the ________ is about the size of a walnut and encircles the urethra as it leaves the urinary bladder
A- testis
B- gonad
C- thyroid gland
D- prostate gland
http://training.seer.cancer.gov/anatomy/reproductive/male/glands.html
D. Prostate gland
The answer is D - prostate gland.
To arrive at this answer, we need to understand the location and function of each option listed.
A. Testis: The testis is a reproductive organ found in males, responsible for the production of sperm. It is not located near the urethra or bladder.
B. Gonad: A gonad refers to an organ that produces gametes (sperm or eggs). While the testis is a type of gonad, it is not the correct answer for this question.
C. Thyroid gland: The thyroid gland is located in the neck region and produces hormones that regulate metabolism. It is not related to the urinary system or the urethra.
D. Prostate gland: The prostate gland is a part of the male reproductive system and is found just below the bladder. It surrounds the urethra as it exits the bladder. The prostate gland produces seminal fluid, which helps nourish and transport sperm.
Therefore, based on the given options and the description provided, the correct answer is D - prostate gland.