Chapter 9 Joints

biaxial joint, metacarpophalangeal joint

A ______ allows for motions within two planes. An example of this joint is a ______ (knuckle joint) of the hand. The joint allows for movement along one axis to produce bending or straightening of the finger, and movement along a second axis, which allows for spreading of the fingers away from each other and bringing them together.

fibrous joint

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

joint cavity, directly connected

A key structural characteristic for a synovial joint that is not seen at fibrous or cartilaginous joints is the presence of a ______. This fluid-filled space is the site at which the articulating surfaces of the bones contact each other. Also unlike fibrous or cartilaginous joints, the articulating bone surfaces at a synovial joint are not ______ to each other with fibrous connective tissue or cartilage. This gives the bones of a synovial joint the ability to move smoothly against each other, allowing for increased joint mobility.

a fibrocartilage pad that provides padding between bones

A meniscus is ________.

bursa (plural = bursae)

Additional structures located outside of a synovial joint serve to prevent friction between the bones of the joint and the overlying muscle tendons or skin. A ______ is a thin connective tissue sac filled with lubricating liquid. They are located in regions where skin, ligaments, muscles, or muscle tendons can rub against each other, usually near a body joint. They reduce friction by separating the adjacent structures, preventing them from rubbing directly against each other. They are classified by their location.

limited mobility

An amphiarthrosis is a joint that has ______.

cartilaginous joint

At a ______, the bones are joined by hyaline cartilage or fibrocartilage.

include the radiocarpal joint

Condyloid joints ________.

dorsiflexion, plantar flexion

Dorsiflexion and plantar flexion are movements at the ankle joint, which is a hinge joint. Lifting the front of the foot, so that the top of the foot moves toward the anterior leg is ______, while lifting the heel of the foot from the ground or pointing the toes downward is ______. These are the only movements available at the ankle joint.

tibiofibular syndesmosis

In addition, at the distal tibiofibular joint, the articulating surfaces of the bones lack cartilage and the narrow gap between the bones is anchored by fibrous connective tissue and ligaments on both the anterior and posterior aspects of the joint. Together, the interosseous membrane and these ligaments form the ______.

produces the bones of the top and sides of the skull

Intramembranous ossification ________.

structurally and functionally

Joints are classified both ______. Structural classifications of joints take into account whether the adjacent bones are strongly anchored to each other by fibrous connective tissue or cartilage, or whether the adjacent bones articulate with each other within a joint cavity.

medial meniscus, lateral meniscus

Located between the articulating surfaces of the femur and tibia are two articular discs, the ______ and ______. Each is a C-shaped fibrocartilage structure that is thin along its inside margin and thick along the outer margin. They are attached to their tibial condyles, but do not attach to the femur.

RICE

Most ankle sprains can be treated using the ______ technique: Rest, Ice, Compression, and Elevation. Reducing joint mobility using a brace or cast may be required for a period of time. More severe injuries involving ligament tears or bone fractures may require surgery.

ligaments

Outside of their articulating surfaces, the bones are connected together by ______, which are strong bands of fibrous connective tissue. These strengthen and support the joint by anchoring the bones together and preventing their separation. These allow for normal movements at a joint, but limit the range of these motions, thus preventing excessive or abnormal joint movements.

supinated position, pronated position

Supination and pronation are movements of the forearm. In the anatomical position, the upper limb is held next to the body with the palm facing forward. This is the ______ of the forearm. In this position, the radius and ulna are parallel to each other. When the palm of the hand faces backward, the forearm is in the ______, and the radius and ulna form an X-shape.

hand from the palm backward position to the palm forward position

Supination is the motion that moves the ________.

are joints where the bones articulate with each other within a fluid-filled joint cavity

Synovial joints ________.

develop at an interzone site

Synovial joints ________.

articular capsule

Synovial joints are characterized by the presence of a joint cavity. The walls of this space are formed by the ______, a fibrous connective tissue structure that is attached to each bone just outside the area of the bone's articulating surface. The bones of the joint articulate with each other within the joint cavity.

annular ligament

The ______ encircles the head of the radius. This ligament supports the head of the radius as it articulates with the radial notch of the ulna at the proximal radioulnar joint. This is a pivot joint that allows for rotation of the radius during supination and pronation of the forearm.

acetabular labrum

The acetabulum is the socket portion of the hip joint. This space is deep and has a large articulation area for the femoral head, thus giving stability and weight bearing ability to the joint. The acetabulum is further deepened by the ______, a fibrocartilage lip attached to the outer margin of the acetabulum.

talocrural joint, dorsiflexion, plantar flexion

The ankle is formed by the ______. It consists of the articulations between the talus bone of the foot and the distal ends of the tibia and fibula of the leg (crural = "leg"). The ankle is thus a uniaxial hinge joint that allows only for ______ and ______ of the foot.

ulnar collateral ligament

The articular capsule of the elbow is thin on its anterior and posterior aspects, but is thickened along its outside margins by strong intrinsic ligaments. These ligaments prevent side-to-side movements and hyperextension. On the medial side is the triangular ______. This arises from the medial epicondyle of the humerus and attaches to the medial side of the proximal ulna. The strongest part of this ligament is the anterior portion, which resists hyperextension of the elbow. The ______ may be injured by frequent, forceful extensions of the forearm, as is seen in baseball pitchers. Reconstructive surgical repair of this ligament is referred to as Tommy John surgery, named for the former major league pitcher who was the first person to have this treatment.

synchondrosis

The epiphyseal plate of a growing long bone in a child is classified as a ________.

lateral flexion

The joints between the articular processes of adjacent vertebrae can contribute to which movement?

rotator cuff muscles

The primary support for the glenohumeral joint is provided by the ________.

glenohumeral joint, largest

The shoulder joint is called the ______. This is a ball-and-socket joint formed by the articulation between the head of the humerus and the glenoid cavity of the scapula. This joint has the ______ range of motion of any joint in the body. However, this freedom of movement is due to the lack of structural support and thus the enhanced mobility is offset by a loss of stability.

subacromial bursa, subscapular bursa

Two bursae, the ______ and the ______, help to prevent friction between the rotator cuff muscle tendons and the scapula as these tendons cross the glenohumeral joint. In addition to their individual actions of moving the upper limb, the rotator cuff muscles also serve to hold the head of the humerus in position within the glenoid cavity. By constantly adjusting their strength of contraction to resist forces acting on the shoulder, these muscles serve as "dynamic ligaments" and thus provide the primary structural support for the glenohumeral joint.

a plane joint

Which of the following is a type of synovial joint?

the metacarpophalangeal joint

Which of these joints is classified as a biaxial diarthrosis?

the manubriosternal joint

Which of these joints is classified as a synarthrosis?

