Male Reproductive System

Question 1

Where does Spermatogenesis occur?

Answer 1

In the seminiferous tubules within the testes

Question 2

What is the typical Rate of Sperm Cell Production?

Answer 2

300-600 Sperm Cells per Gram of Testis Tissue per Second

Question 3

What are the 3 Phases of Spermatogenesis?

Answer 3

1. Mitotic Division
2. Meiotic Division
3. Cytodifferentiation

Question 4

What Germ Cells to do with Spermatogenesis are activated at the start of Puberty in Males?

Answer 4

Spermatogonial Stem Cells

Question 5

When the Spermatogonial Stem Cells are activated, what type of Cell Division do they undego? What is the result of this Cell Division?

Answer 5

Mitotic Cell Division, to create one undifferentiated Spermatogonial Stem Cell and one Spermatogonium which will eventually end up as sperm cells

Question 6

How many Chromosomes do Spermatogonium have?

Answer 6

46

Question 7

Where do the Mitotic Divisions of Spermatogonial Stem Cells occur?

Answer 7

In the basal compartment of the seminiferous tubules

Question 8

Where do Spermatogonium move after arising from Spermatogonial Stem Cells? What do they move between?

Answer 8

They move into the adluminal compartment of the seminiferous tubules, moving between adjacent sertoli cells

Question 9

Once Spermatogonia move into the Adluminal Compartment of the Seminiferous Tubule, what are they called?

Answer 9

Primary Spermatocytes

Question 10

How many Chromosomes do Primary Spermatocytes have?

Answer 10

46

Question 11

Primary Spermatocytes divide into ___ Spermatocytes and have ___ Chromosomes

Answer 11

Primary Spermatocytes divide into Secondary Spermatocytes and have 23 Chromosomes​

Question 12

Secondary Spermatocytes undergo ___, giving rise to 4 daughter cells called ___, having ___ Chromosomes each

Answer 12

Secondary Spermatocytes undergo Meiosis II, giving rise to 4 daughter cells called Spermatids, having 23 Chromosomes each

Question 13

What is another name for Cytodifferentiation?

Answer 13

Spermiogenesis

Question 14

What Shape are Spermatids?

Answer 14

Round

Question 15

What occurs in the process of Cytodifferentiation/Spermiogenesis?

Answer 15

The transformation and shape changing of round spermatids into spermatozoa (sperm)

Question 16

What is the Primary Function of a Sperm Cell?

Answer 16

To swim through the female reproductive tract to deliver genetic information to the Oocyte

Question 17

What are the 3 Parts of a sperm cell?

Answer 17

The head, midpiece and tail

Question 18

What is in the Mid Piece of a Sperm Cell? Why?

Answer 18

Mitochondria to power the tail for swimming

Question 19

What does the Head of a Sperm Cell contain?

Answer 19

DNA

Question 20

What is the Head of the Sperm Cell covered with?

Answer 20

The Acrosome

Question 21

What is inside the Acrosome?

Answer 21

Enzymes which are required for egg penetration

Question 22

What happens to the Excess Cytoplasm in a Spermatid during Cytodifferentiation/Spermiogenesis?

Answer 22

It is “shed” into a structure called the residual body that is later phagocytosed by sertoli cells after the sperm leaves

Question 23

In Males, where does Luteinising Hormone (LH) act?

Answer 23

On the interstitial Leydig cells

Question 24

Upon being acted upon by Luteinising Hormone (LH), what Hormone do Leydig Cells produce?

Answer 24

Testosterone

Question 25

In **Males**, where does **Follicle Stimulating Hormone (FSH)** act?

Answer 25

Sertoli cells inside the seminiferous tubules

Question 26

Upon being acted upon by **Follicle Stimulating Hormone (FSH)** what do **Sertoli Cells Produce**?

Answer 26

Androgen Binding Protein and Inhibin

Question 27

What does **Androgen Binding Protein** do?

Answer 27

It binds to testosterone and allows it to be transported around the body through the bloodstream or to trap testosterone within the seminiferous tubules to help support sperm production

Question 28

What happens to **Sperm Production** in the absence of **Testosterone**?

Answer 28

Spermatogonia will not be able to undergo the last phase of Cytodifferentiation/Spermiogenesis to produce spermatozoa

Question 29

As **Testosterone** levels increase, what happens to **Gonadotrophin Releasing Hormone (GnRH)**, **Follicle Stimulating Hormone (FSH)** and **Luteinising Hormone (LH)** production?

Answer 29

They decrease as they recieve the negative feedback

Question 30

What does **Inhibin** do?

