Musculoskeletal

Question 1

Give an example of a long bone.

Answer 1

Radius.

Also femur, tibia, fibula, humerus, ulna, metatarsals, metacarpals, phalanges.

Question 2

Give an example of a short bone.

Answer 2

Tarsals (in the ankle).

Also carpals.

Question 3

Give an example of a flat bone.

Answer 3

Scapula.

Also sternum, ribs, cranial bones.

Question 4

Give an example of a sesamoid bone.

Answer 4

Patella.

Question 5

Give an example of an irregular bone.

Answer 5

Vertebrae.

Also facial bones.

Question 6

Give an example of a pneumatic bone (irregular and contains air filled spaces).

Answer 6

Maxilla.

Question 7

Name the three regions of a long bone.

Answer 7

Epiphysis, (physis), metaphysis, diaphysis.

Question 8

What is the other name for the primary cartilaginous joints and secondary cartilaginous joints?

Answer 8

Primary = synchrondroses.
Secondary = symphyses.

Question 9

What’s the difference between bipennate and unipennate muscles?

Answer 9

Unipennate muscles have fibres arranged obliquely and inserting on only one side of a tendon. Bipennate muscles have a central tendon with fibres converging on both sides like a feather.

Question 10

What are the canals at the centre of osteons called? What are the transverse canals called?

Answer 10

Longitudinal = Haversian
Transverse = Volkmann's

Question 11

List the layers of connective tissue surrounding muscle.

Answer 11

Epimysium - dense connective tissue surrounding entire muscle belly
Perimysium - surrounds fascicles (groups of 10-100 muscle fibres)
Endomysium - surrounds sarcolemma of a muscle fibre
Sarcolemma - muscle cell membrane

Question 12

What are T tubules?

Answer 12

Invagination a of the sarcolemma which carry the membrane depolarisation signal into the muscle cell for the excitation-contraction coupling.

Question 13

What are three effects of hypercalcaemia?

Answer 13

Stones - renal stones causing colicky pain
Bones - bone pain from calcium resorption
Abdominal groans - abdominal pain from stones, pancreatitis and peptic ulcers

Question 14

What are the five parts of a long bone?

Answer 14

Proximal epiphysis, physis, metaphysis, diaphysis [the shaft], (then distal metaphysis, distal physis, distal epiphysis).
There is also articular cartilage on the epiphysis, which reduces friction and absorbs shock.

Question 15

What is the connective tissue called that surrounds the bone where it’s not covered by articular cartilage?

Answer 15

Periosteum.

Question 16

What are the two layers of the periosteum?

Answer 16

Outer fibrous layer of dense irregular connective tissue.

Inner osteogenic layer of cells which allows bone to increase in width.

Question 17

What are the thick bundles of collagen extending from the periosteum into the bone matrix called?

Answer 17

Sharpey’s fibres.

Question 18

What is the advantage of the medullary cavity in the diaphysis which contains yellow bone marrow?

Answer 18

It minimises bone weight, but the tubular structure maximises bone strength.

Question 19

What lines the medullary cavity?

Answer 19

Endosteum

Question 20

Bone is comprised of cells in an extracelluar matrix, what are the two parts of the extracellular matrix?

Answer 20

Fibres and ground substance.

Question 21

What proportion of the bone extracellular matrix is organic and what is it comprised of?

Answer 21

40% - Type 1 collagen fibres and other non-collagenous proteins

Question 22

What proportion of the bone extracellular matrix is non-organic and what is it comprised of?

Answer 22

60% - hydroxyapatite (calcium, phosphate, other minerals)

Question 23

What makes bone hard?

Answer 23

The crystallised organic mineral salts.

Question 24

What makes bone flexible?

Answer 24

Type 1 collagen fibres provide tensile strength.

Question 25

What are the four types of cells present in bone?

Answer 25

Osteogenic cells - bone stem cells derived from mesoderm, found in endosteum and inner periosteum Osteoblasts - build bone, synthesise and secrete calcium and initiate calcification, form osteocytes when trapped in ECM Osteocytes - mature bone cells in lacunae of osteons, maintain bone metabolism, projections extend to surface osteoblasts through cannaliculi. Osteoclasts - derived from fused monocytes, large and multinucleate with ruffled border.

Question 26

What are the two types of bone?

Answer 26

Spongy/trabecular/cancellous bone. | Compact bone.

Question 27

What are osteons?

Answer 27

Rings of concentric lamellae surrounding a central Haversian canal (containing blood vessels, lymphatics, nerves). There are lacunae between the lamellae which contain osteocytes, and cannaliculi allowing lacunae to communicate with neighbouring osteoclasts and osteoblasts.

Question 28

What are the transverse canals across the compact bone called?

Answer 28

Volkmann's canals.

Question 29

What are the remains of osteons that have been partially destroyed by bone remodelling called?

Answer 29

Interstitial lamellae.

Question 30

Why are trabecular aligned along lines of stress?

Answer 30

They are organised for maximum resistance to compression.

Question 31

What are the characteristics of spongy bone?

Answer 31

It doesn't contain osteons. It is always inside bones, protected by compact bone. It contains lamellae irregularly arraigned as trabeculae. Each trabeculae is concentric lamellae, with cannaliculi radiating from each lacunae.

Question 32

What fills the spaces between trabeculae in cancellous bone?

Answer 32

Red/yellow bone marrow.

Question 33

What are the 6 types of synovial joint?

Answer 33

1) Ball and socket - triaxial e.g shoulder and hip joint 2) Plane - biaxial/triaxial e.g intercarpal joints in wrist 3) Saddle - biaxial e.g carpometacarpal joint in thumb 4) Pivot - uniaxial (rotation around longitudinal axis) e.g between Atlas and Dens 5) Hinge - uniaxial (only flexion and extension) e.g knee 6) Condyloid - biaxial e.g radiocarpal joint in wrist

Question 34

What type of muscle is orbicularis oculis?

Answer 34

Circular

Question 35

What type of muscle has an origin wider than the point of insertion (e.g pectoralis major)?

Answer 35

Convergent

Question 36

What are the two types of parallel muscle?

Answer 36

Fusiform - muscle belly wider than its origin or insertion e.g biceps brachii Non-fusiform - muscle belly not wider so not spindle shaped e.g rectus abdominis

Question 37

What are the three types of pennate muscles?

Answer 37

Unipennate - fibres insert in a diagonal direction onto only one side of the tendon e.g extensor digitorum Bipennate - a row of muscle fibres insert diagonally onto each side of the central tendon like a feather e.g rectus femoris Multipennate - central tendon branches into two or more tendons so there are multiple rows of diagonal fibres