Male Reproductive System

Flashcards covering the anatomy, physiology, and hormonal control of the male reproductive system based on lecture notes.

What are the two primary functions of the reproductive system?

It produces, nurtures, and transports ova and sperm, and it secretes hormones.

What are the primary reproductive organs, also known as gonads, responsible for?

They secrete hormones and produce gametes (ova and sperm).

What are the female gonads and the male gonads called?

The female gonads are the ovaries, and the male gonads are the testes.

What is the role of the secondary reproductive organs?

They nourish and transport eggs and sperm and provide a safe, nourishing environment for fertilized eggs.

What are the three main roles of the male reproductive system?

It produces, nourishes, and transports sperm, deposits sperm within the female reproductive tract, and secretes hormones.

What are the two main functions of the testes?

Production of sperm and secretion of the male hormone testosterone.

Where are the testes located and suspended?

They are located outside the abdominal cavity and suspended in a sac between the thighs called the scrotum.

What is the term for undescended testicles?

Cryptorchidism.

Why do the testes prefer a cooler temperature than body temperature?

Sperm cannot live at body temperature and prefer the cooler temperature found in the scrotum.

What are the smaller units that divide the testis?

Lobules.

What two structures does each testicular lobule contain and what are their functions?

Seminiferous tubules which form sperm, and interstitial cells (Leydig cells) which produce male hormones called androgens, like testosterone.

When does sperm production begin and how long does it continue?

Sperm production begins at puberty and continues throughout life.

What are the two types of cells found in the seminiferous tubules that are involved in sperm formation?

Spermatogenic cells (produce sperm) and supporting cells (sustentacular cells or Sertoli cells) which support, nourish, and regulate spermatogenic cells.

What is spermatogenesis?

The formation of sperm within the seminiferous tubules.

What are undifferentiated spermatogenic cells called?

Spermatogonia.

What is spermiogenesis?

The final stage of sperm development where each immature sperm cell develops a head and a tail.

Where do nonmotile sperm accumulate and begin to mature?

They accumulate in the lumen of the seminiferous tubules and then move to the epididymis.

What is the term for a mature sperm?

Spermatozoon.

How long does the process from spermatogonium to spermatozoon take?

About 70 hours.

What are the three parts of a mature sperm and their functions?

The head (contains genetic information and acrosome with enzymes for fertilization), the body (contains mitochondria for energy), and the tail (a flagellum for movement).

How long can sperm survive after being deposited in the female reproductive tract?

Most live only hours, but some can survive for up to 3 days.

What is the purpose of the genital ducts?

They are where sperm mature and are transported from the testes to outside the body.

Name the four main genital ducts in the male reproductive system.

Epididymides, vas (ductus) deferens, ejaculatory ducts, and urethra.

What is the epididymis and what happens there?

It is the first part of the duct system, a tightly coiled tube where sperm mature, becoming motile and fertile.

What does the vas deferens join with to form the ejaculatory duct?

It joins with the duct of the seminal vesicle.

Where do the two ejaculatory ducts pass through and join?

They pass through the prostate gland and join with the single urethra.

What is unique about the male urethra's function?

It serves both the reproductive and urinary systems, passing either urine or semen, but never both simultaneously.

What are the three accessory glands of the male reproductive system?

Seminal vesicles, prostate gland, and bulbourethral glands (Cowper's Glands).

Where are the seminal vesicles located and what do they secrete?

Located at the base of the bladder, they secrete a thick, yellowish material rich in fructose, vitamin C, and prostaglandins.

What is the function of the seminal vesicle secretions?

They nourish and activate the sperm as they pass through the ducts.

Where is the prostate gland located and what does it secrete?

It is a walnut-like gland located an upper part of the urethra just below the bladder, secreting a milky alkaline substance.

What is the function of the prostate gland's secretion?

It increases sperm motility and counteracts the acidic environment of the vagina, protecting the sperm.

