"the coccygeal body which is situated on the median sacral artery. The relations of the cervical region of the common carotid artery may be discussed in two points: After ligature of the common carotid, the collateral circulation can be perfectly established, by the free communication which exists between the carotid arteries of opposite sides, both without and within the cranium, and by enlargement of the branches of the subclavian artery on the side corresponding to that on which the vessel has been tied. The chief communications outside the skull take place between the superior and inferior thyroid arteries, and the"
"Carotid sheath The carotid sheath is an anatomical term for the fibrous connective tissue that surrounds the vascular compartment of the neck. It is part of the deep cervical fascia of the neck, below the superficial cervical fascia meaning the subcutaneous adipose tissue immediately beneath the skin. The deep cervical fascia of the neck includes four parts: The carotid sheath is located at the lateral boundary of the retropharyngeal space at the level of the oropharynx on each side of the neck and deep to the sternocleidomastoid muscle, extending from the base of the skull to the first rib and"
"body is sent to the cardiorespiratory centers in the medulla oblongata via the afferent branches of the glossopharyngeal nerve. The afferent fibres of the aortic body chemoreceptors are relayed by the vagus nerve. These centers, in turn, regulate breathing and blood pressure, with hypoxia causing an increase in ventilation. A paraganglioma is a tumor that may involve the carotid body and is usually benign. Rarely, a malignant neuroblastoma may originate from the carotid body. Innervated by glossopharyngeal nerve (cranial nerve IX). Carotid body The carotid body (""carotid glomus"" or ""glomus caroticum"") is a small cluster of chemoreceptors and supporting cells"
"to decreased risk of cardiovascular disease. Carotenoids are organic pigments found in the chloroplasts and chromoplasts of plants. They are also found in some organisms such as algae, fungi, some bacteria, and certain species of aphids. There are over 600 known carotenoids. They are split into two classes, xanthophylls and carotenes. Xanthophylls are carotenoids with molecules containing oxygen, such as lutein and zeaxanthin. Carotenes are carotenoids with molecules that are unoxygenated, such as α-carotene, β-carotene and lycopene. In plants, carotenoids can occur in roots, stems, leaves, flowers, and fruits. Carotenoids have two important functions in plants. First, they can contribute"
"sustentacular supportive cells. The carotid body contains the most vascularized tissue in the human body . The thyroid gland is very vascular, but not quite as much as the carotid body. The carotid body functions as a sensor: it responds to a stimulus, primarily O partial pressure, which is detected by the type I (glomus) cells, and triggers an action potential through the afferent fibers of the glossopharyngeal nerve, which relays the information to the central nervous system. The carotid body chemoreceptors are primarily sensitive to decreases in the partial pressure of oxygen (P). This is in contrast to the"
"Serum levels of carotenoids vary between region, ethnicity, and sex in the healthy population. All are absorbed by passive diffusion from the gastrointestinal tract and are then partially metabolized in the intestinal mucosa and liver to vitamin A. From there they are transported in the plasma into the peripheral tissues. Carotenoids are eliminated via sweat, sebum, urine, and gastrointestinal secretions. Carotenoids contribute to normal-appearing human skin color, and are a significant component of physiologic ultraviolet photoprotection. Carotenemia most commonly occurs in vegetarians and young children. Carotenemia is more easily appreciated in light-complexioned people, and it may present chiefly as an"
