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Myosepta
A myotome is the group of muscles that a single spinal nerve innervates. Similarly a dermatome is an area of skin that a single nerve innervates with sensory fibers. Myotomes are separated by myosepta (singular: myoseptum). In vertebrate embryonic development, a myotome is the part of a somite that develops into muscle. Structure The anatomical term myotome which describes the muscles served by a spinal nerve root, is also used in embryology to describe that part of the somite which develops into the muscles. In anatomy the myotome is the motor equivalent of a dermatome. Function Each muscle in the body is supplied by one or more levels or segments of the spinal cord and by their corresponding spinal nerves. A group of muscles innervated by the motor fibres of a single nerve root is known as a myotome. List of myotomes Myotome distributions of the upper and lower extremity are as follows; * C1/ C2: neck flexion/extension * C3: Lateral Neck Flexion * C4: shoulder elevatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cervical Spinal Nerve 8
The cervical spinal nerve 8 (C8) is a spinal nerve of the cervical segment. It originates from the spinal column from below the cervical vertebra 7 (C7). Innervation The C8 nerve forms part of the radial and ulnar nerves via the brachial plexus, and therefore has motor and sensory function in the upper limb. Sensory The C8 nerve receives sensory afferents from the C8 dermatome. This consists of all the skin on the little finger, and continuing up slightly past the wrist on the palmar and dorsal aspects of the hand and forearm.Drake et al. Gray's Anatomy for Students. Second Edition (2010). Clinically, a test of the pad of the little finger is often used to assess C8 integrity.Aland et al. University of Queensland School of Medicine Clinical Skills Handbook 2010 Motor The C8 nerve contributes to the motor innervation of many of the muscles in the trunk and upper limb. Its primary function is the flexion of the fingers, and this is used as the clinical test for C8 inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intervertebral Disc
An intervertebral disc (British English), also spelled intervertebral disk (American English), lies between adjacent vertebrae in the vertebral column. Each disc forms a fibrocartilaginous joint (a symphysis), to allow slight movement of the vertebrae, to act as a ligament to hold the vertebrae together, and to function as a shock absorber for the spine. Structure Intervertebral discs consist of an outer fibrous ring, the ''anulus (or annulus) fibrosus disci intervertebralis'', which surrounds an inner gel-like center, the ''nucleus pulposus''. The ''anulus fibrosus'' consists of several layers (laminae) of fibrocartilage made up of both type I and type II collagen. Type I is concentrated toward the edge of the ring, where it provides greater strength. The stiff laminae can withstand compressive forces. The fibrous intervertebral disc contains the ''nucleus pulposus'' and this helps to distribute pressure evenly across the disc. This prevents the development of stress conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isometric Exercise
An isometric exercise is an exercise involving the static contraction of a muscle without any visible movement in the angle of the joint. The term "isometric" combines the Greek words ''isos'' (equal) and ''-metria'' (measuring), meaning that in these exercises the length of the muscle and the angle of the joint do not change, though contraction strength may be varied. This is in contrast to ''isotonic contractions'', in which the contraction strength does not change, though the muscle length and joint angle do. The three main types of isometric exercise are isometric presses, pulls, and holds. They may be included in a strength training regime in order to improve the body's ability to apply power from a static position or, in the case of isometric holds, improve the body's ability to maintain a position for a period of time. Considered as an action, isometric presses are also of fundamental importance to the body's ability to prepare itself to perform immediately subsequent pow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Wink
The anal wink, anal reflex, perineal reflex, or anocutaneous reflex is the reflexive contraction of the external anal sphincter upon stroking of the skin around the anus. A noxious or tactile stimulus will cause a wink contraction of the anal sphincter muscles and also flexion. The stimulus is detected by the nociceptors in the perineal skin to the pudendal nerve, where a response is integrated by the spinal cord sacral segments S2-S4. The absence of this reflex indicates that there is an interruption of the reflex arc, or damage to the spinal cord, which may be in the sensory afferent limb or the motor efferent limb. The synapse between the afferent and efferent limbs occurs in the lowest sacral segments of the spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c .... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacral Spinal Nerve 4
The sacral spinal nerve 4 (S4) is a spinal nerve of the sacral segment. Nervous System -- Groups of Nerves It originates from the from below the 4th body of the 
Muscles S4 supplies many muscles, either directly or through nerves originating from S4. They are not innervated with S4 as single origin, but partly by S4 and partly by other spinal nerves. The muscl ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacral Spinal Nerve 3
The sacral spinal nerve 3 (S3) is a spinal nerve of the sacral segment. Nervous System -- Groups of Nerves It originates from the from below the 3rd body of the .
Muscles S3 supplies many muscles, either directly or through nerves originating from S3. They are not innervated with S3 as single origin, but partly by S3 and partly by other spinal nerves. The mus ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacral Spinal Nerve 2
The sacral spinal nerve 2 (S2) is a spinal nerve of the sacral segment. Nervous System -- Groups of Nerves It originates from the from below the 2nd body of the
Muscles S2 supplies many muscles, either directly or through nerves originating from S2. They are not innervated with S2 as single origin, but partly by S2 and partly by other spinal nerves. They are ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacral Spinal Nerve 1
The sacral spinal nerve 1 (S1) is a spinal nerve of the sacral segment. Nervous System -- Groups of Nerves It originates from the from below the 1st body of the .
Muscles S1 supplies many muscles, either directly or through nerves originating from S1. They are not innervated with S1 as single origin, but partly by S1 and partly by other spinal nerves. The mu ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbar Spinal Nerve 5
The lumbar nerves are the five pairs of spinal nerves emerging from the lumbar vertebrae. They are divided into posterior and anterior divisions. Structure The lumbar nerves are five spinal nerves which arise from either side of the spinal cord below the thoracic spinal cord and above the sacral spinal cord. They arise from the spinal cord between each pair of lumbar spinal vertebrae and travel through the intervertebral foramina. The nerves then split into an anterior branch, which travels forward, and a posterior branch, which travels backwards and supplies the area of the back. Posterior divisions The middle divisions of the posterior branches run close to the articular processes of the vertebrae and end in the multifidus muscle. The outer branches supply the erector spinae muscles. The nerves give off branches to the skin. These pierce the aponeurosis of the greater trochanter. Anterior divisions The anterior divisions of the lumbar nerves () increase in size from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
