ThyroidThe thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans, it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the isthmus (: isthmi). The thyroid gland is a butterfly-shaped gland located in the neck below the Adam's apple. Microscopically, the functional unit of the thyroid gland is the spherical thyroid follicle, lined with follicular cells (thyrocytes), and occasional parafollicular cells that surround a lumen containing colloid.
LarynxThe larynx (ˈlæɹɪŋks), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about 4–5 centimeters in diameter. The larynx houses the vocal cords, and manipulates pitch and volume, which is essential for phonation. It is situated just below where the tract of the pharynx splits into the trachea and the esophagus.
PharynxThe pharynx (: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates, though its structure varies across species. The pharynx carries food to the esophagus and air to the larynx. The flap of cartilage called the epiglottis stops food from entering the larynx. In humans, the pharynx is part of the digestive system and the conducting zone of the respiratory system.
EsophagusThe esophagus (American English) or oesophagus (British English, see spelling differences; both iːˈsɒfəɡəs,_ɪ-; : esophagi, esophaguses, oesophagi or oesophaguses), colloquially known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the stomach. The esophagus is a fibromuscular tube, about long in adults, that travels behind the trachea and heart, passes through the diaphragm, and empties into the uppermost region of the stomach.
Internal carotid arteryThe internal carotid artery (Latin: arteria carotis interna) is an artery in the neck which supplies the anterior circulation of the brain. In human anatomy, the internal and external carotids arise from the common carotid arteries, where these bifurcate at cervical vertebrae C3 or C4. The internal carotid artery supplies the brain, including the eyes, while the external carotid nourishes other portions of the head, such as the face, scalp, skull, and meninges.
Common carotid arteryIn anatomy, the left and right common carotid arteries (carotids) (pronkəˈrɒtɪd) are arteries that supply the head and neck with oxygenated blood; they divide in the neck to form the external and internal carotid arteries. The common carotid arteries are present on the left and right sides of the body. These arteries originate from different arteries but follow symmetrical courses. The right common carotid originates in the neck from the brachiocephalic trunk; the left from the aortic arch in the thorax.
HyperthyroidismHyperthyroidism is the condition that occurs due to excessive production of thyroid hormones by the thyroid gland. Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism. Some, however, use the terms interchangeably. Signs and symptoms vary between people and may include irritability, muscle weakness, sleeping problems, a fast heartbeat, heat intolerance, diarrhea, enlargement of the thyroid, hand tremor, and weight loss.
Anaplastic thyroid cancerAnaplastic thyroid cancer (ATC), also known as anaplastic thyroid carcinoma, is an aggressive form of thyroid cancer characterized by uncontrolled growth of cells in the thyroid gland. This form of cancer generally carries a very poor prognosis due to its aggressive behavior and resistance to cancer treatments. The cells of anaplastic thyroid cancer are highly abnormal and usually no longer resemble the original thyroid cells and have poor differentiation.
Graves' ophthalmopathyGraves’ ophthalmopathy, also known as thyroid eye disease (TED), is an autoimmune inflammatory disorder of the orbit and periorbital tissues, characterized by upper eyelid retraction, lid lag, swelling, redness (erythema), conjunctivitis, and bulging eyes (exophthalmos). It occurs most commonly in individuals with Graves' disease, and less commonly in individuals with Hashimoto's thyroiditis, or in those who are euthyroid. It is part of a systemic process with variable expression in the eyes, thyroid, and skin, caused by autoantibodies that bind to tissues in those organs.
Cricoid cartilageThe cricoid cartilage ˌkraɪkɔɪd_ˈkɑːrtɪlɪdʒ, or simply cricoid (from the Greek krikoeides meaning "ring-shaped") or cricoid ring, is the only complete ring of cartilage around the trachea. It forms the back part of the voice box and functions as an attachment site for muscles, cartilages, and ligaments involved in opening and closing the airway and in producing speech. The cricoid cartilage is the only laryngeal cartilage to form a complete circle around the airway. It is smaller yet thicker and tougher than the thyroid cartilage above.
