Which of the following provides fetal nutrition and secretes hormones that regulate pregnancy and fetal development

A. The bicarbonate, phosphate, and protein: The major chemical buffer systems in the body are the bicarbonate buffer system, the phosphate buffer system, and the protein buffer system. These buffers help maintain pH balance in the blood and other fluids.

B. The urinary and digestive: The urinary and digestive systems are involved in excretion and digestion, not buffering.

C. The bicarbonate, nucleic acids, and protein: Nucleic acids are not major buffering systems in the body; the bicarbonate, phosphate, and protein systems are the primary ones.

D. The urinary and respiratory systems play roles in regulating acid-base balance through excretion and gas exchange but are not chemical buffer systems themselves.

A. To the lining of the uterine tube: If an embryo attaches to the uterine tube, it results in an ectopic pregnancy, which is not typical or safe.

B. To the myometrium: The myometrium is the muscular layer of the uterus and is not the usual site of embryo attachment.

C. To the perimetrium: The perimetrium is the outermost layer of the uterus and is not involved in embryo implantation. This is incorrect.

D. To the endometrium: The endometrium is the inner lining of the uterus, where the embryo typically implants and attaches. This is the correct answer.