Question

Which of the following muscles has a multipennate arrangement of the musce fascides Select one temporalis deltoid latissimus dors rectus abdominis sternodeidomastoid pectoralis major orbicularis ons biceps brachi

Answer 1

Ans). Deltoid muscle has a multipennate arrangement of mucsle facicles.

The deltoid has three functionally and anatomically distinct parts. The acromial part, sometimes also known as the middle or central, is the largest and the strongest. It arises as four intramuscular septa, which interdigitate with the three tendons at the insertion site (one each for the anterior, posterior and middle parts). The four septa are connected by short, strong muscle fibres.

The clavicular (anterior) and scapular spinal (posterior) parts are both unipennate and converge directly onto the inserting tendon.

The clavicular (anterior) part originates from the superior surface and the anterior border of the lateral third of clavicle.The acromial (middle) part arises from the lateral margin and superior surface of the acromion of scapula.The scapular spinal (posterior) part originates from the lateral 1/3 of the spine of scapula, on the crest.

The muscle fibres then run inferiorly towards the humeral shaft and converge to a narrow strong tendon. It inserts into the deltoid tuberosity in the shaft of humerus.