Principles of skeletal organisation

Question 1

Name the 2 main divisions of the skeletal system

Answer 1

Axial & Appendicular

Question 2

Name some of the parts of the axial skeleton

Answer 2

Axial - cranium, vertebral column, ribs and sternum

Question 3

Name some of the parts of the appendicular skeleton

Answer 3

Appendicular - pectoral girdle, upper limb bones, pelvic girdle, lower limb bones

Question 4

List 5 functions of the skeleton

Answer 4

Movement and muscle attachment

Resistance to gravity and other forces

Protection of soft tissues

Calcium storage

Haematopoiesis: blood cell production (red marrow)

Question 5

Bone as a tissue - recall and read

Answer 5

Molecular structure of bone

Collagen - triple helix structure (Gly-Pro-OHpro), fibrils, staggered ends, aldol-histidine cross links

Denature with heat -> brittle

Flexibility, elasticity

Hydroxyapatite - crystals impregnate collagen matrix

Remove using acid -> overly flexible bones

Hardness/rigidity

Question 6

The Two Types of Bone

Answer 6

Trabecular bone - trabeculae in directions of stress, spongey for low density (strength to weight ratio)

Compact bone - osteons aligned with bone

Question 7

5 Morphological classifications of bones

Answer 7

Long bones (femur) - tubular with expanded epiphyses

Flat bones (parietal, scapula)

Short bones (carpels) - cuboidal

Sesamoid bones (patella) - develop inside tendons to protect them from excessive wear and act as pulleys

Irregular bones (vertebrae)

Question 8

STate the name of bones in the shoulder gidle
Name the function

Answer 8

Movement
Scapula and Clavicle
The shoulder girdle, consisting of the collar bone (clavicle) and the shoulder blade (scapula)provides the bony link between the arm and the trunk.

Question 9

Clavicle - recall

Answer 9

Clavicle

Distancesthe upper limb from the body

Transmits forceto the axial skeleton

Articulates with the acromion and manubrium (smaller end)

Question 10

Clavicle

Answer 10

Distancesthe upper limb from the body

Transmits forceto the axial skeleton

Articulates with the acromion and manubrium (smaller end)

Question 11

Scapula

Answer 11

Articulates with the humerus at theglenoidfossa-shallowto increase the range of movement

Coracoid(ant) serves as a muscular attachment point (short head of biceps, coracobrachialis, pec major + minor)

Question 12

Function of pelvis - Pelvic girdle

Answer 12

Stability

Question 13

Pelvis is composed of …,… and … fused to form a single bone

Answer 13

Pelvis is composed of thepubis,ischiumandilium- fused to form a single bone (develop from separate ossification centres)

Question 14

Pelvic girdle articulation

Answer 14

Articulation

With the femur at theacetabulum(horse shoe shaped) -deeperthan the glenoid fossa to increase stability

With the opposite pubis at thepubic symphysis

With the sacrum at the immobilesacro-iliac joint

Ilium

Uppermost part is the iliac crest which anteriorly forms the anterior superior iliac spine (ASIS)

Line of one crest to the other bisects the L4 vertebra

Question 15

Humerus - recall & read

Answer 15

Function = to act as a mobile lever to direct forearm movement in any direction

Often fractured at the surgical neck

Bone surface

Greater and lesser tuberclesfor attachment of rotator cuff muscles (all attach to GT apart from subscapularis which is LT)

Deltoid tuberosity for attachment of the deltoid

Radial groovefor radial nerve - at risk in case of mid shaft fracture

Articulation

With the glenoid fossa at the head

With theradiusat thecapitulum(lateral)

With theulnaat thetrochlea(medial)

Olecranon fossa= toprevent over extensionof the forearm

Question 16

Femur Bone - Recall & Read

Answer 16

Transmits force through the neck to thecondyleswhich articulate with the tibia

Bone surface

Greater trochanterfor attachment of gluteus medius and minimus (abduction)

Lesser trochanterfor attachment of iliacus and psoas major (flexion)

Linea aspera attachment for thigh adductors
125oangle of neckandmedial slope of shaft- bicondylar angle - adapted to be weight-bearing.

Question 17

General info - to read

Answer 17

Generally speaking,atubercleis a small attachment site for tendons and ligaments, a tuberosity is a medium to large attachment site, and a trochanter is the largest, bulkiest, and roughest attachment sites.

Question 18

fossa

Answer 18

Fossa -A shallow depression in the bone surface. Here it may receive another articulating bone or act to support brain structures.

Question 19

condyle and epicondyle

Answer 19

The condyle is the smooth surface area at the end of a bone that forms part of a joint. The epicondyle is a rounded protuberance at the end of a bone, serving as a place of attachment for ligaments, tendons, and muscles.

Question 20

Mnemonic for pronation and supination - context shopping selecting apples

Answer 20

Pronate = pronate to pick up produce
Supination = To eat it for supper = supinate