An aponeurosis is a type or a variant of the deep fascia, in the form of a sheet of pearly-white fibrous tissue that attaches sheet-like muscles needing a wide area of attachment. Their primary function is to join muscles and the body parts they act upon, whether it be bone or other muscles, they have a shiny, whitish-silvery color, are histologically similar to tendons, are sparingly supplied with blood vessels and nerves. When dissected, aponeuroses are peel off by sections; the primary regions with thick aponeuroses are in the ventral abdominal region, the dorsal lumbar region, the ventriculus in birds, the palmar and plantar regions. The anterior abdominal aponeuroses are located just superficial to the rectus abdominis muscle, it has for its borders the external oblique, pectoralis muscles, the latissimus dorsi. The posterior lumbar aponeuroses are situated just on top of the epaxial muscles of the thorax, which are multifidus spinae and sacrospinalis; the palmar aponeuroses occur on the palms of the hands.
The extensor hoods are aponeuroses at the back of the fingers. The plantar aponeuroses occur on the plantar aspect of the foot, they extend from the calcaneal tuberosity diverge to connect to the bones and the dermis of the skin around the distal part of the metatarsal bones. The anterior and posterior intercostal membranes are aponeuroses located between the ribs and are continuations of the external and internal intercostal muscles, respectively; the epicranial aponeurosis, or galea aponeurotica, is a tough layer of dense fibrous tissue which runs from the frontalis muscle anteriorly to the occipitalis posteriorly. Pennate muscles, in which the muscle fibers are oriented at an angle to the line of action have two aponeuroses. Muscle fibers connect one to the other, each aponeurosis thins into a tendon which attaches to bone at the origin or insertion site. Like tendons, aponeuroses attached to pennate muscles can be stretched by the forces of muscular contraction, absorbing energy like a spring and returning it when they recoil to unloaded conditions.
Serving as an origin or insertion site for certain muscles e.g latissimus dorsi. Aponeurosis of the obliquus externus abdominis Aponeurosis of the serratus posterior superior muscle Plantar aponeurosis Inguinal aponeurotic falx Bicipital aponeurosis Palatine aponeurosis Fascia Gray's s104 - Aponeuroses
The human back is the large posterior area of the human body, rising from the top of the buttocks to the back of the neck and the shoulders. It is the surface of the body opposite from the chest; the vertebral column creates a central area of recession. The breadth of the back is created by the shoulders at the pelvis at the bottom. Back pain is a common medical condition benign in origin; the central feature of the human back is the vertebral column the length from the top of the thoracic vertebrae to the bottom of the lumbar vertebrae, which houses the spinal cord in its spinal canal, which has some curvature that gives shape to the back. The ribcage extends from the spine at the top of the back, more than halfway down the length of the back, leaving an area with less protection between the bottom of the ribcage and the hips; the width of the back at the top is defined by the broad, flat bones of the shoulders. The muscles of the back can be divided into three distinct groups; the superficial group known as the appendicular group, is associated with movement of the appendicular skeleton.
It is composed of latissimus dorsi, rhomboid major, rhomboid minor and levator scapulae. It is innervated by anterior rami of spinal nerves, reflecting its embryological origin outside the back; the intermediate group is known as respiratory group as it may serve a respiratory function. It is composed of serratus posterior serratus posterior inferior. Like the superficial group, it is innervated by anterior rami of spinal nerves; the deep group known as the intrinsic group due to its embryological origin in the back, can be further subdivided into four groups: Spinotransversales - composed of splenius capitis and splenius cervicis. Erector spinae - composed of iliocostalis and spinalis Transversospinales - composed of semispinalis and rotatores Segmental muscles - composed of levatores costarum and intertransversariiThe deep group is innervated by the posterior rami of spinal nerves; the lungs are within the ribcage, extend to the back of the ribcage making it possible for them to be listened into through the back.
The kidneys are situated beneath the muscles in the area below the end of the ribcage, loosely connected to the peritoneum. A strike to the lower back can damage the kidneys of the person being hit; the skin of the human back is thicker and has fewer nerve endings than the skin on any other part of the torso. With some notable exceptions, it tends to have less hair than the chest on men; the upper-middle back is the one area of the body which a typical human under normal conditions might be unable to physically touch. The skin of the back is innervated by the dorsal cutaneous branches, as well as the lateral abdominal cutaneous branches of intercostal nerves; the intricate anatomy of the back provides support for the head and trunk of the body, strength in the trunk of the body, as well as a great deal of flexibility and movement. The upper back has the most structural support, with the ribs attached to each level of the thoracic spine and limited movement; the lower back allows for movement in back bending and forward bending.
