Throughout the book you will find new terms that you might not be familiar with. Let’s see some of the basic anatomy terms, you will come across them quite many times in the book.
Flexion is described as a bending movement that decreases the angle between a segment and its proximal segment or between the bones on two side of a joint. For example, when you bend your elbow, the angle between the upper elbow and lower elbow decreases and similarly when you clench a hand into fist, you flex your hand.
If a joint can move forward or backward, flexion refers to the movement directed to the front (anterior movement). For example, when you move your neck forward, flexion occurs. Shoulder and hip flexion refers to the forward movement of arm or leg.
Those muscles that produce flexion are referred to as flexor muscles. Flexor muscles are present all over the body, for example , flexor carpi radialis and flexor carpi ulnaris stretch from the upper-arm bone (humerus) along the inside of forearm to the bones of hand and flex the wrist. Similarly, your body consists of flexor muscles that help you bend your fingers, your elbow, flex your hip, etc.
Extension is the opposite of flexion and refers to the increase in angle between a segment and its proximal segment or between the bones on two side of a joint. For Example when you straighten your elbow, extension happens; when you stand straight your knees are extended. If a joint can move forward or backward, extension refers to the posterior (backward) movement.
The muscles that cause extension, as by straightening the elbow or knee or bending the spine backwards. Human body consists of many extensors, e.g. the extensor digitorum, which runs from the humerus (bone of the upper arm), to finger tendon and extends the fingers.
It is defined as the movement of a body part toward the body’s midline. So, if a person has his arms straight at the shoulder and he brings them back to their sides, the movement is referred to as adduction. Similarly, if a person has their fingers spread wide apart, bringing them together would be adduction. Closing arm or bringing knees together are also examples of adduction.
Any muscle that causes adduction is called adductor.
Any movement that pulls the body parts away from the midline of the body is called abduction. When hands are swing from the side of the body up to the shoulder or higher, the movement is referred to as abduction. For finger and toes, spreading the digits away from the hand or foot’s centerline is abduction. So, if your fingers are wide spread, they are abducted. Similarly moving the knees away and raising the arms laterally are some examples of abduction.
Also called internal rotation, medial rotation refers to the rotation of the body parts towards the midline.
Also called outer rotation, lateral rotation refers to the rotation of body parts away from the midline
Clavicle, also known as collarbone, is a large bone that serves as a strut between the shoulder blade and the breastbone. There are two collar bones or clavicles- left clavicle and right clavicle. It is the only long bone in human body that lies horizontally. It is easy to palpate and clearly visible in people with less fat, as it creates a bulge in the skin.
Sternum or breastbone is a long flat bone located in the center of the chest. It is shaped like a necktie and connects the ribs via cartilage to form the front rib cage, and helps protect the heart, lungs, and major blood vessels.
Mastoid process is located just behind the ear canal serves for the attachment of sternocleidomastoid, splenius capitis, digastric muscle, and longissimus capitis.
Understanding Arm, shoulder, elbow and
The arm consists of several segments that work together to make it one of the most useful and complex tools of the human body. These parts include
· Upper arm- Extends from the shoulder to the elbow and helps you to lift and pull
· Elbow-The joint in between the upper arm and fore-arm. It helps you to extend arm up to 180 degrees.
· Forearm-The area between the wrist and the elbow. Muscles in the forearm, rotate, flex and extend the wrist.
· Wrist-It is a complex joint that connects the hand to the forearm. It is collection of multiple bones and joints.
· Hand- It is located at the end of the forearm and consists of five fingers. You already know what it can do.