Question

The excretory system of human beings includes a pair of ____, a pair of______ a ______ and _____ which helps in the filtration of blood.
A. kidneys, ureters, urinary bladder, urethra
B. Urethra, ureters, urinary bladder, kidneys
C. Kidneys, urethra, ureters, urinary bladder
D. Kidneys, urinary bladder, ureters, urethra

Answer 1

Hint: The excretory system is responsible for the elimination of the waste materials produced by homeostasis. There are several parts of the body that are involved in this process, such as the sweat glands, the liver, the lungs and the kidney system as well.

Complete answer: Humans have two kidneys situated between the last thoracic and third lumbar vertebra close to the dorsal inner wall of the abdominal cavity. Ureters are a pair of fine whitish distensible muscular tubes of 25 to 30 cm in length and about 3mm in diameter. A urinary bladder is a median pyriform sac which varies in shape, size and position according to the amount of urine contained in it. The fully distended bladder becomes ovoid in outline. The urethra is present only in mammals. It starts from the neck of the urinary bladder and opens outside the body. The kidneys are a pair of bean-shaped organs on either side of the spine, below the ribs and behind the belly. Each of the kidneys is about four or five inches long, roughly in size of a large fist. The kidney’s job is to filter the blood.
The ureter is a tube that carries the urine from the kidney to the urinary bladder. The urinary bladder is a hollow muscular organ in humans and the other vertebrates that store the urine from the kidneys before disposal by urination. The urethra is a thin, fibromuscular tube that begins at the lower opening of the bladder and extends through the pelvic and the urogenital diaphragms to the outside of the body called the external urethral orifice.
Therefore, the correct answer is option A.

Note: The organs of the excretion make up the excretory system. They include the pair of kidneys, the large intestine, the liver, the skin, and the lungs. The kidney filters the blood and forms the urine. They are the part of the urinary system, which also includes the ureters, the bladder, and the urethra.