2 - Repro - Origin of the Sexes 2 Flashcards Preview

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Flashcards in 2 - Repro - Origin of the Sexes 2 Deck (30):
1

At approx. which month of development do the testes reach the scrotum?

~ 9th month

2

What structure passes through the inguinal canal in females?

Round ligament of the uterus

3

Name the ligament which connects the ovary to the uterus:

Ovarian ligament

4

Name the ligament which connects the uterus to the labia majora:

Round ligament of the uterus

5

Name the syndrome caused by a (47, XXY) chromosome defect:

Klinefelter syndrome

6

If an embryo has no gonads due to a defect, would it develop male or female internal genitalia?

Female internal genitalia
- Mullerian ducts form, and Wolffian ducts regress due to lack of androgens

7

Is someone with Klinefelter syndrome a male or female?

Male, with small/undescended testes

8

Why may someone with Klinefelter syndrome have delayed/incomplete puberty?

Less than usual amount of testosterone produced

9

Name the syndrome caused by a (45, XO) chromosome defect:

Turner's syndrome

10

Is someone with Turner's syndrome a male or female?

Female, with no ovaries

11

When is Turner's syndrome usually diagnosed? Why?

- At age when puberty usually occurs
- Girls with Turner's syndrome do not go through puberty, due to lack of ovaries

12

If someone has a (46, XY) karyotype but the fetal genitalia is insensitive to testosterone and DHT, will they be born phenotypically female or male?

Female
- Have undescended testes

13

If someone has a (46, XX) karyotype but have excessive androgen secretion from adrenal glands, will they be born phenotypically female or male?

Male

14

List the reproductive hormones secreted by the hypothalamus:

- Peptide releasing factors
- GnRH
- PRH
- PIH (Dopamine)

15

List the reproductive hormone released by the posterior pituitary:

Oxytocin

16

List the reproductive hormones released by the anterior pituitary:

- FSH
- LH
- Prolactin

17

List the reproductive hormones released by gonads:

- Testosterone
- Oestrogens: Oestradiol, Oestrone, Oestriol
- Progesterone
- Inhibin

18

List the main reproductive hormones released by the placenta:

- hCG
- hPL
- Oestrogens: Oestradiol, Oestrone, Oestriol
- Progesterone

19

Which part of the pituitary gland is formed from the forebrain, and so called the 'neurohypophysis'?

Posterior pituitary

20

Which part of the pituitary gland is formed from an evagination of the developing mouth 'Rathke's pouch', and called the adenohypophysis?

Anterior pituitary

21

Approx how many seminiferous tubules are present in each testes?

~ 250 - 750 per testes

22

Name the cells found in the seminiferous tubules:

- Spermatocytes
- Spermatids
- Sertoli cells
- Myofibroblasts
- Leydig cells

23

What is the importance of the blood-testes barrier (tight junctions between sertoli cells in seminiferous tubules)?

The sperm are genetically different to the father's cells, so must be kept apart otherwise high risk of autoimmune attack

24

Name the cells lining the rete testis and efferent ductules:

1) Columnar ciliated cells
2) Cuboidal cells (remove fluid and concentrate sperm)

25

What is the function of the cuboidal cells lining the rete testis and efferent ductules?

Absorb fluid, concentrating sperm

26

In what stage of meiosis does crossing over occur?

Prophase I

27

In what stage of meiosis does independent assortment take place?

Metaphase I

28

What is the main difference between meiosis in males and females?

Males = 1 germ cell forms 4 spermatogonia
Females = 1 germ cell forms 1 oocyte

29

How many chromosomes is present in a gamete?

23 chromosomes

30

Approx. how many sperm are formed per day?

~ 200 million per day