NVCC BIO 141 Chapter 8

Joint/Articulation

connects two bones

Synarthrosis

immovable joint

high stability

Amphiarthrosis

slightly movable joint

medium stability

Diarthrosis

freely movable joint

least amount of stability

Fibrous Joint

connect bones through fibers without allowing any movement (like sutures)

Cartilaginous Joints

allow only slight movement and consist of bones connected entirely by cartilage

synarthrosis/amphiarthrosis

Synovial Joints

freely movable joints with a joint cavity and fluid

diarthrosis

Fibrous Joint Subclasses

Sutures

Gomphoses

Syndesmoses

Sutures

Areas where the cranial bones have joined together

synarthrosis

Gomphoses

attachment of a tooth to its socket

synarthrosis

Syndesmoses

Joint in which two bones are bound only by ligaments

amphiarthrosis

radius/ulna

tibia/fibula

Cartilaginous Joint Subclasses

Synchondroses

Symphyses

Synchondroses

bones united by hyaline cartilage

synarthrosis (epiphyseal plate)

Symphyses

Bones united by fibrocartilage

amphiarthrosis

intervertebral joints

Parts of Joint Cavity

Articular Capsule

Synovial Fluid

Articular Cartilage

Adipose Tissue

Blood Vessels

Nerves

Articular Capsule

Outer Layer: dense irregular CT; keeps bones from being pulled a part; isolates internal environment from bloody supply

Inner Layer: Synovial membrane loose CT; secreting synovial fluid

Synovial Fluid

lubricates, supplies nutrients, shock absorption

circulates a small amount of fluid since too much or too little is bad

Articular Cartilage

Hyaline cartilage attached to articular bone surfaces

Ligaments

Connect bone to bone

Intrinsic: thickened articular capsules

Extrinsic: in or out of joint cavity

Tendons

Connect muscle to bone, crossing over/around joint when muscle contracts

stabilizes joints

Bursae

flattened fibrous sacs lined with synovial membrane and containing a thin film of synovial fluid

Tendon Sheaths

long bursae surrounding tendons in high stress regions

protecting long tendons as they cross

Nonaxial Joints

allow motion to occur in one or more planes without moving around an axis

wrists/ankles gliding

Uniaxial Joints

allow motion around only one axis (hinge)

elbow

Biaxial Joints

movement in two planes

metacarpals

Multiaxial Joints

allow motion around three axes

shoulder

Flexion

Decreases the angle of a joint

Extension

increases the angle of a joint

Hyperextension

the extreme or overextension of a limb or body part beyond its normal limit

Abduction

Movement away from the midline of the body

Adduction

Movement toward the midline of the body

Circumduction

circular movement of a limb at the far end

Rotation

twisting on an axis

Lateral: away from midline

Internal: towards midline

Opposition

thumb movement toward fingers or palm (grasping)

Reposition

return to anatomical position

Depression

inferior movement of a body part

Elevation

raising a body part

Protraction

anterior movement of a body part in the transverse plane

Retraction

moving a part backward

Inversion

rotation of sole of foot toward midline

Eversion

rotation of sole of foot away from midline

Dorsiflexion

bending of the foot or the toes upward

Plantarflexion

point toes down

Supination

turning the palm upward

Pronation

turning the palm downward

Plane Joint

simplest/least mobile

two flat surfaces

nonaxial (only gliding)

wrist and ankle

Hinge Joint

convex surface of one bone fits into the concave surface of another

uniaxial

elbow, knee, interphalangeal joints of fingers/toes

Pivot Joint

rotating bone turns around an axis; i.e. connection between radius/ulna and humerus

Condylar Joint

biaxial

oval convex regions fits into concave surface

flexion/extension

abduction/adduction

knuckles

Saddle Joint

concave surface in one direction and convex in another; back and forth, side to side

Ball-and-Socket Joint

multiaxial, shoulder and hip

Radial Collateral Ligament

connects the lateral epicondyle of the humerus to the radius

Ulnar Collateral Ligament

Connects the medial epicondyle of the humerus to the ulna

Anular Ligament

ring-shaped band of connective tissue below the elbow joint that encircles the head of the radius

Tibiofemoral Joint

the point where the tibia meets with the femur

Patellofemoral Joint

the point where the kneecap and femur are connected in the trochlear groove

What surrounds the Patella?

Quadriceps Femoris Muscle Group

Patellar Ligament

connects patella to tibial tuberosity

Medial/Lateral Menisci

fibrocartilage pads, at femur-tibia articulations, cushion and stabilize joint, give lateral support

Anterior Cruciate Ligament

A ligament in the knee that attaches to the anterior aspect of the tibial plateau. restricting anterior movement of the tibia on the femur

Posterior Cruciate Ligament

prevents posterior displacement of tibia

Glenohumeral Joint

The synovial ball-and-socket joint of the shoulder

Rotator Cuff

supraspinatus, infraspinatus, teres minor, subscapularis

Why is the glenohumeral joint frequently injured?

shallowness of glenoid fossa

laxity of ligamentous structures

lack of strength and endurance in muscles

Coxal Joint

hip joint

Acetabular Labrum

lip of fibrocartilage that surrounds outer margin of the acetabulum on the hip bone

Articular Capsule of Hip

very strong in hip joint

Iliofemroal Ligament

Y shaped

reinforced anterior side

Ischiofemoral Ligament

spiral-shaped, posteriorly located ligament

Pubofemoral Ligament

triangular thickening of capsule's inferior region

Ligament of the Head of Femur

ligament that spans the acetabulum of the hip bone and the fovea capitis of the femoral head

allows pathway for small artery