Chapter 9: Joints

interosseous membrane

The gap between the bones may be narrow, with the bones joined by ligaments, or the gap may be wide and filled in by a broad sheet of connective tissue called a(n) ________.

articular discs

Located between the articulating surfaces of the femur and tibia are two ________, the medial meniscus and lateral meniscus.

anatomical position

In the ________, the upper limb is held next to the body with the palm facing forward.

upward movement

The ________ of the scapula and shoulder is elevation, while a downward movement is depression.

superior rotation

During ________, the glenoid cavity moves upward as the medial end of the scapular spine moves downward.

Lateral excursion

________ moves the mandible away from the midline, toward either the right or left side.

**articulation**

A **joint**, also called an

**joint cavity**

adjacent bones articulate with each other within a fluid-filled space called a

**fibrous joint**

is where the adjacent bones are united by fibrous connective tissue.

**cartilaginous joint**

the bones are joined by hyaline cartilage or fibrocartilage.

**synovial joint**

the articulating surfaces of the bones are not directly connected, but instead come into contact with each other within a joint cavity that is filled with a lubricating fluid.

**synarthrosis**

An immobile or nearly immobile joint is called a

**uniaxial joint**

only allows for a motion in a single plane (around a single axis).

**biaxial joint**

allows for motions within two planes.

**multiaxial joint**

A joint that allows for the several directions of movement is called a **__** (polyaxial or triaxial joint).

**ligament**

At a syndesmosis joint, the bones are more widely separated but are held together by a narrow band of fibrous connective tissue called a

**suture**

All the bones of the skull, except for the mandible, are joined to each other by a fibrous joint called a

**fontanelles**

These broad areas of connective tissue are called

**synostosis**

This fusion between bones is called a __(“joined by bone”).

**interosseous membrane**

The gap between the bones may be narrow, with the bones joined by ligaments, or the gap may be wide and filled in by a broad sheet of connective tissue called an

**periodontal ligament**

Spanning between the bony walls of the socket and the root of the tooth are numerous short bands of dense connective tissue, each of which is called a

**synchondrosis**

(“joined by cartilage”) is a cartilaginous joint where bones are joined together by hyaline cartilage, or where bone is united to hyaline cartilage.

**symphysis**

A cartilaginous joint where the bones are joined by fibrocartilage is called a__ (“growing together”).

**Synovial joints**

are the most common type of joint in the body.

**synovial membrane**

Lining the inner surface of the articular capsule is a thin

**synovial fluid**

The cells of this membrane secrete **__** (synovia = “a thick fluid”), a thick, slimy fluid that provides lubrication to further reduce friction between the bones of the joint.

**extrinsic ligament**

is located outside of the articular capsule

**intrinsic ligament**

is fused to or incorporated into the wall of the articular capsule

**intracapsular ligament**

is located inside of the articular capsule.

**tendon**

is the dense connective tissue structure that attaches a muscle to bone.

 **articular disc**

which is generally small and oval-shaped, or a meniscus, which is larger and C-shaped.

**bursa**

(plural = bursae) is a thin connective tissue sac filled with lubricating liquid.

**subcutaneous bursa**

is located between the skin and an underlying bone.

**subtendinous bursa**

is found between a tendon and a bone.

**tendon sheath**

is similar in structure to a bursa, but smaller.

**proximal radioulnar joint**

A second pivot joint is found at the

**Flexion and extension**

are movements that take place within the sagittal plane and involve anterior or posterior movements of the body or limbs.

**Lateral flexion**

is the bending of the neck or body toward the right or left side.

**Hyperextension**

is the abnormal or excessive extension of a joint beyond its normal range of motion, thus resulting in injury.

**Hyperflexion**

is excessive flexion at a joint.

**Abduction and adduction**

motions occur within the coronal plane and involve medial-lateral motions of the limbs, fingers, toes, or thumb.

**Circumduction**

is the movement of a body region in a circular manner, in which one end of the body region being moved stays relatively stationary while the other end describes a circle.

**Rotation**

can occur within the vertebral column, at a pivot joint, or at a ball-and-socket joint.

**Pronation**

is the motion that moves the fore

**Supination**

is the opposite motion, in which rotation of the radius returns the bones to their parallel positions and moves the palm to the anterior facing (supinated) position.

**Inversion**

is the turning of the foot to angle the bottom of the foot toward the midline

**eversion**

turns the bottom of the foot away from the midline.

**Protraction**

of the scapula occurs when the shoulder is moved forward, as when pushing against something or throwing a ball.

**Retraction**

 is the opposite motion, with the scapula being pulled posteriorly and medially, toward the vertebral column.

**Depression and elevation**

are downward and upward movements of the scapula or mandible.

**Lateral excursion**

moves the mandible away from the midline, toward either the right or left side.

**Medial excursion**

returns the mandible to its resting position at the midline.

**superior rotation**

the glenoid cavity moves upward as the medial end of the scapular spine moves downward.

**Inferior** rotation

occurs during limb adduction and involves the downward motion of the glenoid cavity with upward movement of the medial end of the scapular spine.

**Opposition**

is the thumb movement that brings the tip of the thumb in contact with the tip of a finger.

**reposition**

Returning the thumb to its anatomical position next to the index finger is called

**atlanto-occipital joint**

is formed by the articulations between the superior articular processes of the atlas and the occipital condyles on the base of the skull.

**atlantoaxial join**t

between the atlas and axis, consists of three articulations.

**temporomandibular joint (TMJ)**

is the joint that allows for opening (mandibular depression) and closing (mandibular elevation) of the mouth, as well as side-to-side and protraction/retraction motions of the lower jaw.

**glenohumeral joint**

The shoulder joint is called the

**glenoid labrum**

The socket formed by the glenoid cavity is deepened slightly by a small lip of fibrocartilage called the

**glenohumeral ligament**

located on the anterior side of the articular capsule.

**coracohumeral ligament**

running from the coracoid process of the scapula to the anterior humerus, and three ligaments

**rotator cuff**

The thickening of the capsule formed by the fusion of these four muscle tendons is called the

**elbow joint**

is a uniaxial hinge joint formed by the **humeroulnar joint**, the articulation between the trochlea of the humerus and the trochlear notch of the ulna.

**radial collateral ligament**

The lateral side of the elbow is supported by the

**annular ligament**

encircles the head of the radius.

**femoropatellar joint**

is found between the patella and the distal femur.

**patellar ligamen**t

Continuing from the patella to the anterior tibia just below the knee is the

**fibular collateral ligament**

(lateral collateral ligament) is on the lateral side and spans from the lateral epicondyle of the femur to the head of the fibula.

**tibial collateral ligament**

(medial collateral ligament) of the medial knee runs from the medial epicondyle of the femur to the medial tibia.

**talocrural joint**

The ankle is formed by the

**deltoid ligament**

On the medial side is the broad