Urogenital

Question 1

What 2 functions does the testis have?

Answer 1

1. Production and transmission of male genes (spermatozoa).

2. Production of reproductive hormones (androgens).

Question 2

What is an androgen?

Answer 2

A hormone that controls the development and maintenance of male characteristics in the body.

Question 3

What is the name of the process of sperm production and development?

Answer 3

Spermatogenesis.

Question 4

What are the 2 main androgens?

Answer 4

Testosterone and dihydrotestosterone.

Question 5

What 2 discrete compartments are there in the testis?

Answer 5

Within the seminiferous tubule and between seminiferous tubules.

Question 6

What is contained within the seminiferous tubules?

Answer 6

Sperm at various stages of development, sertoli cells, tubule lumen.

Question 7

What is outside the seminiferous tubules?

Answer 7

Leydig cells.

Question 8

What do Leydig cells do?

Answer 8

They produce testosterone in the presence of luteinizing hormone (LH).

Question 9

What is the role of Sertoli cells? (vague)

Answer 9

Nourish the developing sperm cells through the stages of spermatogenesis, hence they control spermatogenesis.

Question 10

What are the 3 phases of spermatogenesis in order?

Answer 10

1. Mitotic proliferation
2. Meiotic division
3. Cytodifferentiation (spermiogenesis).

Question 11

What is mitotic proliferation? (Spermatogenesis)

Answer 11

The process that produces large numbers of spermatogonia from gonocytes.

Question 12

Where does mitotic proliferation take place? (Spermatogenesis)

Answer 12

The basal compartment of the seminiferous tubule.

Question 13

Are spermatogonia haploid or diploid?

Answer 13

Diploid, they haven’t undergone meiosis yet.

Question 14

Are spermatogonia genetically identical or not?

Answer 14

They are genetically identical.

Question 15

What is meiotic division? (Spermatogenesis)

Answer 15

The process that generated genetic diversity in developing sperm and creates haploid cells.

Question 16

Where does meiotic division take place? (Spermatogenesis)

Answer 16

The adluminal compartment of the seminiferous tubule.

Question 17

What are developing sperm cells called after the first round of meiotic division?

Answer 17

Spermatocytes.

Question 18

What are developing sperm cells called after the second round of meiotic division?

Answer 18

Spermatids.

Question 19

What is cytodifferentiation (spermiogenesis)? (Spermatogenesis)

Answer 19

Developing sperm cells change from typical ‘cell’ shape into typical ‘sperm’ shape with a head, mid-piece and tail.

Question 20

What are spermatozoa?

Answer 20

Sperm that are fully developed in the testis and have the typical ‘sperm’ shape.

Question 21

What are the 5 cells taking part in the stages of spermatogenesis?

Answer 21

1. Gonocyte
2. Spermatogonia
3. Spermatocyte
4. Spermatid
5. Spermatozoa

Question 22

Towards the end of spermatogenesis, which end of the spermatozoa is orientated so that it protrudes into the seminiferous tubule lumen?

Answer 22

The tail of the spermatozoa.

Question 23

How do Sertoli cells nourish developing sperm cells? (specific)

Answer 23

1. Transfer of developmental proteins to spermatocytes
2. Removal of material from elongating spermatids
3. Mediate (testosterone) hormone action

Question 24

How is a coordinated wave of spermatogenesis achieved?

Answer 24

All the sertoli cells are linked with gap junctions.

Question 25

What are the 2 gonadotrophins?

Answer 25

LH and FSH.

Question 26

What is the precursor for all steroid hormones, including testosterone?

Answer 26

Cholesterol.

Question 27

What does pituitary derived LH stimulate? And hence what does it affect the production of? (male)

Answer 27

Leydig cells and production of testosterone (and DHT).

Question 28

What does FSH act upon? And what does it stimulate? (male)

Answer 28

Acts on sertoli cells by stimulating the production of androgen receptor proteins.

Question 29

What does FSH allow? (male)

Answer 29

It allows sertoli cells to respond to androgens.

Question 30

What can testosterone affect? And how? (male)

Answer 30

Spermatogenesis and testosterone levels: Can affect spermatogenesis by transferring into DHT in sertoli cells. Can also act on the anterior pituitary or hypothalamus and cause reduction in testosterone levels by negative feedback.

Question 31

How many sperm reach the oocyte per million sperm ejaculated?

Answer 31

1 per million.