It does not permit twisting. The back comprises interconnecting nerves, muscles and tendons, all of which can be a source of pain. Back pain is the second most common type of pain in adults. By far the most common cause of back pain is muscle strain; the back muscles can heal themselves within a couple of weeks, but the pain can be intense and debilitating. Other common sources of back pain include disc problems, such as degenerative disc disease or a lumbar disc herniation, many types of fractures, such as spondylolisthesis or an osteoporotic fracture, or osteoarthritis; the curvature of the female back is a frequent theme in paintings, because the sensibilities of many cultures permit the back to be shown nude - implying full nudity without displaying it. Indeed, the practice of showing explicitness on the lower back has been performed for centuries. Certain articles of clothing, such as the haltertop and the backless dress, are designed to expose the back in this manner; the lower back is exposed by many types of shirts in woman's fashion, the more conservative shirts and blouses will reveal the lower back.
This happens for a variety of reasons- the lower waist area is a pivot point for the body and lengthens and arches as a person sits or bends. Secondly, woman's fashion favors tops that are waist length, allowing the back to be left bare during slight movement, bending or sitting; the back serves as the largest canvas for body art on the human body. Because of its size and the relative lack of hair, the back presents an ideal canvas on the human body for lower back tattoos among young women. Indeed, some individuals have tattoos. Others have smaller tattoos at significant locations, such as the shoulder blade or the bottom of the back. Many English idioms mention the back highlighting it as an area of vulnerability; the back is a symbol of strength and hard work, with those seeking physical labor looking for "strong backs", workers being implored to "put their back into it". Flage
The intercostal arteries are a group of arteries that supply the area between the ribs, called the intercostal space. The highest intercostal artery is an artery in the human body that gives rise to the first and second posterior intercostal arteries, which supply blood to their corresponding intercostal space, it arises from the costocervical trunk, a branch of the subclavian artery. Some anatomists may contend that there is no supreme intercostal artery, only a supreme intercostal vein; the anterior intercostal branches of internal thoracic artery supply the upper five or six intercostal spaces. The internal thoracic artery divides into the superior epigastric artery and musculophrenic artery; the latter gives out the remaining anterior intercostal branches. Two in number in each space, these small vessels pass lateralward, one lying near the lower margin of the rib above, the other near the upper margin of the rib below, anastomose with the posterior intercostal arteries from the thoracic aorta.
They are at first situated between the pleurae and the intercostales interni, between the intercostales interni and innermost. They supply the intercostal muscles and, by branches which perforate the intercostales externi, the pectoral muscles and the mamma; the musculophrenic artery arises from the internal thoracic artery, directed obliquely downward and laterally, behind the cartilages of the false ribs. It gives off intercostal branches to the seventh and ninth intercostal spaces; the musculophrenic artery gives branches to the lower part of the pericardium, others which run backward to the diaphragm, downward to the abdominal muscles. The posterior intercostal arteries are arteries that supply blood to the intercostal spaces. There are eleven posterior intercostal arteries on each side; the 1st and 2nd posterior intercostal arteries arise from the supreme intercostal artery, a branch of the costocervical trunk of the subclavian artery. The lower nine arteries are the aortic intercostals, so called because they arise from the back of the thoracic aorta.
The right aortic intercostals are longer than the left because of the position of the aorta on the left side of the vertebral column. The left aortic intercostals run backward on the sides of the vertebrae and are covered by the left lung and pleura. Opposite the heads of the ribs, the sympathetic trunk passes downward in front of them, the splanchnic nerves descend in front by the lower arteries; each artery divides into an anterior and a posterior ramus. A given posterior intercostal artery travels along the bottom of the rib with its corresponding posterior intercostal vein, as well as the intercostal nerve of the given space; the vein is superior to the artery, the intercostal nerve is inferior to it. The mnemonic, "Van," is used to recall the order of the vein and nerve, from superior to inferior. Supreme intercostal vein Superior intercostal vein Posterior intercostal veins Intercostal nerves This article incorporates text in the public domain from page 584 of the 20th edition of Gray's Anatomy Anatomy photo:18:07-0102 at the SUNY Downstate Medical Center - "Thoracic wall: Branches of the Internal Thoracic Artery" http://www.instantanatomy.net/thorax/vessels/aupperintercostalarteries.html Anatomy figure: 21:06-06 at Human Anatomy Online, SUNY Downstate Medical Center - "Branches of the ascending aorta, arch of the aorta, the descending aorta."
