Question

Transitional tissue found in
A. Renal pelvis and ureter
B. Urinary Bladder
C. The upper part of the male urethra
D. All the above

Answer 1

Hint: A transitional tissue is made up of more than one layer of epithelial cells. It is classified under the stratified epithelium. Transitional epithelium present in the organ where distension needed.

Complete answer: Option A: The major calyces open into a broad funnel-shaped structure called renal pelvis placed inner to the hilum. It is lined by transitional epithelium. Renal pelvis leads to the ureter. Ureters develop from the hilum part of the kidneys, descend along the abdominal wall, bend obliquely inwards and upwards to open into the urinary bladder in the region of trigone by oblique slits, one on each side. Ureters are always undergoing peristalsis which helps in passing urine from the kidney to urine bladder. Transitional epithelium is present in ureters that support peristalsis movement. The urinary Bladder is a pyriform sac which varies in shape, size and position according to the amount of urine contained in it. The fully distended bladder ovoid in outline. Wall of the urinary bladder consists of three coats- outer adventitia, middle muscular and inner mucosa. Mucosa has loose connective tissue towards the side of the muscular layer and transitional epithelium. The transitional epithelium in the urinary bladder is known as urothelium. The transitional epithelium helps the urinary bladder in distension. The urethra is present in mammals. Urethra starts from the neck of the urinary bladder and opens outside the body. The urothelium tissue also covers the urethra, upper part of the male urethra and gland ducts of the prostate. Therefore, all the above-mentioned organs have transitional tissues in them.
Hence, the correct answer is option D.

Note: The appearance of a transitional tissue is cuboidal, columnar or squamous (irregular shape). It functions as a barrier between hollow organs and bloodstream and prevents absorption of toxic substances and pathogens by the bloodstream.