What is retrograde ejaculation?

A condition where semen travels backward into the bladder, often caused by nerve or muscle damage.

What is prostatitis?

Inflammation or infection of the prostate gland, which can be caused by viruses, bacteria, autoimmune conditions, or nerve damage.

What is Benign Prostatic Hyperplasia (BPH)?

Enlargement of the prostate gland that is NOT cancerous.

What are the bulbourethral glands also known as and where are they located?

They are pea-shaped glands called Cowper's Glands, located beneath the prostate gland.

What do the bulbourethral glands secrete and what are its functions?

They secrete clear alkaline mucus (pre-ejaculate) that lubricates the urethra, neutralizes residual acidity from urine, and removes debris.

What is semen?

The mixture of sperm and the secretions of the accessory glands.

What percentage of semen comes from the seminal vesicles and the prostate gland?

60% from the seminal vesicles and 40% from the prostate gland.

What are the characteristics of semen regarding its appearance, pH, amount per ejaculation, and sperm count?

It is a milky white liquid with an alkaline pH, typically 2 to 6 mL per ejaculation, containing 200 to 600 million sperm.

What are the components of the male external genitals?

The scrotum and the penis.

What are the two functions of the penis?

It carries urine through the urethra and is the organ of sexual intercourse (copulation).

What are the main parts of the penis?

The glans penis (enlarged tip with erectile tissue), the urinary meatus (urethral opening), and the prepuce (foreskin).

What is smegma and where is it found?

A cheesy substance that accumulates under the prepuce from puberty, requiring daily hygiene.

What is phimosis and how can it be treated?

A condition where the prepuce (foreskin) is too tight and cannot be retracted, often treated by circumcision.

How does an erection occur?

Sexual stimulation causes parasympathetic nerves to fire, penile arteries to dilate, and erectile tissue to fill with blood, making the penis rigid.

What is erectile dysfunction (ED)?

The inability to achieve or maintain an erection.

What is orgasm?

The pleasurable sensations that occur at the height of sexual stimulation, accompanied by emission and ejaculation.

What is emission and what causes it?

The movement of sperm and glandular secretions from the testes and genital ducts into the proximal urethra to form semen, caused by sympathetic nervous system influence leading to rhythmic, peristalsis-type contractions.

What is ejaculation and what causes the penis to become flaccid afterward?

Ejaculation is the expulsion of semen from the urethra to the outside. After ejaculation, sympathetic nerve impulses constrict penile arteries and increase venous drainage, reducing blood flow and causing the penis to become flaccid.

What are the male sex hormones called, and which is the most important?

They are called androgens, with testosterone being the most important.

What are the primary sources of testosterone secretion?

The interstitial cells of the testes (Leydig cells) and a small amount from the adrenal cortex.

When does testosterone secretion significantly increase, and how long does it continue?

It increases at age 10-13 (puberty) and continues continuously throughout the life of the male.

What are the two main necessities for testosterone in males?

Sperm production and the development of male sex characteristics.

What are the primary male sex characteristics?

The enlargement and development of the testes and various accessory organs such as the penis.

What are the secondary male sex characteristics?

Increased hair growth (face, chest, axillary, pubic), deepening of the voice, thickening of skin with increased oil and sweat gland activity (acne, body odor), and increased musculoskeletal growth with development of the male physique (broad shoulders, narrow waist).

What three main organs primarily control the male reproductive system hormonally?

The hypothalamus, anterior pituitary gland, and testes.

How does the hypothalamus initiate hormonal control of male reproduction?

It secretes gonadotropin-releasing hormone (GnRH), which stimulates the anterior pituitary gland.

What are the two gonadotropins secreted by the anterior pituitary gland and their functions in males?

Follicle-stimulating hormone (FSH) stimulates spermatogenesis, and Luteinizing hormone (LH) promotes the development of interstitial cells of the testes and the secretion of testosterone.