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Sacral Ganglia
The sacral ganglia are paravertebral ganglia of the sympathetic trunk.:39 As the sympathetic trunk heads inferiorly down the sacrum, it turns medially. There are generally four or five sacral ganglia. In addition to gray rami communicantes, the ganglia send off sacral splanchnic nerves to join the inferior hypogastric plexus. Near the coccyx, the right and left sympathetic trunks join to form the ganglion impar. The sacral ganglia innervate blood vessels and sweat glands of the lower limbs. Clinical significance Recurrences of genital herpes Genital herpes is an infection by the herpes simplex virus (HSV) of the genitals. Most people either have no or mild symptoms and thus do not know they are infected. When symptoms do occur, they typically include small blisters that break open ... are caused by herpes simplex virus (either HSV-1 or HSV-2) which lies dormant in the sacral ganglia between bouts of active infection. Either primary infection or reactivation may be silent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacral Splanchnic Nerves
Sacral splanchnic nerves are splanchnic nerves that connect the inferior hypogastric plexus to the sympathetic trunk in the pelvis. Structure The sacral sympathetic nerves arise from the sacral part of the sympathetic trunk, emerging anteriorly from the ganglia. They travel to their corresponding side's inferior hypogastric plexus, where the preganglionic nerve fibers synapse with the postganglionic sympathetic neurons, whose fibers ascend to the superior hypogastric plexus, the aortic plexus and the inferior mesenteric plexus, where they are distributed to the anal canal. From the inferior hypogastric plexus, they also innervate pelvic organs and vessels. The sacral sympathetic nerves contain a mix of preganglionic and postganglionic sympathetic fibers, but mostly preganglionic. They also contain general visceral afferent fibers. They are found in the same region as the pelvic splanchnic nerves, which arise from the sacral spinal nerves to provide parasympathetic fibers to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paravertebral Ganglia
The sympathetic ganglia, or paravertebral ganglia are autonomic ganglia, of the sympathetic nervous system. Ganglia are 20,000 to 30,000 afferent and efferent nerve cell bodies that run along on either side of the spinal cord. Afferent nerve cell bodies bring information from the body to the brain and spinal cord, while efferent nerve cell bodies bring information from the brain and spinal cord to the rest of the body. The cell bodies create long sympathetic chains that are on either side of the spinal cord. They also form para- or pre-vertebral ganglia of gross anatomy. The efferent nerve cell bodies bring information from the brain to the body regarding perceptions of danger. This perception of danger can instigate the fight-or-flight response associated with the sympathetic nervous system. The fight-or-flight response is adaptive when there is a real and present danger which can be avoided or diminished through increased sympathetic activity. Sympathetic activity could be in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympathetic Trunk
The sympathetic trunks (sympathetic chain, gangliated cord) are a paired bundle of nerve fibers that run from the base of the skull to the coccyx. They are a major component of the sympathetic nervous system. Structure The sympathetic trunk lies just lateral to the vertebral bodies for the entire length of the vertebral column. It interacts with the anterior rami of spinal nerves by way of rami communicantes. The sympathetic trunk permits preganglionic fibers of the sympathetic nervous system to ascend to spinal levels superior to T1 and descend to spinal levels inferior to L2/3.Greenstein B., Greenstein A. (2002): Color atlas of neuroscience – Neuroanatomy and neurophysiology. Thieme, Stuttgart – New York, . The superior end of it is continued upward through the carotid canal into the skull, and forms a plexus on the internal carotid artery; the inferior part travels in front of the coccyx, where it converges with the other trunk at a structure known as the ganglion impa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rami Communicantes
Ramus communicans (plural rami communicantes) is the Latin term used for a nerve which connects two other nerves, and can be translated as "communicating branch". Structure When used without further definition, it almost always refers to a communicating branch between a spinal nerve and the sympathetic trunk. More specifically, it usually refers to one of the following : * Gray ramus communicans * White ramus communicans The grey and white rami communicantes are responsible for conveying autonomic signals, specifically for the sympathetic nervous system. Their difference in coloration is caused by differences in myelination of the nerve fibres contained within, i.e. there are more myelinated than unmyelinated fibres in the white rami communicantes while the converse is true for the grey rami communicantes. Gray ramus communicans The grey rami communicantes exist at every level of the spinal cord and are responsible for carrying postganglionic nerve fibres from the paravert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Hypogastric Plexus
The inferior hypogastric plexus (pelvic plexus in some texts) is a network () of nerves that supplies the organs of the pelvic cavity. The inferior hypogastric plexus gives rise to the prostatic plexus in males and the uterovaginal plexus in females. The inferior hypogastric plexus is a paired structure, meaning there is one on the left and the right side of the body. These are located on either side of the rectum in males, and at the sides of the rectum and vagina in females. For this reason, injury to this structure can arise as a complication of pelvic surgeries and may cause urinary dysfunction and urinary incontinence. Testing of bladder function is used in that case to show a poorly compliant bladder, with bladder neck incompetence, and fixed external sphincter tone. Structure The plexus is formed from: * a continuation of the superior hypogastric plexus on either side, at the Sacrum Promontory in the interiliac triangle. At this location, the presacral nerve sits in the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coccyx
