Ch. 42 Structure and Function of the Male Genitourinary System-1

Q: Where are the testes located?

A: Outside the abdominal cavity in the scrotum.

Note: They hang in a little skin pouch outside your body so they stay cool.

Q: What contributes to the majority of testicular volume?

A: Cells involved in spermatogenesis.

Note: Most of the testicle is filled with cells that make sperm.

Q: What is the tough, fibrous outer sheath protecting the testes?

A: Tunica albuginea.

Note: It ’s like a strong protective wrapper around the testicle.

Q: What double-layered membrane contains the testes?

A: Tunica vaginalis.

Note: It ’s like a double-layered blanket around the testicle.

Q: What arteries supply blood to the testes?

A: Testicular arteries that branch from the abdominal aorta.

Note: These are tubes that bring fresh blood straight from the big body artery.

Q: What veins drain the testes?

A: Testicular veins, which arise from the pampiniform plexus.

Note: These tubes take used blood away and help keep the testes cool.

Q: When and where does the first stage of testicular descent occur?

A: Between the 7th and 12th weeks of gestation into the inguinal region.

Note: Baby testicles start moving down early in pregnancy.

Q: When and where does the second stage of testicular descent occur?

A: Occurs in the 26th week of gestation into the scrotum.

Note: Later in pregnancy, they move into the scrotum.

Q: What is the condition where the testes fail to descend?

A: Cryptorchidism.

Note: This means the testicles never came down like they should.

Q: What risk is associated with failure of inguinal canal closure?

A: Increased risk of an inguinal hernia.

Note: A hole stays open, and stuff from the belly can poke through.

Q: What is the optimal temperature for sperm production?

A: $2\degree C$ to $3\degree C$ below body temperature.

Note: Sperm are made best when things are a little cooler.

Q: What is the effect of prolonged exposure to elevated temperatures?

A: May impair spermatogenesis.

Note: If the testicles get too warm for too long, sperm-making gets worse.

Q: What structure absorbs heat from arterial blood entering the testes?

A: The pampiniform plexus.

Note: It works like a cooling system for testicle blood.

Q: Which skeletal muscle elevates the testes when cold?

A: Cremaster muscle.

Note: This muscle pulls the testicles up to warm them.

Q: What smooth muscle under the scrotal skin responds to temperature?

A: Dartos muscle.

Note: This muscle tightens the scrotum when cold.

Q: What does the dartos muscle do when cold?

A: Contracts, reducing surface area and decreasing heat loss.

Note: It scrunches the skin so less heat escapes.

Q: Where does sperm production occur?

A: Seminiferous tubules.

Note: These are tiny tubes inside the testicles that make sperm.

Q: Structures the seminiferous tubules lead into?

A: Rete testis.

Note: Multiple interconnecting channels that carry sperm from the seminiferous tubules to the epididymis.

Q: What cells line the seminiferous tubules?

A: Sertoli cells, which secrete hormones required for spermatogenesis.

Note: These cells act like helpers and protectors for growing sperm.

Q: How long does spermatogenesis and maturation take?

A: Approximately 90 days.

Note: It takes about three months to make a mature sperm.

Q: What is the final site for sperm maturation and gain of motility?

A: Epididymis.

Note: This is where sperm learn to swim.

Q: Where is most sperm stored?

A: Ampulla of the vas deferens.

Note: It ’s like a storage closet for sperm.

Q: Storage of sperm until ejaculation?

A: Ductus deferens (vas deferens).

Note: This tube transports sperm from the epididymis to the urethra during ejaculation.

Q: What is the sperm production rate?

A: Up to 300 million sperm cells per day.

Note: The body makes LOTS of sperm every day.

Q: What is sperm lifespan in the female genital tract?

A: Only 1 to 2 days.

Note: Sperm don't live very long once inside the female body.

Q: What is the main function of sperm?

A: To reach the ovum and fuse with it to deliver its 23 chromosomes.

Note: Sperm bring half the baby ’s genetic instructions.

Q: What part of the sperm head contains enzymes for ovum penetration?

A: Acrosome.

Note: It ’s like a little “door opener” for the egg.

Q: What component supplies energy for sperm movement?

A: Mitochondria.

Note: These are the power batteries that help sperm swim.

Q: What procedure surgically disconnects the vas deferens?

A: Vasectomy.

Note: A surgery that blocks the path sperm travel.

Q: What are the three male accessory organs?

A: Seminal vesicles, prostate gland, and bulbourethral glands.

Note: These are helpers that make the fluids sperm swim in.

Q: What structure is formed by the junction of the seminal vesicle and vas deferens?

A: Ejaculatory duct.

Note: This is the hallway where sperm and fluid mix.

Q: What component in seminal fluid provides energy for sperm motility?

A: Fructose.

Note: It ’s sugar that gives sperm energy.

Q: What components in seminal fluid assist fertilization and cause uterine contractions?

A: Prostaglandins.

Note: These chemicals help sperm move inside the female body.

