Male -Female Reproduction

When does the reproductive system become fully active?

It becomes fully active at puberty.

What is one main task shared by male and female reproductive systems?

To form specialized cells for sexual reproduction called gametes.

What are gametes?

Specialized reproductive (sex) cells used in sexual reproduction.

What are male gametes called?

Sperm.

What are female gametes called?

Ova (eggs).

What is the purpose of sexual intercourse in reproduction?

To bring male and female gametes together.

What is fertilization?

The process of combining genetic information from gametes.

When is a zygote formed?

When a sperm and egg fuse.

What is a zygote?

The first cell of a new individual.

What do all body cells come from?

The zygote.

What role does the female reproductive system play after fertilization?

It supports development of the fetus (gestation) and birth (parturition).

What are homologous reproductive structures?

Structures in males and females that share a common developmental origin.

What are the primary sex organs (gonads)?

Testes in males and ovaries in females.

What are the two main functions of gonads?

Producing gametes and secreting sex hormones.

What are the main sex hormones in males?

Testosterone.

What are the main sex hormones in females?

Estrogens and progesterone.

What roles do sex hormones play in the body?

Development and function of reproductive organs, other tissues, sexual behavior, and sex drive.

What is GnRH and where is it released from?

Gonadotropin-releasing hormone, released from the hypothalamus;

What does GnRH do?

Stimulates the anterior pituitary

What does FSH stand for and what does it target?

Follicle-stimulating hormone; it targets the gonads.

What is the function of FSH in males?

Stimulates sperm production.

What is the function of FSH in females?

Stimulates ovum development and estrogen production.

What does LH stand for and what does it target?

Luteinizing hormone; it targets the gonads.

What is the function of LH in males?

Stimulates testosterone production.

What is the function of LH in females?

Triggers ovulation and stimulates estrogen and progesterone production.

What is puberty?

The period when reproductive organs grow to adult size and become functional.

How do low sex hormone levels affect GnRH before puberty?

They suppress the secretion of GnRH from the hypothalamus.

What happens to the hypothalamus as puberty approaches?

It becomes less sensitive to inhibition by sex hormones.

What is the result of decreased sensitivity of the hypothalamus?

Increased GnRH release, which helps trigger puberty.

What are the testes?

Sperm-producing gonads located within the scrotum.

What is the first duct sperm passes through after being produced?

Epididymis.

What is the function of the ductus (vas) deferens?

It transports sperm from the epididymis

What duct carries sperm toward the urethra before ejaculation?

Ejaculatory duct.

What is the final passageway for sperm to exit the body?

Urethra.

What are accessory sex glands?

Glands that produce fluids that support and nourish sperm.

Name the three accessory sex glands in males.

Seminal glands, prostate gland, and bulbo-urethral glands.

What is the scrotum and what is its function?

A sac of skin that contains the testes and regulates their temperature for sperm production.

Why must the testes be cooler than body temperature?

Sperm production requires a temperature about 3°C lower than core body temperature.

How does the body respond to cold temperatures in the scrotum?

The testes are pulled closer to the body to maintain warmth.

What is the function of the dartos muscle?

It is a layer of smooth muscle in superficial fascia that helps regulate scrotal temperature by wrinkling the skin.

What is the function of the cremaster muscles?

Bands of skeletal muscle that elevate the testes closer to the body.

What is the spermatic cord?

A structure that contains the vas deferens, nerves fibers, blood vessels, and lymphatics supplying the testes.

What structures are found within each testicular lobule?

Seminiferous tubules.

What is the function of seminiferous tubules?

They are the site of sperm production.

Where does sperm go after being produced in the seminiferous tubules?

To the epididymis.

Where are sperm stored until ejaculation?

In the tail of the epididymis.

What age group is most commonly affected by testicular cancer?

Men ages 15–35.

What is the most common risk factor for testicular cancer?

Cryptorchidism (undescended testes).

What is a possible complication of mumps related to the testes?

Orchitis (inflammation of the testis), which may increase cancer risk.

What is a common sign of testicular cancer?

A painless, solid mass in the testis.

How is testicular cancer typically treated and what is the prognosis?