Rotation

______ can occur within the vertebral column, at a pivot joint, or at a ball-and-socket joint. ______ of the neck or body is the twisting movement produced by the summation of the small rotational movements available between adjacent vertebrae. At a pivot joint, one bone rotates in relation to another bone. This is a uniaxial joint, and thus ______ is the only motion allowed at a pivot joint. For example, at the atlantoaxial joint, the first cervical (C1) vertebra (atlas) rotates around the dens, the upward projection from the second cervical (C2) vertebra (axis). This allows the head to rotate from side to side as when shaking the head "no." The proximal radioulnar joint is a pivot joint formed by the head of the radius and its articulation with the ulna. This joint allows for the radius to rotate along its length during pronation and supination movements of the forearm.

Synovial joints are

______ the most common type of joint in the body.

suture

A ______ is the narrow fibrous joint found between most bones of the skull.

condyloid, saddle, and ball-and-socket joints

Abduction and adduction movements are seen at ______.

the interosseous membrane of the forearm

An example of a wide fibrous joint is ________.

ligament of the head of the femur

Inside of the articular capsule of the hip joint, the ______ (ligamentum teres) spans between the acetabulum and femoral head. This intracapsular ligament is normally slack and does not provide any significant joint support, but it does provide a pathway for an important artery that supplies the head of the femur.

periodontal ligament, synarthrosis

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 ______. Due to the immobility of a gomphosis, this type of joint is functionally classified as a ______.

femoropatellar joint

The knee joint is the largest joint of the body. It actually consists of three articulations. The ______ is found between the patella and the distal femur.

is supported by the annular ligament

The proximal radioulnar joint ________.

as an amphiarthrosis

The syndesmoses found in the forearm and leg serve to unite parallel bones and prevent their separation. However, a syndesmosis does not prevent all movement between the bones, and thus this type of fibrous joint is functionally classified ______.

Inferior rotation

To increase its weight-bearing support for the bag, the shoulder lifts as the scapula superiorly rotates. ______ occurs during limb adduction and involves the downward motion of the glenoid cavity with upward movement of the medial end of the scapular spine.

eversion

Which motion moves the bottom of the foot away from the midline of the body?

adjacent vertebrae

Which of the following are joined by a symphysis?

hinge joint, uniaxial joints

In a ______, the convex end of one bone articulates with the concave end of the adjoining bone. This type of joint allows only for bending and straightening motions along a single axis, and thus these joints are functionally classified as ______. A good example is the elbow joint, with the articulation between the trochlea of the humerus and the trochlear notch of the ulna. Others of the body include the knee, ankle, and interphalangeal joints between the phalanx bones of the fingers and toes.

elbow joint, humeroulnar joint

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

ankle

The ______ is the most frequently injured joint in the body, with the most common injury being an inversion ______ sprain.

amphiarthrosis

The joint between adjacent vertebrae that includes an invertebral disc is classified as which type of joint?

Abduction and adductionr

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

synchondrosis ("joined by cartilage")

A ______ is a cartilaginous joint where bones are joined together by hyaline cartilage, or where bone is united to hyaline cartilage.

syndesmosis ("fastened with a band"), interosseous membrane

A ______ is a type of fibrous joint in which two parallel bones are united to each other by fibrous connective tissue. 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 ______.

submuscular bursa

A ______ is found between a muscle and an underlying bone, or between adjacent muscles. These prevent rubbing of the muscle during movements. A large ______, the trochanteric bursa, is found at the lateral hip, between the greater trochanter of the femur and the overlying gluteus maximus muscle.

subtendinous bursa

A ______ is found between a tendon and a bone. Examples include the subacromial bursa that protects the tendon of shoulder muscle as it passes under the acromion of the scapula, and the suprapatellar bursa that separates the tendon of the large anterior thigh muscle from the distal femur just above the knee.

subcutaneous bursa

A ______ is located between the skin and an underlying bone. It allows skin to move smoothly over the bone. Examples include the prepatellar bursa located over the kneecap and the olecranon bursa at the tip of the elbow.

tendon sheath

A ______ is similar in structure to a bursa, but smaller. It is a connective tissue sac that surrounds a muscle tendon at places where the tendon crosses a joint. It contains a lubricating fluid that allows for smooth motions of the tendon during muscle contraction and joint movements.

gomphosis ("fastened with bolts"), peg-and-socket joint

A ______ is the specialized fibrous joint that anchors the root of a tooth into its bony socket within the maxillary bone (upper jaw) or mandible bone (lower jaw) of the skull. It is also known as a ______.

uniaxial joint, elbow joint

A ______ only allows for a motion in a single plane (around a single axis). The ______, which only allows for bending or straightening, is an example of a uniaxial joint.

joint, articulation

A ______, also called an ______, is any place where adjacent bones or bone and cartilage come together (articulate with each other) to form a connection.

prevents friction between skin and bone, or a muscle tendon and bone

A bursa ________.

is called a symphysis when the bones are united by fibrocartilage

A cartilaginous joint ________.

symphysis ("growing together"), amphiarthrosis

A cartilaginous joint where the bones are joined by fibrocartilage is called a ______. Fibrocartilage is very strong because it contains numerous bundles of thick collagen fibers, thus giving it a much greater ability to resist pulling and bending forces when compared with hyaline cartilage. This gives symphyses the ability to strongly unite the adjacent bones, but can still allow for limited movement to occur. Thus, a symphysis is functionally classified as an ______.