Thoraxlesson5 at The Anatomy Lesson by Wesley Norman Atlas image: abdo_wall70 at the University of Michigan Health System
Serratus posterior inferior muscle
The Serratus posterior inferior muscle is a muscle of the human body. The muscle lies at the junction of the lumbar regions; the origin arises from the vertebrae T11 through L2. The muscle's insertion is the lower border of the 9th through 12th ribs, it is situated at the junction of the thoracic and lumbar regions: it is of an irregularly quadrilateral form, broader than the serratus posterior superior muscle, separated from it by a wide interval. It arises by a thin aponeurosis from the spinous processes of the lower two thoracic and upper two or three lumbar vertebrae, from the supraspinal ligament. Passing obliquely upward and lateralward, it becomes fleshy, divides into four flat digitations, which are inserted into the inferior borders of the lower four ribs, a little beyond their angles; the thin aponeurosis of origin is intimately blended with the lumbodorsal fascia, aponeurosis of the Latissimus dorsi. The serratus posterior inferior draws the lower ribs backward and downward to assist in rotation and extension of the trunk.
This movement of the ribs contributes to forced expiration of air from the lungs. Serratus anterior muscle Serratus posterior superior muscle This article incorporates text in the public domain from page 404 of the 20th edition of Gray's Anatomy Anatomy figure: 01:05-04 at Human Anatomy Online, SUNY Downstate Medical Center - "Intermediate layer of the extrinsic muscles of the back, deep muscles." Cross section image: pembody/body8a—Plastination Laboratory at the Medical University of Vienna
The thorax or chest is a part of the anatomy of humans and various other animals located between the neck and the abdomen. The thorax includes the thoracic wall, it contains organs including the heart and thymus gland, as well as muscles and various other internal structures. Many diseases may affect the chest, one of the most common symptoms is chest pain. In humans and other hominids, the thorax is the chest region of the body between the neck and the abdomen, along with its internal organs and other contents, it is protected and supported by the rib cage and shoulder girdle. The contents of the thorax include lungs. Arteries and veins are contained –. External structures are nipples. In the human body, the region of the thorax between the neck and diaphragm in the front of the body is called the chest; the corresponding area in an animal can be referred to as the chest. The shape of the chest does not correspond to that part of the thoracic skeleton that encloses the heart and lungs. All the breadth of the shoulders is due to the shoulder girdle, contains the axillae and the heads of the humeri.
In the middle line the suprasternal notch is seen above, while about three fingers' breadth below it a transverse ridge can be felt, known as the sternal angle and this marks the junction between the manubrium and body of the sternum. Level with this line the second ribs join the sternum, when these are found the lower ribs can be counted. At the lower part of the sternum, where the seventh or last true ribs join it, the ensiform cartilage begins, above this there is a depression known as the pit of the stomach; the bones of the thorax, called the "thoracic skeleton" is a component of the axial skeleton. It consists of sternum; the ribs of the thorax are numbered in ascending order from 1-12. 11 & 12 are known as floating ribs because they have no anterior attachment point in particular the cartilage attached to the sternum, as 1-7 are, therefore are termed "floating". Whereas ribs 8-10 are termed false ribs as their costal cartilage articulates with the costal cartilage of the rib above; the anatomy of the chest can be described through the use of anatomical landmarks.
The nipple in the male is situated in front of the fourth rib or a little below. A little below it the lower limit of the great pectoral muscle is seen running upward and outward to the axilla; the female nipple is surrounded for half an inch by the areola. The apex of a normal heart is in the fifth left intercostal space, three and a half inches from the mid-line. Different types of diseases or conditions that affect the chest include pleurisy, flail chest and the most common condition, chest pain; these conditions can be caused by birth defects or trauma. Any condition that lowers the ability to either breathe or to cough is considered a chest disease or condition. Injury to the chest results in up to ¼ of all deaths due to trauma in the United States; the major pathophysiologies encountered in blunt chest trauma involve derangements in the flow of air, blood, or both in combination. Sepsis due to leakage of alimentary tract contents, as in esophageal perforations must be considered. Blunt trauma results in chest wall injuries.
The pain associated with these injuries can make breathing difficult, this may compromise ventilation. Direct lung injuries, such as pulmonary contusions, are associated with major chest trauma and may impair ventilation by a similar mechanism. Chest pain can be the result of multiple issues, including respiratory problems, digestive issues, musculoskeletal complications; the pain can trigger cardiac issues as well. Not all pain, felt is associated with the heart, but it should not be taken either. Symptoms can be different depending on the cause of the pain. While cardiac issues cause feelings of sudden pressure in the chest or a crushing pain in the back and arms, pain, felt due to noncardiac issues gives a burning feeling along the digestive tract or pain when deep breaths are attempted. Different people feel pains differently for the same condition. Only a patient knows if the symptoms are mild or serious. Chest pain may be a symptom of myocardial infarctions. If this condition is present in the body, discomfort will be felt in the chest, similar to a heavy weight placed on the body.
