Week 7 - Joints

Question 1

What is an articulation?

Answer 1

Where two or more bones connect to allow movement and stability.

Question 2

What are the classification of joints?

Answer 2

Functional
Structural

Question 3

What are the classifications to describe movement in joints?

Answer 3

Synarthrosis - Immovable joint, close interlocked surfaces joined with fibres, cartilage or bone.
Ampiarthrosis - slightly moveable joint, surfaces connected by collagen fibres or cartilage
Diarthrosis - Freely movable joint, synovial joint, more complex structure.

Question 4

What are the types of angular movement?

Answer 4

Flexion
Extension
Hyperextension
Abduction
Adduction
Circumduction
Rotation

Question 5

Describe angular movements in the sagittal plane

Answer 5

Flexion - Reducing angle
Extension - Increasing angle
Hyperextension - Extension past anatomical position

Question 6

Describe angular movements in the Frontal plane

Answer 6

Abduction - Away from longitudinal axis
Adduction - Towards longitudinal axis

Question 6

Describe Circumduction

Answer 6

Circular motion without rotation
Combination of flexion/extension and abduction/adduction.

Question 6

Describe Rotation

Answer 6

Motion around longitudinal axis
Left or right rotation
Medial or lateral rotation

Question 7

What are the types of rotation in the forearm?

Answer 7

Pronation - Radius crosses over Ulna, turns palm to face posteriorly.

Supination - to anatomical position, palms face anteriorly.

Question 8

Describe movements of the foot

Answer 8

Inversion - Twist sole medially
Eversion - Twist sole laterally
Dorsiflexion - flexion at ankle, raise toes
Plantar flexion - Extension at ankle, pointing toes.

Question 9

How are joints classified structurally?

Answer 9

Bony
Fibrous
Cartilaginous
Synovial

Question 10

Describe bony joints

Answer 10

Synostosis - Synarthrosis, articulating bones fused. E.g Joint between left and right frontal bone.

Question 11

Describe the different types of Fibrous joints

Answer 11

Suture - synarthrosis, Articulating bones interlock and attached by collagen fibres. E.g Sutures in cranium.

Gomphosis - synarthrosis, tooth fits in socket attached by ligament. E.g joints between teeth and jaws

Syndesmosis - Ampiarthrosis, bones connected by ligament. E.g Joint between tibia and fibula

Question 12

Describe the different types of cartilaginous joints

Answer 12

Synchondrosis - Synarthrosis, bones attached by cartilage. E.g costal cartilage.

Symphysis - Ampiarthrosis, Bones separated by fibrocartilage disk. E.g Pubic symphysis.

Question 13

Describe Synovial joints

Answer 13

Synovial - Diarthrosis, Cartilage, synovial fluid and joint capsule. E.g Typically found at ends of long bones such as the knee.

Question 14

What are the features of a typical synovial joint?

Answer 14

Articular cartilage - smoooth covering, prevents bone touching.
Synovial fluid - High protein content (proteoglycans) Secretred by fibroblasts. Functions are lubrication, nutrient distribution and shock absorption.
Joint capsule - Fibrous connective tissue, Synovial membrane(layer of cells)
Fibrous joint Capsule
Synovial membrane
Articular cartilages
Joint cavity (containing synovial fluid)

Question 15

Describe joint accessory structures and state their function

Answer 15

Cartilages - Cushions the joint, e.g meniscus is a fibrocartilage pad in the knee
Fat pads - Superficial, provide protection.
Ligaments - Support, strengthen joint
Tendons - Attach to muscles, help support joint
Bursae - pockets of synovial fluid, cushion where tendons or ligaments rub.

Question 16

Describe Itervertebral articulations

Answer 16

Intervertebral discs consisting of fibrocartilage pads, annulus fibrosis(outer fibrous layer and nucleus pulposus (elastic core) are situated between Each veterbra. They are gliding joints. A slipped disc causes release of nucleus pulposus causing the disc to become distorted.

Question 17

describe the structure and function of the shoulder (glenohumeral) joint

Answer 17

Articulating bones - Head of humerus, Glenoid cavity of scapula, Acromion, Clavivle,Coracoid process.
Glenoid labrum - Fibrocartilage ring, deepens cavity.
Ligaments
Rotator cuff muscles - tendon of supraspinatus muscle
Bursae
Function - Flexion, extension, hyperextension, abduction, adduction, rotation, circumduction

Question 18

Describe the structure and function of the hip (coxal) joint

Answer 18

Head of femur articulates with deep acetabulum
Acetabular labrum deepens cavity
Strong joint capsule reinforced by a number of ligaments.
Fibrocartilage pad
Function - Flexion, extension, abduction, adduction, hyperextension

Question 19

Describe structure and function of elbow joint

Answer 19

Hinge joint
Articulation - Humeroulnar, Trochlear (humerus) with Trochlear notch(ulna). Humeroradial, Capitulum (humerus) with head of radius.
Ligaments - Radial collateral ligaments, Annular ligaments.
Function - Flexion, extension

Question 20

Describe structure and function of the knee joint

Answer 20

Complex hinge
Articulations - Two femur tibia joints, Medial and lateral condyles, medial and lateral menisci. Patella-patellar surface of femur.
Ligaments - Patellar, Anterior and posterior cruciate, tibial and fibula collateral ligaments
Bursae
Fat Pads
Function - Flexion, extension

Question 21

Summarise Injuries to joints

Answer 21

Sprain - tearing of ligament fibers
Dislocation (luxation) - articulating surfaces displaces, damages articular cartilage,Ligaments, joint capsule.
Subluxation - Partial dislocation

Question 22

Summaries Joint diseases

Answer 22

Osteoarthritis - used to be viewed as wear and tear, damage to articular cartilage and underlying bone, more common with age, obesity and injury. Inflammatory condition.
Rheumatoid arthritis - Autoimmune condition, inflammation of articular cartilage
Gouty arthritis - Deposition of crystals in joint as a result of metabolic disorder (gout)