Question 32

What structures do sperm cells travel through to get to the penis?

Answer 32

Lumen of the seminiferous tubule, rete testis, vasa efferentia, epididymis (head, body, tail), vas deferens.

Question 33

What are the 3 alternate names for the head, body and tail of the epididymis?

Answer 33

Caput (head), Corpus (body), Cauda (tail).

Question 34

How long does passage through the epididymis take?

Answer 34

6-12 days.

Question 35

What happens in the caput (head) of the epididymis?

Answer 35

Fluid from the sertoli cells is reabsorbed so the sperm are concentrated.

Question 36

After the fluid that the sperm travel in is reabsorbed (caput, epididymis) how are the sperm then transported?

Answer 36

Forced through the epididymis by contractions of muscles in the epididymis.

Question 37

What happens in the corpus (body) of the epididymis?

Answer 37

Modifications in the biochemistry of the sperm and its environment, part of sperm maturation, which allows the sperm to stabilise.

Question 38

What happens in the cauda (tail) of the epididymis?

Answer 38

The sperm are stored until ejaculation.

Question 39

What 4 things change in the process of sperm maturation in the epididymis?

Answer 39

1. Sperm structure - loses surplus cytoplasm 2. Sperm membranes - addition of surface glycoproteins 3. Metabolism - depresses to extend cell life 4. Motility - first become motile * see lecture slides for much greater detail and more changes*

Question 40

When do the sperm first become motile?

Answer 40

Once they have traveled through the epididymis.

Question 41

Are the sperm motile before travelling through the epididymis?

Answer 41

NO! - exam question.

Question 42

What 3 things move sperm through uterine tracts?

Answer 42

1. Motility of sperm 2. Fluid currents caused by uterine cilia 3. Uterine contractions

Question 43

What is the fluid aspect of the ejaculate called?

Answer 43

Seminal plasma.

Question 44

Where is seminal plasma derived from?

Answer 44

Secretions of some of the accessory secretory glands.

Question 45

What are the 5 male accessory secretory glands? (Presence varies between species)

Answer 45

Ampullary, vesicular, prostate, bulbourethral, and urethral glands.

Question 46

Which 4 accessory secretory glands are responsible for producing seminal plasma? (Presence varies between species)

Answer 46

Ampullary, vesicular (seminal vesicle), bulbourethral and prostate.

Question 47

What do bulbourethral glands do?

Answer 47

They produce pre-ejaculate in some species, primarily pigs.

Question 48

Describe the location of the ampulla.

Answer 48

Where the vas deferens thicken as the pass over the bladder.

Question 49

How much ejaculate does a ram produce?

Answer 49

1-2ml

Question 50

How much ejaculate does a human produce?

Answer 50

3ml

Question 51

How much ejaculate does a boar produce?

Answer 51

500ml

Question 52

What is the purpose of a pre-ejaculate?

Answer 52

To increase the pH of the female tract to make the environment less hostile for the sperm.

Question 53

What are the 7 constituents of seminal plasma?

Answer 53

1. Glycoproteins 2. Fructose and Sorbitol 3. Citric acid 4. Acid phosphotase 5. Buffers 6. Ascorbic acid 7. Prostoglandins

Question 54

What do prostaglandins do?

Answer 54

Cause softening of the cervix and muscle contractions in uterus.

Question 55

Which species have a fibroelastic penis? | Dog, Ram, Cat, Bull, Boar, Stallion

Answer 55

Ram, Bull, Boar.

Question 56

What erectile tissue does a penis have?

Answer 56

Corpus cavernosum, Corpus spongiosum

Question 57

What does a sigmoid flexure do?

Answer 57

Allows the penis to be retracted into the body until erection.

Question 58

How is a sigmoid flexure formed?

Answer 58

Contracted retractor penis muscles cause the s-shaped bending.

Question 59

Which species have a musculovascular penis? | Dog, Ram, Cat, Bull, Boar, Stallion

Answer 59

Dog, Cat, Stallion.

Question 60

What are the 3 sections of the penis?

Answer 60

The base (attached to ischial arch), the shaft and the glans penis.

Question 61

What are the 2 types of penis?

Answer 61

Fibroelastic penis, musculovascular penis.

Question 62

What 4 muscles are associated with the pelvic urethra and the penis?

Answer 62

Urethralis, bulbospongiosus, ischiocavernosus, retractor penis.