Gland Endocrine glands secrete substances that circulate through the blood stream. The glands secrete their products through basal lamina into the blood stream. Basil lamina typically can be seen a layer around the glands to which a million maybe more tiny blood vessels are attached. These glands often secrete hormones which play an important role in maintaining homeostasis. The pineal gland, thymus gland, pituitary gland, thyroid gland, and the two adrenal glands are all endocrine glands. Exocrine glands secrete their products through a duct onto an outer surface of the body, such as the skin or the gastrointestinal tract. Secretion is
Brain-to-body mass ratio have spinal cords, or in some cases, central nervous systems. Recent research indicates that, in non-human primates, whole brain size is a better measure of cognitive abilities than brain-to-body mass ratio. The total weight of the species is greater than the predicted sample only if the frontal lobe is adjusted for spatial relation. The brain-to-body mass ratio was however found to be an excellent predictor of variation in problem solving abilities among carnivoran mammals. In humans, the brain to body weight ratio can vary greatly from person to person; it would be much higher in an underweight person than an