Sweating, shortness of breath and irregular heartbeat may be experienced. If a heart attack occurs, the bulk of the damage is caused during the first six hours, so getting the proper treatment as as possible is important; some people those who are elderly or have diabetes, may not have typical chest pain but may have many of
The trapezius is a large paired surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula. It supports the arm; the trapezius has three functional parts: an upper part. The trapezius is used to nod your head, it is used to hold up your head. The trapezius muscle resembles a trapezium, or diamond-shaped quadrilateral; the word "spinotrapezius" refers to the human trapezius, although it is not used in modern texts. In other mammals, it refers to a portion of the analogous muscle; the term "tri-axle back plate" was used to describe the trapezius muscle. The superior or upper fibers of the trapezius originate from the spinous process of C7, the external occipital protuberance, the medial third of the superior nuchal line of the occipital bone, the ligamentum nuchae. From this origin they proceed downward and laterally to be inserted into the posterior border of the lateral third of the clavicle; the middle fibers, or transverse of the trapezius arise from the spinous process of the seventh cervical, the spinous processes of the first and third thoracic vertebrae.
They are inserted into the medial margin of the acromion, into the superior lip of the posterior border of the spine of the scapula. The inferior or lower fibers of the trapezius arise from the spinous processes of the remaining thoracic vertebrae. From this origin they proceed upward and laterally to converge near the scapula and end in an aponeurosis, which glides over the smooth triangular surface on the medial end of the spine, to be inserted into a tubercle at the apex of this smooth triangular surface. At its occipital origin, the trapezius is connected to the bone by a thin fibrous lamina adherent to the skin; the superficial and deep epimysia are continuous with an investing deep fascia that encircles the neck and contains both sternocleidomastoid muscles. At the middle, the muscle is connected to the spinous processes by a broad semi-elliptical aponeurosis, which reaches from the sixth cervical to the third thoracic vertebræ and forms, with that of the opposite muscle, a tendinous ellipse.
The rest of the muscle arises by numerous short tendinous fibers. It is possible to feel the muscles of the superior trapezius become active by holding a weight in one hand in front of the body and, with the other hand, touching the area between the shoulder and the neck. Images of the trapezius and the bones to which it attaches, with muscular attachments shown in red Motor function is supplied by the accessory nerve. Sensation, including pain and the sense of joint position, travel via the ventral rami of the third and fourth cervical nerves. Since it is a muscle of the upper limb, the trapezius is not innervated by dorsal rami despite being placed superficially in the back. Contraction of the trapezius muscle can have two effects: movement of the scapulae when the spinal origins are stable, movement of the spine when the scapulae are stable, its main function is to move the scapula. The upper and lower fibers tend to rotate the scapula around the Sternoclavicular articulation so that the acromion and inferior angles move up and the medial border moves down.
This rotation is in the opposite direction to that produced by the rhomboids. The middle fibers retract the scapula; the upper and lower trapezius fibers work in tandem with the serratus anterior to upwardly rotate the scapulae, such as during an overhead press. When activating together, the upper and lower fibers assist the middle fibers with scapular retraction/adduction; when the scapulae are stable a co-contraction of both sides can extend the neck. The upper portion of the trapezius can be developed by elevating the shoulders. Common exercises for this movement are any version of the clean the hang clean. Middle fibers are developed by pulling shoulder blades together; this adduction uses the upper/lower fibers. The lower part can be developed by drawing the shoulder blades downward while keeping the arms straight and stiff, it is used in throwing, with the deltoid muscle and rotator cuff. Many bodybuilders, including eight-time Mr. Olympia winner Ronnie Coleman, perform a maneuver known as a'trap slap' before attempting to lift heavy weights.
