L20 Ch27 The Male Reproductive System

Flashcards covering the anatomy, physiology, and processes of the male reproductive system based on the Chapter 26 lecture transcript.

What are the four primary functions of the reproductive system?

Producing, storing, nourishing, and transporting gametes.

What is the term for the single cell formed by the union of a sperm and an oocyte?

A zygote.

In biological males, what are the primary reproductive organs (gonads)?

The testes.

Where are the epididymides located in relation to the testes?

They are located superiorly and posteriorly to the testes.

Why are the testes located in the scrotum outside the abdominal cavity?

Sperm development requires a specific temperature of approximately $96.6^{\circ}\text{F}$, which is slightly cooler than normal body temperature.

What is the name of the raised ridge that externally divides the scrotum into two chambers?

The raphe.

Which structures connect the abdominal cavity to the testes and enclose the ductus deferens, blood vessels, and nerves?

The spermatic cords.

What are the functional units of the testes where sperm are actually produced?

Seminiferous tubules.

What is the pathway of sperm from production through the testes until they exit?

Seminiferous tubules $\rightarrow$ straight tubules $\rightarrow$ rete testis $\rightarrow$ efferent ductules.

What are the stem cells for sperm called, and when do they begin the process of spermatogenesis?

Spermatogonia; they remain dormant until puberty.

What is the function of the interstitial cells (also known as Leydig cells)?

They are responsible for secreting male sex hormones, primarily testosterone.

What is the chemical nature of testosterone?

It is a lipid synthesized from a cholesterol (steroid) base, characterized by a ring structure of hydrocarbons.

During meiosis in the male, one diploid primary spermatocyte ultimately produces how many spermatids?

Four haploid ($n$) spermatids.

What is spermiogenesis?

The final stage of development where round haploid spermatids undergo physical maturation to transform into mature sperm cells with a head, midpiece, and tail.

What are the key functions of nurse cells (Sertoli cells)?

They provide nourishment, remove waste, secrete developmental factors, and maintain the blood-testis barrier.

Why is the blood-testis barrier necessary?

It isolates the seminiferous tubules from the general circulation to prevent the immune system from attacking developing sperm, which express "non-self" surface markers.

What is the function of the acrosome located in the head of a mature sperm?

It is a vesicle filled with enzymes crucial for penetrating the outer layers of the egg during fertilization.

Which part of the sperm contains mitochondria to provide ATP for movement?

The middle piece.

What are the three distinctive regions of the epididymis?

The head, the body, and the tail.

What is the anatomical path taken by the ductus deferens?

It begins at the tail of the epididymis, ascends through the inguinal canal into the abdominal cavity, curves around the urinary bladder, and joins the seminal gland duct.

Which accessory gland produces about $60\%$ of the semen volume, including fructose and prostaglandins?

The seminal glands (seminal vesicles).

What is the role of the prostatic fluid secreted by the prostate gland?

It accounts for $20-30\%$ of semen volume and contains enzymes that support sperm and prevent semen coagulation within the vagina.

What are the two main purposes of the alkaline mucus secreted by the bulbourethral (Cowper's) glands?

To neutralize residual urinary acids in the urethra and to lubricate the tip of the penis.

What is the typical volume and sperm concentration of a single ejaculation?

A volume of $2-5\,\text{mL}$ with a concentration of $20-100\,\text{million}$ sperm per milliliter.

What are the three cylindrical columns of erectile tissue in the shaft of the penis?

Two corpora cavernosa (posterior) and one corpus spongiosum (anterior, surrounding the urethra).

What is smegma and where is it produced?

A waxy, oily substance produced by preputial glands (Tyson glands) in the prepuce (foreskin) that moisturizes and lubricates the glans penis.

What is the "male climacteric" (andropause) and when does it typically occur?

A period of declining testosterone and reproductive efficiency that generally occurs between the ages of $50$ and $60$.