articular disc, meniscus

A few synovial joints of the body have a fibrocartilage structure located between the articulating bones. This is called an ______, which is generally small and oval-shaped, or a ______, which is larger and C-shaped. These structures can serve several functions, depending on the specific joint.

diarthrosis, synovial joints

A freely mobile joint is classified as a ______. These types of joints include all ______ of the body, which provide the majority of body movements.

anchors a tooth to the jaw

A gomphosis ________.

multiaxial joint, shoulder and hip joints

A joint that allows for the several directions of movement is called a ______ (polyaxial or triaxial joint). This type of diarthrotic joint allows for movement along three axes. The ______ are multiaxial joints. They allow the upper or lower limb to move in an anterior-posterior direction and a medial-lateral direction. In addition, the limb can also be rotated around its long axis. This third movement results in rotation of the limb so that its anterior surface is moved either toward or away from the midline of the body.

joint interzone

A similar process of endochondral ossification gives rises to the bones and joints of the limbs. The limbs initially develop as small limb buds that appear on the sides of the embryo around the end of the fourth week of development. Starting during the sixth week, as each limb bud continues to grow and elongate, areas of mesenchyme within the bud begin to differentiate into the hyaline cartilage that will form models for of each of the future bones. The synovial joints will form between the adjacent cartilage models, in an area called the ______. Cells at the center of this region undergo cell death to form the joint cavity, while surrounding mesenchyme cells will form the articular capsule and supporting ligaments.

found at the first sternocostal joint of the thoracic cage

A synchondrosis is ________.

temporary, permanent, synostosis

A synchondrosis may be ______ or ______. A temporary synchondrosis is the epiphyseal plate (growth plate) of a growing long bone. For many years during childhood growth, the rates of cartilage growth and bone formation are equal and thus the epiphyseal plate does not change in overall thickness as the bone lengthens. During the late teens and early 20s, growth of the cartilage slows and eventually stops. The epiphyseal plate is then completely replaced by bone, and the diaphysis and epiphysis portions of the bone fuse together to form a single adult bone. This fusion of the diaphysis and epiphysis is a ______. Once this occurs, bone lengthening ceases. For this reason, the epiphyseal plate is considered to be a temporary synchondrosis. Because cartilage is softer than bone tissue, injury to a growing long bone can damage the epiphyseal plate cartilage, thus stopping bone growth and preventing additional bone lengthening.

a fibrous joint that unites parallel bones

A syndesmosis is ________.

subtalar joint

Additional joints between the tarsal bones of the posterior foot allow for the movements of foot inversion and eversion. Most important for these movements is the ______, located between the talus and calcaneus bones.

suture ("to bind or sew"), synarthrosis

All the bones of the skull, except for the mandible, are joined to each other by a fibrous joint called a ______. The fibrous connective tissue found here strongly unites the adjacent skull bones and thus helps to protect the brain and form the face. In adults, the skull bones are closely opposed and fibrous connective tissue fills the narrow gap between the bones. It is frequently convoluted, forming a tight union that prevents most movement between the bones. Thus, they are functionally classified as a ______, although some sutures may allow for slight movements between the cranial bones.

humeroradial joint

Also associated with the elbow are the ______ and the proximal radioulnar joint. All three of these joints are enclosed within a single articular capsule.

atlantoaxial joint, radioulnar joint

An example of a pivot joint is the ______, found between the C1 (atlas) and C2 (axis) vertebrae. Here, the upward projecting dens of the axis articulates with the inner aspect of the atlas, where it is held in place by a ligament. Rotation at this joint allows you to turn your head from side to side. A second pivot joint is found at the proximal ______. Here, the head of the radius is largely encircled by a ligament that holds it in place as it articulates with the radial notch of the ulna. Rotation of the radius allows for forearm movements.

intervertebral disc

An example of amphiarthrosis is the cartilaginous joint that unites the bodies of adjacent vertebrae. Filling the gap between the vertebrae is a thick pad of fibrocartilage called an ______. Each strongly unites the vertebrae but still allows for a limited amount of movement between them. However, the small movements available between adjacent vertebrae can sum together along the length of the vertebral column to provide for large ranges of body movements.

synarthrosis

An immobile or nearly immobile joint is called a ______. The immobile nature of these joints provide for a strong union between the articulating bones. This is important at locations where the bones provide protection for internal organs.

pubic symphysis

Another example of an amphiarthrosis is the ______ of the pelvis. This is a cartilaginous joint in which the pubic regions of the right and left hip bones are strongly anchored to each other by fibrocartilage. This joint normally has very little mobility. The strength of this joint is important in conferring weight-bearing stability to the pelvis.

cartilaginous joint, joint cavity

As the name indicates, at a ______, the adjacent bones are united by cartilage, a tough but flexible type of connective tissue. These types of joints lack a ______ and involve bones that are joined together by either hyaline cartilage or fibrocartilage

condyloid joint

At a ______ (ellipsoid joint), the shallow depression at the end of one bone articulates with a rounded structure from an adjacent bone or bones. The knuckle (metacarpophalangeal) joints of the hand between the distal end of a metacarpal bone and the proximal phalanx bone are condyloid joints. Another example is the radiocarpal joint of the wrist, between the shallow depression at the distal end of the radius bone and the rounded scaphoid, lunate, and triquetrum carpal bones. In this case, the articulation area has a more oval (elliptical) shape.

plane joint, multiaxial joint

At a ______ (gliding joint), the articulating surfaces of the bones are flat or slightly curved and of approximately the same size, which allows the bones to slide against each other. The motion at this type of joint is usually small and tightly constrained by surrounding ligaments. Based only on their shape, these joints can allow multiple movements, including rotation. Thus these joints can be functionally classified as a ______. However, not all of these movements are available to every one of these joints due to limitations placed on it by ligaments or neighboring bones. Thus, depending upon the specific joint of the body, these joint may exhibit only a single type of movement or several movements. These are found between the carpal bones (intercarpal joints) of the wrist or tarsal bones (intertarsal joints) of the foot, between the clavicle and acromion of the scapula (acromioclavicular joint), and between the superior and inferior articular processes of adjacent vertebrae (zygapophysial joints).

