Organs Neck

R Parotid Salivary Gland

The parotid gland is one of the three salivary glands contained within the human body. The same applies to many animals. It is the largest of the three glands, as well as the biggest producer of saliva. Saliva, of course, has the lubricating and digestive properties that help protect the alimentary canal linings during meals. Likewise, the antibacterial properties of saliva protect tooth enamel against bacteria. Our two parotid glands are located bilaterally on the inside of our cheeks. If we were to visualize this, the glands lie in front and behind the ears. The word parotid, in fact, is a literal translation for “beside the ear.” When we are at rest, or not eating, the parotid glands account for about ten percent of the saliva in our mouth. It is essential to keep our mouth lubricated at all times to protect the delicate linings of our alimentary canal as dryness can lead to broken skin through which pathogens can enter. However, once activated they will secrete upwards of twenty-five percent of the saliva in our mouths. This increase is imparted by the body’s need for amylase to start the digestion of starches. The main function of parotid glands, like salivary glands in general, lies in facilitating the digestion of food. Source

Vocal Ligament

The vocal ligaments, or inferior thyroarytenoid (thyroartenoideus internus), are two strong bands enclosed within the vocal folds. Each ligament consists of a band of yellow elastic tissue, attached in front to the angle of the thyroid cartilage, and behind to the vocal process of the arytenoid. They are constructed from epithelium (a tissue composed of cells that line the cavities and surfaces of structures throughout the body), but they have a few muscle fibres in them, namely the vocalis muscle. Owing to the connection of the deeper portion of the thyroarytenoid with the vocal fold, this part, if acting separately, is supposed to modify the fold’s elasticity and tension, while the lateral portion rotates the arytenoid cartilage inward, and thus narrows the rima glottidis by bringing the two vocal folds together. Source

Parathyroid Glands

The parathyroid glands are four tiny glands, located in the neck, that control the body’s calcium levels. The parathyroids produce a hormone called parathyroid hormone. PTH raises the blood calcium level by breaking down the bone (where most of the body’s calcium is stored) and causing calcium release. increasing the body’s ability to absorb calcium from food. And increasing the kidney’s ability to hold on to calcium that would otherwise be lost in the urine. Normal parathyroid glands work like the thermostat in your home to keep blood calcium levels in a very tightly controlled range. When the blood calcium level is too low, PTH is released to bring the calcium level back up to normal. When the calcium level is normal or gets a little too high, normal parathyroids will stop releasing PTH. Proper calcium balance is crucial to the normal functioning of the heart, nervous system, kidneys, and bones. Source

R Submandibular Salivary Gland

These are major salivary glands located beneath the floor of the mouth. They each weigh about 15 grams and contribute some 60–67% of unstimulated saliva secretion.

Thyroid Gland

The thyroid gland is a butterfly-shaped organ located in the base of your neck. It releases hormones that control metabolism—the way your body uses energy. The thyroid’s hormones regulate vital body functions, including Breathing, Heart rate, Central and peripheral nervous systems, Body weight, Muscle strength, Menstrual cycles, Body temperature, Cholesterol levels and Much more! The thyroid gland is about 2-inches long and lies in front of your throat. The thyroid is part of the endocrine system, which is made up of glands that produce, store, and release hormones into the bloodstream so the hormones can reach the body’s cells. The thyroid gland uses iodine from the foods you eat to make two main hormones, Triiodothyronine (T3) and Thyroxine (T4). It is important that T3 and T4 levels are neither too high nor too low. Two glands in the brain—the hypothalamus and the pituitary communicate to maintain T3 and T4 balance. The hypothalamus produces TSH Releasing Hormone (TRH) that signals the pituitary to tell the thyroid gland to produce more or less of T3 and T4 by either increasing or decreasing the release of a hormone called thyroid stimulating hormone (TSH). When T3 and T4 levels are low in the blood, the pituitary gland releases more TSH to tell the thyroid gland to produce more thyroid hormones. If T3 and T4 levels are high, the pituitary gland releases less TSH to the thyroid gland to slow production of these hormones. T3 and T4 travel in your bloodstream to reach almost every cell in the body. The hormones regulate the speed with which the cells/metabolism work. For example, T3 and T4 regulate your heart rate and how fast your intestines process food. So if T3 and T4 levels are low, your heart rate may be slower than normal, and you may have constipation/weight gain. If T3 and T4 levels are high, you may have a rapid heart rate and diarrhea/weight loss. Source

Hyoepiglottic Ligament

The hyoepiglottic ligament is an elastic band connecting the anterior surface of the epiglottis to the upper border of the body of the hyoid bone. It is clinically important in performing direct laryngoscopy with a Macintosh laryngoscope blade, the blade tip is placed in the vallecula and moved anteriorly, which causes the hyoepiglottic ligament to pull the epiglottis anteriorly as well and thus expose the glottis.

