Lecture 3 – Male Reproduction and Fertilization

Name the ducts (in order) the sperm has to travel through from the seminiferous tubules to the epididymis.

Rete testis then efferent ductules

What is the function of the epididymis? What will happen if the sperm leaves the epididymis too soon?

Stores sperm until functionally mature; sperm leaving too soon cannot travel to the oocyte

From the epididymis, what is the ‘tube’ that carries the sperm to the ejaculatory duct? What gland also empties into the ejaculatory duct

 Ductus (vas) deferens; seminal vesicle

Name the three parts of the urethra in the order sperm would travel to leave the male body.

 Prostatic, membranous, spongy

Why must the scrotum maintain the testes at a slightly lower temp than body temp?

 Sperm require a temperature 2–3°C lower for proper development

What are the two muscles used to move the testes closer to or further away from the body?

    Dartos muscle and cremaster muscle

 

What is the name of the network of veins that surrounds the testicular artery? Why is it surrounding the testicular artery?

 Pampiniform plexus; cools arterial blood

1.    Match the description with the type of cell it is describing.
 A. Sustentacular cells B. Spermatogonia C. Interstitial cells
 Divides to produce sperm –
 Creates the blood-testis barrier –
 Produces testosterone –
 Can be found inside the seminiferous tubule –
 Can be found in the interstitial space around the seminiferous tubule –
 Produces androgen-binding protein (ABP) –
 Controls sperm count by releasing inhibin –

 Divides to produce sperm – B
 Creates the blood-testis barrier – A
 Produces testosterone – C
 Can be found inside the seminiferous tubule – A and B
 Can be found in the interstitial space around the seminiferous tubule – C
 Produces androgen-binding protein (ABP) – A
 Controls sperm count by releasing inhibin – A

What does rising levels of testosterone do to the release of GnRH, FSH and LH?

  Decreases them through negative feedback

 

Do spermatogonium divide through meiosis?

 No, they divide by mitosis

How many spermatids are made during one round of spermatogenesis?
 

Four

What is happening during spermiogenesis?

 Spermatids elongate, form acrosome and tail, and shed cytoplasm

What does the acrosome cap contain?

Digestive enzymes for the zona pellucida

After spermiogenesis is the sperm fully functional?

 No, it must mature in the epididymis

Match the seminal fluid component with the gland it is being secreted from.
 A. Seminal Vesicles B. Prostate gland C. Bulbourethral gland
 Fructose – A
 Citric acid – B
 Prostaglandins – A
 Mucin – C
 Seminal plasmin – B
 Alkaline fluid – A
 Prostate-specific antigen (PSA) – B

 Fructose – A
 Citric acid – B
 Prostaglandins – A
 Mucin – C
 Seminal plasmin – B
 Alkaline fluid – A
 Prostate-specific antigen (PSA) – B

What is the difference between semen and seminal fluid? How many sperm are typically found within each ejaculate?

 Semen is seminal fluid plus sperm; 200–500 million sperm

Which division of the ANS is responsible for the male erection? Which division is responsible for ejaculation?

 Parasympathetic for erection; sympathetic for ejaculation

How is male climacteric different than female menopause? How are they similar?

Male climacteric is gradual and men still make gametes; menopause is abrupt and stops gametes; both involve hormone decline and similar symptoms

Why is prostate enlargement a concern?

   It interferes with urinary and sexual function

Where in the female reproductive tract does fertilization usually take place? How long is an oocyte viable once it is released from the ovaries?

 Ampulla of the uterine tube; 24 hours

What is capacitation?

 Removal of sperm’s glycoprotein coat to enable fertilization

What causes the opening of calcium channels in the sperm’s plasma membrane?

 Progesterone from the oocyte

How does the sperm get past the corona radiata?

 Uses its flagellum to push through

How does the sperm get past the zona pellucida?

 Uses acrosomal enzymes to digest it

What part of the sperm enters the secondary oocyte

 The nucleus

What does the secondary oocyte have to do before it becomes an ovum?
 

Complete meiosis II

Once the two pronuclei of the sperm and ovum unite, what is formed?

 A zygote