This technique involves a spotter slapping the lifter's upper back, with the desired effect of mentally preparing the recipient for their upcoming lift. Variants of the trap slap include the'lat slap', performed if the trapezius is inaccessible to the spotter. Due to not being healthily developed for some people, it can cause problems such as muscular tensions the descending part. In severe cases these might cause a cervical spine syndrome; this article incorporates text in the public domain from page 432 of the 20th edition of Gray's Anatomy Muscles/TrapeziusUpper at exrx.net Superficial Back Dissection Video showing trapezius
A nerve is an enclosed, cable-like bundle of nerve fibres called axons, in the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called action potentials that are transmitted along each of the axons to peripheral organs or, in the case of sensory nerves, from the periphery back to the central nervous system; each axon within the nerve is an extension of an individual neuron, along with other supportive cells such as Schwann cells that coat the axons in myelin. Within a nerve, each axon is surrounded by a layer of connective tissue called the endoneurium; the axons are bundled together into groups called fascicles, each fascicle is wrapped in a layer of connective tissue called the perineurium. The entire nerve is wrapped in a layer of connective tissue called the epineurium. In the central nervous system, the analogous structures are known as tracts; each nerve is covered on the outside by a dense sheath of the epineurium. Beneath this is a layer of flat cells, the perineurium, which forms a complete sleeve around a bundle of axons.
Perineurial septae subdivide it into several bundles of fibres. Surrounding each such fibre is the endoneurium; this forms an unbroken tube from the surface of the spinal cord to the level where the axon synapses with its muscle fibres, or ends in sensory receptors. The endoneurium consists of an inner sleeve of material called the glycocalyx and an outer, meshwork of collagen fibres. Nerves are bundled and travel along with blood vessels, since the neurons of a nerve have high energy requirements. Within the endoneurium, the individual nerve fibres are surrounded by a low-protein liquid called endoneurial fluid; this acts in a similar way to the cerebrospinal fluid in the central nervous system and constitutes a blood-nerve barrier similar to the blood-brain barrier. Molecules are thereby prevented from crossing the blood into the endoneurial fluid. During the development of nerve edema from nerve irritation, the amount of endoneurial fluid may increase at the site of irritation; this increase in fluid can be visualized using magnetic resonance neurography, thus MR neurography can identify nerve irritation and/or injury.
Nerves are categorized into three groups based on the direction that signals are conducted: Afferent nerves conduct signals from sensory neurons to the central nervous system, for example from the mechanoreceptors in skin. Efferent nerves conduct signals from the central nervous system along motor neurons to their target muscles and glands. Mixed nerves contain both afferent and efferent axons, thus conduct both incoming sensory information and outgoing muscle commands in the same bundle. Nerves can be categorized into two groups based on where they connect to the central nervous system: Spinal nerves innervate much of the body, connect through the vertebral column to the spinal cord and thus to the central nervous system, they are given letter-number designations according to the vertebra through which they connect to the spinal column. Cranial nerves innervate parts of the head, connect directly to the brain, they are assigned Roman numerals from 1 to 12, although cranial nerve zero is sometimes included.
In addition, cranial nerves have descriptive names. Specific terms are used to describe their actions. A nerve that supplies information to the brain from an area of the body, or controls an action of the body is said to "innervate" that section of the body or organ. Other terms relate to whether the nerve affects the same side or opposite side of the body, to the part of the brain that supplies it. Nerve growth ends in adolescence, but can be re-stimulated with a molecular mechanism known as "Notch signaling". If the axons of a neuron are damaged, as long as the cell body of the neuron is not damaged, the axons would regenerate and remake the synaptic connections with neurons with the help of guidepost cells; this is referred to as neuroregeneration. The nerve begins the process by destroying the nerve distal to the site of injury allowing Schwann cells, basal lamina, the neurilemma near the injury to begin producing a regeneration tube. Nerve growth factors are produced causing many nerve sprouts to bud.
When one of the growth processes finds the regeneration tube, it begins to grow towards its original destination guided the entire time by the regeneration tube. Nerve regeneration is slow and can take up to several months to complete. While this process does repair some nerves, there will still be some functional deficit as the repairs are not perfect. A nerve conveys information in the form of electrochemical impulses carried by the individual neurons that make up the nerve; these impulses are fast, with some myelinated neurons conducting at speeds up to 120 m/s. The impulses travel from one neuron to another by crossing a synapse, the message is converted from electrical to chemical and back to electrical. Nerves can be categorized into two groups based on function: An afferent nerve fiber conducts sensory information from a sensory neuron to the central nervous system, where the information is processed. Bundles of fibres or axons, in the peripheral nervous system are called nerves, bundles of afferent fibers are known as sensory nerves.
An efferent nerve fiber conducts signals from a motor neuron in the central nervous system to muscles. Bundles of these fibres are known as efferent nerves; the nervous system is the part of an animal that coordinates its actions by transmitting signals to and from different parts of its body. In vertebrates it consists of two main par