Thyroepiglottic Ligament

The thyroepiglottic ligament is a ligament of the larynx. It connects the long and narrow attached part or stem of the epiglottis to the angle formed by the two laminæ of the thyroid cartilage, a short distance below the superior thyroid notch.

Epiglottis

The epiglottis is a leaf-shaped cartilage that moves down to form a lid over the glottis and protect the larynx from aspiration of foods or liquids being swallowed. Source

R Sublingual Salivary Gland

The sublingual glands lie directly under the mucous membrane covering the floor of the mouth beneath the tongue. The salivary glands are controlled by the two divisions of the autonomic nervous system, the sympathetic and the parasympathetic. The parasympathetic nerve supply regulates secretion by the acinar cells and causes the blood vessels to dilate. Functions regulated by the sympathetic nerves include secretion by the acinar cells, constriction of blood vessels, and, presumably, contraction of the myoepithelial cells. Normally secretion of saliva is constant, regardless of the presence of food in the mouth. The amount of saliva secreted in 24 hours usually amounts to 1–1.5 liters. When something touches the gums, the tongue, or some region of the mouth lining, or when chewing occurs, the amount of saliva secreted increases. The stimulating substance need not be food—dry sand in the mouth or even moving the jaws and tongue when the mouth is empty increases the salivary flow. This coupling of direct stimulation to the oral mucosa with increased salivation is known as the unconditioned salivary reflex. When an individual learns that a particular sight, sound, smell, or other stimulus is regularly associated with food, that stimulus alone may suffice to stimulate increased salivary flow. This response is known as the conditioned salivary reflex. Source

Fan Ligament

The internal literal ligament, fan-shaped, is attached above by its apex to the internal condyle. Passing downward it expands and may be divided into an anterior and a posterior potion, the anterior portion is attached to the inner side of the coronoid process, and the posterior to the inner side of the olecranon processes of the ulnar. It is in constant with the triceps and flexor carpi ulnaris nuscles and the ulnar nerve. Source

Larynx

The larynx is located within the anterior aspect of the neck, anterior to the inferior portion of the pharynx and superior to the trachea. Its primary function is to protect the lower airway by closing abruptly upon mechanical stimulation, thereby halting respiration and preventing the entry of foreign matter into the airway. Other functions of the larynx include the production of sound (phonation), coughing, the Valsalva maneuver, and control of ventilation, and acting as a sensory organ. The larynx is composed of 3 large, unpaired cartilages (cricoid, thyroid, epiglottis), 3 pairs of smaller cartilages (arytenoids, corniculate, cuneiform). Source

Thyrohyoid Membrane

The thyrohyoid membrane is a wide and fibrous layer of tissue that connects the thyroid cartilage to the hyoid bone. The thyroid cartilage is the largest cartilage — a type of strong, flexible tissue — in the neck, part of which forms the Adam’s apple. The hyoid is located in the neck, just below the lower jawbone, or mandible. The thyrohyoid membrane creates the conditions necessary for the upward movement of the larynx during deglutition, or swallowing. The thyrohyoid membrane is a wide and fibrous layer of tissue that connects the thyroid cartilage to the hyoid bone. The thyroid cartilage is the largest cartilage — a type of strong, flexible tissue — in the neck, part of which forms the Adam’s apple. The hyoid is located in the neck, just below the lower jawbone, or mandible. The thyrohyoid membrane creates the conditions necessary for the upward movement of the larynx during deglutition, or swallowing. The thyrohyoid membrane covers the area below the origin point of the middle constrictor muscle, which lies near the lower jawline. The thinner, lateral (side) portions of the thyrohyoid membrane are pierced by the internal laryngeal artery and the internal laryngeal nerve, which is a branch of the superior laryngeal nerve. This nerve helps sense the presence of mucus in the larynx, or voice box, and is part of the coughing reflex. Source

Thymus

The thymus gland, despite containing glandular tissue and producing several hormones, is much more closely associated with the immune system than with the endocrine system. The thymus serves a vital role in the training and development of T-lymphocytes or T cells, an extremely important type of white blood cell. T cells defend the body from potentially deadly pathogens such as bacteria, viruses, and fungi. The thymus is a soft, roughly triangular organ located in the mediastinum of the thoracic cavity anterior and superior to the heart and posterior to the sternum. It has two distinct but identical lobes that are each surrounded by a tough, fibrous capsule. Within each lobe is a superficial region of tissue called the cortex and a histologically distinct deep region called the medulla. Epithelial tissues and lymphatic tissues containing dendritic cells and macrophages make up the majority of both regions of the thymus. The function of the thymus is to receive immature T cells that are produced in the red bone marrow and train them into functional, mature T cells that attack only foreign cells. T cells first reside within the cortex of the thymus where they come in contact with epithelial cells presenting various antigens. The immature T cells that respond to the antigens corresponding to foreign cells are selected to survive, mature, and migrate to the medulla while the rest die via apoptosis and are cleaned up by macrophages. This process is known as positive selection. Upon reaching the medulla, the surviving T cells continue to mature and are presented with the body’s own antigens. Source

