water gland
41reproductive system, animal — Introduction any of the organ systems by which animals reproduce. The role of reproduction is to provide for the continued existence of a species; it is the process by which living organisms duplicate themselves. Animals compete with… …
42endocrine system — Group of ductless glands that secrete hormones necessary for normal growth and development, reproduction, and homeostasis. The major endocrine glands are the hypothalamus, pituitary, thyroid, islets of Langerhans, adrenals, parathyroids, ovaries …
43excretion — excretion1 /ik skree sheuhn/, n. 1. the act of excreting. 2. the substance excreted, as urine or sweat, or certain plant products. [1595 1605; < LL excretion (s. of excretio) that which is sifted out. See EXCRETE, ION] excretion2 /ik skree… …
44pregnancy — /preg neuhn see/, n., pl. pregnancies. the state, condition, or quality of being pregnant. [1520 30; PREGN(ANT) + ANCY] * * * Process of human gestation that takes place in the female s body as a fetus develops, from fertilization to birth (see… …
45Life Sciences — ▪ 2009 Introduction Zoology In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… …
46radiation — radiational, adj. /ray dee ay sheuhn/, n. 1. Physics. a. the process in which energy is emitted as particles or waves. b. the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and… …
47animal development — Introduction the processes that lead eventually to the formation of a new animal starting from cells derived from one or more parent individuals. Development thus occurs following the process by which a new generation of organisms is produced by …
48nervous system, human — ▪ anatomy Introduction system that conducts stimuli from sensory receptors to the brain and spinal cord and that conducts impulses back to other parts of the body. As with other higher vertebrates, the human nervous system has two main… …
49renal system — ▪ anatomy Introduction in humans (human body), organ system that includes the kidneys, where urine is produced, and the ureters, bladder, and urethra for the passage, storage, and voiding of urine. In many respects the human excretory, or… …
50Endocrine system — In physiology, the endocrine system is a system of glands, each of which secretes a type of hormone directly into the bloodstream to regulate the body. The endocrine system is in contrast to the exocrine system, which secretes its chemicals using …
