Modification of deep fascia

Deep fascia

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Definition: Deep fascia is a fascia, a layer of dense irregular connective tissue that wraps the neck, the limbs and body wall like a bandage or stocking 

It covers muscles, nerves, bone and blood vessel.

Important features of deep fascia:

·         It is devoid of fat

·         It is inelastic and tough

·         It has nerve supply and very sensitive structure.

·         It is a golden rule that when fascia approaches bone it becomes attached to it , blending with the covering periosteum 

Modification of deep fascia:

1.      Each muscle is covered by deep fascia known as epimysium which sends in the septa to enclose each muscle fasciculus known as perimysium. From the perimysium septa pass to enclose each Muscle fiber. These fine septa are the endomysium. This connective tissue layer support the muscle and convey nerve , blood vessels and lymphatics.

2.      Deep fascia covers each nerve as epineurium, each nerve fascicle as perineurium and individual nerve fibered as endoneurium. These connective tissue coverings support the nerve fibers and carry capillaries and lymphatics.

3.      From deep fascia , the intermuscular septa is arises which  separating functionally different group of muscles into separate compartments.

4.      It also forms septa between various muscles. These septa are specially well developed in the calf muscles of lower limb. The contraction of calf muscles in the tight sleeve of deep fascia helps in pushing the venous blood and lymph towards the ‘heart. Thus the deep fascia helps in venous and lymphatic return from the lower limb.

5.      The deep fascia is dense around the artery and rather loose around the vein to give an allowance for the vein to distend.
deep fascia forms sheaths around large arteries, e.g. carotid sheath, axillary sheath

6.      Deep fascia is modified to form the capsule, synovial membrane and bursae in relation to the joints.

7.      Deep fascis forms tendon sheaths wherever tendons cross over a joint. This mechanism prevents wear and tear of the tendon.

8.       In the region of palm and sole it is modified  to form aponeuroses. in the forearm and leg, the deep fascia is modified to form the interosseous membrane, which keeps:

• The two bones at optimum distance.
• Increases surface area for attachment of muscles.
• Transmits weight from one bone to other

Distribution of deep fascia

Deep fascia

Definition: Deep fascia is a fascia, a layer of dense irregular connective tissue that wraps the neck, the limbs and body wall like a bandage or stocking 

It covers muscles, nerves, bone and blood vessel.

Important features of deep fascia:

·         It is devoid of fat

·         It is inelastic and tough

·         It has nerve supply and very sensitive structure.

·         It is a golden rule that when fascia approaches bone it becomes attached to it , blending with the covering periosteum

Distribution of deep fascia

Very well developed: 

1.       iliotibial tract of fascia lata

2.       palmar and planter aponeurosis

3.       flexor and extensor retinaculum

Well developed:

• In the limbs,  it forms tough &  tight sleeves
•  In the neck, it forms a collar.

So thin usually considered as absent:

·         Over the rectus sheath of abdomen

·         Over the trunk  except thoracolumbar fascia at the back of thorax & abdomen

Absent

·         Face except  parotid fascia

·         Ischioanal fascia

Internal urethral sphincter / Sphincter urethrae : easy and brief description

Sphincter vesicae  

·         The internal sphincter muscle of urethra: located at the bladder's inferior end and the urethra's proximal end at the junction of the urethra with the urinary bladder. The internal sphincter is a continuation of the detrusor muscle and is made of smooth muscle, therefore it is under involuntary or autonomic control. This is the primary muscle for prohibiting the release of urine.

In males and females, both internal and external urethral sphincters function to inhibit the release of urine. In males, the internal sphincter muscle of urethra functions to prevent reflux of seminal fluids into the male bladder during ejaculation.

Histology of sphincter urethrae:

All part of musculature of urinary bladder is composed of outer and inner longitudinal and middle circularly arranged smooth muscle cell . in the bladder neck the outer longitudinal layer merge with circular layer and it become thick and formed sphincter urethrae

Function

The internal urethral sphincter provides involuntary control of urination.

The muscular coat of the urinary bladder is composed of inner longitudinal, middle circular,and outer longitudinal layers of smooth muscle that are frequently interlaced and are indistinguishable as distinct layers. The internal sphincter muscle of the urethra is formed by the thick, middle circular layer

Verumontanum or seminal colliculus : easy and brief description

Verumontanum is translated from Latin to mean 'mountain ridge
Verumontanum or  seminal colliculus  is a median elevation situated within the posterior wall of prostatic  urethra.
It is used as landmark of prostatic urethra during different laparoscopic procedure
.Embryologically, it is derived from the uterovaginal primordium.
The landmark is important in classification of several urethral developmental disorders.
Relation of verumontanum :
Median portion of verumontanum is elevated receive three opening
One opening of prostatic utricle at the centra
Two opening of ejaculatory duct on the two side of opening of prostatic utricle
Urethral crest: it is situated at the upper part of verumontanum , near the neck of urinary bladder.
Urethral sinus: it is situated in the lateral side of the verumontanum with receive several opening of prostatic gland

Clinical features  Verumontanum mucosal hyperplasia

• The presence of verumontanum mucosa gland hyperplasia is an asymptomatic morphologic variant of the glands underlying the posterior wall of the prostatic urethra

Diagnosis

• Can be identified in TURP specimens or in needle biopsies of the prostate

Treatment

• Not required

Microscopic (histologic) description

• Crowded small acinar proliferation, usually arranged in a well circumscribed nodule
• The glands can have intraluminal concretions that vary in color from orange to gray or green
• May be seen underlying the urethral urothelium

Differential diagnosis

• Verumontanum mucosal gland hyperplasia (VMGH), when present in a prostate needle biopsy, could be mistaken for low grade prostatic adenocarcinoma (Gleason pattern 3)
• The lobular architecture and the presence of basal cells are features to differentiate it from Gleason pattern 3 cancer
• Another helpful feature is the presence of corpora amylacea or the orange-grey-green concretions that are features of VMGH and not of prostatic carcinoma
• Occasionally, it can present with a papillary architecture simulating prostatic duct adenocarcinoma
• In contrast to prostatic duct carcinoma, the cells in VMGH are more cuboidal and without nuclear atypia