Which of the following valves separates the atrial and ventricular chambers of the heart?

A. Ureters are fibrotic tubes connecting the kidneys to the urinary bladder:
Ureters are not simply fibrotic tubes; they are muscular, tubular structures that transport urine from the kidneys to the urinary bladder. The term "fibrotic" does not accurately describe their functional and structural properties.

B. Ureters are covered by an outer layer of epithelial tissue:
While ureters are lined with epithelial tissue (transitional epithelium. , this is not their outermost layer. They have a more complex structure with an outer layer of connective tissue, a middle layer of smooth muscle, and an inner layer of epithelial tissue.

C. Ureters are connected inside the urinary bladder by a two-way valve:
Ureters are connected to the urinary bladder via openings, but these openings are not equipped with a two-way valve. Instead, they are equipped with a mechanism that prevents backflow of urine from the bladder into the ureters.

D. Ureters are extraperitoneal tubular structures:
The ureters are indeed extraperitoneal, meaning they are located outside the peritoneal cavity. They are retroperitoneal structures that run posterior to the peritoneum, making this the correct statement.

A. Tricuspid:
The tricuspid valve, located between the right atrium and right ventricle, has three leaflets (or cusps. and is open during the systolic phase to allow blood flow from the right atrium to the right ventricle. It does not fit the description of having two leaflets.

B. Aortic:
The aortic valve, situated between the left ventricle and the aorta, has three leaflets and is closed during diastole to prevent backflow of blood from the aorta into the left ventricle. It is not closed during the systolic phase and does not have two leaflets.

C. Mitral:
The mitral valve, located between the left atrium and left ventricle, has two leaflets (or cusps. and is closed during the systolic phase of the cardiac cycle. This closure prevents the backflow of blood from the left ventricle into the left atrium as the ventricle contracts, making it the correct answer.

D. Pulmonic:
The pulmonic valve, located between the right ventricle and the pulmonary artery, has three leaflets and is closed during diastole to prevent backflow from the pulmonary artery into the right ventricle. It does not have two leaflets and is not closed during the systolic phase.