Chp 11 Pectoral Girdle/ Upper Limb/ Pelvic Girdle/ Lower Limb

Question 15

Upper limbs consist of four parts: shoulder, arm, forearm & hand

Question 16

Pectoral girdle:
➢ bones (clavicle and scapula) in the appendicular skeleton that connect the arm (humerus) to the axial skeleton (manubrium)

➢ Clavicle (Collar Bone)
➢ Scapula (Shoulder Blade)
➢ Humerus (Upper arm bone)
➢ Manubrium (A bone between ribcages)

Question 17

Scapula (肩胛骨):
Acromial process of scapula articulates with the lateral end of the clavicle to form the acromioclavicular joint

Question 18

Clavicle:
Medial end of scapula articulates with manubrium to form _____________________ joint.

Answer 18

sternoclavicular

Question 19

Capsular ligament:
anterior sternoclavicular ligament & posterior sternoclavicular ligament
=> connect them

Question 20

Bone of the arm
-Humerus
-Proximally, identify:
➢ Head
➢ Neck (Anatomical and surgical neck => anatomical is the real neck, surgical neck is the neck which is more easily fractured)
➢ Tubercle, tuberosity
-Shaft

-Distally, identify:
➢ Condyle (smooth): Trochlea & Capitulum
➢ M & l epicondyles (rough): for muscle attachment

Question 20

Glenohumeral Joint:
(Ball & socket joint)
➢ Head of humerus articulate with the glenoid cavity of the scapula

Question 21

Radius—thumb side (lateral)

Ulna—little finger side (medial)

Interosseous membrane
–attach the shaft (軸) of ulna and radius and link them together

Question 22

Elbow joint
- contains two joint together
- contains humeroulnar joint & humeroradial joint

Question 23

Carpal bones:
(Sam likes to play the toy car hard)
(From lateral to medial)
Scaphoid
Lunate
Triquetrum
Pisiform
Trapezium
Trapezoid
Capitate
Hamate

Question 24

Each finger has 3 phalanges except thumb (2 only)

Five metacarpal bones articulate proximally with the distal carpal bones; and distally with the
proximal phalanges

Question 25

Brachial Plexus:
(*****EXAM MUST HAVE THIS QUESTION)
-comes from the anterior rami of C5-T1
-anterior ramus=ventral ramus
➢ Roots emerges from the scalene muscles , where the 5 ventral rami fuse to form 3 trunks

➢ C5-T1 (roots)
➢ C5-C6: Superior trunk C7: Middle trunk C8-T1: Inferior trunk
➢ Divisions
➢ Cords
➢ Terminal branches
(musculocutaneous; axillary; radial; median; ulnar
=> only need to remember these fives is enough!)

Roots of the plexus (C5-T1) emerges through the gap between the anterior and the middle scalene muscles; cords are running underneath the ______________.

Answer 25

clavicle

Question 26

Muscles can be grouped according to their
primary actions:

Agonist (Prime mover):
➢ Main muscle responsible for producing a specific movement of the body via concentric contraction.

Fixator:
➢ Stabilises the proximal parts of a muscle while
movements occur in distal parts.

Antagonist (to the agonist):
➢ Opposes the action of another muscle.

Synergist:
➢ Complements the action of agonist; providing a weaker component of the same movement.

Question 27

Subclavius muscle is under the clavicle.
=> anchor and depress scapula

Pectoralis minor
=> draw scapula inferiorly and anteriorly

Question 28

Trapezius:
Action to scapula:
Upper part elevates
Middle part retracts (縮回)
Lower parts depresses

Levator scapulae:
Elevate scapula

Rhomboid minor & rhomboid major:
retract scapula

Serratus anterior:
protract (延長) scapula

Question 29

Muscles that move the arm:

Deltoid
(powerful abductor)

Pectoralis major
(medial rotation, flexion & adduction of humerus)

Latissimus Dorsi
(medial rotation & adduction of humerus)

Rotator Cuff
(stabilise shoulder joint during shoulder movements)

Question 30

Rotator Cuff Muscle: stabilise shoulder joint

1) Subscapularis: Medial rotation of humerus

2) Supraspinatus: Initiate arm abduction; then assist deltoid in abduction
=> easily injured upon shoulder abduction

3) Infraspinatus: Main lateral rotator of the shoulder joint

4) Teres minor: lateral rotator of the shoulder joint

=> works as a group to stabilise the shoulder

Question 31

Main elbow flexor:
-Biceps brachii
=>Works better while flexion comes with supination (旋後) but not pronation (旋前)

-Brachialis:
=>Works all the time during flexion (major)

-Brachioradialis:
=>Works better while flexion comes by taking up the role of biceps

Question 32

Main elbow extensor:
- long head: originates from scapula

• lateral and medial head: originates from posterior humerus
• Triceps brachii is an extensor of the
  forearm.

Question 32

Anterior Compartment of Forearm—extrinsic muscles:
FCR—flexes and abducts hand at wrist

FCU—flexes and adducts hand at wrist

FDS—flexes middle phalanges of
fingers (except thumb)

FPL—flexes thumb

FDP—flexes distal phalanges of fingers
(except thumb)

PQ—pronates forearm

Question 32

Muscle Action (Elbow, Wrist & Fingers )
Major Elbow Flexor:
* Brachialis
* Biceps (supine); Brachioradialis (prone)
Major Wrist & Fingers Flexors:
* Flexor digitorum superficialis
* Flexor digitorum profundus
Major Elbow Extensor:
* Triceps brachii
Major Wrist & Fingers Extensors:
* Extensor digitorum
Major Muscle Controlling Thumb Movement:
* Flexor pollicis longus & brevis, Abductor pollicis brevis, Opponens
pollicis

Question 33

Radial nerve palsy:
-Injury of radial nerve
-Wrist and fingers cannot extend
-Extensor muscles paralysed