The hepatic portal system extends from where to where?

In the human dental formula,the numbers in the numerator indicate . . . . . . .

Brunner's glands are found in which of the following layers?

Which is the hardest material of the human body?

Which of the following controls the peristaltic movement of the intestine?

Select the correct statement$(s)$:
$(A)$ The alimentary canal begins with an anterior opening,the mouth.
$(B)$ Each tooth is embedded in a socket of jaw bone.
$(C)$ Humans exhibit a diphyodont type of dentition.
$(D)$ The oesophagus and the trachea open into the larynx.