Chapter 9 review

What is the functional classification of synovial joints?

Functionally, synovial joints are diarthroses, freely movable joints.

Gliding

a simple movement in which nearly flat bone surfaces move back-and-forth and from side-to-side with respect to one another

fibrous membrane

consists of dense irregular connective tissue (mostly collagen fibers) that attaches to the periosteum of the articulating bones. A thickened continuation of the periosteum between the bones

Movements at synovial joints are grouped into four main categories:

(1) gliding, (2) angular movements, (3) rotation, and (4) special movements

The structural classification of joints is based on two criteria:

(1) the presence or absence of a space between the articulating bones, called a synovial cavity, (2) the type of connective tissue that binds the bones together

triaxial

(multiaxial), permitting movement in three axes

The following factors contribute to keeping the articular surfaces in contact and affect range of motion

1. Structure or shape of the articulating bones. 2. Strength and tension (tautness) of the joint ligaments 3. Arrangement and tension of the muscles 4. Contact of soft parts. 5. Hormones 6. Disuse

synchondrosis

A cartilaginous joint in which the connecting material is hyaline cartilage

gomphosis

A fibrous joint in which a cone-shaped peg fits into a socket.

Synovial joints

A fully movable or diarthrotic joint in which a synovial (joint) cavity is present between the two articulating bones.

synostosis

A joint in which the dense fibrous connective tissue that unites bones at a suture has been replaced by bone, resulting in a complete fusion across the suture line.

arthrosis

A joint or articulation.

Fibrous joints

A joint that allows little or no movement, such as a suture, syndesmosis or interosseous membrane.

Cartilaginous joints

A joint without a synovial (joint) cavity where the articulating bones are held tightly together by cartilage, allowing little or no movement.

symphysis

A line of union. A slightly movable cartilaginous joint.

Circumduction

A movement at a synovial joint in which the distal end of a bone moves in a circle while the proximal end remains relatively stable.

Supination

A movement of the forearm in which the palm is turned anteriorly.

joint

A point of contact between two bones, between bone and cartilage, or between bone and teeth. Also called an articulation or arthrosis.

bursae

A sac or pouch of synovial fluid located at friction points, especially about joints.

What is the structural difference between a synchondrosis, symphysis, and epiphyseal cartilage?

A synchondrosis is held together by hyaline cartilage, a symphysis is held together by fibrocartilage, and epiphyseal cartilage is a hyaline cartilage growth center during endochondral bone formation.

hinge joint

A synovial joint in which a convex surface of one bone fits into a concave surface of another bone, such as the elbow, knee, ankle, and interphalangeal joints. Also called a ginglymus joint.

pivot joint

A synovial joint in which a rounded, pointed, or conical surface of one bone articulates with a ring formed partly by another bone and partly by a ligament, as in the joint between the atlas and axis and between the proximal ends of the radius and ulna. Also called a trochoid joint. they are Uniaxial

saddle joint

A synovial joint in which the articular surface of one bone is saddle-shaped and the articular surface of the other bone is shaped like the legs of the rider sitting in the saddle, as in the joint between the trapezium and the metacarpal of the thumb. Also called sellar joint. Biaxial

ball-and-socket joint

A synovial joint in which the rounded surface of one bone moves within a cup-shaped depression or socket of another bone, as in the shoulder or hip joint. Also called a spheroid joint. Triaxial (multiaxial)

condyloid joint

A synovial joint structured so that an oval-shaped condyle of one bone fits into an elliptical cavity of another bone, permitting side-to-side and back-and-forth movements, such as the joint at the wrist between the radius and carpals. Also called an ellipsoidal joint. They are Biaxial.

torn cartilage

A tearing of an articular disc (meniscus) in the knee.

suture

An immovable fibrous joint that joins skull bones

Dorsiflexion

Bending the foot in the direction of the dorsum (upper surface)

hyperextension

Continuation of extension beyond the anatomical position, as in bending the head backward.

ligaments

Dense regular connective tissue that attaches bone to bone

articular discs

Fibrocartilage pad between articular surfaces of bones of some synovial joints. Also called a meniscus

STUCTURALLY, joints are classified as one of the following types:

Fibrous joints Cartilaginous joints Synovial joints

Functionally, why are sutures classified as synarthroses, and syndesmoses as amphiarthroses?

Functionally, sutures are classified as synarthroses because they are immovable; syndesmoses are classified as amphiarthroses because they are slightly movable.

articular cartilage

Hyaline cartilage attached to articular bone surfaces

periodontal disease

Inflammation and degeneration of the gums

bursitis

Inflammation of a bursa.

plane joints (synovial)

Joint in which the articulating surfaces are flat or slightly curves that permits back-and-forth and side-to-side movements and rotation between the flat surfaces. Planar joint

On what basis are joints classified?

