Humerus muscle attachment

Article: • • • • • Images: • Gross anatomy The ischium has a body and ramus. Superiorly, it forms the inferoposterior part of the Osteology The body of the ischium can be divided into: • a femoral surface that faces inferiorly, anteriorly, and laterally bounded by the margin of the obturator foramen and forms the lateral limit of the ischial tuberosity • a dorsal surface that is continuous superiorly with the iliac gluteal surface and inferiorly forms the large ischial tuberosity, which is palpable, usually 5 cm lateral to midline and 5 cm superior to the gluteal skin fold • the posterior border contains the inferior portion of the ischial spine 7 • a pelvic surface which is flat and smooth, facing the pelvic cavity; inferior to this is a part of the lateral wall of the The ramus of ischium contains anterior and posterior surfaces, the posterior surface is divided into the perineal and pelvic areas. The superior border completes the obturator foramen and the lower border, together with the medial border of the inferior pubic ramus, bounds the subpubic angle and pubic arch. The ischial tuberosity is divided transversely into superior and inferior areas, superior part subdivided by an oblique bony ridge separating the various muscle attachments. Articulations The ischium contributes to two-fifths of the acetabular articular surface. The ramus forms a temporary cartilaginous synchondrosis joint with the inferior pubic ramus (ischiopubic synchondrosis) during childhood until i...

Learning Objectives By the end of this section, you will be able to: • Identify the divisions of the upper limb and describe the bones in each region • List the bones and bony landmarks that articulate at each joint of the upper limb The upper limb is divided into three regions. These consist of the arm, located between the shoulder and elbow joints; the forearm, which is between the elbow and wrist joints; and the hand, which is located distal to the wrist. There are 30 bones in each upper limb (see humerus is the single bone of the upper arm, and the ulna (medially) and the radius (laterally) are the paired bones of the forearm. The base of the hand contains eight bones, each called a carpal bone, and the palm of the hand is formed by five bones, each called a metacarpal bone. The fingers and thumb contain a total of 14 bones, each of which is a phalanx bone of the hand. Humerus The humerus is the single bone of the upper arm region ( head of the humerus. This is the large, round, smooth region that faces medially. The head articulates with the glenoid cavity of the scapula to form the glenohumeral (shoulder) joint. The margin of the smooth area of the head is the anatomical neck of the humerus. Located on the lateral side of the proximal humerus is an expanded bony area called the greater tubercle. The smaller lesser tubercle of the humerus is found on the anterior aspect of the humerus. Both the greater and lesser tubercles serve as attachment sites for muscles that ac...

Shoulder Muscles: The shoulder muscles are associated with movements of the upper limb. The shoulder muscles produce the characteristic shape of the shoulder and can be classified into two groups: Extrinsic shoulder muscles – arise from the torso, and inserts to the clavicle, scapula or humerus). Intrinsic shoulder muscles – arise from the scapula and/or the clavicle, and inserts to the humerus. The shoulder muscles can be separated into three important groups: 1. Superficial muscles (Extrinsic) 2. Deep muscles (Intrinsic) 3. Muscles of the shoulder & arm Contents • 1 Superficial Muscles • 2 Deep Muscles • 3 Muscles of the shoulder & arm • 4 Shoulder Movements Superficial Muscles • Pectoralis Major • Trapezius • Latissimus dorsi • Deltoid Pectoralis Major Muscle: The pectoralis major is a thick, fan-shaped muscle, located at the chest. It makes up the bulk of the chest muscles and rests under the breast. Origin: It has two head. • Clavicular head: Anterior surface of medial half of clavicle • Sternal head: Anterior surface of manubrium and sternum up to sixth costal cartilages 2nd to 6th costal cartilages Aponeurosis of the external oblique muscle of the abdomen Insertion: Lateral lip of bicipital groove of humerus Nerve supply: Medial and lateral pectoral nerves Action: • Adduction and medial rotation of the shoulder • Clavicular part produces flexion of the arm • Sternal part is used in • Extension of the flexed arm against resistance • Climbing Trapezius: The trapezius ...

