A gland that is found on both sides of the trachea (“windpipe”) in humans. This gland secretes the hormone thyroxine, which increases the rate of metabolism.
A gland located in the front of the neck that secretes thyroid hormones, which are important in body metabolism.
The endocrine gland situated in the neck that secretes thyroid hormone, which regulates many body functions including maintenance of reproductive function, metabolism, intelligence, and physical growth.
Gland located at the base of the neck which produces hormones.
A two-lobed gland in the front of the neck that produces several key thyroid hormones. These help regulate metabolism (the body’s biochemical processes), growth and physical development (see growth and growth disorders), and levels of calcium in the body, often working with hormones from other glands, such as the hypothalamus, pituitary gland, and parathyroid gland. Too little thyroid production leads to a condition known as hypothyroidism (or myxedema), which in children can cause extremely short stature. Symptoms of hypothyroidism include weight gain, dry skin, hair loss, constipation, cold sensitivity, and fatigue. By contrast, too much thyroid hormone, or hyperthyroidism, can cause weight loss, diarrhea, sweating, heat intolerance, and fatigue.
Large endocrine gland situated at the base of the neck. It consists of two lobes, one on each side of the trachea, connected by an isthmus. Under the influence of thyroid- stimulating hormone (TSH) released from the anterior pituitary gland, the thyroid secretes the hormone thyroxine into the bloodstream; it is essential for normal growth and development in children and normal metabolic rates in adults. Disorders of the thyroid include goiter, myxedema, and cretinism.
A gland in the endocrine system, located under the larynx (voice box) and wrapped around the top of the trachea (windpipe). The thyroid gland consists of two lobes, one on each side of the windpipe, joined by a piece of tissue called the isthmus.
A large endocrine gland situated in the base of the neck. It consists of two lobes, one on either side of the trachea, that are joined by an isthmus (sometimes a third lobe extends upward from the isthmus). The thyroid gland consists of a large number of closed follicles inside which is a jellylike colloid, which contains the principle active substances that are secreted by the gland. The thyroid gland is concerned with regulation of the metabolic rate by the secretion of thyroid hormone, which is stimulated by thyroid-stimulating hormone from the pituitary gland and requires trace amounts of iodine. Thyroid extract is used in the treatment of thyroid deficiency diseases.
A highly vascular organ situated in front of the neck. It consists of a narrow isthmus crossing the windpipe close to its upper end, and joining two lateral lobes which run upwards, one on each side of the larynx. The gland is therefore shaped somewhat like a horseshoe, each lateral lobe being about 5 cm (2 inches) long and the isthmus about 12 mm (½ inch) wide, and it is firmly bound to the larynx. The weight of the thyroid gland is about 28-5 grams (1 ounce), but it is larger in females than in males, and in some women increases in size during menstrution. It often reaches an enormous size in the condition known as goitre.
A large endocrine gland located in the center of the base of the neck. The gland is composed of two lobes, one on each side of the trachea, and an isthmus of tissue connecting the lower two thirds of each lobe. The isthmus is usually located at the level of the second to third tracheal rings. The whole gland is surrounded by a thin fibrous capsule attached in back to the cricoid cartilage and the first few tracheal rings. The lobes of the thyroid lie under the sternothyroid and sternohyoid muscles. The thyroid is filled with capillary networks (supplied by the superior and inferior thyroid arteries) that surround the many spherical units (follicles) packed inside the gland. Thyroid follicles consist of a ring of follicular cells surrounding a space filled with a clear colloid (a mixture of thyroglobulin proteins and iodine), from which the thyroid hormones (thyroxine and related molecules) are synthesized. These hormones regulate the rate of cellular metabolism throughout the body. All the steps in synthesizing and releasing thyroid hormones are stimulated by thyroid-stimulating hormone (TSH) secreted by the pituitary gland. Another class of thyroid cells, the parafollicular or C cells, is found outside the follicles; C cells secrete calcitonin, a calcium-lowering hormone.
Controls how quickly the body burns energy (metabolism), makes proteins, and controls how sensitive the body should be to other hormones.
An endocrine gland located at the front of the neck, that regulates the rate of metabolism and
helps to regulate the amount of calcium in the blood.
A gland shaped like a butterfly that sits just below the larynx that releases thyroxine.
The thyroid is a primary gland located at the front of the throat, often referred to as the “master gland” because it regulates other glands and hormones in the body. When the gland is overactive, it leads to a condition known as hyperthyroidism or Graves’ disease, marked by weight loss, hand tremors, protruding eyes, and irregular heart activity. On the other hand, underactivity results in a condition named myxedema, which manifests as rough hair and skin, mental lethargy, and other signs. Enlargements of the thyroid, known as goiters or Derbyshire neck, arise from insufficient iodine consumption.