T2 L1 Morphological plan of upper limb

Question 1

Why are most mammals quadrupedal?

Answer 1

Allows for locomotion and climbing

Question 2

Describe some anatomical evolutions

Answer 2

Changes to foot, hip, knee, vertebral column, skull
Longer clavicles allowing greater range of movement
Opposable thumbs

Question 3

Describe the arrangement of the upper limb from coarse to fine muscle groups

Answer 3

Shoulder
Arm
Elbow
Forearm
Wrist
Hand

Question 4

What is the interosseous membrane?

Answer 4

Broad thin plane of fibrous tissue which holds the radius and ulna together
Allows slight movement between the bones for pronation / supination

Question 5

What movements can limbs make?

Answer 5

Flexion / extension
Abduction / adduction
Lateral / medial rotation
Pronation / supination
Circumduction
Opposition

Question 6

What movements can the glenohumeral joint make?

Answer 6

Extension / flexion
Abduction / adduction
Lateral (external) / medial (internal) rotation

Question 7

What movements can the elbow joint make?

Answer 7

Extension / flexion

Pronation / supination

Question 8

What movements can the wrist (radiocarpal) joint make?

Answer 8

Extension / flexion

Abduction / adduction

Question 9

Give an example of a saddle shaped joint

Answer 9

Joint between 1st carpal and 1st metacarpal (carpometacarpal)

Question 10

What movements can the metacarpophalangeal joint make?

Answer 10

Extension / flexion

Abduction / adduction

Question 11

What movements can the interphalangeal joints make?

Answer 11

Extension / flexion

Question 12

What are the 2 functional compartments?

Answer 12

Anterior (flexor) compartment

Posterior (extensor) compartment

Question 13

What is the origin, insertion and function of pectoralis major?

Answer 13

Origin = sternum, medial part of clavicle, costal cartilage
Insertion = lateral lip of bicipital groove
Function = Adduction, flexion, medial rotation

Question 14

What is the origin, insertion and function of pectoralis minor?

Answer 14

Origin = ribs 3,4,5
Insertion = Coracoid process
Function = protraction

Question 15

What is the origin, insertion and function of serratus anterior?

Answer 15

Origin = medial wall of thorax (upper 8 ribs)
Insertion = medial edge of scapula
Function = protraction

Question 16

What is the origin, insertion and function of deltoid muscle?

Answer 16

Origin = spine of scapula, acromion, lateral 1/3 clavicle
Insertion = deltoid tuberosity of humerus
Function = abductor
- posterior fibres for extension and lateral rotation
- anterior fibres for flexion and medial rotation

Question 17

What is the origin, insertion and function of teres major?

Answer 17

Origin = inferior angle of scapula
Insertion = medial lip of intertubercular sulcus of humerus 
Function = adduction and medial rotation

Question 18

What is the origin, insertion and function of biceps brachii?

Answer 18

Origin = supraglenoid tubercle, coracoid process of scapula
Insertion = radial tuberosity, fascia of forearm
Function = flexion, supination

Question 19

What is the origin, insertion and function of coracobrachialis?

Answer 19

Origin = coracoid process of scapula
Insertion = shaft of humerus
Function = flexion

Question 20

What is the origin, insertion and function of brachialis?

Answer 20

Origin = medial and lateral surfaces of humeral shaft
Insertion = ulna tuberosity 
Function = flexion

Question 21

What is the origin, insertion and function of triceps brachii?

Answer 21

Origin = infraglenoid tubercle, humerus
Insertion = ulna
Function = extension

Question 22

Where do the flexors of the forearm mainly come from?

Answer 22

Medial epicondyle

Question 23

Where do the extensors of the forearm mainly come from?

Answer 23

Lateral epicondyle

Question 24

What movements can the vertebral column make?

Answer 24

Extension / flexion
Lateral flexion / lateral extension
Rotation

Question 25

What is the function of the 4 curvatures of the vertebral column?

Answer 25

Bipedalism Shock absorption Flexibility

Question 26

What is the purpose of primary kyphoses?

Answer 26

Allows foetus to adopt a curved posture

Question 27

What is the purpose of secondary lordosis?

Answer 27

Important for transition from crawling to walking

Question 28

What is hyperkyphoses?

Answer 28

Rounded back

Question 29

Why is whiplash common?

Answer 29

Injury to anterior longitudinal ligament is common as this is the only ligament to resist hyperextension

Question 30

What is the function of the intervertebral joints?

Answer 30

Weight bearing and strength

Question 31

What is the function of the intervertebral discs?

Answer 31

Shock absorbers

Question 32

Why does the disc thickness increase down the vertebral column?

