Prostate Gland Overview

Prostate Gland

• The prostate is the largest accessory sex organ in males
• Its secretions are alkaline and comprise a significant portion of semen
• This fluid contains acid phosphatase, fibrinolysin, prostaglandin, and zinc
• Prostatic fluid accounts for about 20% of the seminal fluid volume
• In females, the equivalent structures are the paraurethral glands

Prostate Gland - Outline

• Introduction
• Location and shape
• Relations and arterial supply
• Structures inside
• Lobes
• Capsule of the prostate
• Function
• Clinical examination

Prostate Gland - Introduction

• Weight: 8 grams
• Size: width 4 cm, length 3 cm, anterior-posterior diameter 2 cm
• The prostatic ducts (20-30 in number) open into the prostatic sinuses on the posterior wall of the prostatic urethra

Prostate Gland - Location

• Located in the true pelvis, inferior to the bladder neck, superior to the urogenital diaphragm, behind the pubic symphysis, and in front of the ampulla of the rectum

Prostate Gland - Shape

• Inverted cone/pyramidal
• About the size of a walnut
• Base is directed upwards, apex downwards

Prostate Gland - Relations

• Base: bladder neck, pierced by the urethra and ejaculatory duct
• Apex: urogenital diaphragm
• Anterior: retropubic space and puboprostatic ligament
• Posterior: lower 1/3rd of the rectum
• Sides: levator ani

Prostate Gland - Arterial Supply

• Inferior vesical and middle rectal arteries
• Branches of the internal iliac artery
• Venous drainage: internal pudendal vein, internal iliac vein
• Lymph drainage: internal iliac and sacral lymph nodes

Prostate Gland - Structures Inside

• Urethra
• Ejaculatory ducts
• Prostatic utricle
• Prostatic urethra, extending from the base to the apex
• Urethral crest
• Two seminal colliculi
• Three prostatic sinuses

Prostate Gland - Anatomical Lobes

• Anatomical lobes: median lobe and two lateral lobes, which show glandular tissue
• Surgical lobes: median lobe, two lateral lobes, anterior and posterior lobes

Prostate Gland - Lobes (Surgical)

• Anterior lobe: no glands
• Posterior lobe
• Two side lobes (right and left)
• Middle lobe: glandular tissue, prone to enlargement, potentially obstructing the urethra

Prostate Gland - Capsules

• Fibrous capsule (true capsule)
• Fibrous sheath or false capsule
• Rectoprostatic fascia (Denonvillers fascia)
• Venous plexus between the true and false capsule

Prostate Gland - Structural Zones

• Prostatic urethra
• Prostatic glands proper (main prostatic glands)
• Prostate gland
• Submucosal glands
• Mucosal glands

Prostate Gland - Tissues

• Fibrous tissue forms posteromedian septum
• Muscular tissue: smooth muscle derived from detrusor muscles, arranged in sheets, striated muscle derived from sphincter urethrae
• Fibromuscular stroma stimulated by estrogen, inhibited by testosterone
• Glandular tissue: arranged in three concentric layers around the urethra (inner mucous glands, intermediate submucous glands, outer main prostatic glands)
• All openings are through prostatic sinuses, stimulated by testosterone

Prostate Gland - Glandular Tissue Composition

• Tubuloalveolar glands arranged in 3 concentric groups (mucosal, submucosal, chief)
• All of them open into the urethra
• Fibromuscular tissue forms the stroma, glandular tissue forms the parenchyma

Prostate Gland - Lumen

• Includes small colloid masses called corpora amylacea

Prostate Gland - Functions

• Secretes prostatic fluid (alkaline), containing acid phosphatase
• Acid phosphatase increases in prostate cancer from duct obstructions
• Secretes prostaglandin

Prostate Gland - Examination

• Prostate examination (PR)
• Ultrasound
• Biopsy
• PSA

Applied Anatomy (Prostate)

• Prostatitis
• Benign prostatic hyperplasia (BPH)
• Prostate cancer

Female Urethra

• 4 cm long
• Related to the anterior wall of the vagina
• Opens into the vestibule of the vagina
• External urethral sphincter in the deep perineal pouch

Male Urethra

• Length: 20 cm
• S-shaped
• Four parts: preprostatic, prostatic, membranous, spongy
• First part has internal urethral sphincter (smooth muscle)
• Second part is the prostatic part, receiving openings from the utricle, seminal colliculus, and ejaculatory duct
• Third part is the membranous part, surrounded by the external urethral sphincter (skeletal muscle)
• Fourth part is the spongy part (bulbar and navicular fossa), bulbourethral glands open at the bulbar fossa

Male Urethra (Comparison of Parts)

• Compare the prostatic, membranous, and spongy parts in terms of length, location, width, openings, and relations

Male Urethra (Details)

• Internal urethral sphincter: smooth muscle between bladder neck and prostate
• External urethral sphincter: skeletal muscle supplied by pudendal nerve

Explore the essential features and functions of the prostate gland, the largest accessory sex organ in males. This quiz covers its anatomical structure, location, relation to other organs, and clinical significance. Test your knowledge on the composition of prostatic fluid and its role in the male reproductive system.