Reproductive system 1

Question 1

What is gametogenesis

Answer 1

The creation of gametes
-Diploid cells divide/differentiate and form mature haploid gametes.

Question 2

Gametes examples

Answer 2

Ovum/egg and spermatozoon/sperm

Question 3

What are the components of the male reproductive system

Answer 3

-Testes
-Scrotum
-Epididymis (with Vas deferens)
-Spermatic cord
-Penis
-Urethra
-Accessory Reproductive glands (eg seminal vesicles, prostate glands, Cowper’s glands)

Question 4

What are testes and what is their function

Answer 4

-Oval glands carried in scrotum
-Functions are hormone production (testosterone) and the site of spermatogenesis.

Question 5

What are the layers surrounding testis

Answer 5

Parietal peritoneum layer (thick outer layer) and Visceral peritoneum layer (thinner and tightly adhered to outer testis surface)

Question 6

Development of testes

Answer 6

They develop in abdomen near the kidney and then descend into the scrotum, guided by the gubernaculum, during neonatal development.

Question 7

Where are Seminiferous tubules

Answer 7

In lobules in the inner testis

Question 8

What do seminiferous tubules contain

Answer 8

1. Spermatogenic cells (for spermotegenesis)
2. Sertoli cells (for nutritional support and oestrogen production)
3. Leydig cells (secrete testosterone)

Question 9

What is Cryptorchidism

Answer 9

One or both testes don’t descend into scrotum, testosterone still produce but male is usually sterile.

Question 10

What is a sertoli cell tumour

Answer 10

Rapid Sertoli cell growth causing the overproduction of oestrogen and therefore feminisation of dogs.

Question 11

What are the functions of the scrotum

Answer 11

-Regulate temperature of testes
-Supports/protects testes
-Has thin skin, sweat glands and no subcut fat to keep testes cool.
-muscles bring them closer/further from body depending on temp

Question 12

What is the epididymis

Answer 12

Large coiled duct that efferent ducts drain into

Question 13

Function of Epididymis

Answer 13

Sperm maturation and storage

Question 14

What is the Vas Deferens and its function

Answer 14

-Muscular tube in the spermatic cord connecting epididymis tail to urethra

Question 15

What is the Spermatic cord

Answer 15

Tube like connective tissue that links testes to the rest of the body

Question 16

What are the functions of the penis

Answer 16

-Urination
-Delivering semen to female vagina
-Erection: penis size increases and becomes rigid to help deliver semen
Ejaculation: Contractions pump semen into female

Question 17

What is the structure of the penis

Answer 17

1. Roots/crura attach penis to pelvis
2. Body is 2 bundles of erectile tissue (corpus spongiosum and cavernosum)
3. Glans
4. Prepuce is a sheath of hairy skin that retracts on mating.
5. Urethra runs through os penis.

Question 18

What are the penis types

Answer 18

-Musculocavernous
-Fibroelastic

Question 19

Musculocavernous penis

Answer 19

-Large spaces fill up with blood and penis widens and lengthens during erection.
-Dog, stallian, cat, person

Question 20

Fibroelastic penis

Answer 20

-Small spaces fill up with blood and s shaped sigmoid flexure straightens out during erection.
-Less blood required
-Bull, boar, roam

Question 21

What are functions of the urethra

Answer 21

-Carries urine from bladder
-Conveys sperm and seminal fluid through ejaculation

Question 22

What do accessory reproductive glands do

Answer 22

-Make non spermatozoa part of semen
-Secrete alkaline fluid
-Helps spermatozoa reach oviducts

Question 23

Compare cat to dog male repro

Answer 23

-Cat and dog both have os penis
-Dog has bulb on glans that makes male and female stick together after breeding
-Cat has a glans covered in spines to stimulate female vagina

Question 24

Ram penis

Answer 24

-Has long urethral process on left of penis to spray cervix with semen

Question 25

Pig penis

Answer 25

-Has no glans and no urethral process
-Tip of penis forms spiral to engage with cervix

Question 26

What does interstitial cell stimulating hormone do in males

Answer 26

stimulates interstitial cells to produce testosterone

Question 27

what does fsh do in male

Answer 27

Stimulates sertoli cells to make oestrogen

Question 28

Describe structure of spermatozoa

Answer 28

-Head has the nucleus with genetic material and acrosome (enzymes that penetrate ovum)
-midpiece has mitochondria
-Flagellum is for movement

Question 29

Sperm movement mechanisms

Answer 29

1. Flagellar
2. Uterine muscle contractions propel the sperm
3. Maturation primes sperm for fertilisation
4. Occyte releases chemical signals for guidance

Question 30

Pathway of the sperm

Answer 30

1. Sperm is deposited into vagina, cervix or uterus (species dependent)
2. There are 2 transport phases
   -Rapid phase: Female repro tract has muscular contractions to propel sperm
   -Slow sustained phase: Transport continues for hours until sperm reach fertilisation site
3. Sperm binds to isthmus and become immobile
4. When female ovulates, sperm is released and becomes hypermobile to reach egg

Question 31

Fertilisation of the oocyte

Answer 31

1. Sperm penetrates granulosa layer]
2. Acrosomal reaction occurs and spermatozoon binds to zona pellucida
3. Spermatozoon penetrates through zone pellucida
4. Membranes fuse and nucleus enters oocyte.

Question 32

Events of spermatogenesis

Answer 32

1. Spermatogenesis occurs during puberty and requires hormones.
2. Primary spermatocyte (diploid cell) divides
3. A secondary spermatocyte is produced and divides into spermatids
4. These mature into sperm and gain the shape.

Question 33

Composition of semen

Answer 33

-Sperm
-Seminal vesicle fluid
-Prostate gland fluid
-Cowpers gland fluid
-Water and salt