Answer 30

Provide negative feedback to Follicle Stimulating Hormone (FSH) production

Question 31

What is a typical **Sperm Count**?

Answer 31

Around 20 million sperm/ml of ejaculate

Question 32

What is **Oligospermia**?

Answer 32

A sperm count lower than 20 million sperm/ml of ejaculate

Question 33

What is **Azoospermia**?

Answer 33

When there is no sperm in ejaculate

Question 34

What does it mean if **Sperm Cells** are **Immotile**?

Answer 34

They can't swim

Question 35

What is a **Treatment** for **Oligospermia**?

Answer 35

IVF (In Vitro Fertilisation), when approximately 50,000 sperm are placed in droplets with an Oocyte

Question 36

What is a treatment for **Azoospermia** and **Immotile Sperm**?

Answer 36

ICSI (IntraCytoplasmic Sperm Injection), in which a sperm is injected directly into an Oocyte. The sperm can be collected directly from a biopsy of the testes

Question 37

Identify the **Spermatogonium**

Answer 37

Question 38

Identify **Primary Spermatocytes**

Answer 38

Question 39

Identify **Secondary Spermatocytes**

Answer 39

Question 40

Identify the **Spermatids**

Answer 40

Question 41

Identify the **Sperm Cells**

Answer 41

Question 42

Identify the **Sertoli Cells**

Answer 42

Question 43

Identify the **Leydig Cells**

Answer 43

Question 44

Identify the **Mid Piece** and **Mitochondria**

Answer 44

Question 45

Identify the **Nucleus**

Answer 45

Question 46

Identify the **Acrosome**

Answer 46

Question 47

What is **Cryptorchidism**?

Answer 47

When the testes don't descend into the scrotum before birth

Question 48

Are **Cryptorchid** individuals **Fertile**?

Answer 48

No

Question 49

How many **Seminiferous Tubules** are in each **Testis**?

Answer 49

Approximately 80 in each testis

Question 50

From the **Seminiferous Tubules**, what is the next area **Sperm Cells** move into?

Answer 50

The Rete Testis

Question 51

From the **Rete Testis**, where do **Sperm Cells** move to?

Answer 51

The Epididymis

Question 52

How long do **Sperm Cells** spend in the **Epididymis**?

Answer 52

Around 10-14 days

Question 53

From the **Epididymis**, where do **Sperm Cells** move to?

Answer 53

The vas deferens

Question 54

What happens to **Sperm** **Cells** in the **Epididymis**?

Answer 54

They acquire the ability to swim and fertilize

Question 55

What does the **Epididymis** do to the liquid around the **Sperm Cells**?

Answer 55

Reabsorbs it to concentrate the sperm

Question 56

How long can **Sperm** stay in the **Vas Deferens**?

Answer 56

Several months

Question 57

How long is the **Vas Deferens**?

Answer 57

Approximately 45cm long

Question 58

Where does the **Vas Deferens** lead to from the **Epididymis**?

Answer 58

The ejaculatory duct

Question 59

Where do the **Seminal Vesicles** empty into?

Answer 59

The ejaculatory duct

Question 60

Where does the **Ejaculatory Duct** join the **Urethra**?

Answer 60

At the prostate

Question 61

What does the **Ampulla** of the **Vas Deferens** allow for?

Answer 61

It allows for a greater capacity for sperm storage

Question 62

What are the **Characteristics** of the **Seminal Vesicle Secretions**?

Answer 62

1. Mucoid (sticky) 2. Alkaline 3. Contains Fructose 4. Contains Prostaglandins 5. Contains Clotting Proteins

Question 63

What is the **Purpose** of the **Fructose** in the **Seminal Gland Secretion**?

Answer 63

To provide energy to the sperm as it swims through the female reproductive tract

Question 64

What is one of the **Hypothetical Purposes** of the **Prostaglandins** in the **Seminal Gland Secretion**?

Answer 64

To cause contractions within the female reproductive tract to assist the movement of sperm towards the fallopian tubes

Question 65

What is the **Purpose** of the **Clotting Proteins** in the **Seminal Vesicle** secretion?

Answer 65

To create a plug that stops sperm from leaving the female reproductive system

Question 66

Is the **Seminal Vesicle** secretion ejected into the **Ejaculatory Duct** before or after **Sperm Cells**?

Answer 66

After, as it washes the sperm down the ejaculatory duct

Question 67

What **Shape** is the **Prostate Gland**?

Answer 67

A donut shape the size of a golf ball

Question 68

Is **Prostatic Fluid** secreted behind or ahead of **Sperm Cells** during **Ejaculation**?

