Glands such as the thyroid, that secrete their products directly into the blood rather than through ducts are classified as

Such glands are classified as endocrine glands.

Explanation:

Endocrine glands also known as ductless glands produce and secretes hormones (chemical substances) directly into the bloodstream to regulate the activities of cells or organs. The endocrine glands make-up the endocrine system. This system influence reproduction, metabolism, growth and many other body functions. The endocrine glands include the hypothalamus, the pituitary, thyroid, ovaries, testes, pineal gland, parathyroids, pancreas and adrenal glands.

In contrast to the endocrine glands is the exocrine glands. The exocrine glands produce and secretes their hormones through ductal system onto epithelial surface. Example of exocrine glands are sebaceous glands of the skin, the pyloric and Cardia glands of the stomach, salivary glands etc.

cats appear to have glowing cat eyes because the back of their eyeballs includes a special reflective surface called the tapetum lucidum. this lets them see better during the night, giving them a much better vision.