Joints are classified structurally, based on their anatomical characteristics, and functionally, based on the type of movement they permit.

Abduction

Movement away from the midline of the body

Depression

Movement in which a part of the body moves inferiorly.

Elevation

Movement in which a part of the body moves superiorly.

Opposition

Movement of the thumb at the carpometacarpal joint in which the thumb moves across the palm to touch the tips of the fingers on the same hand.

adduction

Movement toward the midline of the body.

rotation

Moving a bone around its own axis, with no other movement.

Eversion

The movement of the sole laterally at the ankle joint or of an atrioventricular valve into an atrium during ventricular contraction

Inversion

The movement of the sole medially at the ankle joint.

synovial fluid

Secretion of synovial membranes that lubricates joints and nourishes articular cartilage.

articular capsule

Sleevelike structure around a synovial joint composed of a fibrous capsule and a synovial membrane. Joint capsule.

kinesiology

Study of movement of body parts

arthroplasty

Surgical replacement of joints, for example, the hip and knee joints

FUNCTIONALLY, joints are classified as one of the following types:

Synarthrosis Amphiarthrosis Diarthrosis

synovial membrane

The deeper of the two layers of the articular capsule of a synovial joint, composed of areolar connective tissue that secretes synovial fluid into the synovial (joint) cavity.

Protraction

The movement of the mandible or shoulder girdle forward on a plane parallel with the ground.

synovial cavity

The space between the articulating bones of a synovial joint, filled with synovial fluid. Or joint cavity.

arthrology

The study or description of joints

When there is damage to articular cartilage in the knee joint, especially involving the femur, there is an alternative to partial or total knee replacement

autologous chondrocyte implantation (ACI)

There are two principal interosseous membrane joints in the human body:

between the radius and ulna in the forearm, and the other occurs between the tibia and fibula in the leg

Many plane joints are

biaxial

Synarthrosis

immovable joint

Special movements

elevation, depression, protraction, retraction, inversion, eversion, dorsiflexion, plantar flexion, supination, pronation, and opposition

accessory ligaments

extracapsular ligaments and intracapsular ligaments

The major angular movements are

flexion, extension, lateral flexion, hyperextension, abduction, adduction, and circumduction

metopon =

forehead

Diarthrosis

freely movable joint

If the suture persists beyond age 6, it is called a

frontal (metopic) suture

Epiphyseal cartilages

hyaline cartilage growth centers during endochondral bone formation, not joints associated with movements

Chondritis

inflammation of cartilage

Synovitis

inflammation of the synovial membrane of a joint

What is the final category of the fibrous joint?

interosseous membrane

temporomandibular joint (TMJ)

is a combined hinge and plane joint formed by the condylar process of the mandible and the mandibular fossa and articular tubercle of the temporal bone. Also is the only freely movable joint between skull bones

interosseous membrane

is a substantial sheet of dense irregular connective tissue that binds neighboring long bones and permits slight movement (amphiarthrosis)

articulation

joint

Arthralgia

joint pain

Extracapsular ligaments

lie outside the articular capsule

Intracapsular ligaments

occur within the articular capsule but are excluded from the synovial cavity by folds of the synovial membrane

lateral flexion

occurs along the frontal plane and involves the intervertebral joints

Subluxation

partial dislocation of a joint

Biaxial

permit movement in two axes

Synovial joints are divided into six categories based on type of movement:

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

labrum

prominent in the ball-and-socket joints of the shoulder and hip, is the fibrocartilaginous lip that extends from the edge of the joint socket.

Bursectomy

removal of a bursa

syndesmosis

slightly movable bones united by fibrous connective tissue, forming an interosseous membrane or ligament

Amphiarthrosis

slightly movable joint

axis

straight line around which a bone rotates (revolves) or slides

The three types of fibrous joints are

sutures, syndesmoses, and interosseous membranes

The three types of cartilaginous joints are

synchondroses, symphyses, and epiphyseal cartilages

Tendon sheaths

synovial sheaths are tubelike bursae; they wrap around certain tendons that experience considerable friction as they pass through tunnels formed by connective tissue and bone

angular movements

there is an increase or a decrease in the angle between articulating bones.

Hinge joints are uniaxial because

they typically allow motion around a single axis

flexion

to bend

extension

to stretch out

Range of motion (ROM)

to the range, measured in degrees of a circle, through which the bones of a joint can be moved