Joint Structure and Function

What are the movements around the AP axis in the coronal plane?

ABduction and ADduction

Name the 2 functions of interarticular disks and give 3 examples.

Functions: 1) improve fit between incongruous bones 2) increase ROM Ex: TMJ, SC joint, knee menisci

Give an example of an extracapsular ligament?

SC joint

What is the exception to the "little movement" rule of fibrous joints?

The interosseus membrane between the radius and ulna because it moves a lot through pronation and supination of the forearm

Name 3 examples of synovial joints.

There are a lot in your body, but some examples include the shoulder joint, knee joint, and joints between the ear ossicles.

What are the movements around the vertical axis in the horizontal plane?

medial and lateral rotation

Every plane has an axis that is BLANK to it.

perpendicular

The sagittal plane divides the body into...

right and left

Ligaments are working when they are....

Tight!

Give an example of capsular ligaments?

shoulder, hip

Give an example of an intracapsular ligament?

cruciate ligaments in the knee

What is the outer layer of the joint capsule made of?

dense CT

What is the inner layer of the joint capsule made of?

synovial membrane

The transverse plane divides the body into...

top and bottom

What are interarticular disks?

wedges of cartilage (usually fibrocartilage) that are within the joint capsule and surrounded by synovial fluid

What is Weeping Lubrication?

when stress is put on the joint (when it moves), synovial fluid gets squeezed out of cartilage and moves into the synovial joint cavity to increase lubrication.

What are the movements around the transverse axis in the sagittal plane?

flexion and extension

What movements cause circumduction?

flexion, extension, aBduction and ADduction

The coronal plane divides the body into...

front and back

Structure determines...

function!

What's the main job of ligaments?

limit unwanted movement in a certain direction

What are the characteristics of fibrous joints?

-bone-to-bone connection with dense CT -no joint cavity -usually very little movement (synarthrosis)

What are the characteristics of synovial joints?

-bones are united by a joint capsule -joint capsule is enclosed by a joint cavity -joint cavity is line by a synovial membrane -synovial membrane contains synovial fluid -articular surfaces are lined with hyaline cartilage - allows for free movement

What are the characteristics of cartilaginous joints?

-bones are united by cartilage: either hyaline or fibrocartilage -no joint cavity -slight movement - amphiarthrosis

What are bursae?

-closed sacs of synovial membrane -filled with synovial fluid

What are the strange movements of the foot and ankle?

-dorsflexion/plantarflexion -inversion/eversion

What is the purpose of synovial fluid?

-lubrication -nourishment

Are ligaments active or passive stabilizers?

Passive - because they don't contract

What's the difference between osteoarthritis and rheumatoid arthritis?

-osteoarthritis is normal wear and tear of a joint -rheumatoid arthritis is joint inflammation due to autoimmune disease - everything in the joint swells up

What's the purpose of bursae?

-reduce fiction

How do we classify joints by structure? (3)

1) Fibrous 2) Cartilaginous 3) Synovial

What are the competing needs of joints?

1) Stability - for strength/support 2) Mobility - to increase ROM

What are the 3 types of fibrous joints? Give an example of each.

1) Suture: skull bones 2) Gomphosis: periodontal membrane holds teeth down to mandible 3) Interossesus membrane: between radius and ulna

Name the multiaxial synovial joint(s) and give an example.

1) ball & socket -shoulder joint 2) saddle - thumb joint 3) gliding/plane - intercarpal joints

Name 5 factors that can limit joint movement

1) bone shape 2) ligaments 3) disease 4) apposition of muscle masses/soft tissue 5) tension in opposing muscles

Name the 3 types of ligaments.

1) capsula: thickenings of the joint capsule itself 2) extracapsular: located outside the joint capsule 3) intracapsular: located inside the joint capsule

Name the biaxial synovial joint(s) and give an example.

1) condyloid/ellipsoid - metacarpophalangeal joints

Give 2 examples of hyaline cartilaginous joints.

1) epiphyseal growth plate 2 costal cartlage

Name the uniaxial synovial joint(s) and give an example.

1) hinge - elbow joint 2) pivot - radioulnar joint

Give 2 examples of fibrocartilage cartilaginous joints.

1) intervertebral discs 2) pubic symphysis

What are the 3 different accessory structures?

1) ligaments 2) interarticular disks 3) bursae

How do we classify joints by freedom of movement? (3) Give an example of each.

1) synarthrosis - little to no movement (ex: skull) 2) amphiarthosis - slight movement (ex: joints between individual vertebral bones) 3) diarthrosis - free movement (ex: shoulder)

How many different shapes of synovial joints do we have?

6

Can we have both stability and mobility?

Nah - it's usually a tradeoff between the two

Extreme stretch or tear of a ligament is called a...

Sprain