Cha 9 joints

Movements at synovial joints are grouped into four main categories

(1) gliding, (2) angular movements, (3) rotation, and (4) special movements, which occur only at certain joints.

Bursae

*Saclike structures *The fluid-filled bursal sacs cushion the movement of these body parts against one another. * located between the skin and bones, tendons and bones, muscles and bones, or ligaments and bones *are strategically situated to alleviate friction in some joints, such as the shoulder and knee joints

tendon sheaths of synovial joints

*are tubelike bursae; they wrap around certain tendons that experience considerable friction as they pass through tunnels formed by connective tissue and bone. *reduce friction at joints * protects all sides of a tendon from friction as the tendon slides back and forth. *are found where tendons pass through synovial cavities, such as the tendon of the biceps brachii muscle at the shoulder joint * are also found at the wrist and ankle, where many tendons come together in a confined space *and in the fingers and toes, where there is a great deal of movement

The six specific synovial joints, in order from least mobile to freely mobile:

-plane joints -hinge joints -pivot joints -condylar joints -saddle joints -ball-and-socket joints

ligaments (liga- = bound or tied)

. The strength of these fiber bundles is one of the principal mechanical factors that hold bones close together in a synovial joint.

Articular discs (menisci) of Synovial Joints

1) shock absorption; (2) a better fit between articulating bony surfaces; (3) providing adaptable surfaces for combined movements; (4) weight distribution over a greater contact surface; and (5) distribution of synovial lubricant across the articular surfaces of the joint.

synovial fluid functions

1. lubrication 2. nutrient distribution 3. shock absorption

Amphiarthrosis ; amphi- = on both sides

A slightly movable joint

Depression:to press down

A special movement, is the inferior movement of a part of the body. EX- the movement of the mandible while opening your mouth to chew food and the movement of your shoulders in an inferior direction Inferior movement of body part.

Elevation: to lift up

A special movement, is the superior movement of a body part. EX- the superior movement of the mandible while closing your mouth at the tempromandibular joint and the movement of the shoulders in a superior direction(shrugging your shoulders) Superior movement of body part.

Pronation

A special movement. is a movement of the forearm at the proximal and distal radioulnar joints in which the distal end of the radius crosses over the distal end of the ulna and the palm is turned posteriorly Movement of forearm that turns palm posteriorly.

Protraction:to draw forth

A special movement. Is the anterior movement of a body part form anatomy position, as when moving your jaw anteriorly at the tempromandibular joint or hunching your shoulders anteriorly by crossing your arms Anterior movement of body part in transverse plane.

Retraction:to draw back

A special movement. Is the posteriorly directed movement of a body part from anatomic position Posterior movement of body part in transverse plane.

Opposition:

A special movement. It enables the hand to grasp objects and is the most distinctive digital movement in humans, the opposite movement is called reposition

Supination

A special movemnt. is a movement of the forearm at the proximal and distal radioulnar joints in which the palm is turned anteriorly . This position of the palms is one of the defining features of the anatomical position. Its opposing movement is pronation. Movement of forearm that turns palm anteriorly.

Multiaxial(or triaxial):

A type of synovial joint, a joint is said to be multi axial if the bone moves in multiple planes or axes

Uniaxial

A type of synovial joint, a joint is said to be uniaxial if the bone moves in just one plane or axes

Biaxial:

A type of synovial joint, a joint is said to be uniaxial if the bone moves in two planes or axes

Hyperextension:

An angular motion. Is the extension of a joint beyond 180 degrees Bending the head backward

Flexion:

An angular motion. It is the movement in an anterior-posterior (AP) plane of the body that decreases the angle between the articulating bones. Bones are brought closer together as the angle between them decreases. occur along the sagittal plane

Extenstion:

An angular motion. It is the opposite of flexion, it is a movement in an anterior-posterior plane that increases the angle between the articulating bones. Extension is a straightening action that usually occurs in the sagittal pane of the body

Lateral flexion:

An angular motion. Occurs when the trunk of the body moves in a coronal plane laterally away from the body. This type of movement occurs primarily between the vertebrae in the cervical and lumbar regions of the vertebral column Another example is movement of the trunk sideways to the right or left at the waist.

