Seminal Vesicles and Prostate Gland S-IV RM25

Seminal vesicles and Prostate gland S-IV RM25

 Learninig Objectives

 At the end of the lecture student will able :

 To define the seminal vesicles and prostate of male reproductive system.

 Explain the relation and anatomical position of these gland.

 Discuss the clinical associations of these gland

 Seminal vesicles

 Thin walled lobulated sacs situated b/w bladder & rectum.

 Each vesicle is about 5 cm long. Applied base of bladder above prostate.

 Directed upwards & laterally.

 Produce 60% of seminal fluid.

 Their tops are just covered by peritoneum of rectovesical pouch.

 Rectovesical fascia lies behind them.

 Each lies lateral to ampulla of the ductus deferens of its own side.

 At lower end of ampulla behind prostate the duct of seminal vesicle join ductus to form ejaculatory ductus.

 Arterial supply of seminal vesicle

 Supplied by branches from.

› Inferior vesical arteries.

› Middle rectal arteries

 Prostate

 Definition

 Accessory gland of male reproduction .

 Secretion of prostate , seminal vesicles & bulbourethral glands form seminal fluid.  Largest male accessory gland

 Located in lesser pelvis

 Gross Features:

 Conical shape with:

› base (sup)

› Apex (inf),

 Surfaces:

› Posterior

› Anterior

› right & left inferolateral

 Relations

 Attached inferiorly to urinary bladder by ligaments

 Posterior to pubic symphysis

 Surrounds superior portion of urethra

 Anterior to rectum

 Anterior Surface

 Ant. Surface lies at the back of retropubic space

 Connected to body of pubic bone by puboprostatic ligament.

 Posterior Surface:

 Post.surface lies anterior to rectum

 Separated from it by retrovesical fascia(Denonvillier’s fascia)

 Ejaculatory duct pierces this surface

 Inferolateral surfaces are related to the inferior fibres of levator ani

 Base (aka:vesicular surface): superior › Attached to neck of urinary

› Prostatic urethra enters middle of base close to anterior surface

› bladder

 Apex: inferior

› Prostatic urethra emerges from front of apex to become membranous urethra

› Surrounded by sphincter urethrae

› Contacts medial margins of levator ani muscles

 Capsule of prostate gland

 Double Capsule:

 True capsule: Formed by a thin layer of connective tissue at the periphery

 False Capsule: Lies outside the true capsule and is formed by condensation of the pelvic fascia

 B/W these lies the prostatic plexus of veins

 Lobes of the prostate gland

 Anterior lobe

 Connects the two lateral lobes in front of the urethra

 Contains little or no glandular tissue

 Rare site for adenoma

 Posterior lobe

 Connects the two lateral lobes behind the urethra

 Lies behind median lobe

 Site of origin for primary carcinoma

 Adenoma never occurs here

 Median lobe

 Lies posterior and superior to prostatic utricle and ejaculatory ducts

 May project into urinary bladder  Utricle lies within lobe

 Vestigial remains of uterine homolog

 Sometimes called “uterus masculinis”

 Common site for adenoma

 LOBES

 The "lobe" classification is more often used in anatomy.

 Histological zones

 Peripheral zone:

 Upto 70% of prostate

 Surrounds distal urethra

 Accounts for 70-80% of prostatic cancer

 Central zone:

 Upto 25% of prostate

 Surrounds ejaculatory duct

 Accounts for 2.5% of prostate.cancers

 Transition zone:

 Upto 5% of prostate area

 Surrounds proximal urethra

 Accounts for 10-20% of prostatic cancers

 Blood supply of Prostate

 Arteries derived from:

 a. Internal pudendal artery

 b. Inferior vesical artery

 c. Middle rectal artery

 Veins:a. Form venous plexus  b. Drain into internal iliac veins

 c. Communicate with vesical & vertebral venous plexuses

 Lymphatics: a. Most terminate in internal iliac & sacral nodes (unable to palpate)

 b. From posterior: to external iliac nodes

 Prostatic secretions

 Thin, milky, alkaline (looks like skim milk)

 Discharged at ejaculation

 c. Make up ~ 1/3 of semen

 Age changes in prostate

 Grows throughout life

 Responsible for BPH

 Small at birth

 Enlarges at puberty

 3. Maximum at about 13

 4. Progressive enlargement after 40

 5. Sometimes: undergoes atrophy

 Benign Prostatic Hyperplasia(BPH):

 Affects ~90% of men >50 years of age

 Characterizied by Hyperplasia of prostatic stromal and epithelial cells

 Forming discrete nodules in the periurethral region of the prostate, compressing urethra and causing symptoms of:

› urinary hesitency

› frequent urination

› Dysuria › urinary retention

 BPH

 Diagnosis

 Rectal examination

 transrectal US (TRUS)

 PSA level.

 Drug treatment

 Alpha blockers,5 alpha inhibitors.

 Surgery…..TURP(Transurethral resection of prostate). Shown in the diagram.

 Prostate cancer

 Most common cancer in males

 Metastasizes via blood (hematogenous) or lymph (lymphogenous)

 Common sites: vertebrae, pelvis

 a. Via venous plexus surrounding prostate

 b. Bone or direct metastasis most common

 PSA (Prostate Specific Antigen)

 Glycoprotein, kallikrein related serine protease

 Produced by secretory epithelium, drains into ductal system

 cleaves and liquefies seminal coagulum formed after ejaculation

 The traditional PSA threshold level of 4.0 ng/mL is considered reasonable for further evaluation of Prostate Cancer

 Annual PSA testing recommended for:

› men 50+

› men 40+ at increased risk

 The age to begin screening is linked to risk: › At age 50 years for average-risk men

› At age 45 years for higher-risk men (African American ethnicity or first-degree relative with prostate cancer before age 65 years)

› At age 40 years for appreciably higher-risk men (multiple family members diagnosed with prostate cancer before age 65 years)

 Prostate cancer screening is not recommended in men with a life expectancy of less than 10 year