing embryo until approximately 6 – 7 weeks after mating had occurred and concluded that Aristotle’s theory was incorrect and that menstrual blood did not contribute to the development of a fetus
Harvey was unable to identify the correct mechanism of sexual reproduction and incorrectly asserted that the fetus did not develop from a mixture of male and female ‘seeds’

20. Skill: Annotate diagrams of the male and female reproductive system to show the names of their structures and function
The male reproductive anatomy plays a vital part in the successful fertilization of the egg. Each part plays a small role in the journey of the sperm.
Be able to match each of these structures with its function in relation to the journey of a sperm.
Vas deferens
Bladder
Seminal vesicle
The sperm’s journey:
Spermatogenesis in the testis
Maturation in the epididymis
Carried along the vas deferens
Seminal vesicles provide fructose for energy and protective mucus
Prostate adds fluids that neutralize the acidic environment of the vagina
Prostate
Urethra
Penis
Epididymis
Testis

21. Skill: Annotate diagrams of the male and female reproductive system to show the names of their structures and function
Vasectomys are simple procedures done to sever the Vas deferens, in order to prevent sperm from leaving the body.

22. Skill: Annotate diagrams of the male and female reproductive system to show the names of their structures and function

23. Skill: Annotate diagrams of the male and female reproductive system to show the names of their structures and function

24. Skill: Annotate diagrams of the male and female reproductive system to show the names of their structures and function
Be able to relate each of these structures to the journey of the egg through the female reproductive system.
The egg’s journey:
Oogenesis in the ovaries
Maturation in the follicle in the ovary
Released into the fallopian tube
If fertilization occurs in fallopian tube, meiosis II will occur, and egg will implant in endometrium.
If fertilization does not occur, egg will be shed during menstruation cycle

25. Cervix: Lower portion of the uterus, which projects into the vagina
Skill: Annotate diagrams of the male and female reproductive system to show the names of their structures and function
Major Organs:
Ovaries : Produce Ova and sex hormones, approximately size and shape of a large almond
Follicles: A single egg with surrounding cells that nourish and protect it. Women are born with all the follicles they will have (40,000 – 400,000)
Oviduct (Fallopian Tubes): Transport the egg from ovary to uterus, site of fertilization
Cervix: Lower portion of the uterus, which projects into the vagina
- Pap Smears occur here, recommended yearly
Vagina: Thin walled, muscular chamber, receives penis and sperm, acidic pH to kill weak sperm and bacteria, part of birth canal

26. Skill: Annotate diagrams of the male and female reproductive system to show the names of their structures and function
Be able to relate each of these structures to the journey of the egg through the female reproductive system.
The egg’s journey:
Oogenesis in the ovaries
Maturation in the follicle in the ovary
Released into the fallopian tube
If fertilization occurs in fallopian tube, meiosis II will occur, and egg will implant in endometrium.
If fertilization does not occur, egg will be shed during menstruation cycle

27. The menstrual cycle is controlled by negative and positive feedback mechanisms involving ovarian and pituitary hormones. 1
GnRH – Gonadotropin releasing hormone*
(not required)
This hormone starts the whole process by beginning production of the next two hormones from the pituitary, FSH and LH. 2
Role of Follicle Stimulating Hormone (FSH) and Leuteinizing Hormone (LH)
The pituitary then releases FSH and LH to cause for the maturation of follicles into mature eggs, and eventually LH allows the most mature egg cell to be released. 3
Role of Estrogen and Progesterone
Estrogen and progesterone are released from follicle, and perform two major tasks:
1. Increase the thickness of uterine lining (Endometrium)
2. Cause the peak in LH, which results in release of most mature egg.
Animation of Ovulation

28. The menstrual cycle is controlled by negative and positive feedback mechanisms involving ovarian and pituitary hormones.
Click on the animation above to go to watch the graph form (APBI Schools.org.uk)

30. The menstrual cycle is controlled by negative and positive feedback mechanisms involving ovarian and pituitary hormones.

33. Your Task: Go to the following URL and follow the tutorial to set up your own database from the Excel Spreadsheet.
Follow the protocol, until it gets to the questions.
Answer the following questions:
How many volunteers show progesterone levels greater than 1ng/ml on day 9 of menses?
Which volunteer shows FSH levels over 10UI/L during 5 days. Are these days consecutive?
Click “Continue on Next Page” And follow Investigation 1 and 2.
Raise your hand after you and your group have satisfied the criterion for the Investigation.

34. The use in IVF of drugs to suspend the normal secretion of hormones, followed by the use of artificial doses of hormones to induce superovulation and establish a pregnancy.

35. The Contraceptive Pill.
By taking a supplement of hormones, the menstrual cycle can be manipulated to prevent pregnancy.
Explain how it works.
day1
Take the red* pill
it is a placebo (no hormones)
it is an iron supplement
Take the blue* pill
every day at the same time for 21 days
it is made with estrogen and progestin (synthetic progesterone)
(*They’re not really red and blue) 21 7 14
Morpheus image from
Other contraceptive pills work in other ways.