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Encyclopedia > Latissimus dorsi muscle
Latissimus dorsi
Latissimus dorsi
Muscles connecting the upper extremity to the vertebral column.
Latin musculus latissimus dorsi
Gray's subject #121 432
Origin: spinous processes of thoracic T6-T12, thoracolumbar fascia, iliac crest and inferior 3 or 4 ribs
Insertion: floor of intertubercular groove of the humerus
Artery: subscapular artery, dorsal scapular artery
Nerve: thoracodorsal nerve
Action: pulls the forelimb dorsally and caudally
Antagonist: deltoid, trapezius
Dorlands/Elsevier m_22/12549548

The latissimus dorsi (plural: latissimi dorsi) is the large, flat, dorso-lateral muscle on the trunk, posterior to the arm, and partly covered by the spinotrapezius on its median dorsal region. Image File history File links No higher resolution available. ... Image File history File links Size of this preview: 380 × 599 pixelsFull resolution (733 × 1156 pixels, file size: 311 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ... For other uses, see Latin (disambiguation). ... A typical adult human skeleton consists of the following 206 bones depending on age, though this number does vary owing to a variety of anatomical variations; for example, a small portion of the human population have an extra rib, or an extra lumbar vertebra. ... Diagram of a tsetse fly, showing the head, thorax and abdomen The thorax is a division of an animals body, that lies between the head and the abdomen. ... Fascia is specialized connective tissue layer which surrounds muscles, bones, and joints, providing support and protection and giving structure to the body. ... Human male pelvis, viewed from front Human female pelvis, viewed from front The pelvis is the bony structure located at the base of the spine (properly known as the caudal end). ... A typical adult human skeleton consists of the following 206 bones depending on age, though this number does vary owing to a variety of anatomical variations; for example, a small portion of the human population have an extra rib, or an extra lumbar vertebra. ... The tubercles of the humerus are separated from each other by a deep groove, the intertubercular groove (bicipital groove, sulcus intertubercular), which lodges the long tendon of the Biceps brachii and transmits a branch of the anterior humeral circumflex artery to the shoulder-joint. ... The humerus is a long bone in the arm or fore-legs (animals) that runs from the shoulder to the elbow. ... Section of an artery For other uses, see Artery (disambiguation). ... Axillary artery and its branches - anterior view of right upper limb and thorax. ... The Dorsal scapular artery (or descending scapular artery) is a blood vessel which supplies the latissimus dorsi, levator scapulae, rhomboids, and trapezius. ... List of human nerves External links List of nerves This is an incomplete list, which may never be able to satisfy certain standards for completeness. ... The Posterior cord is a division of the brachial plexus. ... Kinesiology is the scientific study of human movement. ... A forelimb is an anterior limb on an animals body. ... In anatomy, the dorsum is the upper side of animals that typically run, fly or swim in a horizontal position, and the back side of animals (like humans) that walk upright. ... It has been suggested that Human Anatomical Terms be merged into this article or section. ... An antagonist is a kind of muscle that acts in opposition to the movement generated by the agonist and is responsible for returning a limb to its initial position. ... In human anatomy, the deltoid muscle is the muscle forming the rounded contour of the shoulder. ... This article is about the human skeletal muscle. ... Elseviers logo. ... This article is about the human skeletal muscle. ...

Contents

Overview

The latissimus dorsi is a triangular, flat muscle, which covers the lumbar region and the lower half of the thoracic region, and is gradually contracted into a narrow fasciculus at its insertion into the humerus. This makes up some of the armpit and stretches down near the glutes The humerus is a long bone in the arm or fore-legs (animals) that runs from the shoulder to the elbow. ...


It arises by tendinous fibers from the spinous processes of the lower six thoracic vertebrae and from the posterior layer of the lumbodorsal fascia, by which it is attached to the spines of the lumbar and sacral vertebræ, to the supraspinal ligament, and to the posterior part of the crest of the ilium. The thoracolumbar fascia (lumbodorsal fascia) is a deep investing membrane which covers the deep muscles of the back of the trunk. ... The supraspinal ligament (supraspinous ligament) is a strong fibrous cord, which connects together the apices of the spinous processes from the seventh cervical vertebra to the sacrum; at the points of attachment to the tips of the spinous processes fibrocartilage is developed in the ligament. ... The term Illion, Ilium has several meanings, including in legends, in anatomy, and in the arts: Ilion or Ilium is an alternative name for the legendary city of Troy. ...


