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Sheath MET 199932
Sheath pronounced as , may refer to: * Scabbard, a sheath for holding a sword, knife, or other large blade, as well as guns, such as rifles. * The outer covering of a cable * Condom, a kind of contraception * Debye sheath, a layer of a plasma in physics * Heliosheath, the region of the heliosphere beyond the termination shock * Koteka, a penis sheath worn by some natives of New Guinea * ''Sheath'' (album), a 2003 techno album by LFO * Sheath dress, a type of dress * Kosha, an element in human being makeup according to Hinduist philosophy Botany * Leaf sheath, the leaf base when it forms a vertical coating surrounding the stem Anatomy * Carotid sheath, connective tissue around the neck's vascular compartment * Myelin sheath, an insulating layer over the axon of a neuron * Preputial sheath, protective skin around the penis or clitoris ** Clitoral hood ** Penile sheath, the foreskin into which a penis retracts * Rectus sheath, the laminas around abdominal muscles * Root sheath, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scabbard
A scabbard is a sheath for holding a sword, knife, or other large blade. As well, rifles may be stored in a scabbard by horse riders. Military cavalry and cowboys had scabbards for their saddle ring carbine rifles and Lever action, lever-action rifles on their horses for storage and protection. Scabbards have been made of many materials over the millennia, including leather, wood, and metals such as brass or steel. Most commonly, sword scabbards were worn suspended from a sword belt or shoulder belt called a baldric. Antiquity Wooden scabbards were typically covered in fabric or leather; the leather versions also usually bore metal fittings for added protection and carrying ease. Japanese blades typically have their sharp cutting edge protected by a wooden scabbard called a Japanese sword mountings#Saya, saya. Many scabbards, such as ones the Greeks and Romans used, were small and light. It was designed for holding the sword rather than protecting it. All-metal scabbards were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myelin Sheath
Myelin is a lipid-rich material that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon. The myelinated axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However, unlike the plastic covering on an electrical wire, myelin does not form a single long sheath over the entire length of the axon. Rather, myelin sheaths the nerve in segments: in general, each axon is encased with multiple long myelinated sections with short gaps in between called nodes of Ranvier. Myelin is formed in the central nervous system (CNS; brain, spinal cord and optic nerve) by glial cells called oligodendrocytes and in the peripheral nervous system (PNS) by glial cells called Schwann cells. In the CNS, axons carry electrical signals from one nerve cell body to another. In the PNS, axons carry signals to muscles and glands or from sensor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sheaf (other) , a wheel or roller with a groove along its edge for holding a belt, rope or cable
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Sheaf may refer to: * Sheaf (agriculture), a bundle of harvested cereal stems * Sheaf (mathematics), a mathematical tool * Sheaf toss, a Scottish sport * River Sheaf, a tributary of River Don in England * ''The Sheaf'', a student-run newspaper serving the University of Saskatchewan * Aluma, a settlement in Israel whose name translates as ''Sheaf'' See also * Sceafa, a king of English legend * Sheath (other) * Sheave A sheave () or pulley wheel is a grooved wheel often used for holding a belt, wire rope, or rope and incorporated into a pulley. The sheave spins on an axle or bearing inside the frame of the pulley. This allows the wire or rope to move fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vagina
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen. At the deep end, the cervix (neck of the uterus) bulges into the vagina. The vagina allows for sexual intercourse and birth. It also channels menstrual flow, which occurs in humans and closely related primates as part of the menstrual cycle. Although research on the vagina is especially lacking for different animals, its location, structure and size are documented as varying among species. Female mammals usually have two external openings in the vulva; these are the urethral opening for the urinary tract and the vaginal opening for the genital tract. This is different from male mammals, who usually have a single urethral opening for both urination and reproduction. The vaginal opening is much larger than the nearby urethral opening, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tendon Sheath
A tendon sheath is a layer of synovial membrane around a tendon. It permits the tendon to stretch and not adhere to the surrounding fascia. It has two layers: * synovial sheath * fibrous tendon sheath Fibroma Fibromas are benign tumors that are composed of fibrous or connective tissue. They can grow in all organs, arising from mesenchyme tissue. The term "fibroblastic" or "fibromatous" is used to describe tumors of the fibrous connective tissue. Whe ... of the tendon sheath has been described. References Musculoskeletal system {{anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root Sheath (hair)
The inner or epidermic coat of the hair follicle is closely adherent to the root of the hair, and consists of two strata named respectively the outer and inner root sheaths. Outer root sheath The outer root sheath corresponds with the stratum mucosum (stratum germinativum and stratum spinosum) of the epidermis, and resembles it in the rounded form and soft character of its cells; at the bottom of the hair follicle these cells become continuous with those of the root of the hair. Inner root sheath The inner root sheath (IRS) consists of # a delicate cuticle next the hair, composed of a single layer of imbricated scales with atrophied nuclei; # Huxley's layer # Henle's layer Henle's layer is the third and the outermost layer of the inner root sheath of the hair follicle, consisting of a single layer of cubical cells with clear flattened nuclei. It is named after German physician, pathologist and anatomist A ... The term "trichilemmal" refers to the outer root she ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rectus Sheath
