Download MBBS (Bachelor of Medicine and Bachelor of Surgery) Latest Prostate Lecture PPT
PROSTATE GLAND
INRODUCTION
The Prostate is a conical Fibro-Musculo-Glandular organ surrounding
the proximal part of male urethra.
? Corresponds with paraurethral glands of female developmentally.
? Secretion of Prostate forms considerable part of semen.
? Is slightly acidic, contains acid phosphatase, fibrinolysin,
prostaglandin and large amount of Zinc.
? Situation:
Lesser pelvis below the neck of bladder, above urogenital
diaphragm, behind the lower part of symphysis pubis,
anterior to rectal ampulla and on each side embraced by
levator ani muscle.
? Measurements:
? Chest nut in appearance.
? Transverse (at base): 4 cm.
? Vertical: 3 cm
? Anteroposterior: 2 cm.
? Weight : 8 gm.
Presenting Parts of Prostate gland
-Apex: Directed downwards, in contact with Superior fascia of
urogenital diaphragm.
- Base : Directed upwards, surrounding the neck of the bladder,
pierced by urethra in median plane at the junction of ant. 1/3rd and
post. 2/3rd of the gland.
Presenting Parts of Prostate gland
? Anterior surface : narrow
and convex and situated
about 2cm behind lower part
of symphysis pubis
separated by retropubic fat,
prostatic venous plexus and
deep dorsal vein of penis.
? Posterior surface: broad,
flat, related to the ampulla of
rectum separated by
rectovesical fascia.This
surface is palpable by rectal
examination about 4 cm
above anus.
Presenting Parts of Prostate gland
? Posteror surface is subdivided by transverse groove into
upper small and lower large areas. It is pierced by
ejaculatory ducts on each side. The upper area forms
median lobe; lower area is subdivided by a median sulcus
into two lateral lobes.
Presenting Parts of Prostate gland
? Each of two Infero-lateral surfaces, related to the anterior
fibres of levator ani which acts as levator prostate; anterior
recess of the ischio-rectal fossa lies outside the levator ani.
LOBES OF PROSTATE GLAND
5 lobes: Median, Anterior, Posterior and two lateral.
left view of a sagittal section Coronal section through posterior half of gland;
LOBES OF PROSTATE GLAND
The median lobe: is wedge shaped, apex directed below towards
colliculus seminalis, base forms uvula vesicae at the apex of trigonum
vesicae.
Bounded anteriorly by urethra, behind and on each side by the
ejaculatory duct, behind and in the median plane by prostatic utricle.
This lobe is predominantly fibro-muscular with mucus glands.
LOBES OF PROSTATE GLAND
The two lateral lobes are separated superficially by posterior median
sulcus , but deep to the sulcus and behind urethra both the lobes are
continuous.
This continuity is described as posterior lobe surgically.
Each lateral lobe covers sides of urethra and in front of urethra are
connected by fibro-muscular isthmus,which is known as anterior lobe
in foetal life containing glands.(may persist upto 6 years after birth)
FASCIAL RELATIONS
The prostate is related to the two capsules and one fascia behind
1. True Capsule
Formed by the condensation of the peripheral fibrous stroma of the
gland
2. False Capsule
Formed by the visceral layer by the pelvic fascias.
(The prostatic venous plexus lies between these capsules)
Hence plane of enucleation of prostatic adenoma lies deep to both the
capsules.
Surgical Capsule/pathological capsule
Formed by the non adenomatous tissue of the prostate which
is pushed by the hypertrophied gland to the periphery
Fascia Behind the Prostate
it is also known as rectovesical, prostatoperitonial,denonvillier's fascia
Structures traversing the Prostate gland
?
Prostatic urethra: runs vertically
downwards from base to slightly in
front of apex, at the junction of ant.
1/3rd and post. 2/3rd of gland.
?
Pair of ejaculatory ducts: each
passes postero-lateral to median
lobe, opens at the colliculus on each
side of prostatic utricle.
?
Prostatic utricle: is mucus cul ?de-
sac, about 6mm long, extends
upwards, and backwards from
colliculus behind the median lobe.
