Principles of articulation Flashcards Preview

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Flashcards in Principles of articulation Deck (45):
1

What is an articulation/joint/arthrosis?

a point of contact between:
neighbouring bones
bone and cartilage
bone and teeth

2

How are different types of joint classified?

- structure
- function
- movement

3

Give some examples of shoulder articulation

glenohumeral
sternoclavicular
acromioclavicular

4

Describe structural classification of a joint

Presence or absence of a synovial cavity and the type of connective tissue.

Described as either fibrous, cartilaginous, or synovial

5

Describe the functional classification of a joint

Based on the degree of movement permitted:
Synarthrosis (immovable)
Amphiarthrosis (partially moveable)
Diarthrosis (freely moveable)

6

Describe the structure of fibrous joints

No synovial cavity
Held together by a fibrous connective tissue

7

What is the function of fibrous joints?

Permits little or no movement (synarthrosis/amphiarthrosis)

8

List the 3 types of fibrous joint

1. Suture
2. Syndesmosis
3. Interosseous membrane

9

Describe a suture

Unite skull bones
Thin layer of dense connective tissue
Irregular
Interlocking edges provide strength, permit no movement (synarthrosis)

10

hat does ossification of a suture form?

synostosis

11

Give an example of a synostosis

left & right sides of frontal bone fuse ~6 years of age

12

Describe a syndesmosis

More connective tissue than seen in a suture
Crosses a greater distance than a suture
Connective tissue typically arranged into bundles (ligament)

13

What is the function of a syndesmosis

Typically permit slight movement (amphiarthrosis)

14

Give some examples of a syndesmosis

Anterior tibiofibular ligament
Gomphosis

15

Describe interosseous membranes

Sheet of dense connective tissue
Binds adjacent long bones
Amphiarthrosis

16

Give some examples of interosseous membranes

between the radius and ulna in forearm, and tibia and fibia in the leg

17

Describe cartilaginous joints

No synovial cavity
Held together by a fibrocartilage or hyaline cartilage
Permits little or no movement (synarthrosis/amphiarthrosis)

18

Give some examples of cartilaginous joints

Synchrondosis
Symphysis

19

Describe synchrondosis

The connective tissue is hyaline cartilage
Synarthrosis

20

Give an example of a synchrondosis

epiphyseal plate (growth plate)

21

What happens to the epiphysis, metaphysis and epiphyseal plate at skeletal maturity?

fuse forming a synostosis

22

Describe a symphysis

Connective tissue is fibrocartilage
Adjacent bones lined with hyaline cartilage, but with a broad disc of fibrocartilage connects the bones
Amphiarthrosis

23

Where do symphysis occur? Give examples

All symphysis occur in the midline of the body:
Junction of the manubrium and sternum
Intervertebral discs
Pubic symphysis

24

Describe synovial joints

Synovial (joint) cavity between articulating bones
Freely moveable - diarthrosis
Layer of hyaline cartilage called articular cartilage

25

Describe the articular cartilage

Covers the bones at synovial joints
Avascular
Composed of collagen and proteoglycan
Orientation of collagen structure imparts resistance to compression & an extremely low resistance surface

26

Describe the articular capsule

Encapsulates a synovial joint
Composed of two layers
Outer fibrous membrane connects to periosteum
Flexibility permits movement
Fibres arranged into bundles – high tensile strength
Inner layer termed synovial membrane
areolar connective tissue rich in elastic fibres
occasionally contains structural articular fat pads

27

Describe synovial fluid

Secreted by synovial membrane
Rich in hyaluronic acid, secreted by fibroblast-like cells, and interstitial fluid from blood plasma
Lubricates articular surface – reducing friction
Provides some shock-absorbing properties
Supplyies nutrition to, and removes waste products from the avascular articular cartilage
Phagocytes remove microbes and debris

28

Describe the accessory ligaments of the synovial joint

Intracapsular ligaments lie within the joint capsule
- Excluded from synovial fluid by folds in synovial membrane
- e.g. anterior and posterior cruciate ligaments of the knee

