The secretion of estrogens is controlled by ______.

Cone cells are the most densely arranged at the ______.

_________ is characterized by a decrease in blood Ca2+ level, which may result in cardiac arrest and tetany of skeletal muscles.

The X shape of the optic nerves is called the ______________.

Pain in the left chest and left upper limb may be a sign of a ______.

Deafness that can be overcome by using a hearing aid is called __________ deafness.

The predominant tissues composing the subcutaneous tissue are _________ tissue and ________ tissue.

New cells of the epidermis are continuously formed in the ______.

There are _____ pairs of true ribs, _____ pairs of false ribs,and _____ pairs of floating ribs.

The ____________ are bundles of myelinated and unmyelinated axons of interneurons that extend up and down within the spinal cord.