MEDICAL BIOLOGY, ANATOMY, HUMAN PHYSIOLOGY AND PATHOLOGY - Y.I. Fedoniuk 2010

ANATOMY, PHYSIOLOGY, PATHOLOGY

CHAPTER 9. REPRODUCTIVE PROCESS

ANATOMY OF THE REPRODUCTIVE ORGANS

MALE REPRODUCTIVE ORGANS

8. PENIS. MALE URETHRA

The Penis consists of two corpora cavernosa and one corpus spongiosum. The corpus spongiosum lies ventral to the corpora cavernosa and is traversed by the Urethra. The posterior part of the penis is called the ROOT, and the anterior, expanded part is the glans. The middle portion forms the body (shaft) of the penis. The external urethral orifice is located on the glans. The Skin near the glans forms a fold known as the prepuce (foreskin). Its inner surface contains Sebaceous Glands, the secretion of which is called smegma. The outer envelope of the corpora cavernosa is a dense fibrous tunica albuinea, from which numerous trabeculae extend inward. The spaces between the trabeculae are filled with Blood. The size of the penis varies depending on the volume of blood within the cavernous bodies.

The male urethra (urethra masculina) is an unpaired tubular organ approximately 16–22 cm long with a diameter of 0.5–0.7 cm (Fig. 9.3). It serves for The excretion of urine and semen. The urethra extends from the Urinary Bladder to the external orifice on the glans penis. It is divided into three parts: the prostatic part (passing through the Prostate Gland), the membranous part (passing through the urogenital Diaphragm), and the spongy ( penile) part. Surrounded by the corpus spongiosum, the prostatic part is the widest, whereas the membranous part is the narrowest. The urethra has an S-shaped curve. When a catheter is introduced into the urethra, its anterior curvature is straightened, leaving only the posterior, more fixed curvature. The mucous membrane of the urethra is lined in different regions by various types of epithelium: transitional, pseudostratified columnar, simple columnar, and stratified squamous. The muscular layer consists of circular and longitudinal smooth Muscle fibers.

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Fig. 9.3. Median sagittal section of the male pelvis



Last update: 08/08/2026

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