The rectus sheath, also called the rectus fascia,. is formed by the aponeuroses of the transverse abdominal and the internal and external oblique muscles. It contains the rectus abdominis and pyramidalis muscles. Structure The rectus sheath can be divided into anterior and posterior laminae. The arrangement of the layers has important variations at different locations in the body. Below the costal margin For context, above the sheath are the following two layers: # Camper's fascia (anterior part of Superficial fascia) # Scarpa's fascia (posterior part of the Superficial fascia) Within the sheath, the layers vary: Below the sheath are the following three layers: # transversalis fascia # extraperitoneal fat # parietal peritoneum The rectus, in the situation where its sheath is deficient below, is separated from the peritoneum only by the transversalis fascia, in contrast to the upper layers, where part of the internal oblique also runs beneath the rectus. Because of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penile Sheath
Almost all mammal penises have foreskins or prepuce, although in non-human cases the foreskin is usually a sheath (sometimes called the ''preputial sheath'', ''praeputium'' or ''penile sheath'') into which the whole penis is retracted. In koalas, the foreskin contains naturally occurring bacteria that play an important role in fertilization. In some bat species, the prepuce contains an erectile tissue structure called the ''accessory corpus cavernosus''. During musth, a male elephant may urinate with the penis still in the sheath, which causes the urine to spray on the hind legs.Sukumar, pp. 100–08. Male dogs have a conspicuous penis sheath. In stallions, the retractor penis muscle contracts to retract the stallion's penis into the sheath and relaxes to allow the penis to extend from the sheath. The penis sheath of a male axis deer is elongated and urine-stained. When rubbing trees with their horns, these stags sometimes move the penis back and forth rapidly inside its she ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clitoral Hood
In the female human body, the clitoral hood (also called preputium clitoridis and clitoral prepuce) is a fold of skin that surrounds and protects the clitoral glans, glans of the clitoris; it also covers the external shaft of the clitoris, develops as part of the labia minora and is homology (biology), homologous with the foreskin (also called the ''prepuce'') in the male reproductive system. The clitoral hood is composed of Mucocutaneous junction, muccocutaneous tissues; these tissues are between the mucous membrane and the skin, and they may have immunological importance because they may be a point of entry of mucosal vaccines. The clitoral hood is also important not only in the protection of the clitoral glans, but also in pleasure, as its tissue forms part of the erogenous zones of the vulva. Development and variation The clitoral hood is formed during the Fetus, fetal stage by the cellular lamella. The cellular lamella grows down on the dorsal side of the clitoris and is event ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 investing layer (encloses the SCM and Trapezius) * The carotid sheath (encloses the vascular region of the neck) * The pretracheal fascia (encloses the visceral region of the neck) * The prevertebral fascia (encloses the vertebral region of the neck) Structure 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. It extends from the base of the skull to the first rib and sternum, varying between C7 and T4. It merges with the axillary sheath when it reaches the subclavian vein. Contents The four major stru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Cable
An electrical cable is an assembly of one or more wires running side by side or bundled, which is used to carry electric current. One or more electrical cables and their corresponding connectors may be formed into a ''cable assembly'', which is not necessarily suitable for connecting two devices but can be a partial product (e.g. to be soldered onto a printed circuit board with a connector mounted to the housing). Cable assemblies can also take the form of a cable tree or cable harness, used to connect many terminals together. Etymology The original meaning of ''cable'' in the electrical wiring sense was for submarine telegraph cables that were armoured with iron or steel wires. Early attempts to lay submarine cables without armouring failed because they were too easily damaged. The armouring in these early days (mid-19th century) was implemented in separate factories to the factories making the cable cores. These companies were specialists in manufacturing wire rope of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leaf Sheath
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the shoot system. In most leaves, the primary photosynthetic tissue is the palisade mesophyll and is located on the upper side of the blade or lamina of the leaf but in some species, including the mature foliage of ''Eucalyptus'', palisade mesophyll is present on both sides and the leaves are said to be isobilateral. Most leaves are flattened and have distinct upper (adaxial) and lower (abaxial) surfaces that differ in color, hairiness, the number of stomata (pores that intake and output gases), the amount and structure of epicuticular wax and other features. Leaves are mostly green in color due to the presence of a compound called chlorophyll that is essential for photosynthesis as it absorbs light en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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