L Parotid Salivary Gland

The parotid gland is one of the three salivary glands contained within the human body. The same applies to many animals. It is the largest of the three glands, as well as the biggest producer of saliva. Saliva, of course, has the lubricating and digestive properties that help protect the alimentary canal linings during meals. Likewise, the antibacterial properties of saliva protect tooth enamel against bacteria. When we are at rest, or not eating, the parotid glands account for about ten percent of the saliva in our mouth. It is essential to keep our mouth lubricated at all times to protect the delicate linings of our alimentary canal as dryness can lead to broken skin through which pathogens can enter. However, once activated they will secrete upwards of twenty-five percent of the saliva in our mouths. This increase is imparted by the body’s need for amylase to start the digestion of starches. The main function of parotid glands, like salivary glands in general, lies in facilitating the digestion of food. Source

Mouth

Also known as the oral cavity, the mouth is the hollow cavity that allows food and air to enter the body. The mouth contains many other organs – such as the teeth, tongue, and the ducts of the salivary glands – that work together to aid in the ingestion and digestion of food. The mouth also plays a major role in the production of speech through the movements of the tongue, lips and cheeks. The mouth is a hollow cavity formed by the space between the lips, cheeks, tongue, hard and soft palates and the throat. Its external opening is located along the body’s midline inferior to the nose and superior to the chin. Source

Uvula

This is a conic projection from the posterior edge of the middle of the soft palate, composed of connective tissue containing a number of racemose glands, and some muscular fibers (musculus uvulae). It also contains a large number of serous glands that produce a lot of thin saliva.

R Palatine Tonsils

The palatine tonsils (what the term tonsils generally refer to) are two lymphatic tissue masses. There is one located on each side of the oral pharynx, in the back of the throat. The function of palatine tonsils has yet to be discovered, however they are part of the immune system and are thought to assist in defending the body from respiratory infections. Source

L Palatine Tonsils

L Arytenoid Cartilage

The arytenoid cartilage is a pair of pyramid-shaped pieces of cartilage found in the larynx (voice box), which are essential to the production of vocal sound. Cartilage is tough, yet flexible tissue located at the ends of joints. The arytenoid cartilage is located on the dorsal (back) side of the larynx above the cricoid lamina, a signet ring-shaped cartilage that lies near the bottom of the larynx. Source

R Corniculate

The corniculate cartilages are 2 small, conical cartilages that articulate with the apices of the arytenoid cartilages, serving to extend them posteriorly and medially. They are located in the posterior parts of the aryepiglottic folds of mucous membrane. Source

L Corniculate

R Arytenoid Cartilage

Tongue

The tongue is a muscular organ in the mouth. The tongue is covered with moist, pink tissue called mucosa. Tiny bumps called papillae give the tongue its rough texture. Thousands of taste buds cover the surfaces of the papillae. Taste buds are collections of nerve-like cells that connect to nerves running into the brain. The tongue is anchored to the mouth by webs of tough tissue and mucosa. The tether holding down the front of the tongue is called the frenum. In the back of the mouth, the tongue is anchored into the hyoid bone. The tongue is vital for chewing and swallowing food, as well as for speech. The four common tastes are sweet, sour, bitter, and salty. A fifth taste, called umami, results from tasting glutamate (present in MSG). The tongue has many nerves that help detect and transmit taste signals to the brain. Because of this, all parts of the tongue can detect these four common tastes. Source

L Sublingual Salivary Gland

A salivary gland is the tissue in our mouths that expels saliva. Anytime our mouth comes near a hot sandwich we feel them activate. Salivary glands are only found in mammals. As exocrine glands, they expel saliva into the epithelial surface of our mouths by way of ducts, rather than through the bloodstream. Each day, our glands produce as much as a quart of saliva. Saliva is a mixture of water, mucus, antibacterial substance, and digestive enzymes. One of the most recognizable digestive enzymes in the human body is alpha-amylase. This enzyme is able to break down the starch in our food to simpler and more easily digestible sugars like glucose and maltose. Whenever we chew, we are activating these glands in preparation for the safe breakdown of our meal.

Cricoid Cartilage

The cricoid cartilage is a ring of cartilage that surrounds the trachea, or windpipe. It is located near the middle and center of the neck. This cartilage consists of strong connective tissue constituting the dorsal (back) part of the larynx, or voice box. The cricoid cartilage is located slightly below the thyroid cartilage, which it connects with through the medial cricothyroid ligament. It also joins the first tracheal ring through the cricotracheal ligament. The thyroid gland has an anatomical relationship with this cartilage. The gland’s two lobes extend above on either sides of the cricoid, but the thyroid isthmus — a bridge of tissue that joins the two halves of the thyroid over the trachea — is below it. The lateral (side) and front portions of this cartilage are slightly narrower than the back portion. The primary role of the cricoid cartilage is to provide connectivity for different ligaments, cartilages, and muscles, which facilitate the opening and shutting of the air passage and the production of sound. Source