HISTOLOGY OF URINARY BLADDER

HISTOLOGY OF URINARY BLADDER

IMAG0377_1IMAG0373_1

IDENTIFICATION POINTS

  • MUCOSA LINED BY TRANSITIONAL EPITHELIUM.
  • SUBMUCOSA IS ABSENT.
  • MUSCULAR LAYER CONTAINING DETRUSOR MUSCLES.

INTRODUCTION

– IT IS A MUSCULAR BAG LIKE STRUCTURE WHICH TEMPORARILY STORES URINE FOR VOIDING.

– NORMAL STORING CAPACITY IS 200-300ml.

STRUCTURE

MUCOSA:

INNER MOST LAYER OF URINARY BLADDER LINED BY TRANSITIONAL EPITHELIUM WITH LAMINA PROPRIA RICH IN BLOOD VESSELS UNDERNEATH IT. MUCOSA IS THROWN INTO MANY FOLDS WHICH EXPANDS TO COLLECT MORE QUANTITY OF URINE WITHIN THE BLADDER.

MUSCULAR LAYER:

IRREGULAR CONSISTING OF INNER LONGITUDINAL,MIDDLE CIRCULAR AND OUTER LONGITUDINAL MUSCLE LAYERS. FEW MUSCLE FIBERS AROUND THE INTERNAL URETHRIC ORIFICE FORM AN INTERNAL URETHRAL SPHINCTER WHICH CONTROL THE OUTFLOW OF URINE FROM THE BLADDER.

ADVENTITIA:

OUTERMOST PROTECTIVE COVERING LAYER MADE UP OF DENSE IRREGULAR CONNECTIVE TISSUE.

FUNCTIONS:

  • TRANSITIONAL EPITHELIUM PREVENTS THE ENTRY OF URINE AND ITS TOXIC SUBSTANCES INTO THE URINARY BLADDER. HERE THE CELLS ALSO DECREASE IN SIZE AND LAYERS TO ACCOMMODATE LARGE QUANTITY OF URINE.
  • PROMINENT MUSCULAR COAT IS RESPONSIBLE FOR MICTURITION PROCESS BY PRODUCING POWERFUL CONTRACTIONS.
  • ADVENTITIA IS PROTECTIVE AND SUPPORTIVE IN NATURE.

CLINICAL:

  • USUALLY TRANSITIONAL EPITHELIUM  LINING THE URINARY BLADDER IS 4-6 CELL LAYER-THICK. IF IT INCREASES MORE THAN 6 CELL-LAYER THICK, THEN IT IS SUGGESTIVE OF CARCINOMA OF URINARY BLADDER.
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s