NEET BIOLOGY

Detailed explanation-1: -Bladder. This triangle-shaped, hollow organ is located in the lower abdomen. It is held in place by ligaments that are attached to other organs and the pelvic bones. The bladder’s walls relax and expand to store urine, and contract and flatten to empty urine through the urethra.

Detailed explanation-2: -The bladder is a hollow, muscular organ situated centrally in the pelvis; it stores urine until it is convenient to release it. At a certain volume, stretch receptors in its wall transmit nervous impulses that initiate a conscious desire to urinate. The urethra then conducts urine from the bladder to the outside.

Detailed explanation-3: -The detrusor muscle is located within the walls of the bladder and is composed of smooth muscle fibers that are longitudinal and circular.

Detailed explanation-4: -Urine is made in the renal tubules and collects in the renal pelvis of each kidney. The urine flows from the kidneys through the ureters to the bladder. The urine is stored in the bladder until it leaves the body through the urethra.

Detailed explanation-5: -Contraction of internal urethral sphincter stops the flow through the internal urethral orifice preventing the flow of urine from the bladder. The internal urethral sphincter is made of a layer of smooth muscle that is surrounded by striated muscle.