"carotenoid called staphyloxanthin. This carotenoid is a virulence factor with an antioxidant action that helps the microbe evade death by reactive oxygen species used by the host immune system. Microorganisms can be genetically modified to produce certain C40 carotenoids, including lycopene and beta carotene. Carotenoid Carotenoids (), also called tetraterpenoids, are organic pigments that are produced by plants and algae, as well as several bacteria and fungi. Carotenoids give the characteristic color to carrots, corn, canaries, and daffodils, as well as egg yolks, rutabagas, buttercups, and bananas. Carotenoids can be produced from fats and other basic organic metabolic building blocks"
"and aortic bodies to the brainstem, which responds accordingly (e.g. increasing ventilation). Both carotid and aortic bodies increase sensory discharge during hypoxia. Carotid bodies are considered the primary peripheral chemoreceptor and have been shown to contribute more to a hypoxic response. However, in the chronic absence of the carotid body, the aortic body is able to perform a similar respiratory regulatory role, suggesting that it possesses efficacious mechanisms of signal transduction as well. The differing locations of the two bodies ideally position them to take advantage of different information; the carotid bodies, located on one of the main arteries of"
"Carotenoid Carotenoids (), also called tetraterpenoids, are organic pigments that are produced by plants and algae, as well as several bacteria and fungi. Carotenoids give the characteristic color to carrots, corn, canaries, and daffodils, as well as egg yolks, rutabagas, buttercups, and bananas. Carotenoids can be produced from fats and other basic organic metabolic building blocks by all these organisms. The only animals known to produce carotenoids are aphids and spider mites, which acquired the ability and genes from fungi or it is produced by endosymbiotic bacteria in whiteflies. Carotenoids from the diet are stored in the fatty tissues of"
"animals, and exclusively carnivorous animals obtain the compounds from animal fat. There are over 1100 known carotenoids; they are split into two classes, xanthophylls (which contain oxygen) and carotenes (which are purely hydrocarbons, and contain no oxygen). All are derivatives of tetraterpenes, meaning that they are produced from 8 isoprene molecules and contain 40 carbon atoms. In general, carotenoids absorb wavelengths ranging from 400–550 nanometers (violet to green light). This causes the compounds to be deeply colored yellow, orange, or red. Carotenoids are the dominant pigment in autumn leaf coloration of about 15-30% of tree species, but many plant colors,"
"Carnitine-acylcarnitine translocase deficiency Carnitine-acylcarnitine translocase deficiency (CATD) is a rare, autosomal recessive metabolic disorder that prevents the body from converting long-chain fatty acids into energy, particularly during periods without food. Carnitine, a natural substance acquired mostly through the diet, is used by cells to process fats and produce energy. People with this disorder have a faulty enzyme that prevents long-chain fatty acids from being transported into the innermost part of the mitochondria for processing. The signs of carnitine-acylcarnitine translocase deficiency usually begin within the first few hours of life. Seizures, an irregular heartbeat, and breathing problems are often the first"
"Carotenosis An excess of dietary carotenoids may cause a marked orange discoloration of the outermost skin layer. This benign and reversible condition – which is most easily observed in light-skinned people and may be mistaken for jaundice – is known as carotenosis or carotenoderma or carotenodermia. Carotenemia, or carotenaemia (xanthaemia), is the presence of the orange pigment carotene in the blood from excessive intake of carrots or other vegetables containing the pigment resulting in increased serum carotenoids. Carotenoids are lipid-soluble compounds that include alpha- and beta-carotene, beta-cryptoxanthin, lycopene, lutein, and zeaxanthin. The primary serum carotenoids are beta-carotene, lycopene, and lutein."