It also arises by muscular fibers from the external lip of the crest of the ilium lateral to the margin of the sacrospinalis, and from the three or four lower ribs by fleshy digitations, which are interposed between similar processes of the obliquus abdominis externus. Sacrospinalis is a very thick, lateral portion of an epaxial muscle in mammals which continues anteriorly up to the neck and divides into three muscles: semispinalis, longissimus, and iliocostalis. ... The external oblique muscle (of the abdomen) (also external abdominal oblique muscle) is the largest and the most superficial (outermost) of the three flat muscles of the lateral anterior abdomen. ...


From this extensive origin the fibers pass in different directions, the upper ones horizontally, the middle obliquely upward, and the lower vertically upward, so as to converge and form a thick fasciculus, which crosses the inferior angle of the scapula, and usually receives a few fibers from it.


The muscle curves around the lower border of the teres major, and is twisted upon itself, so that the superior fibers become at first posterior and then inferior, and the vertical fibers at first anterior and then superior. Teres major is a muscle of the upper limb and one of six scapulohumeral muscles. ...


It ends in a quadrilateral tendon, about 7 cm. long, which passes in front of the tendon of the teres major, and is inserted into the bottom of the intertubercular groove of the humerus; its insertion extends higher on the humerus than that of the tendon of the pectoralis major. Location The clavicular head of the pectoralis major takes its origin from the anterior surface of the medial half of the clavicle. ...


The lower border of its tendon is united with that of the teres major, the surfaces of the two being separated near their insertions by a bursa; another bursa is sometimes interposed between the muscle and the inferior angle of the scapula. Bursae visible top right and bottom right A bursa (plural bursae or bursas; Latin: Bursa synovialis) is a small fluid-filled sac located at the point where a muscle or tendon slides across bone. ... Left scapula - front view () Left scapula - rear view () In anatomy, the scapula, or shoulder blade, is the bone that connects the humerus (arm bone) with the clavicle (collar bone). ...


The tendon of the muscle gives off an expansion to the deep fascia of the arm.


Actions

The latissimus dorsi is responsible for extension, adduction, transverse extension, and internal rotation of the shoulder joint. It also has a synergistic role in extension and lateral flexion of the lumbar spine. The leg extension is an isolation exercise. ... In anatomy and physiology, adduction is the moving of limbs towards the midline of the body. ... In anatomy, internal rotation (also known as medial rotation) is rotation towards the center of the body. ... This article does not cite its references or sources. ... This page is a candidate to be copied to Wiktionary. ...


Variations

The number of dorsal vertebræ to which it is attached vary from four to eight; the number of costal attachments varies; muscle fibers may or may not reach the crest of the ilium.


A muscular slip, the axillary arch, varying from 7 to 10 cm. in length, and from 5 to 15 mm. in breadth, occasionally springs from the upper edge of the latissimus dorsi about the middle of the posterior fold of the axilla, and crosses the axilla in front of the axillary vessels and nerves, to join the under surface of the tendon of the pectoralis major, the coracobrachialis, or the fascia over the biceps brachii. This axillary arch crosses the axillary artery, just above the spot usually selected for the application of a ligature, and may mislead the surgeon during the operation. It is present in about 7% of subjects and may be easily recognized by the transverse direction of its fibers. Location The clavicular head of the pectoralis major takes its origin from the anterior surface of the medial half of the clavicle. ... Coracobrachialis is one of the three muscles that attach to the coracoid process of the scapula. ... A person flexing his biceps brachii In human anatomy, the biceps brachii is a muscle on the upper arm that acts to flex the elbow. ... In human anatomy, the axillary artery is a large blood vessel that conveys oxygenated blood to the lateral aspect of the thorax, the axilla (armpit) and the upper limb. ...


A fibrous slip usually passes from the lower border of the tendon of the Latissimus dorsi, near its insertion, to the long head of the triceps brachii. This is occasionally muscular, and is the representative of the dorsoepitrochlearis brachii of apes. Triceps brachii The triceps brachii muscle is a large three-headed skeletal muscle found in humans. ... This article is about the biological superfamily. ...


