A light-sensitive neuroendocrine organ attached to the roof of the THIRD VENTRICLE of the brain. The pineal gland secretes MELATONIN, other BIOGENIC AMINES and NEUROPEPTIDES.
A biogenic amine that is found in animals and plants. In mammals, melatonin is produced by the PINEAL GLAND. Its secretion increases in darkness and decreases during exposure to light. Melatonin is implicated in the regulation of SLEEP, mood, and REPRODUCTION. Melatonin is also an effective antioxidant.
An enzyme that catalyzes the transfer of a methyl group from S-adenosylmethionine to N-acetylserotonin to form N-acetyl-5-methoxytryptamine (MELATONIN).
Neoplasms which originate from pineal parenchymal cells that tend to enlarge the gland and be locally invasive. The two major forms are pineocytoma and the more malignant pineoblastoma. Pineocytomas have moderate cellularity and tend to form rosette patterns. Pineoblastomas are highly cellular tumors containing small, poorly differentiated cells. These tumors occasionally seed the neuroaxis or cause obstructive HYDROCEPHALUS or Parinaud's syndrome. GERMINOMA; CARCINOMA, EMBRYONAL; GLIOMA; and other neoplasms may arise in the pineal region with germinoma being the most common pineal region tumor. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2064; Adams et al., Principles of Neurology, 6th ed, p670)
An acetyltransferase with specificity towards the amine group of aromatic alkylamines (arylalkylamines) such as SEROTONIN. This enzyme is also referred to as serotonin acetylase despite the fact that serotonin acetylation can also occur through the action of broad specificity acetyltransferases such as ARYLAMINE N-ACETYLTRANSFERASE.
An enzyme that catalyzes the transfer of acetyl groups from ACETYL-COA to arylamines. It can also catalyze acetyl transfer between arylamines without COENZYME A and has a wide specificity for aromatic amines, including SEROTONIN. However, arylamine N-acetyltransferase should not be confused with the enzyme ARYLALKYLAMINE N-ACETYLTRANSFERASE which is also referred to as SEROTONIN ACETYLTRANSFERASE.
One of two salivary glands in the neck, located in the space bound by the two bellies of the digastric muscle and the angle of the mandible. It discharges through the submandibular duct. The secretory units are predominantly serous although a few mucous alveoli, some with serous demilunes, occur. (Stedman, 25th ed)
The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation.
The absence of light.
The largest of the three pairs of SALIVARY GLANDS. They lie on the sides of the FACE immediately below and in front of the EAR.
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
Receptor, Melatonin, MT1
A melatonin receptor subtype that is primarily found in the HYPOTHALAMUS and in the KIDNEY.
Small, sacculated organs found within the DERMIS. Each gland has a single duct that emerges from a cluster of oval alveoli. Each alveolus consists of a transparent BASEMENT MEMBRANE enclosing epithelial cells. The ducts from most sebaceous glands open into a HAIR FOLLICLE, but some open on the general surface of the SKIN. Sebaceous glands secrete SEBUM.
Involuntary contraction of the muscle fibers innervated by a motor unit. Fasciculations can often by visualized and take the form of a muscle twitch or dimpling under the skin, but usually do not generate sufficient force to move a limb. They may represent a benign condition or occur as a manifestation of MOTOR NEURON DISEASE or PERIPHERAL NERVOUS SYSTEM DISEASES. (Adams et al., Principles of Neurology, 6th ed, p1294)
Any fluid-filled closed cavity or sac that is lined by an EPITHELIUM. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues.
Encyclopedias as Topic
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
Endocrine Gland Neoplasms
Tumors or cancer of the ENDOCRINE GLANDS.
A branch of psychology which investigates the correlation between experience or behavior and the basic neurophysiological processes. The term neuropsychology stresses the dominant role of the nervous system. It is a more narrowly defined field than physiological psychology or psychophysiology.
Fields of science encompassing studies and research from the disciplines of PHYSICS; CHEMISTRY; BIOLOGICAL SCIENCES; and MATHEMATICS; that are related to the planet EARTH. Subfields include atmospheric chemistry; CLIMATOLOGY; ENVIRONMENTAL SCIENCES; GEOGRAPHY; GEOLOGY; geophysics; METEOROLOGY; OCEANOGRAPHY; PALEONTOLOGY; mineralogy; and seismology.
A state of consciousness in which the individual eliminates environmental stimuli from awareness so that the mind can focus on a single thing, producing a state of relaxation and relief from stress. A wide variety of techniques are used to clear the mind of stressful outside interferences. It includes meditation therapy. (Mosby's Medical, Nursing, and Allied Health Dictionary, 4th ed)