pivot joint, uniaxial diarthrosis

At a ______, a rounded portion of a bone is enclosed within a ring formed partially by the articulation with another bone and partially by a ligament. The bone rotates within this ring. Since the rotation is around a single axis, these joints are functionally classified as a ______ type of joint.

saddle joint, biaxial joints

At a ______, both of the articulating surfaces for the bones have a saddle shape, which is concave in one direction and convex in the other. This allows the two bones to fit together like a rider sitting on a saddle. These joints are functionally classified as ______. The primary example is the first carpometacarpal joint, between the trapezium (a carpal bone) and the first metacarpal bone at the base of the thumb. This joint provides the thumb the ability to move away from the palm of the hand along two planes. Thus, the thumb can move within the same plane as the palm of the hand, or it can jut out anteriorly, perpendicular to the palm. This movement of the first carpometacarpal joint is what gives humans their distinctive "opposable" thumbs. The sternoclavicular joint is also classified as a ______.

fibrous joint suture, syndesmosis, and gomphosis.

At a ______, the adjacent bones are directly connected to each other by fibrous connective tissue, and thus the bones do not have a joint cavity between them. The gap between the bones may be narrow or wide. There are three types of these joints. A ______

synovial joint

At a ______, 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. These joints allow for free movement between the bones and are the most common joints of the body.

secretes the lubricating synovial fluid

At a synovial joint, the synovial membrane ________.

tendon, "dynamic ligament"

At many synovial joints, additional support is provided by the muscles and their tendons that act across the joint. A ______ is the dense connective tissue structure that attaches a muscle to bone. As forces acting on a joint increase, the body will automatically increase the overall strength of contraction of the muscles crossing that joint, thus allowing the muscle and its tendon to serve as a ______ to resist forces and support the joint. This type of indirect support by muscles is very important at the shoulder joint, for example, where the ligaments are relatively weak.

synostosis

At some sutures, the connective tissue will ossify and be converted into bone, causing the adjacent bones to fuse to each other. This fusion between bones is called a ______ ("joined by bone"). Examples of ______ fusions between cranial bones are found both early and late in life. At the time of birth, the frontal and maxillary bones consist of right and left halves joined together by sutures, which disappear by the eighth year as the halves fuse together to form a single bone. Late in life, the sagittal, coronal, and lambdoid sutures of the skull will begin to ossify and fuse, causing the suture line to gradually disappear.

the joint cavity is filled with a thick, lubricating fluid

At synovial joints, ________.

patellar ligament

At the femoropatellar joint, the patella slides vertically within a groove on the distal femur. The patella is a sesamoid bone incorporated into the tendon of the quadriceps femoris muscle, the large muscle of the anterior thigh. The patella serves to protect the quadriceps tendon from friction against the distal femur. Continuing from the patella to the anterior tibia just below the knee is the ______. Acting via the patella and ______, the quadriceps femoris is a powerful muscle that acts to extend the leg at the knee. It also serves as a "dynamic ligament" to provide very important support and stabilization for the knee joint.

multiaxial joints

Ball-and-socket joints are classified functionally as ______. The femur and the humerus are able to move in both anterior-posterior and medial-lateral directions and they can also rotate around their long axis. The shallow socket formed by the glenoid cavity allows the shoulder joint an extensive range of motion. In contrast, the deep socket of the acetabulum and the strong supporting ligaments of the hip joint serve to constrain movements of the femur, reflecting the need for stability and weight-bearing ability at the hip.

elevation, depression,

Depression and elevation are downward and upward movements of the scapula or mandible. The upward movement of the scapula and shoulder is ______, while a downward movement is ______. These movements are used to shrug your shoulders. Similarly, ______ of the mandible is the upward movement of the lower jaw used to close the mouth or bite on something, and ______ is the downward movement that produces opening of the mouth.

superior rotation

During ______, the glenoid cavity moves upward as the medial end of the scapular spine moves downward. This is a very important motion that contributes to upper limb abduction. Without this rotation of the scapula, the greater tubercle of the humerus would hit the acromion of the scapula, thus preventing any abduction of the arm above shoulder height. This rotation of the scapula is thus required for full abduction of the upper limb. This rotation is also used without arm abduction when carrying a heavy load with your hand or on your shoulder. You can feel this rotation when you pick up a load, such as a heavy book bag and carry it on only one shoulder.

the process that replaces hyaline cartilage with bone tissue

Endochondral ossification is ________.

permanent synchondroses, synarthrosis

Examples of ______ are found in the thoracic cage. One example is the first sternocostal joint, where the first rib is anchored to the manubrium by its costal cartilage. (The articulations of the remaining costal cartilages to the sternum are all synovial joints.) Additional synchondroses are formed where the anterior end of the other 11 ribs is joined to its costal cartilage. Unlike the temporary synchondroses of the epiphyseal plate, these ______ retain their hyaline cartilage and thus do not ossify with age. Due to the lack of movement between the bone and cartilage, both temporary and permanent synchondroses are functionally classified as a ______.

sutures, manubriosternal joint

Examples of synarthrosis include ______, the fibrous joints between the bones of the skull that surround and protect the brain, and the ______, the cartilaginous joint that unites the manubrium and body of the sternum for protection of the heart.

flexion, extension

For the vertebral column, ______ (anterior ______) is an anterior (forward) bending of the neck or trunk, while ______ involves a posterior-directed motion, such as straightening from a flexed position or bending backward.

articular cartilage, smoothly

Friction between the bones at a synovial joint is prevented by the presence of the ______, a thin layer of hyaline cartilage that covers the entire articulating surface of each bone. However, unlike at a cartilaginous joint, the cartilages of each bone are not continuous with each other. Instead, the ______ acts like a Teflon® coating over the bone surface, allowing the articulating bones to move ______ against each other without damaging the underlying bone tissue.

