该 乙iceps Brachii (肱二头肌) is a huge, thick muscle of the higher arm together with heads. The Biceps Brachii is a stronger elbow flexor whilst the 桡尺关节 (forearm) is supinated. The Biceps Brachii is a stronger forearm supinator while the elbow is flexed.
- Long head: originates on the Supraglenoid tubercle above the socket of the 肩胛骨. It lies in the intracapsular area but it nevertheless stays extra synovial. The lengthy biceps tendon makes a pointy turn at the humeral head and continues its course inside the bicipital groove (intertubercular sulcus). This turning point is secured by way of 韧带 on the capsular place (biceps pulley).
- Brief head: arises at the coracoid procedure of the scapula where it partially blends with the foundation tendon of the 喙.
Each head unites to 1 massive muscle at the anterior aspect of the humerus and attached to the radial tuberosity. A fibrous membrane emerging from the distal a part of the muscle (bicipital aponeurosis, additionally known as lacertus fibrosus) inserts at the deep fascia of the forearm.
Function of Biceps Brachii
The Biceps Brachii is a two-joint muscle. Within the shoulder joint each muscle heads partially implement opposite moves. The long head pulls the arm far away from the trunk (绑架) and turns it inwards (向内旋转) whereas the quick head pulls the arm again in the direction of the trunk (收). When each heads settlement concurrently it results in an arm bend (屈曲).
In the elbow joint the muscle bends the forearm (屈曲) and rotates it outwards (supination). The supination is most effective with a flexed elbow. In addition to the movement features, the biceps has the critical mission to guide the humeral head inside the shoulder joint.
Histology of Biceps Brachii
The biceps Brachii is a skeletal muscle, and as such is an organ made typically of skeletal muscle and connective tissues. Skeletal muscle mass is fabricated from many elongated cells referred to as fibers; every fiber is wrapped in a skinny fibrous connective tissue sheath called endomysium. Many fibers are similarly bundled into agencies called fascicles, which can be in flip wrapped with an extra fibrous connective tissue known as perimysium. Many blood vessels and nerves bypass among the fascicles to offer blood flow and verbal exchange to the skeletal muscle fibers.
此外, the fascicles, nerves, and blood vessels are bundled yet again to shape the entire biceps muscle, wrapped in an outer layer of fibrous connective tissue called epimysium. On the proximal give up of the fast head, the tendon merges with the Periosteum of the scapula on the coracoid process to form the beginning of the short head. On the opposite quit of the biceps, the distal tendon merges with the periosteum of the radius at the radial tuberosity to shape the insertion of the biceps.
The short head of the biceps brachii acts upon the bones of the top limb throughout each the elbow and shoulder joints. Together with the lengthy head of the biceps brachii, the short head flexes and supinates the forearm at the elbow. The biceps is regularly incorrectly idea because of the top flexor on the elbow, when in fact it is a synergist to the authentic high flexor, 该 肱肌. The biceps do act because the high supinator of the elbow and is assisted by the supinator muscle of the forearm.
At the shoulder joint, the biceps brachii provides some help to the deltoid to flex the humerus or flow it anteriorly. The quick head also affords a few particular capabilities that are not provided via the lengthy head. It acts as an adductor to transport the humerus towards the body’s midline and pull the arm in the direction of the trunk. The short head additionally acts as a fixator to stabilize the shoulder joint.
What are the most common injuries to the Biceps brachii muscle?
One of the maximum commonplace accidents to Biceps brachii is Biceps Tendinitis. Biceps tendinitis generally has consequences from overuse from sports activities. It’s common for swimmers, baseball games, tennis players, 和别的. It is able to also occur as a regular a part of getting old. Signs include:
- Pain and irritation generally across the lengthy head of Biceps brachii on the anterior a part of the shoulder.
- Consult your medical doctor for assessment and treatment tips.