Condylar joint(or condyloid or ellipsoid joints):

Are biaxial joints with an oval, convex surface on one bone that articulates with a concave articular surface on the second bone. Biaxial joints can move in two aces, such as back-and-forth and side-to-side Examples are the radiocarpal (wrist)

Ball-and-socket joint:

Are multi axial joints in which the spherical articulation head of one bone fits into the rounded, cup-like socket of a second bone Examples are the shoulder and hip joints

name and describe the common body movements.

Common body movements : origin - attachment to the immovable bone insertion - attach to the movable bone Movements occur along tranverse, frontal, or sagittal plane.

Dorsiflexion:

Dorsiflexion is limited to the ankle. Dorsiflexion occurs when the talocrural(ankle) joint is bent such that the superior surface of the foot and toes moves toward the leg. This movement occurs when you dig your heels, and it prevents your toes from scraping the ground when you take a step Bending foot in direction of dorsum (superior surface)

angular movements

Either increases or decreases the angle between two bones. These movements may occur at many of the synovial joints; they include the following specific types: flexion and extension, hyperextension, lateral flexion, abduction and adduction, and circumduction

.Medial and lateral patellar retinacula of the knee

Fused tendons of insertion of the quadriceps femoris muscle and the fascia lata (fascia of thigh) that strengthen the anterior surface of the joint

Rotation:rota- = revolve

Is a pivoting motion in which a bone turns on its own longitudinal axis. Rotational movement occurs at the atlantoaxial joint, which pivots when you rotate your head to gesture "no". Some limb rotations are described as either away from the median plane or toward it One example is turning the head from side to side at the atlanto-axial joint (between the atlas and axis), as when you shake your head "no"

Circumduction:

Is a sequence of movements in which the proximal end of an appendage remains relatively stationary while the distal end makes a circular motion. The resulting movement makes an imaginary cone shape. Circumduction is a complex movement that occurs as a result of a continuous sequence of flexion, abduction, extension, and adduction Examples of circumduction are moving the humerus in a circle at the shoulder joint moving the hand in a circle at the wrist joint,

Gliding motion:

Is a simple movement in which two opposing surfaces slide slightly back-and-forth or side-to-side with repect to one another. In a gliding motion, the angle between the bones does not change, and only limited movement is possible in any direction. Gliding motion typically occurs alone plane joints The intercarpal and intertarsal joints are examples

Hinge joint:

Is a uniaxial joint in which one articulating bone with a rounded surface fits into a ring formed by a ligament and another bone. The first bone rotates on its longitudinal axis relative to the second bone Examples are the knee, elbow, ankle

Saddle joint:

Is named so because the articular surfaces of the bones have convex and concave regions that resemble the shape of the saddle. It allows greater range of movement than either a condylar or hinge joint biaxial An example the carpometacarpal joint between the trapezium of the carpus and metacarpal of the thumb.

Tempromandibular Joint(TMJ):

Is the articulation formed at the point where the head of the mandible articulates with the articular tubercle of the temporal bone anteriorly and the mandibular fossa posteriorly. This small, complex articulation is the only mobile joint between skull bones

Plane joint(or planar or gliding joint):

Is the simplest synovial articulation and the least mobile type of diarthrosis. This type of synovial joint is also known as a uniaxial joint because only side-to-side movements are possible. The articular surfaces or the bones are flat or planar. EXs- inter carpal and inter tarsal joints(the joints between the cube-shaped carpal and tarsal bones)

Articular capsule of the knee

No complete, independent capsule unites the bones of the knee joint.

Inversion:to turn inward

Occurs only at the intertarsal joints of the foot. In Inversion, the sole of the foot turns medially Medial movement of sole.

Eversion: to turn outward

Occurs only at the intertarsal joints of the foot. In eversion, the sole turns to face laterally Lateral movement of sole.

