M3 Reproductive

Question 1

Where is sperm produced?

Answer 1

Seminiferous tubules

Question 2

What are gonads?

Answer 2

Ovaries in female and testis in male

Question 3

Describe the sperm’s pathway from production to storage

Answer 3

The sperm is first produced in the seminiferous tubules, it is then directed in to the rete testis, where it is distributed into the efferent tubules and enters the epididymus. The immature sperm passes through the head, body and tail of the epididymus where it is stored till ejaculation.

Question 4

Muscle activity and the pampinform venous plexus helps to maintain the cooler temperature of the testis, how do they do that?

Answer 4

• The scrotum’s wrinkled exterior decreases surface area and increases thickness, improving insulation and prevents heat loss.
• the dartos and cremaster muscles can contract and pull the testis upwards and relax to regulate the temperature in response to cold or fear.
• the pampinform venous plexus coils around the testicular artery, cooling the arterial blood before it enters the testis.

Question 5

Describe the sperms journey through the epididymis

Answer 5

Immature, non-motile sperm moves slowly along the duct of the epididymis through a fluid that contains antimicrobial proteins. Takes around 20 days. During which the sperm gains the ability to swim.

Question 6

What is the structure of the epididymis

Answer 6

Head, body and tail
Head is made up of the efferent ductules.
The duct of the epididymis completes the head and makes up the body and tail

Question 7

What are the 2 functions of the stereocillia on the epididymal epithelium?

Answer 7

1. To absorb excess testicular fluid
2. To pass nutrients to sperm stored temporarily in the lumen

Question 8

What are the 2 major functions of Meiosis in females?

Answer 8

1. Reduction of chromosome number: from diploid to haploid
2. Genetic variation

Question 9

How are reproductive hormones produced in females?

Question 10

How are reproductive hormones regulated in females?

Question 11

What are the functions of reproductive hormones in females?

Question 12

Describe how the Hypothalamic-Pituitary-Gonadal (HPG) axis regulates female hormone production

Question 13

Identify hormones produced in the menstrual cycle

Question 14

Describe the phases of the menstrual cycle.

Answer 14

Uterine:
1. Menstrual phase: Gn rises, functional layer of endometrium shed
2. Proliferative phase: LH surge and FSH rise before ovulation, rising estrogen and functional layer regenerates
3. Secretory phase: LH drop remains enough for progesterone production. Progesterone functions
Ovarian:
1. Follicular phase: Follicular development
2. Luteal phase: Corpus Luteum development

Question 15

Describe the function of the Fimbrae

Answer 15

Brush the ovulated oocyte into the infundibulum.

Question 16

What does the ovary contain?

Answer 16

Follicles
Stromal matrix (nerves/blood vessels/connective tissues)
Tunica albuginea
Surface epithelium

Question 17

What are the stages of follicular maturation?

Answer 17

1. Primordial Follicle
2. Primary follicle
3. Secondary follicle
4. Pre-antral follicle
5. Antral follicle
6. Ovulation (antral follicle ruptures)
7. Corpus luteum

Question 18

What is antrum?

Answer 18

Fluid-filled spaces in the follicle.

Question 19

What is the purpose of granulosa cells?

Answer 19

1. Produce hormones (estrogen)
2. Protects con-growing follicles

Question 20

What is the purpose and functions of progesterone?

Answer 20

To maintain pregnancy
1. Limits Fimbrae movement and smooth muscle contraction.
2. Promotes blood supply and endometrial glands to provide nutrient-rich secretion for implantation
3. Thickens the cervical mucus to block entry of more sperm, pathogens or debris.

Question 21

At what stage in Oogenesis is Prophase I?

Answer 21

The oocyte arrests in prophase I, where the oocyte has undergone recombination, but the follicle cannot develop further till puberty (Still diploid).

Question 22

At what stage in Oogenesis is Metaphase I?

Answer 22

Enters metaphase I at Meiosis I, Polar body discarded.
This happens during ovulation, at the end of Metaphase I, the chromosome is pulled apart. Haploid

Question 23

At what stage in Oogenesis is Metaphase II

Answer 23

Begins Meiosis II but arrests in Metaphase II. It only completes after fertilisation.

Question 24

Compare and contrast Spermatogenesis and Oogenesis (6)

Answer 24

1. S takes around 74 days, O takes 13-50 years.
2. S occurs from puberty to old age, O occurs from fetal life to menopause.
3. S produces 4 sperm, O produces 1 ovum and 2-3 polar bodies.
4. S can produce over 1 trillion sperm, O can only produce less than 500 ovum
5. S has 5% error rate, O has a 20% error rate.
6. S has 1 sustentocyte that sustains many spermatocytes, O has many granulosa cells sustaining 1 oocyte.

Question 25

Compare and contrast Male and female reproductive systems (6)

Answer 25

1. M: Gonads outside of the body, F: gonads inside the abdominal cavity
2. M: Gonads continuous with reproductive tract, F: not continuous.
3. M: release of gametes continuous, F: Monthly
4. M: only 1 gonadal steroid (testosterone), F: 2, estrogen + progesterone
5. M: Does not prepare for a newborn, F: prepares for a newborn.
6. M: Gametes are replenished throughout life, F: Gamete is finite, exhausted by menopause.

Question 26

what is the function of Sertoli cells?

Answer 26

Produce Androgen binding protein when stimulated by FSH, keeping testosterone level high to maintain spermatogenesis.

Produce Inhibin, decreasing FSH release.

Question 27

What is the function of Leydig cells?

Answer 27

Stimulated by LH and produce Testosterone which then binds to ABP released by the Sertoli cells

Question 28

What does testosterone trigger in spermatogenesis?

Answer 28

Negative feedback to the anterior pituitary stops FSH, LH and GnRH release.

Question 29

What is produced in the seminal gland?

Answer 29

Semen: Fructose sugar, Coagulating enzyme, Prostaglandins, citric acid