biaxial joints

Functionally, condyloid joints are ______ that allow for two planes of movement. One movement involves the bending and straightening of the fingers or the anterior-posterior movements of the hand. The second movement is a side-to-side movement, which allows you to spread your fingers apart and bring them together, or to move your hand in a medial-going or lateral-going direction.

synostoses

Growing layers of cartilage also form synchondroses that join together the ilium, ischium, and pubic portions of the hip bone during childhood and adolescence. When body growth stops, the cartilage disappears and is replaced by bone, forming ______ and fusing the bony components together into the single hip bone of the adult. Similarly, ______ unite the sacral vertebrae that fuse together to form the adult sacrum

rotator cuff

However, the primary support for the shoulder joint is provided by muscles crossing the joint, particularly the four rotator cuff muscles. These muscles (supraspinatus, infraspinatus, teres minor, and subscapularis) arise from the scapula and attach to the greater or lesser tubercles of the humerus. As these muscles cross the shoulder joint, their tendons encircle the head of the humerus and become fused to the anterior, superior, and posterior walls of the articular capsule. The thickening of the capsule formed by the fusion of these four muscle tendons is called the ______.

rheumatoid arthritis

In ______, the joint capsule and synovial membrane become inflamed. As the disease progresses, the articular cartilage is severely damaged or destroyed, resulting in joint deformation, loss of movement, and severe disability. The most commonly involved joints are the hands, feet, and cervical spine, with corresponding joints on both sides of the body usually affected, though not always to the same extent. ______ is also associated with lung fibrosis, vasculitis (inflammation of blood vessels), coronary heart disease, and premature mortality. With no known cure, treatments are aimed at alleviating symptoms. Exercise, anti-inflammatory and pain medications, various specific disease-modifying anti-rheumatic drugs, or surgery are used to treat ______.

zygapophysial joints, cervical, lumbar

In addition to being held together by the intervertebral discs, adjacent vertebrae also articulate with each other at synovial joints formed between the superior and inferior articular processes called ______ (facet joints). These are plane joints that provide for only limited motions between the vertebrae. The orientation of the articular processes at these joints varies in different regions of the vertebral column and serves to determine the types of motions available in each vertebral region. The ______ and ______ regions have the greatest ranges of motions.

fontanelles

In newborns and infants, the areas of connective tissue between the bones are much wider, especially in those areas on the top and sides of the skull that will become the sagittal, coronal, squamous, and lambdoid sutures. These broad areas of connective tissue are called ______.

shock absorption, cushioning, meniscus

In some places, an articular disc may act to strongly unite the bones of the joint to each other. Examples of this include the articular discs found at the sternoclavicular joint or between the distal ends of the radius and ulna bones. At other synovial joints, the disc can provide ______ and ______ between the bones, which is the function of each ______ within the knee joint. Finally, an articular disc can serve to smooth the movements between the articulating bones, as seen at the temporomandibular joint. Some synovial joints also have a fat pad, which can serve as a cushion between the bones.

the interosseous membrane

In the forearm, ______ is flexible enough to allow for rotation of the radius bone during forearm movements. Thus in contrast to the stability provided by the tibiofibular syndesmosis, the flexibility of ______ membrane allows for the much greater mobility of the forearm.

radius and ulna, tibia and fibula

In the forearm, the wide gap between the shaft portions of the ______ bones are strongly united by an interosseous membrane. Similarly, in the leg, the shafts of the ______ are also united by an interosseous membrane.

the syndesmosis

In the leg, ______ between the tibia and fibula strongly unites the bones, allows for little movement, and firmly locks the talus bone in place between the tibia and fibula at the ankle joint. This provides strength and stability to the leg and ankle, which are important during weight bearing.

anterior, posterior

In the limbs, flexion decreases the angle between the bones (bending of the joint), while extension increases the angle and straightens the joint. For the upper limb, all ______-going motions are flexion and all ______-going motions are extension. These include anterior-posterior movements of the arm at the shoulder, the forearm at the elbow, the hand at the wrist, and the fingers at the metacarpophalangeal and interphalangeal joints. For the thumb, extension moves the thumb away from the palm of the hand, within the same plane as the palm, while flexion brings the thumb back against the index finger or into the palm. These motions take place at the first carpometacarpal joint. In the lower limb, bringing the thigh forward and upward is flexion at the hip joint, while any posterior-going motion of the thigh is extension.

cervical, thoracic, lumbar

In the neck, the articular processes of ______ vertebrae are flattened and generally face upward or downward. This orientation provides this vertebral column with extensive ranges of motion for flexion, extension, lateral flexion, and rotation. In the ______ region, the downward projecting and overlapping spinous processes, along with the attached thoracic cage, greatly limit flexion, extension, and lateral flexion. However, the flattened and vertically positioned thoracic articular processes allow for the greatest range of rotation within the vertebral column. The ______ region allows for considerable extension, flexion, and lateral flexion, but the orientation of the articular processes largely prohibits rotation.

adhesive capsulitis ("frozen shoulder")

Injuries to the shoulder joint are common. Repetitive use of the upper limb, particularly in abduction such as during throwing, swimming, or racquet sports, may lead to acute or chronic inflammation of the bursa or muscle tendons, a tear of the glenoid labrum, or degeneration or tears of the rotator cuff. Because the humeral head is strongly supported by muscles and ligaments around its anterior, superior, and posterior aspects, most dislocations of the humerus occur in an inferior direction. This can occur when force is applied to the humerus when the upper limb is fully abducted, as when diving to catch a baseball and landing on your hand or elbow. Inflammatory responses to any shoulder injury can lead to the formation of scar tissue between the articular capsule and surrounding structures, thus reducing shoulder mobility, a condition called ______.

