Lecture Notes: Penis | Description, Anatomy, & Physiology

Introduction

• The penis is the copulatory organ in male higher vertebrates, serving as a channel for urine in mammals.
• Corresponds to the cirrus in lower invertebrates.

Anatomy of the Human Penis

• Structure:
  • Divided into two main areas: the body (external portion) and the root.
  • The root begins below the bulbourethral glands.
  • Corpus Spongiosum:
    • A long cylindrical body of tissue extending through the penis to the glans.
    • Contains the urethra, which carries both semen and urine.
  • Corpora Cavernosa:
    • Two cylindrical bodies running alongside the bulbourethral glands.
    • Occupy the sides and upper portion above the corpus spongiosum.
• Glans Penis:
  • The expanded tip of the corpus spongiosum.
  • Urethra ends in a slitlike opening at the tip.
• Foreskin:
  • A circular fold of skin covering the glans.
  • Can be removed via circumcision.

Physiology

• Erectile Tissue:
  • Made of muscle, collagen, and elastic fiber.
  • Blood flow into corpora cavernosa leads to erection by trapping blood.
  • Corpus spongiosum has constant blood flow, enlarges less during erection.

Common Conditions and Anomalies

• Developmental Abnormalities:
  • Rare conditions like absence, torsion, or duplication of the penis.
  • Size anomalies linked to hormonal imbalances or disorders.
• Infections and Diseases:
  • Balanitis (inflammation of the glans) and posthitis (infection of the foreskin) can result from poor hygiene.
  • Tumors usually affect the foreskin or glans, with cancer being rare in circumcised men.

Safe Sex

• Practices:
  • Reduces risk of sexually transmitted diseases (STDs), especially AIDS.
  • Includes condom use, abstinence, and monogamy.

Additional Resources

• External Resources:
  • Links to additional information from various medical and health sites, including WebMD, Medscape, and Healthline.

These notes cover the essential aspects of the penis, its anatomy, physiology, common conditions, and safe sexual practices as outlined in the Britannica article. Use these as a quick reference for study and review.