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Flashcards in MSK - Bones Deck (39)
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1
Q

Name the classification of bones by shape?

Describe the features of each

A

Flat bone - (frontal) Curved to protect organs

Short Bone - (carpal)
Equal in length and wide

Long Bone - (femur)
Longer than they are wide. Muscles act on them as rigid leavers

Irregular bone - (vertebra)
Irregular in size and shape

Sesamoid bone - (patella) embedded within tendon or muscle

Sutural bone - within a cranial suture

2
Q

What cartilage is on the head of a long bone?

A

Articular cartilage

3
Q

When is the medullary cavity red and yellow?

A

Red - actively forming blood cells

Yellow - red marrow is replaced by fat

4
Q

What type of bone do short bones consist of?

Do they have a epiphysis or diaphysis?

What is located between the trabeculae?

A

Mainly spongy bone

No epiphysis and diaphysis

Bone marrow

5
Q

Where does the nutrient artery enter the diaphysis?

A

Nutrient foramen

6
Q

What area does the periosteal artery supply?

A

Periosteum and outer 1/3rd of cortex

7
Q

Where do the metaphyseal arteries enter metaphysis?

A

Site of attachment of capsule

8
Q

What is avascular necrosis?

What are the causes?

What happens?

A

Death of bone due to interruption of blood supply

Fracture, dislocation, steroid use, radiation, decompression sickness

Leads to collapse of necrotic segment and secondary osteoarthritis

9
Q

What happens if you break the neck of the femur in terms of blood supply?

A

Blood supply can be interrupted from lateral an medial femoral circumflex blood supply

Obturator artery cannot supply enough blood alone, bone dies which leads o arthritis

10
Q

What is a joint?

Name 3 structural classifications

Name 3 functional classifications

A

Articulation between two or more bones

Fibrous, cartilaginous, synovial

Synarthrosis - immovable
Amphiarthrosis - slightly movable
Diarthrosis - freely movable

11
Q

Describe the movement in synarthrosis, amphiarthrosis and diarthrosis

A

Synarthrosis - immovable

Amphiarthrosis - slightly movable

Diarthrosis - freely movable

12
Q

What type of joint is a suture joint?

Where does it occur?

How much movement does it have?

A

Fibrous joint

Only occurs in cranium

Synarthrosis

13
Q

What type of joint is a syndesmosis?

How much movement does it have?

Where do they occur?

A

Fibrous joint

Amphiarthrosis - small amount of movement

Posterior sacroiliac joint

14
Q

What type of joint is a gomphosis?

Where are they found?

A

Fibrous joint

Tooth - sits in tooth so key and fibrous tissue that unites it with bone

15
Q

How are primary cartilaginous joints united?

How are they functionally classified?

Give an example

A

Hyaline cartilage

Synarthrosis - immovable joint

1st sternocostal joint, epiphyseal growth plates

16
Q

Describe a secondary cartilaginous joint

How much movement is there?

Give an example

A

Articulating bones covered with hyaline cartilage with a pad of fibrocartilage between them

Amphiarthrosis

Symphysis pubic, intervertebral disc

17
Q

What is a synovial joint?

How much movement do they have?

A

Joint cavity contains synovial fluid

Diarthrosis - freely movable

18
Q

What are the three exceptions of hyaline cartilage in synovial joints?

A

Acromioclavicular
Sternoclavicular
Temporomandibular

Atypical synovial joints
Contain fibrocartilage

19
Q

Describe synovial fluid

What is it composed of?

What are its functions?

How much is in a large joint?

A

Clear or pale yellow fluid.

Composition: Hyaluronic acid, lubricants, proteinase, collagenase

Functions: Reduces friction, shock absorption, nutrient and waste transportation.

Fluid volume

20
Q

What are the characteristics of a synovial joint and describe.

A

Articular cartilage - hyaline (3 exceptions), low frictions movement, resists compression

Fibrous capsule - collagen, completely encloses joint except when interrupted by synovial protrusions, stabilises joint.

Synovial membrane - thin, highly vascularised membrane. Produces synovial fluid. Lines capsule, covers exposed osseous surfaces, tendon sheaths, bursae. Does NOT cover Articular cartilage.

Synovial fluid - clear or pale yellow fluid. Reduces friction, shock absorption, nutrient and waste transportation.

Intra-Articular discs - fibrocartilage (not covered by synovium)

Fat pads

21
Q

What are bursae and tendon sheaths?

