Male Reproductive System Flashcards

Exam Reminders

• Lecture final includes a true or false section.
• Four choices for drawings; choose two.
• Four choices for short answer; choose two.
• Material covers urinary, digestive, reproductive systems, and embryonic development.

Male Reproductive System

Spermatic Cord

• A cord containing various structures, passing through the inguinal canal.
• Composed of:
  • Vas deferens: Tube transporting sperm from the epididymis to the ejaculatory ducts.
  • Cremaster muscle: Involved in thermal regulation of the testes.
  • Dartos muscle: Surrounds the testes, aiding thermal regulation.
  • Testicular arteries: Supplies blood to the testes.
  • Pampiniform plexus: A network of veins draining blood from the testes. Organized as a plexus to cool blood, preventing the testes from overheating.
  • Nerves and Lymphatic vessels: Travel through the spermatic cord and inguinal canal.

Thermal Regulation of Testes

• Testes need to be at 34 degrees Celsius for sperm production.
• Dartos and cremaster muscles are crucial for thermal regulation.

Undescended Testes (Cryptorchidism)

• Testes do not fully descend.
• If not corrected, male will be infertile due to high body temperature.
• Surgery can help testes descend and attach to the scrotum.

Inguinal Hernia

• Organs or membranes protrude through the inguinal canal.
• Small intestine or parietal peritoneum may peek through.
• Caused by increased abdominal pressure (e.g., lifting heavy objects, straining during defecation).
• Can occur during embryonic development if small intestine is dragged down with the testes.
• Requires surgery to fix.

Testicular Torsion

• Testes rotate, causing pain and blocking blood flow and sperm.
• Can happen spontaneously or due to rapid temperature changes (e.g., alternating between hot tub and swimming pool).
• Rapid changes in temperature cause the cremaster and dartos muscles to contract and relax rapidly, causing the testes to rotate.
• Requires immediate medical attention.
• Surgeons make an incision to rotate it back.

Varicocele

• Varicose veins in the pampiniform plexus.
• Blood pools, raising testes temperature, leading to infertility.
• Often occurs in men in their 20s-40s.
• Leading cause of infertility in men.

Testicular Cancer

• Common in men in their 20s.
• Treatment: Gonadectomy (removal of the testis) is required until medical technology improves.
• No specific testicular cancer awareness day; men are assumed to do self-exams regularly.
  *Self-examination: a cancerous lump feels like a frozen pea or peanut.

Epididymis

• Contains simple columnar epithelium with stereocilia.
• Functions include sperm storage, maturation, and nourishment.

Vas Deferens (Ductus Deferens)

• Muscular tube that transports sperm to the ejaculatory ducts via peristalsis.
• Loops around the urinary bladder.

Vasectomy

• Incision on the posterior scrotum, cutting and tying off the vas deferens.
• Prevents sperm from entering the ejaculatory ducts.
• Most common birth control method in the US.
• Reversible within a week; scar tissue makes reversal more difficult over time.
• Rarely, spontaneous reattachment can occur (one in a million chance).

Sperm Pathway

Male

• Seminiferous tubule (sperm production) → epididymis (maturation) → vas deferens → ejaculatory ducts → male urethra (prostatic, membranous, penile/spongy).

Female

• Vagina → cervix → uterus → fallopian tubes (fertilization site).

Male Urethra

• Prostatic urethra (in the prostate).
• Membranous urethra (through the external urethral sphincter).
• Penile or spongy urethra (through the penis).

Accessory Glands and Organs

• Seminal vesicles.
• Prostate gland.
• Bulbo-urethral glands. Secrete seminal fluids that mix with the sperm cells.

Seminal Fluids Functions

• Provide a fluid medium for sperm to swim in.
• Nourish sperm with fructose (sugar) for ATP production.
• Neutralize acidity in the male urethra and female vagina.

Bulbourethral Gland Added Function

• Secretes lubricating mucus for ejaculation.

Prostate Gland

• Contains the ejaculatory duct and prostatic urethra.
• Contracts during ejaculation to release fluids.
• Grows throughout life, potentially pinching the prosthetic urethra, causing urinary incontinence.
• Medications can help loosen the prostate.
• Prostate cancer is common due to continuous cell growth.
• Detection: rectal exam where the medical person inserts a digit to search for nodules.
• Often slow-growing; may be left untreated due to the prostate's vital functions.

Penis

• Capable of expanding to five to six times its original size.
• Parts include:
  • Roots: Located in the abdominal region.
  • Bulb: Underneath the bulbourethral gland.
  • Body/Shaft: Main region.
  • Glans: Head of the penis, covered by prepuce (foreskin).

Glans

• The male equivalent of female clitoris.
• Very sensitive and associated with orgasm, it is also covered in prepuce.

Circumcision

• Surgical removal of the foreskin.
• Most common surgical procedure in the United States.
• Reasons include cultural, religious, and perceived health benefits (no strong medical evidence).

Erectile Tissue

• Corpora cavernosa: Can be fully engorged with blood.
• Corpus spongiosum: Cannot fully engorge to avoid pinching the urethra.

Process:

• Vasodilation of arteries allows blood to enter erectile tissue.
• Fibrous connective tissues form compartments where blood accumulates.
• Venules constrict to maintain erection.

Viagra

• Originally a blood pressure medication that vasodilates arteries.
• Prolonged erection (over six hours) can cause blood clots and tissue damage.

Broken Penis

• The capsule of erectile tissue breaks.
• Caused by rigorous intercourse.

Review Questions and Concepts

• Cardiac Sphincter: Located between the stomach and esophagus.
• Proximal Convoluted Tubule (PCT): Secretes waste products into the nephron.
• Neonatal Jaundice:
  • Caused by the breakdown of fetal hemoglobin into bilirubin.
  • Newborns have a special kind of hemoglobin to have higher affinity than the mom's hemoglobin.
  • Excess bilirubin accumulation leads to jaundice because of liver immaturity.
• Urinary System (Blood Regulation):
  • Regulates water amount in blood to control blood pressure.
  • Kidneys produce erythropoietin (EPO), stimulating red blood cell production in response to low oxygen levels.
• Colorectal Cancer:
  • Polyps (growths inward toward the lumen) can become cancerous.
  • Colonoscopies detect and remove polyps.
  • Diverticula are pouches in the colon wall.
• Diverticulitis:
  • Inflammation of diverticula, potentially causing abdominal soreness.
• Glomerular Ultrafiltrate:
  • v Fluid that comes out from the glomerulus and enters inside of the nephron.
• Lithotripsy:
  • Uses ultrasound waves to break up kidney stones for easier passage.
• Gubernaculum:
  • Dense regular connective tissue attached to the testes; shortens during development, pulling the testes down. Is not some thing pulling at the other end, rather that the structure just gets shorter.
  • Pulls down part of the Parietal Peritoneum.
• Important Dates:
  • Histology quiz/Lecture Final: Twenty First.
  • Moral Data: The twenty Sixth.
  • Lab Practical at 10:10AM: The twenty Eighth.
• Office Hours:
  • If a student wants to talk about the grades do so a week before finals.