Inversion, eversion

Inversion and eversion are complex movements that involve the multiple plane joints among the tarsal bones of the posterior foot (intertarsal joints) and thus are not motions that take place at the ankle joint. ______ is the turning of the foot to angle the bottom of the foot toward the midline, while ______ turns the bottom of the foot away from the midline. The foot has a greater range of inversion than eversion motion. These are important motions that help to stabilize the foot when walking or running on an uneven surface and aid in the quick side-to-side changes in direction used during active sports.

embryonic development, mesenchyme

Joints form during ______ in conjunction with the formation and growth of the associated bones. The embryonic tissue that gives rise to all bones, cartilages, and connective tissues of the body is called ______.

posterior, straightening

Knee flexion is the bending of the knee to bring the foot toward the ______ thigh, and extension is the ______ of the knee. Flexion and extension movements are seen at the hinge, condyloid, saddle, and ball-and-socket joints of the limbs.

extrinsic ligament, intrinsic ligament, intracapsular ligament

Ligaments are classified based on their relationship to the fibrous articular capsule. An ______ is located outside of the articular capsule, an ______ is fused to or incorporated into the wall of the articular capsule, and an ______ is located inside of the articular capsule.

deltoid ligament

Like the hinge joints of the elbow and knee, the talocrural joint of the ankle is supported by several strong ligaments located on the sides of the joint. On the medial side is the broad ______. The deltoid ligament supports the ankle joint and also resists excessive eversion of the foot.

synovial membrane, synovial fluid (synovia = "a thick fluid"), diarthrosis

Lining the inner surface of the articular capsule is a thin ______. The cells of this membrane secrete ______, a thick, slimy fluid that provides lubrication to further reduce friction between the bones of the joint. This fluid also provides nourishment to the articular cartilage, which does not contain blood vessels. The ability of the bones to move smoothly against each other within the joint cavity, and the freedom of joint movement this provides, means that each synovial joint is functionally classified as a ______.

axis

Most diarthrotic joints are found in the appendicular skeleton and thus give the limbs a wide range of motion. These joints are divided into three categories. An ______ in anatomy is described as the movements in reference to the three anatomical planes: transverse, frontal, and sagittal. Thus, diarthroses are classified as uniaxial (for movement in one plane), biaxial (for movement in two planes), or multiaxial joints (for movement in all three anatomical planes).

downward, forward, articular tubercle

Movement at the TMJ during opening and closing of the mouth involves both gliding and hinge motions of the mandible. With the mouth closed, the mandibular condyle and articular disc are located within the mandibular fossa of the temporal bone. During opening of the mouth, the mandible hinges ______ and at the same time is pulled anteriorly, causing both the condyle and the articular disc to glide ______ from the mandibular fossa onto the downward projecting ______. The net result is a forward and downward motion of the condyle and mandibular depression. The temporomandibular joint is supported by an extrinsic ligament that anchors the mandible to the skull. This ligament spans the distance between the base of the skull and the lingula on the medial side of the mandibular ramus.

abduction

Movement at the shoulder joint that moves the upper limb laterally away from the body is called ________.

circumduction

Movement of a body region in a circular movement at a condyloid joint is what type of motion?

Protraction, Retraction

Protraction and retraction are anterior-posterior movements of the scapula or mandible. ______ of the scapula occurs when the shoulder is moved forward, as when pushing against something or throwing a ball. ______ is the opposite motion, with the scapula being pulled posteriorly and medially, toward the vertebral column. For the mandible, ______ occurs when the lower jaw is pushed forward, to stick out the chin, while ______ pulls the lower jaw backward.

medial rotation, lateral rotation

Rotation can also occur at the ball-and-socket joints of the shoulder and hip. Here, the humerus and femur rotate around their long axis, which moves the anterior surface of the arm or thigh either toward or away from the midline of the body. Movement that brings the anterior surface of the limb toward the midline of the body is called (internal) ______. Conversely, rotation of the limb so that the anterior surface moves away from the midline is (external) ______. Be sure to distinguish both rotations, which can only occur at the multiaxial shoulder and hip joints, from circumduction, which can occur at either biaxial or multiaxial joints.

pivot, hinge, condyloid, saddle, plane, and ball-and socket-joints

Synovial joints are subdivided based on the shapes of the articulating surfaces of the bones that form each joint. The six types of synovial joints are ______.

temporomandibular joint, articular disc

The ______ (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. This joint involves the articulation between the mandibular fossa and articular tubercle of the temporal bone, with the condyle (head) of the mandible. Located between these bony structures, filling the gap between the skull and mandible, is a flexible ______. This disc serves to smooth the movements between the temporal bone and mandibular condyle.

medial tibiofemoral joint, lateral tibiofemoral joint

The ______ and ______ are located between the medial and lateral condyles of the femur and the medial and lateral condyles of the tibia. All of these articulations are enclosed within a single articular capsule. The knee functions as a hinge joint, allowing flexion and extension of the leg. This action is generated by both rolling and gliding motions of the femur on the tibia. In addition, some rotation of the leg is available when the knee is flexed, but not when extended. The knee is well constructed for weight bearing in its extended position, but is vulnerable to injuries associated with hyperextension, twisting, or blows to the medial or lateral side of the joint, particularly while weight bearing.

atlantoaxial joint, ligament

The ______, between the atlas and axis, consists of three articulations. The paired superior articular processes of the axis articulate with the inferior articular processes of the atlas. These articulating surfaces are relatively flat and oriented horizontally. The third articulation is the pivot joint formed between the dens, which projects upward from the body of the axis, and the inner aspect of the anterior arch of the atlas. A strong ______ passes posterior to the dens to hold it in position against the anterior arch. These articulations allow the atlas to rotate on top of the axis, moving the head toward the right or left, as when shaking your head "no."

is a uniaxial hinge joint

The ankle joint ________.

anterior cruciate ligament , posterior cruciate ligament

The articular capsule of the posterior knee is thickened by intrinsic ligaments that help to resist knee hyperextension. Inside the knee are two intracapsular ligaments, the ______ and ______. The posterior cruciate ligament is the stronger ligament. It serves to support the knee when it is flexed and weight bearing, as when walking downhill. In this position, the posterior cruciate ligament prevents the femur from sliding anteriorly off the top of the tibia. The anterior cruciate ligament becomes tight when the knee is extended, and thus resists hyperextension.