Surgical removal of the testis, often with radiation or chemotherapy; about 90% cure rate.

What is the main function of the epididymis?

Sperm maturation, storage, and gaining motility (ability to swim).

How long does sperm maturation take in the epididymis?

About 20 days.

What happens during ejaculation in relation to the epididymis?

It contracts to push sperm into the ductus deferens.

What is the function of the vas (ductus) deferens?

Transports sperm from the epididymis to the urethra.

How does the vas deferens move sperm?

Through smooth muscle contraction

Where does the vas deferens lead and what does it form?

It joins the seminal vesicle duct to form the ejaculatory duct in the prostate.

What is a vasectomy?

A surgical procedure that cuts and seals the vas deferens to prevent sperm from entering semen.

How effective is a vasectomy as birth control?

Nearly 100% effective.

What is the function of the seminal vesicles?

Produce seminal fluid that nourishes and supports sperm.

What substances are found in seminal vesicle fluid?

Fructose, citric acid, and prostaglandins.

What percentage of semen is produced by the seminal vesicles?

About 60%.

What happens to the seminal vesicles during ejaculation?

Smooth muscle contracts to release fluid.

How is the ejaculatory duct formed?

By the joining of the seminal vesicle duct and the vas deferens.

Where is the prostate gland located?

Around the urethra, just below the bladder.

What type of fluid does the prostate gland secrete?

A milky, slightly acidic fluid.

What is the function of prostate fluid?

Activates sperm, provides nutrition, and helps semen become more fluid.

What does Prostate-specific antigen do?

It thins semen to help sperm move.

How much of semen volume comes from the prostate gland?

About one-third; 30%

What is benign prostatic hyperplasia (BPH)

A noncancerous enlargement of the prostate that constricts the urethra.

How does benign prostatic hyperplasia affect urination?

Causes difficulty urinating and incomplete bladder emptying (urinary retention).

What complications can result from benign prostatic hyperplasia ?

Urinary tract infections and kidney damage.

How is benign prostatic hyperplasia treated

Medications to relax smooth muscle/reduce growth or surgery

What is prostate cancer’s significance in men?

It is a leading cause of cancer death, affecting about 1 in 6 men in the U.S.

When does prostate cancer typically begin to develop

Around age 40 (earlier with family history)

How is prostate cancer treated?

Radiation therapy and sometimes surgery.

Bulbourethral glands location?

Pea-sized glands below (inferior to) the prostate

What is the function of the bulbourethral glands?

Produce mucus for lubrication and protection

What is the role of pre-ejaculate?

Lubricates the glans penis

How do bulbourethral glands protect sperm?

They neutralize acidic urine in the urethra.; sperm hates acid

Why is neutralizing acid important for sperm?

Sperm are sensitive to acidic environments

How much of semen volume comes from bulbourethral glands?

About 10%

What is the function of the urethra in males?

Carries both urine and semen

What are the three parts of the male urethra?

Prostatic, membranous, spongy

Prostatic urethra location?

Surrounded by the prostate

Membranous urethra location?

In the urogenital diaphragm

Spongy urethra location?

Runs through the shaft penis

Where does the urethra open?

External urethral orifice

What is the penis?

Male copulatory organ

Main parts of the penis?

Root, shaft, and glans

What is the prepuce?

Foreskin covering the glans

What is circumcision?

Surgical removal of foreskin

Health effects of circumcision?

Decreases HIV risk (~60%) and some infections

What is erectile tissue?

Tissue that fills with blood to cause erection; found in both men and females

What are the erectile tissues of the penis?

Corpora cavernosa (paired, dorsal) and corpus spongiosum (around urethra)

Corpora cavernosa

paired dorsal erectile bodies

Corpus spongiosum

surrounds urethra (inferior)

What is an erection of male and what happens during it?

It is the enlargement and stiffening of the penis. Erectile tissue fills with blood, making the penis enlarged and rigid.

What is the male perineum?

Diamond-shaped region between pubic symphysis, coccyx, and ischial tuberosities

What is semen?

Milky-white mixture of sperm and accessory gland secretions