Extracapsular ligaments lie outside the joint capsule
- e.g. fibular and tibial collateral ligaments of the knee

29

Describe the accessory articular discs

Fibrocartilage pads lie between articular cartilage of some synovial joints e.g.meniscus of the knee
Called meniscii or articular discs
Help maintain joint stability
Direct the flow of synovial fluid

30

What pathology can happen in the accessory articular discs

Meniscal tears - common in athletes

31

Describe the nerve supply of the synovial joint

Nerve endings same as those that supply associated muscles
Distributed to the articular capsule and associated ligaments
Pain and proprioception

32

Describe the blood supply of the synovial joint

Many components of the synovial joint are avascular
Rely on numerous branching of arteries and veins to supply associated tissue

33

What are bursae?

Bursae are fluid filled sacs lined with synovial like membrane
Bursae cushion movement between body parts

34

What are tendon sheaths?

Tendon sheaths are similar to bursae
Specialised membranes that wrap around tendons
Especially where many tendons come together and/or pass through a synovial joint capsule

35

List the different types of synovial joint based on movement

Planar
Hinge
Pivot
Condyloid
Saddle
Ball & Socket

36

Describe planar joints and give examples

Surfaces flat or slightly curved
Permit back and forth, and side to side movements
Examples include:
- intercarpal joints (between carpal bones at the wrist)
- intertarsal joints (between tarsal bones at the ankle)

37

Describe hinge joints and give examples

Concave surface of one bone fits the
convex surface of another
Permits motion in a single axis (flexion and extension)
Examples include:
- knee joints
- elbow joints

38

Describe pivot joints and give examples

Rounded or pointed surface of one bone
pivots inside a ring formed by the other bone and a ligament
Permits rotation in it’s longitudinal axis (monoaxial)
Examples include:
- radioulnar joints
- atlanto-axial joint

39

Describe condyloid joints and give examples

Convex oval projection of one bone fit into
the oval depression of the other.
Permits movement around two axis (biaxial; flexion and extension, and abduction and adduction)
Examples include:
- wrist joint
- metacarpophalangeal joints

40

Describe saddle joints and give examples

One bone fits into the saddle shaped bone it opposes
Modified condyloid joint
Permits movement around two axis (biaxial; flexion and extension, abduction and adduction, (sometimes limited rotation))
Examples include:
- carpometacarpal joint

41

Describe ball and socket joints and give examples

Ball-like surface of one bone fits into the
cup-like depression of the other
Triaxial movement around three planes (triaxial; flexion and extension, abduction and adduction, and rotation)
Examples include:
- shoulder joint
- hip joint

42

Describe the structure of the ball and socket joint

Synovial ball and socket joint
Joint between the proximal humerus and the scapula (glenoid fossa)
Due to the shallowness of the glenoid cavity, it is the most mobile joint in the body
Glenoid labrum; a narrow rim of fibrocartilage – deepens glenoid
Stabilised by three ligaments:
glenohumeral
coracohumeral
transverse humeral
Four associated bursae

43

Describe the rotator cuff muscles

Most strength from rotator cuff muscles
supraspinatus
infraspinatus
teres minor
subscapularis
Join the scapula with the humerus
Encircle the joint and fuse with joint capsule

44

Describe the acromioclavicular joint

Technically a synovial gliding joint (planar) but it acts like a pivot
Joint between the acromion (part of the scapula) and the clavical
Stabilised by three ligaments:
acromioclavicular
coracoacromial
coracolclavicular (conoid and trapezoid)
Allows the movement of the scapula, permitting greater arm rotation (above the head)

45

Describe the sternoclavicular joint

Synovial saddle joint
Medial clavicle fits into a hollow formed by the superlateral surface of the manubrium and the medial costal cartilage of the first rib.
Fibrocartilagenous articular disc divides the joint into two synovial cavities
Reinforced by interclavicular, anterior, and posterior sternoclavicular ligaments
Although a saddle joint – is capable of triaxial movement – all movement is passive