coracohumeral ligament, glenohumeral ligament

The articular capsule that surrounds the glenohumeral joint is relatively thin and loose to allow for large motions of the upper limb. Some structural support for the joint is provided by thickenings of the articular capsule wall that form weak intrinsic ligaments. These include the ______, running from the coracoid process of the scapula to the anterior humerus, and three ligaments, each called a ______, located on the anterior side of the articular capsule. These ligaments help to strengthen the superior and anterior capsule walls.

atlanto-occipital joint

The articulations formed between the skull, the atlas (C1 vertebra), and the axis (C2 vertebra) differ from the articulations in other vertebral areas and play important roles in movement of the head. The ______ is formed by the articulations between the superior articular processes of the atlas and the occipital condyles on the base of the skull. This articulation has a pronounced U-shaped curvature, oriented along the anterior-posterior axis. This allows the skull to rock forward and backward, producing flexion and extension of the head. This moves the head up and down, as when shaking your head "yes."

mobility

The functional classification of joints is determined by the amount of ______ found between the adjacent bones. Joints are thus functionally classified as a synarthrosis or immobile joint, an amphiarthrosis or slightly moveable joint, or as a diarthrosis, which is a freely moveable joint (arthroun = "to fasten by a joint"). Depending on their location, fibrous joints may be functionally classified as a synarthrosis (immobile joint) or an amphiarthrosis (slightly mobile joint). Cartilaginous joints are also functionally classified as either a synarthrosis or an amphiarthrosis joint. All synovial joints are functionally classified as a diarthrosis joint.

narrow

The gap separating the bones at a symphysis may be narrow or wide. Examples in which the gap between the bones is ______ include the pubic symphysis and the manubriosternal joint. At the pubic symphysis, the pubic portions of the right and left hip bones of the pelvis are joined together by fibrocartilage across a ______ gap. Similarly, at the manubriosternal joint, fibrocartilage unites the manubrium and body portions of the sternum.

osteoarthritis, femoral neck

The hip is prone to ______, and thus was the first joint for which a replacement prosthesis was developed. A common injury in elderly individuals, particularly those with weakened bones due to osteoporosis, is a "broken hip," which is actually a fracture of the ______.

fracture, interosseous membrane, muscles

The interosseous membranes of the leg and forearm also provide areas for muscle attachment. Damage to a syndesmotic joint, which usually results from a ______ of the bone with an accompanying tear of the ______, will produce pain, loss of stability of the bones, and may damage the ______ attached to the interosseous membrane. If the fracture site is not properly immobilized with a cast or splint, contractile activity by these muscles can cause improper alignment of the broken bones during healing.

wide

The intervertebral symphysis is a ______ symphysis located between the bodies of adjacent vertebrae of the vertebral column. Here a thick pad of fibrocartilage called an intervertebral disc strongly unites the adjacent vertebrae by filling the gap between them. The gap of the intervertebral symphysis is important because it allows for small movements between the adjacent vertebrae. In addition, the thick intervertebral disc provides cushioning between the vertebrae, which is important when carrying heavy objects or during high-impact activities such as running or jumping.

ball-and-socket joint

The joint with the greatest range of motion is the ______. At these joints, the rounded head of one bone fits into the concave articulation of the adjacent bone. The hip joint and the glenohumeral (shoulder) joint are the only ones of the body. At the hip joint, the head of the femur articulates with the acetabulum of the hip bone, and at the shoulder joint, the head of the humerus articulates with the glenoid cavity of the scapula.

fibular collateral ligament (lateral collateral ligament), tibial collateral ligament (medial collateral ligament)

The knee joint has multiple ligaments that provide support, particularly in the extended position. Outside of the articular capsule, located at the sides of the knee, are two extrinsic ligaments. The ______ is on the lateral side and spans from the lateral epicondyle of the femur to the head of the fibula. The ______ of the medial knee runs from the medial epicondyle of the femur to the medial tibia.

glenoid labrum

The large range of motions at the shoulder joint is provided by the articulation of the large, rounded humeral head with the small and shallow glenoid cavity, which is only about one third of the size of the humeral head. The socket formed by the glenoid cavity is deepened slightly by a small lip of fibrocartilage called the ______, which extends around the outer margin of the cavity.

anterior talofibular ligament, posterior talofibular ligament, calcaneofibular ligament

The lateral side of the ankle has several smaller ligaments. These include the ______ and the ______, both of which span between the talus bone and the lateral malleolus of the fibula, and the ______, located between the calcaneus bone and fibula. These ligaments support the ankle and also resist excess inversion of the foot.

radial collateral ligament

The lateral side of the elbow is supported by the ______. This arises from the lateral epicondyle of the humerus and then blends into the lateral side of the annular ligament.

osteoarthritis

The most common type of arthritis is ______, which is associated with aging and "wear and tear" of the articular cartilage. The bone tissue underlying the damaged articular cartilage also responds by thickening, producing irregularities and causing the articulating surface of the bone to become rough or bumpy. Joint movement then results in pain and inflammation. In individuals with more advanced osteoarthritis, the affected joints can become more painful and therefore are difficult to use effectively, resulting in increased immobility. There is no cure for osteoarthritis, but several treatments can help alleviate the pain. Treatments may include lifestyle changes, such as weight loss and low-impact exercise, and over-the-counter or prescription medications that help to alleviate the pain and inflammation. For severe cases, joint replacement surgery (arthroplasty) may be required.

iliofemoral ligament, pubofemoral ligament, and ischiofemoral ligament

The surrounding articular capsule is strong, with several thickened areas forming intrinsic ligaments. These ligaments arise from the hip bone, at the margins of the acetabulum, and attach to the femur at the base of the neck. The ligaments are the ______, all of which spiral around the head and neck of the femur. The ligaments are tightened by extension at the hip, thus pulling the head of the femur tightly into the acetabulum when in the upright, standing position. Very little additional extension of the thigh is permitted beyond this vertical position. These ligaments thus stabilize the hip joint and allow you to maintain an upright standing position with only minimal muscle contraction.

synchondrosis, symphysis

There are two types of cartilaginous joints. A ______ is a cartilaginous joint where the bones are joined by hyaline cartilage. Also classified as a synchondrosis are places where bone is united to a cartilage structure, such as between the anterior end of a rib and the costal cartilage of the thoracic cage. The second type of cartilaginous joint is a ______, where the bones are joined by fibrocartilage.

thoracic

Which region of the vertebral column has the greatest range of motion for rotation?