STRUCTURE OF PROSTATE GLAND
Consist of 1/4th fibrous, 1/4th muscular and 2/4th glandular
tissue.
? Fibrous tissue: forms true capsule at the periphery,postero-
median fibrous septum connects capsule with urethral crest.
?Muscular tissue: smooth muscle, continuous with detrusor
muscle, arranged in outer and inner sheets, connected by
radiating fibres. Spaces between these fibres occupied by
?follicles of the gland.
?There are transversely oriented arched striated muscle
fibres within the prostate anterior to the urethra, blending
with fibrous capsule postero-laterally and with postero-
median septum.
Glands of prostate are arranged in 3 layers:
? Inner mucous glands
? Intermediate submucous glands
? Outer main glands
BLOOD SUPPLY
Arterial supply :
1. Inferior vesical artery
2. Middle rectal artery
3. Internal pudendal arteries
Venous drainage:
Veins form prostatic plexus in between true and false capsules. Plexus
receives deep dorsal vein of penis anteriorly and communicates above
with the vesical venous plexus. Finally draining into internal iliac vein.
Few veins from prostate pass backwards through anterior sacral
foramina , draining into internal vertebral venous plexus, known as
paravertebral veins of Batson. (metastatic spread of cancer prostate to
vertebrae)
Lymphatic drainage:
1. Internal iliac group of lymph nodes.
2. External iliac group of lymph nodes
3. Sacral group of lymph nodes.
Nerve supply:
1. Superior Hypogastric plexus conveys sympathetic
nerves(L1,L2 preganglionic fibres)
2. Parasympathetic fibres derived from pelvic splanchnic
nerves conveying preganglionic fibres from S2, S3, and
S4.(secretomotor to gland)
AGE CHANGES IN PROSTATE GLAND
In newborn: consist basically of duct system in
fibromuscular stroma. Before puberty grows slowly and
rudimentary follicles bud out from sides of ducts.
At Puberty: shows sudden growth, doubles in size. Follicles
shows infoldings. Above 45 years age mucous folds
disappears and follicles contains corpora amylacea.
In old age: It may atrophy or show hypertrophy.
APPLIED ANATOMY
? Prostatitis
? Benign hypertrophy of prostate.
? Prostatectomy:
i) Suprapubic approach
ii) Transurethral resection of prostate
(TURP)
?Carcinoma of Prostate.
?Digital per rectal examination.
URETHRA
Male urethra
The male urethra is
about 20.0 cm
long and is divided
into three parts-
? Prostatic,
? Membranous
? Spongy
(penile).
The anterior urethra
? It is about 16 cm long and
surrounded by the corpus
spongiosum. It is subdivided
into:
? The bulbar urethra which is
more proximal, surrounded by
the Bulbospongiosus muscles
and lie entirely within the
perineum.
? The penile urethra which is
distal and continues to the tip
of the penis.
The posterior urethra
? It is about 4 cm long and lies in the
pelvis
proximal to the corpus spongiosum.
The
posterior urethra is divided into:
? The pre-prostatic part of the urethra.
? The prostatic part is the widest and
passes through the prostate.
? The membranous (sphincteric) part is
the shortest and narrowest part. In the
deep perineal pouch, it
is surrounded by distal (external)
urethral sphincter.
Parts of male urethra
Preprostatic urethra
? approximately 1 cm in length.
? extends from the base of the bladder
to the prostate.
? Small periurethral glands at this site
may contribute to benign prostatic
hyperplasia (BPH) and symptoms of
outflow obstruction in older men.
Prostatic urethra
? is 3?4 cm in length
? passes through the substance of
the prostate, closer to the anterior
than the posterior surface of the
gland.
? It is continuous above with the
preprostatic part and emerges
from the prostate slightly anterior
to its apex.
? - Length: 3.0 cm
Prostatic urethra
- Features:
In its posterior prostatic urethra wall there
is urethral crest with a round swelling
colliculus seminalis in the middle.
? There are three openings on
the colliculus seminalis:
? One median for prostatic utricle.