Plantar flexion:

Plantar flexion is limited to the ankle, and is the movement at the talocrural joint permits the extensions of the foot so that the toes point inferiorly. When a ballerina is standing on her tiptoes, her ankle joint is in full plantar flexion Bending foot in direction of plantar surface (sole).

articular capsule

Sleevelike structure around a synovial joint composed of a fibrous capsule and a synovial membrane. is composed of two layers, an outer fibrous membrane and an inner synovial membrane

Special Movements:

Some motions occur only at specific joints and do not readily fit into any of the functional categories previously discussed. These special movements include depression and elevation, protraction and retraction, and opposition

describe the general structure of cartilaginous joints. Name and give an example of each of the two common types of cartilaginous joints.

Structure of cartilagenous : united by cartilage no joint cavity Two Types : synchondroses - symphyses -

describe the structural characteristics of synovial joints.

Synovial Joints Distinguishing Features : - All are diathrotic - Include all limb joints, most joints of the body 1. Articular cartilage : hyaline cartilage 2. Joint synovial cavity ; small potential space 3. Articular joint capsule : - outer fibrous capsule of dense irregular connective tissue - inner synovial membrane of loose connective tissue 4. Synovial Fluid -viscous slippery filtrate of plasma and hyaluronic acid -lubricates and nourishes articular cartilage 5. Three possible types of reinforcing ligaments - capsular (intrinsic) - part of the fibrous capsule - extracapsular - outside the capsule - intrascapular - deep to capsule covered by the synovial membrane 6. Rich nerve and blood vessel supply - nerve fibers detect pain, monitor, joint position, and stretch - capillary beads produce filtrate for synovial fluid.

synovial joints

The bones forming the joint have a synovial cavity and are united by the dense irregular connective tissue of an articular capsule, and often by accessory ligaments.

Syndesmosis

The dense irregular connective tissue is typically arranged as a bundle (ligament), allowing the joint to permit limited movement.

Adduction:

The opposite of abduciton. Adductions means to "move toward", and is the medial movement of a body part toward the midline. Adduction occurs when you bring you bring your raised arm or thigh back toward the midline, or in the case of digits, toward the midline of the hand. Adducting the wrist(also known as ulnar deviation) involved pointing the hand and fingers medially, toward the body movements usually occur along the frontal plane.

example of symphysis

The pubic between the anterior surfaces of the hip bones at the intervertebral joints between the bodies of vertebrae

Explain the inverse relationship between mobility and stability within a joint.

There is a trade off, high mobility = low stability and vice versa

Cartilaginous joints

There is no synovial cavity, and the bones are held together by cartilage

fibrous joints

There is no synovial cavity, and the bones are held together by dense irregular connective tissue that is rich in collagen fibers.

Later rotation(or external rotation):

Turns the anterior surface of the femur or humerus laterally

Medial rotation(or internal rotation):

Turns the anterior surface of the femur or humerus medially

Abduciton:

Which means to "move away", is the lateral movement of a body part away from the body midline. Abductions occurs when either the arm or the thigh is moved laterally away from the midline. Abduction of either the fingers or the toes meanest hat you spread them apart, away from the loges digit, which is acting as the midline Abduciting the wrist(also known as radial deviation) involved pointing the hand and fingers laterally, away from the body movements usually occur along the frontal plane.

interosseous membrane

a substantial sheet of dense irregular connective tissue that binds neighboring long bones and permits slight movement (amphiarthrosis). One occurs between the radius and ulna in the forearm and the other occurs between the tibia and fibula in the leg

synovial joints contain

accessory ligaments called extracapsular ligaments and intracapsular ligaments

joint

also called an articulation or arthrosis is a point of contact between two bones, between bone and cartilage, or between bone and teeth

Synchondrosis chondro- = cartilage;

an almost immovable joint between bones bound by a layer of cartilage, as in the vertebrae.

rotator cuff muscles

anchor the humerus to the scapula most of the strength results from the muscles that surround the shoulder joint work as a group to hold the head of the humerus in the glenoid cavity.

synovial joints

are diarthroses, freely movable joints.

The bones at a synovial joint are covered by a layer of hyaline cartilage called

articular cartilage.

articular fat pads

at many synovial joints the synovial membrane includes accumulations of adipose tissue

The outer layer, known as the parietal layer

attached to the bone

Laterally is a tibiofemoral joint,

between the lateral condyle of the femur, lateral meniscus, and lateral condyle of the tibia, which is the weight-bearing bone of the leg.