Skeletal muscle basics: Attachment of Muscles Of the three types of muscle—smooth, cardiac, and skeletal—it is the third type that attaches to bones, causing them to rotate around joints. It is this combined functioning of muscles, When studying the Points of attachment: origin and insertion First you need to remember that the muscles have two main parts: the large muscle belly, and the end regions, which are called the points of attachment or simply the origins and insertions. Figure 1: The parts of a muscle: muscle belly and points of attachment Most muscles pass across a joint and are attached to both bones that form the joint. When a muscle contracts, one of the attached bones remains stationary while the other moves along with the contraction. For convenience we say that the muscle section attached to the stationary bone is called the origin, and the point of muscle attachment on the moving bone is called the insertion. Keep in mind that origin and insertion are relative terms, and can be reversed depending on the action involved. The origin The origin of a muscle is the point at which it originates on the skeleton. An easy way to determine the origin of any muscle is to find the point at which the muscle moves the least. Therefore, the origin bone is the more stationary of the two bones at a joint when contraction occurs. We can also say that the origin is the point of attachment of a muscle closest to the body’s midline, or center. The insertion The insertion is the...

hannah kemp Hannah is a graduate of DePaul University in Chicago, IL with a BS in Biological Sciences and a minor in Journalism. Since her graduation in 2017, she has been involved in various ecological research projects in Michigan, Wisconsin, Minnesota, Alaska, and Massachusetts. Her areas of interest include marine biology, ecology, genetics, and environmental science. Hannah has also worked for four years as a science tutor and interned at Chicago's Field Museum of Natural History in 2018. • Instructor It's easy to assume that muscle is muscle; that the tissues within hearts, tongues, and arms are pretty much all the same. However, mammalian bodies are made up of three different Skeletal muscles are the muscles that are attached to the skeletal system. They are voluntary muscles, meaning one has conscious control over them, unlike hearts or stomachs. These tissues make up the majority of the muscle in bodies and account for 30-40% of the overall body mass. Tendons, tough bands of connective tissue, connect the skeletal muscles to bones. Typically, skeletal muscle is attached to bone on both ends. These attachment sites have different functions and are called the muscle origin and muscle insertion. Origin and Insertion Most skeletal muscle is attached to bone on its ends by way of what we call tendons. As the muscles contract, they exert force on the bones, which help to support and move our body along with its appendages. In most cases, one end of the muscle is fixed i...

• 1 Anterior Compartment • 1.1 Biceps Brachii • 1.2 Coracobrachialis • 1.3 Brachialis • 1.4 Clinical Relevance: Rupture of the Biceps Tendon • 2 Posterior Compartment • 2.1 Triceps Brachii • 3 Prosection Images The upper arm is located between the shoulder joint and elbow joint. It contains four muscles – three in the anterior compartment (biceps brachii, brachialis, coracobrachialis), and one in the posterior compartment (triceps brachii). In this article, we shall look at the anatomy of the muscles of the upper arm – their attachments, innervation and actions. Anterior Compartment There are three muscles located in the anterior compartment of the upper arm – biceps brachii, coracobrachialis and brachialis. They are all innervated by the musculocutaneous nerve. A good memory aid for this is BBC – biceps, brachialis, coracobrachialis. Arterial supply to the anterior compartment of the upper arm is via muscular branches of the brachial artery. Biceps Brachii The biceps brachii is a two-headed muscle. Although the majority of the muscle mass is located anteriorly to the As the tendon of biceps brachii enters the forearm, a connective tissue sheet is given off – the bicipital aponeurosis. This forms the roof of the • Attachments: Long head originates from the supraglenoid tubercle of the • Function: Supination of the forearm. It also flexes the arm at the elbow and at the shoulder. • Innervation: Musculocutaneous nerve. The bicep tendon reflex tests spinal cord segment C6. Co...