? Two lateral for the ejaculatory ducts.
? On either side of urethral crest, there is a
shallow depression-prostatic sinusfor
prostatic glands ducts opening.
Membranous urethra
? lies in the deep perineal pouch.
? This is the narrowest segment of male
urethra.
? It is having thickened circular muscles in
its walls i.e. sphincter urethrae- that acts as
a voluntary external sphincter.
? more susceptible to injury, during
passage of instrument through urethra due
to
I. Its narrowest part with delicate walls.
II. Its angulation with the spongy urethra.
III. Length: 2.0 cm
Spongy (penile) urethra
? The longest part of male urethra.
? Length-I5 cm.
? It begins below the perineal membrane
and ends at external urethral meatus.
? This part lies within the bulb of penis,
corpus spongiosum and glans of penis.
? There are two dilatations in this part:
i. One intrabulbar fossa in the bulb of
penis.
ii. One navicular fossa in the glans of
penis.
Spongy (penile) urethra
? The ducts of bulbo-urethral (Cowper's)
gland open in this part just below
urogenital diaphragm.
? The dorsal wall of spongy urethra has
- Openings of many mucus glands.
- Lacunae or pit-like recesses directed
forwards. The lacuna magna lies in the
navicular fossa.
? The spongy urethra ends at external
urethral meatus, that is a sagittal slit,
about 6 mm long at the tip of the glans.
? The external meatus is guarded by two
lateral labia. It is the narrowest point of
male urethra. If an instrument can pass
through it, it can easily pass through rest
of urethra.
URETHRAL MUCOSA
1. Prostatic urethra above the
seminal colliculus is lined by
transitional epithelium and
below it by stratified columnar
epithelium.
2. Membranous urethra is lined
by stratified columnar
epithelium.
3. Spongy urethra up to navicular
fossa is lined by stratified
columnar epithelium. The
navicular fossa and external
urethral orifice are lined by
stratified squamous epithelium.
ARTERIAL SUPPLY
? Urethral artery
? just below the perineal membrane it arises from
? the internal pudendal artery
? or common penile artery
? runs through the corpus spongiosum, to reach the glans penis.
? It supplies ? the urethra and ? erectile tissue around it.
In addition, the urethra is supplied by
? the dorsal penile artery
? via its circumflex branches on each side and
? retrogradely from the glans, by its terminal branches.
? The blood supply through the corpus spongiosum is so plentiful that
the urethra can be divided without compromising its vascular
supply.
APPLIED
1.Rupture of the urethra.
2. Catheteristion of
urethra.
3.Hypospadias.
Female urethra
? it is about 4.0 cm long and 6mm
diameter.
? It extends from the neck of bladder to
the external urethral meatus.
? the external orifice is situated in front
of the vaginal opening and about 2.5 cm
behind the clitoris.
? It is homologous with upper part of
Prostatic urethra of males.
? Location: The female urethra is
embedded in anterior wall of vagina.
Thus in cases of difficult child-birth, it is
more likely to be lacerated.
Lumen of Urethra on cross section
? At the internal orifice- crescentic
with the convexity directed in front
.
? At the middle- transverse slit.
? At the external orifice- sagittal slit.
Glands around the female urethra
? Urethral glands-
? These are tubular mucous glands
? surround the entire urethra.
? Para-urethral glands-
? These correspond with the prostate gland of male
? their ducts open close to the external urethral orifice.
? Greater vestibular glands-
? compound racemose glands
? situated behind the bulb of the vestibule in the superficial perineal pouch
? ducts of the glands open in the vagina below the hymen.
? Corresponds to the bulbourethral glands of male
? Urethral lacunae-
? These are pit like mucous recesses which project from the entire
female urethra.
Applied
? Infection of the female urinary bladder is more common due to the
shortness of the urethra.
? Stress incontinence is associated with the funneling of the bladder
neck during normal standing usually observed in multiparous women
with symtoms of sudden dribbling of urine during increases intra-
abdominal pressure.
This post was last modified on 30 November 2021