Anatomy ch 9

Factors Affecting Contact and Range of Motion at Synovial Joints

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

Atlantoaxial joints

3 articulations • 2 (R and L) lateral atlantoaxial joints (b/w inferior facets of C1 and superior facets of C2) -Plane joints • 1 median atlantoaxial joints (b/w dens of C2 and anterior arch of C1 -Pivot joint

What is a joint?

A joint is a point of contact between: 1. Two or more bones 2. Cartilage and bone 3. Teeth and bone

Tendon sheaths

Elongated bursa that wraps completely around tendon

Elbow Joint

Hinge joint with 2 articulations 1. Humeroulnar joint: -Trochlear notch of ulna & trochlea of humerus 2. Humeroradial joint: -Head of radius & capitulum of humerus • Collateral ligaments maintain integrity of joint • flexion and extension

abduction

Movement away from the midline of the body

gliding

Movement of relatively flat bone surfaces back-and-forth and side-to-side over one another; little change in angle between bones

opposition

Movement of the thumb across the palm of the hand

adduction

Movement toward the midline of the body

a gomphosis is

a fibrous joint in which the root of a tooth is anchored into its bony jaw socket by strong periodontal ligaments

a symphysis is

a joint where bones are joined by fibrocartilage

a synchondrosis is

a type of joint where adjacent bones are joined with cartilage

hinge joint

allows flexion/extension knee, elbow, ankle

joints created by the intevertebral discs are ___ joints

amphiarthotic

because it is slightly movable, the pubic sympehsis is classified as a ___ joint

amphiarthrotic

Protraction

anterior movement of a body part in the transverse plane

example of protraction

anterior movement of the mandible

Dorsiflexion

bending of the foot or the toes upward

plantar flexion

bending of the sole of the foot by curling the toes toward the ground

at a synovial joint, the bones:

come into contact with each other within a joint cavity that is filled with a lubricating fluid

a bursa is a

connective tissue sac containing lubricating fluid that prevents friction between skin and bone, tendons and bone, or between muscles

flexion

decrease in the angle between articulating bones

opening your mouth occurs by _____ of the mandible

depression

an example of a hinge joint is the

elbow

Hyperextension

extension beyond anatomical position

the acetabulum articulates with the

femoral head

a meniscus is

fibrocartilage structure inside a synovial joint that acts as a cushion

ball and socket

flexion/extension, adduction/abduction, circumduction shoulder and hip

saddle joint

flexion/extension, adduction/abduction, circumduction thumb

synovial joints are also considered to be

freely movable

extension

increase in angle of articulating bones

angular

increase or decrease in angle between bones

depression

inferior movement of a body part

an example of a plane (gliding( joint is the

intercarpal joint

an example of a syndemosis includes a

interosseous membrane

An example of a pivot joint is the

joint between the axis and atlas vertebrae

eversion

lateral movement of sole

example of plantar flexion

lifting the heel and standing on your toes

inversion

medial movement of sole

supination

movement of the forearm that turns palms anteriorly

pronation

movement of the forearm that turns palms posteriorly

lateral flexion

movement of trunk in frontal plane

Shoulder Joint/ Glenohumeral joint

movements: flexion, extension, abduction, adduction, external/lateral rotation, internal/medial rotation and circumduction. • Most movable joint • Head of humerus articulates w/ glenoid fossa of scapula • Ball & socket joint

what is an example of abduction

moving the limb laterally away from the midline of the body

joints that can move in more than two directions are known as ___ joints

multiaxial

Retraction

posterior movement of a body part in the transverse plane

an example of a ball and socket joint is the

shoulder

example of elevation

shrugging the shoulders

elevation

superior movement of a body part

an example of a synathrosis is the

suture joints of the skull

skull structures are fictionally classified as

synathrosis

an ankle is also known as the ____ joint

talocrural

what is an example of pronation

the motion that moves the forearm from the anatomical position to the palm backward position

a synovial membrane is a

thin layer that lines the inner surface of the joint cavity at a synovial joint, produces synovial fluid

an example of a saddle joint is the

thumb

what is an example of eversion body movement

turning the sole of the foot away from the midline of the body

example of inversion body movement

turning the sole of the foot towards the midline of the body

Atlanto-occipital joint

• Articulation b/w the atlas and the occipital bone • Condyloid joints

Hip Joint

• Ball-and-socket joint • Good range of motion •flexion, extension, abduction, adduction, circumduction, and hip rotation. • Acetabular labrum • Deep bony socket • Articular capsule

Knee Joint

• Between femur, tibia & patella • Hinge joint between tibia & femur • Gliding joint between patella & femur • Articular capsule • Lateral & medial menisci flexion, extension, medial rotation and lateral rotation

Synovial Joints

• Joint cavity • Diarthroses • Articular cartilage • Articular capsule • Synovial membrane • Synovial fluid

Cartilaginous Joints

• Lack a synovial cavity • Articulating bones are held together with cartilage • Permit little or no movement

Fibrous Joints

• Lack a synovial cavity • Bones joined by dense irregular (fibrous) connective tissue • Little or no movement

Temporomandibular Joint

• Mandible articulates w/ temporal bone • Synovial joint (hinge & plane) rotation and translation

synovial joints classified by shape of joint surface

• Plane Joints • Hinge Joints • Pivot Joints • Condylar (Condyloid/ Ellipsoid) Joints • Saddle Joints • Ball-and-Socket Joints

synovial joints classified by movements allowed

• Uniaxial joint • Biaxial joint • Multiaxial joint

Friction Reducing Features of synovial joints

▪ Synovial Fluid ▪Bursa ▪ Tendon Sheaths ▪Fat pads ▪Articular discs or menisci ▪Accessory ligaments

3 structural types of fibrous joints

❑ Sutures ❑ Syndesmosis ❑ Gomphosis

types of cartilaginous Joints

❑ Synchondrosis ❑ Symphyses

structurally classified joints

➢ Fibrous ➢ Cartilaginous ➢ Synovial

functionally classified joints

➢ Synarthrosis ➢ Amphiarthrosis ➢ Diarthrosis