"the pretracheal fascia, and the prevertebral fascia. The cervical part of the sympathetic trunk is embedded in prevertebral fascia immediately posterior to the sheath. Carotid sheath The carotid sheath is an anatomical term for the fibrous connective tissue that surrounds the vascular compartment of the neck. It is part of the deep cervical fascia of the neck, below the superficial cervical fascia meaning the subcutaneous adipose tissue immediately beneath the skin. The deep cervical fascia of the neck includes four parts: The carotid sheath is located at the lateral boundary of the retropharyngeal space at the level of the oropharynx"
"Carotene The term carotene (also carotin, from the Latin ""carota"", ""carrot"") is used for many related unsaturated hydrocarbon substances having the formula CH, which are synthesized by plants but in general cannot be made by animals (with the exception of some aphids and spider mites which acquired the synthesizing genes from fungi). Carotenes are photosynthetic pigments important for photosynthesis. Carotenes contain no oxygen atoms. They absorb ultraviolet, violet, and blue light and scatter orange or red light, and (in low concentrations) yellow light. Carotenes are responsible for the orange colour of the carrot, for which this class of chemicals is"
"high-energy light and protects these organs from intracellular damage. Humans and other animals are mostly incapable of synthesizing carotenoids, and must obtain them through their diet. Carotenoids are a common and often ornamental feature in animals. For example, the pink color of salmon, and the red coloring of cooked lobsters and scales of the yellow morph of common wall lizards are due to carotenoids. It has been proposed that carotenoids are used in ornamental traits (for extreme examples see puffin birds) because, given their physiological and chemical properties, they can be used as visible indicators of individual health, and hence"
"food supply from which the carotenoid is obtained. There is a positive correlation between the chromas of the tail and breast feathers and body condition. Carotenoids play an important role in immune function for many animals, so carotenoid dependent signals might indicate health. Frogs constitute another conspicuous illustration of the principle. There are two types of dichromatism for frog species: ontogenetic and dynamic. Ontogenetic frogs are more common and have permanent color changes in males or females. Litoria lesueuri is an example of a dynamic frog that has temporary color changes in males during breeding season. Hyperolius ocellatus is an"
"Phytoene Phytoene (FY-toe-een) is a 40-carbon intermediate in the biosynthesis of carotenoids. The synthesis of phytoene is the first committed step in the synthesis of carotenoids in plants. Phytoene is produced from two molecules of geranylgeranyl pyrophosphate (GGPP) by the action of the enzyme phytoene synthase. The two GGPP molecules are condensed together followed by removal of diphosphate and proton shift leading to the formation of phytoene. Dietary phytoene and phytofluene are found in a number of human tissues including the liver, lung, breast, prostate, colon, and skin. Accumulation of these carotenoids in the skin may protect the skin by"
"(resulting in carotenes not being a form of vitamin A for this species); while cats can convert a trace of β-carotene to retinol, although the amount is totally insufficient for meeting their daily retinol needs. Chemically, carotenes are polyunsaturated hydrocarbons containing 40 carbon atoms per molecule, variable numbers of hydrogen atoms, and no other elements. Some carotenes are terminated by hydrocarbon rings, on one or both ends of the molecule. All are coloured to the human eye, due to extensive systems of conjugated double bonds. Structurally carotenes are tetraterpenes, meaning that they are synthesized biochemically from four 10-carbon terpene units,"
"is known as the carotid sinus or the carotid bulb. The ascending portion of the cervical segment occurs distal to the bulb, when the vessel walls are again parallel. The internal carotid runs vertically upward in the carotid sheath and enters the skull through the carotid canal. During this part of its course, it lies in front of the transverse processes of the upper three cervical vertebrae. It is relatively superficial at its start, where it is contained in the carotid triangle of the neck, and lies behind and medial to the external carotid, overlapped by the sternocleidomastoid muscle, and"