Answer 32

Have to absorb more stress

Question 33

What are the articulating surfaces of the intervertebral joints separated by?

Answer 33

Fibrocartilage

Question 34

What is annulus fibrosus?

Answer 34

Rings of fibrocartilage (secondary cartilage) Outer layer Binds 2 adjacent bony surfaces together for strength

Question 35

What are facet joints?

Answer 35

Joints between vertebral arches

Question 36

What does movement of the facet joints depend on?

Answer 36

Joint angle

Question 37

What are the movements of cervical facet joints and why?

Answer 37

Slight slope so extension / flexion and rotation

Question 38

What are the movements of the thoracic facet joints and why?

Answer 38

Angle is almost vertical so only rotation

Question 39

What are the movements of the lumbar facet joints?

Answer 39

Extension / flexion

Question 40

What do the extrinsic muscles of the back do?

Answer 40

Move upper limbs / ribs

Question 41

What do the intrinsic muscles of the back do?

Answer 41

Postural / move vertebral column

Question 42

What is the origin, insertion and function of trapezius?

Answer 42

Origin = external occipital prominence, spinous process of cervical and thoracic vertebrae Insertion = lateral part of clavicle, acromion and spine of scapula Function = move scapula - upper fibres = elevate scapula - Middle fibres = retract scapula - lower fibres = depress scapula

Question 43

What is the origin, insertion and function of latissimus dorsi?

Answer 43

``` Origin = thoracolumbar fascia, spinous processes of T6-T12, iliac crest and inferior 3 ribs Insertion = bicipital groove of humerus Function = adduction, extension, medial rotation ```

Question 44

What is the origin, insertion and function of levator scapulae?

Answer 44

``` Origin = transverse cervical process Insertion = anterior angle of scapula Function = elevate scapula ```

Question 45

What is the origin, insertion and function of rhomboids?

Answer 45

``` Origin = thoracic and last cervical spinous processes Insertion = medial border scapula Function = retract scapula ```

Question 46

What are the intermediate back muscles used for?

Answer 46

Accessory respiratory muscles that help expand chest cavity during inspiration

Question 47

What are the deep muscles?

Answer 47

Splenus Erector spinae Multifidus

Question 48

What are the 3 muscle blocks of erector spinae?

Answer 48

Spinales Longissimus Iliocostalis

Question 49

What is the origin, insertion and function of multifidus?

Answer 49

``` Origin = transverse processes Insertion = spinous processes Function = major stabiliser of back ```

Question 50

What is the trapezius innervated by?

Answer 50

11th cranial nerve

Question 51

What is the innervation of the extrinsic muscles?

Answer 51

Anterior primary ramus

Question 52

What is the innervation of the intrinsic muscles?

Answer 52

Posterior primary ramus

Question 53

How is the mesoderm formed?

Answer 53

Produced through gastrulation | Invading epiblast cells travel through primitive streak to form mesoderm

Question 54

What happens when the mesoderm undergoes further changes?

Answer 54

Forms paraxial, intermediate and lateral plate mesoderm

Question 55

What does the paraxial mesoderm give rise to?

Answer 55

Somites

Question 56

What is lateral plate mesoderm important for?

Answer 56

Limb development

Question 57

When do limb buds appear?

Answer 57

As out-pocketings from body wall during week 5

Question 58

What is mesenchyme made from?

Answer 58

Lateral plate mesoderm

Question 59

What does atypical ectodermal ridge (AER) do?

Answer 59

Keeps cells at distal region in a state of proliferation and undifferentiated

Question 60

What is spatial patterning of the limb under control of?

Answer 60

Hox genes

Question 61

What does limb mesenchyme produce?

Answer 61

Connective tissue of the limbs e.g. tendons, ligaments, fascia, cartilage and bone

Question 62

What happens to the limbs at week 6?

Answer 62

Limb extends further and flattens so hand / foot plate forms as a paddle shaped feature. Digital rays then form in this region. Tissue between each ray undergoes programmed cell death to form fingers and toes

Question 63

Where do limb muscle cells originate?

Answer 63

Somites

Question 64

What happens to the limb muscle cells from the somite?

Answer 64

Delaminate from somite and migrate into limb bud then congregate close to skeletal elements Muscle cells organise into ventral and dorsal muscle masses then further cleavage to form individual muscles of limb

Question 65

What is phocomelia?

Answer 65

Parts of limb are absent at proximal regions | Due to lack of cell proliferation and failure of limb bud to grow

Question 66

What is syndactyly?

Answer 66

Fusion of digits or joining of digits with soft tissue | Due to lack of cell death or cell proliferation problems