The coccyx ( : coccyges or coccyxes), commonly referred to as the tailbone, is the final segment of the vertebral column in all apes, and analogous structures in certain other mammals such as horses. In tailless primates (e.g. humans and other great apes) since '' Nacholapithecus'' (a Miocene hominoid),Nakatsukasa 2004, ''Acquisition of bipedalism'' (SeFig. 5entitled ''First coccygeal/caudal vertebra in short-tailed or tailless primates.''.) the coccyx is the remnant of a vestigial tail. In animals with bony tails, it is known as ''tailhead'' or ''dock'', in bird anatomy as ''tailfan''. It comprises three to five separate or fused coccygeal vertebrae below the sacrum, attached to the sacrum by a fibrocartilaginous joint, the sacrococcygeal symphysis, which permits limited movement between the sacrum and the coccyx. Structure The coccyx is formed of three, four or five rudimentary vertebrae. It articulates superiorly with the sacrum. In each of the first three segments may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ganglion Impar
The pelvic portion of each sympathetic trunk is situated in front of the sacrum, medial to the anterior sacral foramina. It consists of four or five small sacral ganglia, connected together by interganglionic cords, and continuous above with the abdominal portion. Below, the two pelvic sympathetic trunks converge, and end on the front of the coccyx in a small ganglion, the ganglion impar, also known as azygos or ganglion of Walther. Clinical significance A study found that in some cases a single injection of nerve block at the ganglion impar offered complete relief from coccydynia Coccydynia is a medical term meaning pain in the coccyx or tailbone area, often brought on by a fall onto the coccyx or by persistent irritation usually from sitting. Synonyms Coccydynia is also known as coccygodynia, coccygeal pain, coccyx pain, .... References * Munir MA, Zhang J, Ahmad M. (2004)A modified needle-inside-needle technique for the ganglion impar block. Can J Anaesth. 2004 Nov;51( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Vessel
The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away from the tissues. Blood vessels are needed to sustain life, because all of the body's tissues rely on their functionality. There are five types of blood vessels: the arteries, which carry the blood away from the heart; the arterioles; the capillaries, where the exchange of water and chemicals between the blood and the tissues occurs; the venules; and the veins, which carry blood from the capillaries back towards the heart. The word ''vascular'', meaning relating to the blood vessels, is derived from the Latin ''vas'', meaning vessel. Some structures – such as cartilage, the epithelium, and the lens and cornea of the eye – do not contain blood vessels and are labeled ''avascular''. Etymology * artery: late Middle English; from L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sweat Gland
Sweat glands, also known as sudoriferous or sudoriparous glands, , are small tubular structures of the skin that produce sweat. Sweat glands are a type of exocrine gland, which are glands that produce and secrete substances onto an epithelial surface by way of a duct. There are two main types of sweat glands that differ in their structure, function, secretory product, mechanism of excretion, anatomic distribution, and distribution across species: * Eccrine sweat glands are distributed almost all over the human body, in varying densities, with the highest density in palms and soles, then on the head, but much less on the trunk and the extremities. Its water-based secretion represents a primary form of cooling in humans. * Apocrine sweat glands are mostly limited to the axillae (armpits) and perineal area in humans. They are not significant for cooling in humans, but are the sole effective sweat glands in hoofed animals, such as the camels, donkeys, horses, and cattle. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Limbs
The human leg, in the general word sense, is the entire lower limb of the human body, including the foot, thigh or sometimes even the hip or gluteal region. However, the definition in human anatomy refers only to the section of the lower limb extending from the knee to the ankle, also known as the crus or, especially in non-technical use, the shank. Legs are used for standing, and all forms of locomotion including recreational such as dancing, and constitute a significant portion of a person's mass. Female legs generally have greater hip anteversion and tibiofemoral angles, but shorter femur and tibial lengths than those in males. Structure In human anatomy, the lower leg is the part of the lower limb that lies between the knee and the ankle. Anatomists restrict the term ''leg'' to this use, rather than to the entire lower limb. The thigh is between the hip and knee and makes up the rest of the lower limb. The term ''lower limb'' or ''lower extremity'' is commonly used to de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genital Herpes
Genital herpes is an infection by the herpes simplex virus (HSV) of the genitals. Most people either have no or mild symptoms and thus do not know they are infected. When symptoms do occur, they typically include small blisters that break open to form painful ulcers. Flu-like symptoms, such as fever, aching, or swollen lymph nodes, may also occur. Onset is typically around 4 days after exposure with symptoms lasting up to 4 weeks. Once infected further outbreaks may occur but are generally milder. The disease is typically spread by direct genital contact with the skin surface or secretions of someone who is infected. This may occur during sex, including anal and oral sex. Sores are not required for transmission to occur. The risk of spread between a couple is about 7.5% over a year. HSV is classified into two types, HSV-1 and HSV-2. While historically HSV-2 was more common, genital HSV-1 has become more common in the developed world. Diagnosis may occur by testing lesions using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpes Simplex Virus
Herpes simplex virus 1 and 2 (HSV-1 and HSV-2), also known by their taxonomical names '' Human alphaherpesvirus 1'' and ''Human alphaherpesvirus 2'', are two members of the human ''Herpesviridae'' family, a set of viruses that produce viral infections in the majority of humans. Both HSV-1 and HSV-2 are very common and contagious. They can be spread when an infected person begins shedding the virus. As of 2016, about 67% of the world population under the age of 50 had HSV-1. In the United States, about 47.8% and 11.9% are estimated to have HSV-1 and HSV-2, respectively, though actual prevalence may be much higher. Because it can be transmitted through any intimate contact, it is one of the most common sexually transmitted infections. Symptoms Many of those who are infected ''never'' develop symptoms. Symptoms, when they occur, may include watery blisters in the skin or mucous membranes of the mouth, lips, nose, genitals, or eyes ( herpes simplex keratitis). Lesions heal w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