Medially is another tibiofemoral joint

between the medial condyle of the femur, medial meniscus, and medial condyle of the tibia.

An intermediate patellofemoral joint

between the patella and the patellar surface of the femur.

fibrous membrane

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

Articular discs (menisci) of Synovial Joints

crescent-shaped pads of fibrocartilage lie between the articular surfaces of the bones and are attached to the fibrous capsule.

Describe the general structure of fibrous joints. Name and give an example of each of the type of fibrous joints.

fibrous - 1) bones joined by dense fibrous connective tissue 2) no joint cavity 3) types : sutures - in the skull syndesmoses - distal tibiafibular gomphoses - socket of tooth (unique to gomphoses)

Classify joints structurally

fibrous, cartilaginous, synovial

elbow joint allows

flexion and extension of the forearm

The hip joint allows

flexion, extension, abduction, adduction, lateral rotation medial rotation, and circumduction of the thigh

The shoulder joint allows

flexion, extension, hyperextension, abduction, adduction, medial rotation, lateral rotation, and circumduction of the arm It has more freedom of movement than any other joint of the body.

diarthrosis joint

freely movable joint

elbow joint

hinge joint formed by humerus, ulna, and radius

epiphyseal cartilage

hyaline cartilage growth centers during endochondral bone formation, not joints associated with movements is an immovable joint

synarthrosis joint syn- = together)

immovable joint

an example of a Sutures

in the skull between the parietal and frontal bones.

synovial membrane

inner layer of the articular capsule is composed of areolar connective tissue with elastic fibers

hip joint (coxal joint)

is a ball-and-socket joint formed by the head of the femur and the acetabulum of the hip bone.

shoulder joint (glenohumeral joint)

is a ball-and-socket joint formed by the head of the humerus and the glenoid cavity of the scapula.

Sutures

is a fibrous joint composed of a thin layer of dense irregular connective tissue; sutures occur only between bones of the skull. They are immovable or slightly movable

The inner layer of a tendon sheath, the visceral layer

is attached to the surface of the tendon.

An example of epiphyseal cartilage

is the epiphyseal (growth) plate that connects the epiphysis and diaphysis of a growing bone

knee joint (tibiofemoral joint)

is the largest and most complex joint of the body It is a modified hinge joint (because its primary movement is a uniaxial hinge movement)

synovial fluid

joint-lubricating fluid secreted by the synovial membrane a viscous, clear or pale yellow fluid

extracapsular ligaments

outside the capsule Examples are the fibular and tibial collateral ligaments of the knee joint.

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

the chondrocytes in the articular cartilage of a synovial joint

receive oxygen and nutrients from synovial fluid derived from blood; all other joint tissues are supplied directly by capillaries

intracapsular ligaments

stabilizing ligaments located inside joint capsule Examples are the anterior and posterior cruciate ligaments of the knee joint.

What are the rotator cuff muscles?

supraspinatus, infraspinatus, teres minor, subscapularis

three types of fibrous joints are

sutures, syndesmoses, and interosseous membranes.

Classify joints functionally

synarthroses, amphiarthroses, diarthroses

The three types of cartilaginous joints.

synchondroses, symphyses, and epiphyseal

The unique characteristic of a synovial joint is the presence of a space called

synovial cavity or joint cavity between the articulating bones.

Knee joint consists of

that consists of three joints within a single synovial cavity: 1.Laterally is a tibiofemoral joint, 2.Medially is another tibiofemoral joint, 3.An intermediate patellofemoral joint

One example of a synchondrosis is

the joint between the first rib and the manubrium sternum

Recall that cartilage is an avascular tissue, so it does not have blood vessels to perform the latter function.

true

symphysis

two bones joined by fibrocartilage slightly movable joint

Pivot joints or trochoid joint are

uniaxial the rounded or pointed surface of one bone articulates with a ring formed partly by another bone and partly by a ligament ex of pivot joints are the atlanto-axial joint, in which the atlas rotates around the axis and permits the head to turn from side-to-side as when you shake your head "no"