Biology

Facial Nerve

Facial Nerve

Facial Nerve Definition Facial nerve is the seventh cranial nerve, supplying the muscles controlling facial expression, glands of the palate and nose, and the taste buds in the anterior two-thirds of the tongue. It is a mixed nerve that has fibers both going out and coming in (both efferent and a.....

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Parotid Gland

Parotid Gland

Parotid Gland Definition Parotid gland is either of the pair of salivary glands situated below and in front of each ear. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Approximately 20% of saliva is.....

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Osteocyte

Osteocyte

Osteocyte Definition Osteocyte is a cell characteristic of mature bone tissue. It is derived from osteoblasts and embedded in the calcified matrix of bone. Osteocytes are found in small, round cavities called lacunae and have thin, cytoplasmic branches. The adult human body has about 42 billion o.....

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Osteoclast

Osteoclast

Osteoclast Definition Osteoclast is a specialized bone cell that absorbs bone, allowing for the deposition of new bone and maintenance of bone strength. The osteoclast disassembles and digests the composite of hydrated protein and mineral at a molecular level by secreting acid and a collagenase, .....

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Androgen Receptor

Androgen Receptor

Androgen Receptor Definition Androgen receptor is a key mediator of androgen function within normal and malignant prostate cells. It is mainly expressed in androgen target tissues, such as the prostate, skeletal muscle, liver, and central nervous system (CNS), with the highest expression level ob.....

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Transcription Factor

Transcription Factor

Transcription Factor Definition Transcription factors (TFs) are proteins that regulate the transcription of genes—that is, their copying into RNA, on the way to making a protein.  They are usually proteins, although they can also consist of short, non-coding RNA. TFs are also usually found wor.....

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Heat Shock Protein

Heat Shock Protein

Heat Shock Protein Definition Heat shock protein (HSP) is an intracellular protein that increases in concentration during metabolic stress, such as exposure to heat. HsPs affect protein assembly, folding, sorting, and uptake into organelles. There are various kinds of HsPs, each performing differ.....

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Steroid Hormone Receptor

Steroid Hormone Receptor

Steroid Hormone Receptor Definition Steroid hormone receptor includes 48 receptors for the gonadal and adrenal steroids, nonsteroidal ligands such as thyroid hormones, vitamin D, retinoic acid, and fatty acids, as well as numerous “orphan” receptors whose endogenous ligands, if necess.....

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Glucocorticoid Receptor

Glucocorticoid Receptor

Glucocorticoid Receptor Definition Glucocorticoid Receptor (GR) also known as NR3C1 (nuclear receptor subfamily 3, group C, member 1), which is mediates actions of glucocorticoids (GCs) on gene transcriptional regulation. GCs are widely used in treating diseases such as autoimmune disorders. The .....

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Glucocorticoid

Glucocorticoid

Glucocorticoid Definition Glucocorticoid is any of a group of anti-inflammatory steroidlike compounds, such as hydrocortisone, that are produced by the adrenal cortex, are involved in carbohydrate, protein, and fat metabolism, and are used as anti-inflammatory agents. Glucocorticoids (GCs) are st.....

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Cortisol

Cortisol

Cortisol Definition Cortisol is the principal steroid hormone produced by the adrenal cortex. It regulates carbohydrate metabolism and the immune system and maintains blood pressure. When natural or synthetic cortisol is used as a pharmaceutical, it is also known as hydrocortisone. It functions t.....

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Adrenal Gland

Adrenal Gland

Adrenal Gland Definition Adrenal gland is a small gland located on top of the kidney. The outer portion, or cortex, secretes steroid hormones (corticosteroids). The inner portion, or medulla, secretes epinephrine and norepinephrine. Each gland has an outer cortex which produces steroid hormones a.....

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