A

Specialised areas of synovial membrane

Bursa - sac lined with synovial membrane, filled with synovial fluid, communicating or non-communicating with joint cavity

Tendon sheaths - elongated bursa, wrapped around a tendon

22
Q

What is the blood supply to synovial joints?

What is the blood supply to Articular cartilage?

Describe the blood supply to fibrous capsule and ligaments

And synovial membrane?

A

Periarticular arterial plexus

Articular cartilage is avascular - completely dependent on diffusion to get nutrients

Fibrous capsule and ligaments have poor blood supply

Synovial membrane has rich blood supply

23
Q

What is Hilton’s Law?

A

The nerves supplying the joint capsule also supply the muscles moving the joint and skin overlying the insertions of these muscles

24
Q

What are the six types of synovial joints?

What is classification based upon?

A
Planar
Hinge 
Pivot 
Condyloid
Saddle
Ball and socket 

Shape of Articular surface

25
Q

Describe the planar joint

Name some examples

A

Flat or slightly curved articulating surface
Gliding or sliding movements
Non axial

Sternoclavicular, acromioclavicular joint, intercarpal joints

26
Q

What is the hinge joint?

Name three examples

A

Uniaxial

Pulley-shaped - convex surface of one bone fits into concave surface of the other

Knee, ankle, humeroulnar joint of elbow

27
Q

Describe a pivot joint?

Give an example

A

Uniaxial

Rounded or pointed surface of one bone articulates within ring formed by the concavity of another bone and fibrous ligament

Proximal radioulnar joint - used for pronation and supination

28
Q

What is a condyloid joint?

What movements does it allow?

Give an example

A

Biaxial joint - oval shaped condyle of one bone rests on elliptical cavity of another

Flexion, extension, abduction and adduction

Wrist (radiocarpal), Metacarpophalangeal joints

29
Q

Describe a saddle joint

What movements does it allow?

Give an example

A

Biaxial joint

One bone is saddle shaped (concavoconvex), the other bone resembles the legs of the rider

Flexion, extension, abduction and adduction

1st carpometacarpal joint

30
Q

Describe a ball and socket

Describe movements

Name two examples

A

Multiaxial

Ball-life surface of one bone fits into cup like surface of another

Movements: flexion, extension, abduction, adduction and rotation

Hip, shoulder

31
Q

What is difference between symphyses and syndesmoses?

A

Symphyses - connected by fibrocartilage

Syndesmoses - connective tissue

32
Q

What are the functions of the skeleton? (5)

A

Support - framework for posture
Protection - skull protects brain
Movement - attachment site for muscles and tendons, joints allow range of motion
Mineral and growth factor storage - resevoir for Ca2+ and phosphate, release minerals into the blood, IGF
Haematopoeisis - marrow within cavities of bones

33
Q

What are the factors that affect stability and range of motion at a synovial joint?

A
Structure/shape of articulating bone 
Strength and tension of joint ligaments 
Arrangement and tone of muscles
Apposition of neighbouring soft tissues
Hormones e.g. Relaxin in pregnancy - softens collagen bundles
Use/disuse
34
Q

What happens when people ‘crack joints?’

A
Bones are pulled away from each other
Synovial cavity expands
Synovial fluid volume stays constant 
Partial vacuum produced
Gasses dissolved in synovial fluid are pulled out of solution
Makes popping sound
35
Q

What is the effect of ageing on joints?

A

Decreased production of synovial fluid
Thinning of articular cartilage
Shortening of ligaments and decreased flexibility
Degenerative changes

36
Q

What is arthritis?

What are the symptoms?

What are the signs?

What is the most common type?

A

Inflammation and stiffness of a joint

Symptoms: pain, swelling, stiffness

Signs: redness, swelling, deformity, tenderness, reduced range of movement, abnormal gait

Osteoarthritis

37
Q

What is rheumatoid arthritis?

What happens?

What damage to other organs can it cause?

What is the peak age?

What gender is it more common in?

A

Autoimmune disorder - autoantibodies attack the synovium causing synovial inflammation

Joint erosion and deformity MCPJ and PIPJ (first joint in fingers)

Can cause damage to other organs - eyes, skin, lungs, heart and blood vessels, kidneys, blood (anaemia)

40-50 years

Women

38
Q

What are the Xray features of rheumatoid arthritis?

A

Narrowing of joint space
Periarticular osteopenia
Juxta-Articular bony erosions (non cartilage protected bone)
Subluxation and gross deformity (bones not in correct environment, starting to ulnar deviate - if in hand)

39
Q

What factors restrict movement around a joint?

A

Ligaments, muscle tendons, interference from other structures, depth of bony articulation (less stable, more mobile)