Download MBBS Prostate Lecture PPT

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