"police accountability have come to light, including questions over how his body was covered in bruises and whether or not carotid restraint was used against him. Carotid restraint is a form of restriction, which compresses one or both carotid arteries, and is used by police enforcement to control dangerous individuals The European Court of Human Rights has condemned France in 1998 for their apparent use of carotid constriction. This same method of restraint was seen to be used against Hakim Sjimi who died of positional asphyxia as a result of overwhelming pressure being placed on his chest and neck by"
"or pigment cells, or from the excess production of pigment. Carotenoids are the most common group of pigments found in nature. Over 600 different kinds of carotenoids are found in animals, plants, and microorganisms. Animals are incapable of making their own carotenoids and thus rely on plants for these pigments. Carotenoproteins are especially common among marine animals. These complexes are responsible for the various colors (red, purple, blue, green, etc.) to these marine invertebrates for mating rituals and camouflage. There are two main types of carotenoproteins: Type A and Type B. Type A has carotenoids (chromogen) which are stoichiometrically associated"
"Acetylcarnitine Acetyl--carnitine, ALCAR or ALC, is an acetylated form of -carnitine. It is naturally produced by the body, although it is often taken as a dietary supplement. Acetylcarnitine is broken down in the blood by plasma esterases to carnitine which is used by the body to transport fatty acids into the mitochondria for breakdown. Carnitine is both a nutrient and made by the body as needed; it serves as a substrate for important reactions in which it accepts and gives up an acyl group. Acetylcarnitine is the most abundant naturally occurring derivative and is formed in the reaction: where the"
"Acetylcarnitine Acetyl--carnitine, ALCAR or ALC, is an acetylated form of -carnitine. It is naturally produced by the body, although it is often taken as a dietary supplement. Acetylcarnitine is broken down in the blood by plasma esterases to carnitine which is used by the body to transport fatty acids into the mitochondria for breakdown. Carnitine is both a nutrient and made by the body as needed; it serves as a substrate for important reactions in which it accepts and gives up an acyl group. Acetylcarnitine is the most abundant naturally occurring derivative and is formed in the reaction: where the"
"Carnosine Carnosine (""beta""-alanyl--histidine), featuring the characteristic imidazole-ring, is a dipeptide molecule, made up of the amino acids beta-alanine and histidine. It is highly concentrated in muscle and brain tissues. Carnosine and carnitine were discovered by Russian chemist Vladimir Gulevich. It has been proven to scavenge reactive oxygen species (ROS) as well as alpha-beta unsaturated aldehydes formed from peroxidation of cell membrane fatty acids during oxidative stress. It also buffers pH in muscle cells, and acts as a neurotransmitter in the brain. It is also a zwitterion, a neutral molecule with a positive and negative end. Like carnitine, carnosine is composed"
"are separated from each other by a very narrow interval which contains the trachea; but at the upper part, the thyroid gland, the larynx and pharynx separate the two arteries. The common carotid artery is contained in a sheath known as the carotid sheath, which is derived from the deep cervical fascia and encloses also the internal jugular vein and vagus nerve, the vein lying lateral to the artery, and the nerve between the artery and vein, on a plane posterior to both. On opening the sheath, each of these three structures is seen to have a separate fibrous cover."
"CRTISO, a carotenoid isomerase, is needed to convert the cis-lycopene into an all-trans lycopene in the presence of reduced FAD. This all-trans lycopene is cyclized; cyclization gives rise to carotenoid diversity, which can be distinguished based on the end groups. There can be either a beta ring or an epsilon ring, each generated by a different enzyme (lycopene beta-cyclase [beta-LCY] or lycopene epsilon-cyclase [epsilon-LCY]). Alpha-carotene is produced when the all-trans lycopene first undergoes reaction with epsilon-LCY then a second reaction with beta-LCY; whereas beta-carotene is produced by two reactions with beta-LCY. Alpha- and beta-carotene are the most common carotenoids in"
