Male Reproductive System

Write the correct answer for each question.

How is sperm cooled inside the testis?

There is a complex capillary network that cools down the testis. In order for sperm to be healthy, the temperature must be lower than the body's core temperature for optimal production and maturation (35ºC).

What are the main organs in the male reproductive system?

The main organs in the male reproductive system include the testes, epididymis, vas deferens, seminal vesicles, one prostate gland, two semi-uretha gland, two seminiferous tubules and penis.

How long does sperm production take?

It takes a few months from the pregential to eventual sperm to be produced. However, lots get made everyday on average of 200 million.

How does sperm get made?

Spermatogonia (precursors of the sperm)→outside the corners of the seminiferous tubules→inwards to the lumen→later development of the sperm.

True or False: Are the capillaries within the seminiferous tubules?

False; capillaries surround the seminiferous tubules, not within them.

What do sertoli cells do?

Sertoli cells support and nourish developing sperm cells, help regulate spermatogenesis.

What do leydig cells do?

Leydig cells produce testosterone and other hormones, playing a crucial role in male fertility and development.

Why might sperm look foreign to immune cells?

Sperm may look foreign because they express surface proteins that are different from those found on the body's own cells, triggering an immune response.

How do the sertoli cells prevent the immune system to damage foreign looking sperm?

Sertoli cells create a blood-testis barrier, isolating sperm from the immune system (because the immune cells are circulating within the bloodstream) and preventing immune cell access, thus shielding sperm from potential damage.

How do the sertoli cells help nourish the sperm?

They absorb any nutrients that the developing sperm will need, and it filter any waste products that need to be excreted through circulation.

How does spermatogonia go through meiosis?

After spermatogonia creates more diploids through mitosis, it takes one of those cells and continue on with meiosis→the one cell will have their gap junctions closed, generating that blood-testis barrier→it will become a primary sematocyte→ undergoes two meiotic divisions to ultimately form four haploid spermatids at the end of meiosis 2→ spermatids will undergo spermeogenesis→ they will differentiate to look like sperm→pinch off the cytoplasm to create a tail→sperm pinched out of the lumen.

Once the cytoplasm is gone, why is the tip of the head structure important.

The tip of the head structure of the sperm is important for fertilizing the egg.

What are the mitochondria in the tail useful for?

The mitochondria in the tail of the sperm provide the energy required for motility, allowing the sperm to swim and reach the egg for fertilization.

What secretions do sperm need to pick up?

Sperm need to pick up secretions from seminal vesicles, vas deferens, prostate gland, and bulbourethral glands, which help in nourishing and facilitating their motility when they reach outside of the body. These exocrine glands help deliver sperm to the female reproductive tract.

True or false: Is semen made up of 1% of sperm?

True

True or False: Is 99% of semen are those other secretions from the accessory glands?

True, 99% of semen consists of fluids and secretions from the accessory glands such as the seminal vesicles and prostate gland.

What makes up semen?

Mucus, nutrients, enzymes, prostaglandins and fluids. They use muscle contraction to propel contents along.

Whyis it important for bublourethal glands to create alkoline secretions to neutralize the acid.

The urethra is connected to the urinary system, and urine can be very acidic. The semen would need to neutralize the pH to make it easier for the sperm to adapt.

What happens if you have too much testosterone produced in the testis?

You are going to have negative regulation of GNRH, inhibin (regulated by FSH), FSH and LH levels.

Describe testosterone secretion throughout life.

Testosterone levels spike high before a male baby is born, it decreases during early childhood, it spikes up again during puberty, and it remains high throughout adulthood. Testosterone levels tend to decline with age a bit.

Describe genital growth in males.

In fetal development, males have genital growth, it stays consistent until puberty. In puberty, the majority amount of testicles are taken up by germ cells, instead of sertoli cells.

What is primary hypogrenadism?

A condition characterized by insufficient testosterone production due to problems with the testes, resulting in delayed or incomplete puberty and infertility.

What is secondary hypogrenadism?

Is when there is damage at the gonads or problems with the hypothalamus or pituitary gland, leading to low testosterone levels and often normal or low sperm production.

If there is no negative regulation upstream, the hypothalamus and the GNRH are…..

increasing FSH and LH to try and compensate for low testosterone levels.

What is DHT?

Dihydrotestosterone, a function for male baldness, prostate development and the male genitalia which are all derived from testosterone.

If the alpha-reductase is blocked, what would happen if there is no DHT produced?

Accumulation of DHT in the prostate can be blocked→not that many growth in the prostate tissue→increases hair growth for those who are bald.

Are there any other side effects from blocking alpha-reductase?

Yes, depression, mood swings, sexual dysfunction, and fatigue. 

What happens if athletes take too much steroids?

Male aggression and too much muscle mass.