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Flashcards in Reproductive System Deck (392)
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1

What are the benefits of sexual reproduction?

Production of new individuals and mixing of genotypes to create genetic diversity.

2

Why is infertility becoming more common?

STI's
Obesity
Cigarette smoking (can cause erectile dysfunction and poor sperm)
Increasing age at childbearing

3

How many couples does infertility affect?

1 in 7

4

Name two assisted reproductive techniques (ART). What percentage of babies born in most Western countries are by ART?

In vitro fertilisation (IVF)
Intracytoplasmic sperm injection (ICSI)
2-5%

5

Describe the production of spermatozoon and the fertility in males over life.
Describe the fertility of females over their lifetime.

Constant production at ~300 million per day from puberty.
Constant fertility. Gradual decline with age.
Cyclical fertility from puberty, 3-5 days per month.

6

Compare the number of follicles in utero and the number that will be ovulated.

In utero, 7 million follicles, declining to near zero at menopause, only ~400 follicles will be ovulated.

7

Compare the sizes of sperm and eggs.

Sperm: smallest cell in the body
Egg: largest cell in the body

8

What is the rate of production of sperm per testicle? Compare the weights of sperm and eggs.

1500 per second per testicle
175,000 sperm weigh as much as one female egg.

9

How far must sperm swim to reach the egg?

15 cm

10

List the endocrine glands controlling the reproductive processes. What happens with regard to the endocrine system when puberty starts?

- Hypothalamus, pituitary, adrenal glands, testes and ovaries
- Activation of the hypothalamic-pituitary axis and production of hormones.

11

What are the two main functions of the gonads?

Produce gametes
Produce reproductive hormones

12

What does testosterone bind to in the body?

Cells with an androgen receptor

13

List the main water soluble reproductive hormones.

Gonadotrophin releasing hormone (GnRH)
Follicle stimulating hormone
Luteinising hormone
Oxytocin

14

Water soluble hormones are usually _______ and ________

Peptides
Proteins

15

What is the site of secretion of GnRH?
What is the site of secretion of FSH and LH?

Hypothalamus
Anterior pituitary

16

What is the site of production and secretion of oxytocin?

Production: Hypothalamus
Secretion: Posterior pituitary

17

List the main lipid soluble reproductive hormones.

Androgens (Testes)
Oestrogens (Ovary)
Progestagens (Ovary)

18

Lipid soluble hormones are _______ _________

Steroid hormones

19

What are the two main types of androgens?

Testosterone
5 alpha dihydrotestosterone (more active form)

20

What are the three types of oestragen?
What is the one type of progestagen?

Oestradiol (most potent)
Oestrone
Oestriol

Progesterone

21

What are steroid hormones made from? What percentage of steroid hormones are free?

Cholesterol - obtained from diet
2-3% free (able to diffuse into cells whilst bound hormones cannot)

22

Which is faster out of action due to water soluble hormones vs lipid soluble hormones?

Action due to water soluble hormones

23

If a person were to lose their pituitary gland, what would be the result?

They would be castrate: loss of all reproductive function

24

Compare the sizes of the posterior and anterior lobes of the pituitary

The posterior lobe is much smaller

25

Out of the hypothalamus and pituitary, which is part of the central nervous system?

Hypothalamus

26

What kind of arrangement is the hypothalamic/pituitary/gonadal axis? What is beneficial about this?

Hierarchical arrangement: allows signal amplification

27

What is the main function of the hypothalamus?

To act as a homeostatic regulator for reproduction, stress, body temperature, hunger, thirst, and sleep.

28

Why is the hypothalamus called a neuroendocrine organ?

It processes both neural and hormonal information.

29

What is another name for the posterior pituitary?

Neurohypophysis

30

How are nerves situated between the hypothalamus and the posterior lobe?

The cell bodies are found in the hypothalamus and the long axon tracts extend down to the lobe.