Triangles

  • The lateral margin of the latissimus dorsi is separated below from the obliquus externus abdominis by a small triangular interval, the lumbar triangle of Petit, the base of which is formed by the iliac crest, and its floor by the obliquus internus abdominis.
  • Another triangle is situated behind the scapula. It is bounded above by the trapezius, below by the latissimus dorsi, and laterally by the vertebral border of the scapula; the floor is partly formed by the rhomboideus major. If the scapula is drawn forward by folding the arms across the chest, and the trunk bent forward, parts of the sixth and seventh ribs and the interspace between them become subcutaneous and available for auscultation. The space is therefore known as the triangle of auscultation.

The Obliquus externus abdominis (External or descending oblique muscle), situated on the lateral and anterior parts of the abdomen, is the largest and the most superficial of the three flat muscles in this region. ... Human male pelvis, viewed from front Human female pelvis, viewed from front The pelvis is the bony structure located at the base of the spine (properly known as the caudal end). ... The internal oblique muscle (of the abdomen) is the intermediate muscle of the abdomen, lying just underneath the external oblique and just above (superficial to) the transverse abdominal muscle. ... Trapezius In human anatomy, the trapezius is a large superficial muscle on a persons back. ... The Rhomboid major is a muscle of the human body. ... Left scapula - front view () Left scapula - rear view () In anatomy, the scapula, or shoulder blade, is the bone that connects the humerus (arm bone) with the clavicle (collar bone). ... Auscultation is the technical term for listening to the internal sounds of the body, usually using a stethoscope. ...

Nerves

The Latissimus dorsi is supplied by the sixth, seventh, and eighth cervical nerves through the thoracodorsal (long subscapular) nerve. Thoracodorsal is the attribution to the: Thoracodorsal nerve Thoracodorsal artery Category: ...


Training

To increase the power of this muscle, the muscle can be trained with the following exercises: This article is about strength training using weight (gravity) to generate resistance to contraction. ...

Most latissimus dorsi exercises concurrently recruit the teres major, posterior fibers of the deltoid, long head of the triceps brachii, among numerous other stabilizing muscles. Compound exercises for the 'lats' typically involve elbow flexion and tend to recruit the biceps brachii, brachialis, and brachioradialis for this function. Depending on the line of pull, the trapezius muscles can be recruited as well; horizontal pulling motions such as rows recruit both latissimus dorsi and trapezius heavily. For clients with low cadiac output who are not candidates for cardiac transplantation, a procedure called Cardiomyoplasty may support the failing heart. This procedure involves wrapping the latissimus dorsi muscle around the heart and electrostimulating it in synchrony with ventricular systole. The Pulldown exercise or the Cable Lat Pulldown is a compound exercise designed to stress and develop the Latissimus dorsi (Lat). ... An exercise that is used with a dumbbell as you kneel over the side of a workout bench with an arm and leg to one side. ... Chin Up is a song from Charlottes Web the 1973 Hanna Barbera animated musical. ... pull-up A pull-up is an upper body compound pulling exercise. ... A jumper from Marks & Spencer A sweater, pullover, jumper or jersey is a relatively heavy garment intended to cover the torso and arms of the human body (though in some cases sweaters are made for dogs and occasionally other animals) and typically supposed to go over a shirt, blouse, t... In strength training, rowing (or a row, usually preceded by a qualifying adjective — for instance a seated row) is a form of muscular resistance training exercise that shares many characteristics of rowing a boat without involving water or a boat. ... The Deadlift is a weight training exercise where one lifts a loaded barbell (or, in the case of the trapbar deadlift, a loaded trapbar) off the ground from a stabilized bent-over position. ... Teres major is a muscle of the upper limb and one of six scapulohumeral muscles. ... In human anatomy, the deltoid muscle is the muscle forming the rounded contour of the shoulder. ... Triceps brachii The triceps brachii muscle is a large three-headed skeletal muscle found in humans. ... A person flexing his biceps brachii In human anatomy, the biceps brachii is a muscle on the upper arm that acts to flex the elbow. ... Brachialis is a flexor muscle in the upper arm. ... Brachioradialis is a muscle located in the forearm, that acts to flex the forearm. ... Trapezius In human anatomy, the trapezius is a large superficial muscle on a persons back. ...


Additional images

External links


  Results from FactBites:
 
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