The medial meniscus is attached to the tibial collateral ligament.

Which statement is true concerning the knee joint?

syndesmosis

Which type of fibrous joint connects the tibia and fibula?

hinge joint

Which type of joint allows for only uniaxial movement?

ball-and-socket

Which type of joint provides the greatest range of motion?

medial meniscus

While both menisci are free to move during knee motions, the ______ shows less movement because it is anchored at its outer margin to the articular capsule and tibial collateral ligament. The menisci provide padding between the bones and help to fill the gap between the round femoral condyles and flattened tibial condyles. Some areas of each meniscus lack an arterial blood supply and thus these areas heal poorly if damaged.

Superior and inferior rotation

______ are movements of the scapula and are defined by the direction of movement of the glenoid cavity. These motions involve rotation of the scapula around a point inferior to the scapular spine and are produced by combinations of muscles acting on the scapula.

Flexion and extension

______ are typically movements that take place within the sagittal plane and involve anterior or posterior movements of the neck, trunk, or limbs.

Functional classifications

______ describe the degree of movement available between the bones, ranging from immobile, to slightly mobile, to freely moveable joints. The amount of movement available at a particular joint of the body is related to the functional requirements for that joint. Thus immobile or slightly moveable joints serve to protect internal organs, give stability to the body, and allow for limited body movement. In contrast, freely moveable joints allow for much more extensive movements of the body and limbs.

Arthritis

______ is a common disorder of synovial joints that involves inflammation of the joint. This often results in significant joint pain, along with swelling, stiffness, and reduced joint mobility. There are more than 100 different forms. It may arise from aging, damage to the articular cartilage, autoimmune diseases, bacterial or viral infections, or unknown (probably genetic) causes.

Gout

______ is a form of arthritis that results from the deposition of uric acid crystals within a body joint. Usually only one or a few joints are affected, such as the big toe, knee, or ankle. The attack may only last a few days, but may return to the same or another joint. ______ occurs when the body makes too much uric acid or the kidneys do not properly excrete it. A diet with excessive fructose has been implicated in raising the chances of a susceptible individual developing ______.

Temporomandibular joint disorder

______ is a painful condition that may arise due to arthritis, wearing of the articular cartilage covering the bony surfaces of the joint, muscle fatigue from overuse or grinding of the teeth, damage to the articular disc within the joint, or jaw injury. This joint disorders can also cause headache, difficulty chewing, or even the inability to move the jaw (lock jaw). Pharmacologic agents for pain or other therapies, including bite guards, are used as treatments.

Hyperextension, hyperflexion

______ is the abnormal or excessive extension of a joint beyond its normal range of motion, thus resulting in injury. Similarly, ______ is excessive flexion at a joint. Hyperextension injuries are common at hinge joints such as the knee or elbow. In cases of "whiplash" in which the head is suddenly moved backward and then forward, a patient may experience both hyperextension and hyperflexion of the cervical region.

Bursitis

______ is the inflammation of a bursa near a joint. Most commonly associated with the bursae found at or near the shoulder, hip, knee, or elbow joints. Treatments for the disorder include antibiotics if caused by an infection, or anti-inflammatory agents, such as nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroids if due to trauma or overuse. Chronic ______ may require that fluid be drained, but additional surgery is usually not required.

Pronation,

______ is the motion that moves the forearm from the supinated (anatomical) position to the (palm backward) position. This motion is produced by rotation of the radius at the proximal radioulnar joint, accompanied by movement of the radius at the distal radioulnar joint. The proximal radioulnar joint is a pivot joint that allows for rotation of the head of the radius. Because of the slight curvature of the shaft of the radius, this rotation causes the distal end of the radius to cross over the distal ulna at the distal radioulnar joint. This crossing over brings the radius and ulna into an X-shape position.

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. It involves the sequential combination of flexion, adduction, extension, and abduction at a joint. This type of motion is found at biaxial condyloid and saddle joints, and at multiaxial ball-and-sockets joints.

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. It helps to remember that ______ is the motion you use when scooping up soup with a spoon

Opposition, reposition

______ is the thumb movement that brings the tip of the thumb in contact with the tip of a finger. This movement is produced at the first carpometacarpal joint, which is a saddle joint formed between the trapezium carpal bone and the first metacarpal bone. Thumb ______ is produced by a combination of flexion and abduction of the thumb at this joint. Returning the thumb to its anatomical position next to the index finger is called ______.

Abduction, adduction

______ moves the limb laterally away from the midline of the body, while ______ is the opposing movement that brings the limb toward the body or across the midline. For example, abduction is raising the arm at the shoulder joint, moving it laterally away from the body, while adduction brings the arm down to the side of the body. Similarly, abduction and adduction at the wrist moves the hand away from or toward the midline of the body.

Dislocation

______ of the TMJ may occur when opening the mouth too wide (such as when taking a large bite) or following a blow to the jaw, resulting in the mandibular condyle moving beyond (anterior to) the articular tubercle. In this case, the individual would not be able to close his or her mouth.

Lateral flexion

______ of the vertebral column occurs in the coronal plane and is defined as the bending of the neck or trunk toward the right or left side. These movements of the vertebral column involve both the symphysis joint formed by each intervertebral disc, as well as the plane type of synovial joint formed between the inferior articular processes of one vertebra and the superior articular processes of the next lower vertebra.

Spreading, anterior

______ the fingers or toes apart is also abduction, while bringing the fingers or toes together is adduction. For the thumb, abduction is the ______ movement that brings the thumb to a 90° perpendicular position, pointing straight out from the palm. Adduction moves the thumb back to the anatomical position, next to the index finger.