pineal

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Related to pineal glands: pituitary glands, Thymus glands, Thyroid glands

pineal

 [pin´e-al]
1. shaped like a pine cone.
2. pertaining to the pineal body.
pineal body a small, conical structure attached by a stalk to the posterior wall of the third ventricle of the cerebrum, believed by many to be an endocrine gland. In certain amphibians and reptiles the gland is thought to function as a light receptor. In most mammals, including humans, it appears to be the major or unique site of melatonin biosynthesis; the effect of melatonin on the body and the exact function of the pineal body remain obscure. Called also epiphysis cerebri and pineal gland.

pin·e·al

(pin'ē-ăl),
1. Shaped like a pine cone. Synonym(s): piniform
2. Pertaining to the pineal body.
[L. pineus, relating to the pine, pinus]

pineal

/pin·e·al/ (pin´e-il)
1. pertaining to the pineal body.
2. shaped like a pine cone.

pineal

(pĭn′ē-əl, pī′nē-)
adj.
1. Having the form of a pine cone.
2. Of or relating to the pineal gland.

pineal

[pin′ē·əl]
Etymology: L, pineus, pine cone
1 pertaining to the pineal body.
2 resembling a pine cone.

pineal

adjective Referring to the pineal gland or region of the brain.

Pronunciation
Medspeak-UK: pronounced, PIE knee ull
Medspeak-US: pronounced, PIN ee tull

pin·e·al

(pin'ē-ăl)
1. Shaped like a pinecone.
Synonym(s): piniform.
2. Pertaining to the pineal body.
[L. pineus, relating to the pine, pinus]

pineal

1. shaped like a pine cone.
2. pertaining to the pineal body.

pineal body, pineal gland
a small, conical endocrine gland attached by a stalk to the dorsal wall of the third ventricle of the cerebrum. In certain amphibians and reptiles the gland functions as a light receptor. In most mammals, including humans, it appears to be the major or unique site of melatonin biosynthesis. The effect of melatonin on the body and the exact function of the pineal body remain uncertain. There is an increasing body of evidence that the pineal body is inhibitory to the gonads and that it is the principal mechanism in the known effect of environmental illumination on estrous cycles. It is proposed that the retina perceives the changes in light intensity and stimulates the pineal gland via the sympathetic nervous system.
pineal extract
pineal eye
in lower vertebrates the pineal body is a third or pineal eye.
pineal gland
see pineal body (above).
References in periodicals archive ?
Studies have recently examined several other genes that are involved in retinal dystrophies that potentially lead to blindness, and they found that these genes are also expressed in the pineal gland (Bailey et al.
In the first, the self-reported sleep problems of individuals with retinitis pigmentosa were examined and, in the second, an attempt was made to determine if those who have a genetic mutation that causes their visual disorder but is also expressed in the pineal gland are more likely to experience sleep-related difficulties than those whose mutation is expressed only in the retina.
The effect of copper on (3H) tryptophan metabolism in organ cultures of rat pineal glands.
The brain's pineal gland is the central structure in the circadian system that produces the hormone melatonin at night under the control of the SCN.
16), (17), (22) Shaped like a tiny pine cone (hence the name), the pineal gland is filled with nerve cells that respond to light or darkness (some biologists refer to the pineal as the "third eye" for this reason).
Through its secretion of melatonin, the pineal gland acts as the body's central clock, telling the brain and other organs when it's time to be active and when it's time to rest.
In dark situations, sympathetic input from the superior sympathetic ganglion at the pineal gland leads to increased melatonin production.
The consequence is a circadian rhythm of melatonin production and release from the pineal gland.
The pineal gland was once considered a vestigial organ, comparable to the appendix.
Blum and colleagues (1973) compared the alcohol consumption patterns of rats whose pineal glands had been removed with those of control animals both in total darkness and under a normal light-dark cycle.
Melatonin is a hormone naturally produced by the pineal gland in the brain which has been linked with changes in sleep and biological rhythms and has been the recipient of national media and news coverage.
This work has provided evidence that each of these proteins, or a near relative, is present in pineal glands of some species but not in other body tissues.