BIOL 2401 CHPT 9: JOINTS

What are joints?

where two bones meet and where movement ocurs

What is the tradeoff for joints?

Strength and mobility

What are the two classifications schemes of joints?

Structural and functional

What are the structural classifications of joints?

fibrous, cartilaginous, synovial, and bony

What are the functional classifications of joints?

synarthroses, amphiarthroses, diarthroses

What is a synathrosis joint?

immovable joint

What are the characteristics of a synarthrosis?

- Very strong

- Edges of bones may touch or interlock

- May be fibrous or cartilaginous

What are the four types of synarthrotic joints?

suture, gomphosis, synchondrosis, synostosis

What is a synarthrosis suture joint?

- Found only between bones of skull

- Edges of bones interlock

- Bound by dense fibrous connective tissue

What is a synarthrosis gromphosis joint?

- Binds teeth to bony sockets

- Fibrous connection (periodontal ligament)

What is a synarthrosis synchondrosis joint?

- Rigid cartilaginous bridge between two bones

- Found between vertebrosternal ribs and sternum

What is a synarthrosis synostosis joint?

- Created when two bones fuse

What is an example of synostosis?

epiphyseal lines

What are the characteristics of amphiarthrosis?

- More moveable than a synarthrosis

- Stronger than a diarthrosis

- May be fibrous or cartilaginous

What are the two types of amphiarthrosis ?

syndesmosis, symphysis

What is a syndesmosis?

bones connected by ligaments

What is a symphysis?

two bones joined by fibrocartilage

What is synovial joints?

Free moving joints, at the ends of long bones

What are synovial joints surrounded by?

A 2 layered joint capsule that contains a synovial membrane

What is the function of synovial fluid?

Fills joint cavity and reduce friction

What is articular cartilage of the synovial joint?

It covers articulating surfaces

What is the function of articular cartilage?

reduces friction and absorbs shock

What is synovial fluid?

It resembles interstitial fluid that has the consistency of egg yolk

What are the primary functions of synovial fluid?

lubrication, nutrient distribution, shock absorption

Are synovial joints mobile?

Yes, but relatively weak

What accessory structures are stabilized by synovial joints?

- Cartilages and fat pads

- Ligaments

- Tendons

- Bursae

What cartilages are in synovial joints?

Meniscus

What is a meniscus?

a fibrocartilage pad that provides padding between bones

What is the function of fat pads in synovial joints?

Adipose tissue covered by synovial membrane that protect articular cartilages.

What is the function of ligaments in synovial joints?

Support, strengthen joints

What is the function of tendons in synovial joints?

Attach muscles around joint

What is bursae?

Small pockets of synovial fluid

What is the function of bursae in synovial joints?

Cushion areas where tendons or ligaments rub against other tissues

What are the factors function that stabilize synovial joints?

Responsible for preventing injury by limiting range of mostion, and for stabilizing the joint

What are the factors that stabilize synovial joints?

Collagen fibers of joint capsule and ligaments

Shapes of articulating surfaces and menisci

Other bones, muscles, or fat pads

Tendons attached to articulating bones

What is dislocation (luxation)?

articulating surfaces forced out of position and damages articular cartilage, ligaments, joint capsule

What is subluxation?

partial dislocation

Movements are described in terms that reflect the

-Plane or direction of movement

-Relationship between structures

What is monaxial?

Movement in one plane

What is an example of monaxial?

Elbow and ankle

What is biaxial?

movement in two planes

What is Triaxial?

movement in three planes

What is an example of biaxial?

wrist and ribs

What is an example of Triaxial?

shoulder and hip

What are the types of movement at synovial joints?

gliding, angular movements, rotation, special movements

What is gliding movement?

when two flat surfaces slide past each other

What is angular motion?

rotation around an axis

What is Flexion?

decreasing the angle of a joint

What are the types of angular movement? (6)

flexion, extension, hyperextension, abduction, adduction, circumduction

What is extension?

Increasing the angle of a joint

What is hyperextension?

extension beyond anatomical position

What is abduction?

movement away from the midline

What is adduction?

movement toward the midline

What is circumduction?

moving the arm in a circle around the shoulder

What is rotational movement?

the movement of a bone as it rotates around its longitudinal axis

What is medial rotation?

Rotation toward the midline

What is lateral rotation?

rotation away from the midline

What movements are in rotational movement?

Medial and lateral rotation, pronation, supination

What is pronation?

turning the forearm so that the palm is down

What is supination?

turning the forearm so the palm is up

What are the special movements?

supination, pronation, inversion, eversion, protraction, retraction, elevation, depression, opposition

What is inversion?

twists sole of foot medially

What is eversion?

twists sole of foot laterally

What is dorsiflexion?

flexing the foot and toes upward

What is plantar flexion?

bending the foot and toes downward

What is opposition?

brings thumb to touch tips of fingers

What is reposition?

returning thumb to the zero position

What is protraction?

Moving a body part forward, away from the middle of the body.

What is retraction?

moving a body part in the posterior direction

What is depression?

lowering a body part

What is the classification of synovial joints by shape?

Plane, hinge, condylar, saddle, pivot, ball-and-socket

What is elevation?

raising a body part

What is lateral Flexion?

bends vertebral column from side to side

What are the examples of the plane joint?

- Intercarpal joint

- Vertebrocostal

What is the plane joint?

Flattened or slightly curved surface litmited mostion nonaxial

What is an example of a hinge joint?

elbow and knee

What is hinge joint?

angular motion in a single plane (monaxial)

What is an example of a condylar joint?

metacarpophalangeal joint

What is a condylar joint?

Oval articular face within a depression (biaxial)

What is an example of the saddle joint?

carpometacarpal joint of the thumb

What is a saddle joint?

Articular faces fit together like a rider in a saddle - Biaxial

What is an example of a pivot joint?

Alanto-axial joint

Proximal radio-ulnar joint

What is a pivot joint?

Allows a bone to rotate around an axis - monaxial

What's is an example of a ball-and-socket joint?

Shoulder and hip joint

What is a ball-and-socket joint?

Round head in a cup-shaped depression - Triaxial

What type of joint is a elbow joint?

hinge joint

What type of joint is a shoulder joint?

ball and socket

What are the degenerative changes of joints?

Rheumatism, arthritis, osteoarthritis, rheumatoid arthritis, gouty arthritis

What type of joint is the knee joint?

Complex jingle joint

What is the function of the knee joint?

transfers weight from femur to tibia

What are the three articulations of the knee joint?

Two femur-tibia articulations

At medial and lateral condyles

One between patella and patellar surface of femur

What is a joint capsule and joint cavity of the knee?

Medial and lateral menisci

What is the function of the medal and lateral menisci of the knee?

They contain fibrocartilage pads at femur-tibia articulations, that cushion and stabilize the joint

What is the first knee joint ligament?

Patellar ligament (anterior)

What is the 2 and 3 knee joint ligament?

Two popliteal ligaments (posterior)

What is the 4 and 5 knee joint ligament?

Anterior and posterior cruciate ligaments

What are the major supporting ligaments in the knee joint? (7)

Patellar ligament, two popliteal ligaments, anterior and posterior cruciate ligaments, tibial collateral ligament, and fibular collateral ligament.

What is rheumatism?

Pain and stiffness in musculoskeletal system

What is arthritis?

inflammation of the joints

What is osteoarthritis?

Caused by wear and tear of joint surfaces, or genetic factors affecting collagen formation