"soybean oil, and sunflower oil. Karukas contain 44.90% palmitic acid. The cetyl ester of palmitic acid (cetyl palmitate) occurs in spermaceti. Excess carbohydrates in the body are converted to palmitic acid. Palmitic acid is the first fatty acid produced during fatty acid synthesis and is the precursor to longer fatty acids. As a consequence, palmitic acid is a major body component of animals. In humans, one analysis found it to make up 21–30% (molar) of human depot fat, and it is a major, but highly variable, lipid component of human breast milk. Palmitate negatively feeds back on acetyl-CoA carboxylase (ACC),"
"in carrots and apricots, is responsible for their orange-yellow colors. Dried carrots have the highest amount of carotene of any food per 100 gram serving, measured in retinol activity equivalents (provitamin A equivalents). Vietnamese gac fruit contains the highest known concentration of the carotenoid lycopene. The diet of flamingos is rich in carotenoids, imparting the orange-colored feathers of these birds. Reviews of epidemiological studies seeking correlations between carotenoid consumption in food and clinical outcomes have come to various conclusions: Carotenoids are also important components of the dark brown pigment melanin, which is found in hair, skin, and eyes. Melanin absorbs"
"Systemic primary carnitine deficiency Systemic primary carnitine deficiency (SPCD), also known as carnitine deficiency, systemic primary (CDSP), carnitine uptake defect (CUD), carnitine transporter deficiency (CTD) or systemic carnitine deficiency (SCD) is an inborn error of fatty acid transport caused by a defect in the transporter responsible for moving carnitine across the plasma membrane. Carnitine is an important amino acid for fatty acid metabolism. When carnitine cannot be transported into tissues, fatty acid oxidation is impaired, leading to a variety of symptoms such as chronic muscle weakness, cardiomyopathy, hypoglycemia and liver dysfunction. The specific transporter involved with SPCD is OCTN2, coded"
"as the cricoid cartilage and carina. Cartilage is composed of specialized cells called chondrocytes that produce a large amount of collagenous extracellular matrix, abundant ground substance that is rich in proteoglycan and elastin fibers. Cartilage is classified in three types, ""elastic cartilage"", ""hyaline cartilage"" and ""fibrocartilage"", which differ in relative amounts of collagen and proteoglycan. Cartilage does not contain blood vessels (it is avascular) or nerves (it is aneural). Nutrition is supplied to the chondrocytes by diffusion. The compression of the articular cartilage or flexion of the elastic cartilage generates fluid flow, which assists diffusion of nutrients to the chondrocytes."
"Meso-zeaxanthin ""Meso""-zeaxanthin (3R,3´S-zeaxanthin) is a xanthophyll carotenoid, as it contains oxygen and hydrocarbons, and is one of the three stereoisomers of zeaxanthin. Of the three stereoisomers, ""meso""-zeaxanthin is the second most abundant in nature after 3R,3´R-zeaxanthin, which is produced by plants and algae. To date, ""meso""-zeaxanthin has been identified in specific tissues of marine organisms and in the macula lutea, also known as the ""yellow spot"", of the human retina. Carotenoids are essential for animal life, but animals cannot produce them. Indeed, animals obtain carotenoids from diet, with herbivores sourcing them from plants or algae, and carnivores, in turn, sourcing"
"general, contain six ubiquitous carotenoids: neoxanthin, violaxanthin, antheraxanthin, zeaxanthin, lutein and β-carotene. Lutein is a yellow pigment found in fruits and vegetables and is the most abundant carotenoid in plants. Lycopene is the red pigment responsible for the color of tomatoes. Other less common carotenoids in plants include lutein epoxide (in many woody species), lactucaxanthin (found in lettuce), and alpha carotene (found in carrots). In cyanobacteria, many other carotenoids exist such as canthaxanthin, myxoxanthophyll, synechoxanthin, and echinenone. Algal phototrophs such as dinoflagellates use peridinin as a light harvesting pigment. While carotenoids can be found complexed within chlorophyll-binding proteins such as"
"carotenoid in the outermost layer of the epidermis. Adults' fat stores are often yellow from accumulated carotenoids, including β-carotene, while infants' fat stores are white. Carotenodermia is quickly reversible upon cessation of excessive intakes. The proportion of carotenoids absorbed decreases as dietary intake increases. Within the intestinal wall (mucosa), β-carotene is partially converted into vitamin A (retinol) by an enzyme, dioxygenase. This mechanism is regulated by the individual's vitamin A status. If the body has enough vitamin A, the conversion of β-carotene decreases. Therefore, β-carotene is considered a safe source of vitamin A and high intakes will not lead to"