Q: What organ is located inferior to the bladder?

A: Prostate gland.

Note: The prostate sits right under the bladder.

Q: Why are prostatic secretions important?

A: Neutralizes the acidic environment of the vas deferens and the vagina, which is essential for fertilization.

Note: The prostate makes fluid that protects sperm from acidic environments.

Q: Secretions produced by the prostate gland?

A: Alkaline fluid containing citric acid, calcium, acid phosphate, a clotting enzyme, and profibrinolysin.

Note: Protects sperm and helps them survive in the acidic environment of the vagina.

Q: What secretion neutralizes acids from urine in the urethra?

A: Alkaline mucus from the bulbourethral (Cowper) glands.

Note: This mucus cleans and protects the pathway before sperm travel.

Q: What is the tip of the penis called?

A: Glans.

Note: It ’s the rounded end of the penis.

Q: What loose skin covers the glans?

A: Prepuce.

Note: This is the soft skin flap on top.

Q: What is the removal of the foreskin called?

A: Circumcision.

Note: It means cutting off the foreskin.

Q: What are the two lateral masses of erectile tissue?

A: Corpora cavernosa.

Note: These are two spongy tubes that fill with blood.

Q: What is the ventral mass of erectile tissue?

A: Corpus spongiosum.

Note: This soft tube keeps the urethra open during an erection.

Q: What is the most abundant androgen and main testicular hormone?

A: Testosterone.

Note: It ’s the main male hormone.

Q: What cells secrete testosterone?

A: Leydig cells.

Note: These cells make testosterone inside the testicles.

Q: What hypothalamic hormone regulates gonadotropic hormones?

A: GnRH.

Note: It ’s the brain ’s hormone boss that starts the process.

Q: What anterior pituitary hormone regulates testosterone production?

A: LH.

Note: This hormone tells the testicles to make testosterone.

Q: What anterior pituitary hormone helps initiate spermatogenesis?

A: FSH.

Note: This hormone helps start sperm-making.

Q: What is the role of testosterone in development?

A: Essential to the development and maintenance of primary and secondary male sex characteristics.

Note: It makes boys grow into men and keeps male traits.

Q: What is the definition of hypogonadism?

A: Reduced function of the gonads.

Note: It means the testicles aren ’t working well.

Q: What conditions cause Primary Hypogonadism?

A: Mumps and Klinefelter syndrome.

Note: Certain illnesses or genetic issues can hurt testicles.

Q: What hormonal results indicate Primary Hypogonadism?

A: High LH and FSH.

Note: The brain shouts “work harder,” but the testicles can ’t.

Q: What causes Secondary Hypogonadism?

A: Lack of secretion of LH and FSH from the anterior pituitary.

Note: The brain isn ’t sending the “make hormones” message.

Q: Condition caused by decreased/absent GnRH secretion from the hypothalamus?

A: Tertiary Hypogonadism.

Note: The hypothalamus fails to signal the pituitary to release LH and FSH.

Q: Hormonal results indicating secondary or tertiary hypogonadism?

A: Low or normal LH and FSH.

Note: The pituitary isn ’t getting the correct signals to produce gonadotropins.

Q: What are adult manifestations of hypogonadism?

A: Fatigue, depression, decreased libido, erectile dysfunction, loss of secondary sex characteristics, and decreased bone density or osteoporosis.

Note: Adults can feel tired, sad, weak, and lose male features.

Q: What is the treatment for hypogonadism?

A: Testosterone therapy.

Note: Doctors give extra testosterone to help.

Q: When do testosterone levels typically begin to decrease?

A: $25-30$ years of age in healthy, nonobese males.

Note: Men ’s hormones start slowly dropping after their mid-20s.

Q: How does aging affect seminal fluid?

A: Reduced volume and viscosity, leading to a decrease in the force of ejaculation.

Note: Older men make less semen, so it shoots out less strongly.

Q: What age-related changes occur in the testes?

A: Become smaller and lose their firmness.

Note: Testicles shrink and get softer with age.

Q: Age-related change in the prostate?

A: The prostate gland enlarges.

Note: Common with aging, can contribute to urinary symptoms.

Q: What is the definition of Erectile Dysfunction (ED)?

A: Persistent inability to achieve and maintain an erection sufficient for satisfactory sexual intercourse.

Note: It means a man can ’t get or keep an erection.

Q: What is the major etiologic factor for ED?

A: Aging.

Note: Getting older is the biggest reason it happens.

Q: What conditions are common in older males with ED?

A: Type II diabetes mellitus, cardiovascular disease, and hyperlipidemia.

Note: These health issues can make blood flow worse, causing ED.

Q: What conditions predict cardiac disease?

A: Hypogonadism, erectile dysfunction, and type II diabetes mellitus.

Note: These are warning signs of future heart trouble.

Q: Risk associated with low testosterone levels?

A: Increases risk of cardiovascular disease.

Note: Hormonal decline can impact heart and vessel health.