Answer 68

Ahead

Question 69

Does the **Urethra** pass under, over or through the **Prostate Gland**?

Answer 69

Through

Question 70

What are the **Characteristics** of the **Prostatic Fluid**?

Answer 70

1. It is slightly acidic (pH 6.5) 2. Contains citrate 3. It is milky in colour 4. Contains phosphate and calcium 5. Contains Prostate Specific Antigen (PSA) and other enzymes

Question 71

What is the **Purpose** of the **Citrate** in the **Prostatic Fluid**?

Answer 71

To provide materials for ATP production in the Sperm Cells

Question 72

Why is **Prostatic Fluid** a milky colour?

Answer 72

Because it contains phosphate and calcium

Question 73

What is the **Purpose** of the **Prostatic Specific Antigen (PSA)** and other enzymes in the **Prostatic Fluid**?

Answer 73

To break down the coagulum formed by the seminal vesicle secretion after 10-15 minutes

Question 74

When the **Prostatic Fluid** and **Seminal Vesicle Secretion** interact, the different pH levels do what?

Answer 74

Neutralise each other

Question 75

What is the **Composition** of **Semen**?

Answer 75

1. Sperm (10%) 2. Seminal Vesicle Fluid (60%) 3. Prostatic Fluid (30%) 4. Other Secretions (Small Amounts)

Question 76

What is the pH of **Semen**?

Answer 76

Approximately 7.5

Question 77

Why is the pH of **Semen** 7.5?

Answer 77

To provide a survivable environment for sperm cells, as if they were directly exposed to the vaginal environment (pH approx 4.5) they would quickly die

Question 78

What is the average **Ejaculatory Volume**?

Answer 78

2-5ml

Question 79

What is **Benign Prostatic Hyperplasia**?

Answer 79

Excessive growth of the prostate

Question 80

What is a **Common Symptom** of **Benign Prostatic Hyperplasia**?

Answer 80

Difficulty voiding the bladder

Question 81

What can **Benign Prostatic Hyperplasia** cause?

Answer 81

Weakening of the bladder and urinary tract and kidney infections

Question 82

What is the **Incidence** of **Benign Prostatic Hyperplasia** across different age groups?

Answer 82

\<40: Rare 50-59: 17% 60-69: 27% 70-79: 35% \>85: 90%

Question 83

What are some **Treatments** for **Benign Prostatic Hyperplasia**?

Answer 83

1. Surgery 2. Specific 5 α-reductase inhibitors

Question 84

What do **5** **α-Reductase Inhibitors** do?

Answer 84

Stop the prostate enlarging or shrink it

Question 85

What are **2 Different** **5 α-Reductase Inhibitors**? What are their **Half Lives**?

Answer 85

Finasteride: 5-7 hours Duasteride: 5 Weeks

Question 86

How do **5 α-Reductase Inhibitors** work?

Answer 86

They prevent 5 α-Reductase from converting Testosterone into the twice as potent 5 α Dihydrotestosterone. The prostate grows at a slower/lesser rate when acted on by Testosterone than 5 α Dihydrotestosterone

Question 87

**Prostate Cancer** can typically be **Detected** through elevated levels of what in the bloodstream?

Answer 87

Prostate Specific Antigen

Question 88

What are the **3 Main Structures** present in the **Penis**?

Answer 88

1. Corpora Cavernosa (x2) 2. Corpus Spongiosum 3. Penile Urethra

Question 89

**Sexual Stimulation** in a **Male** results in the release of what?

Answer 89

Nitric oxide and prostaglandin E1

Question 90

What do **Nitric Oxide** and **Prostaglandin E1** cause?

Answer 90

The relaxation of smooth muscle in the Corpora Cavernosa, resulting in blood filling the Corpora Cavernosa (up to 8x more than usual)

Question 91

What is the function of the **Corpus Spongiosum?**

Answer 91

To prevent the obstruction of the urethra during an erection

Question 92

For the **Smooth Muscles** in the **Corpora Cavernosa** to relax, and to thus achieve an erection, ___ is needed. ___ breaks this down

Answer 92

For the **Smooth Muscles** in the **Corpora Cavernosa** ​to relax, **Guanosine Monophosphate** **(cGMP)** is needed. **Phosphodiesterase** breaks this down

Question 93

How does **Viagra** work?

Answer 93

It inhibits phosphodiesterase, increasing cGMP levels and allowing for smooth muscle relaxation within the corpora cavernosa and thus allowing for an erection to occur