7. Upper Extemitry Skeleton

Question 1

Why are upper and lower limbs serial homologues?

Answer 1

Because early in tetrapod evolution, forelimbs and hind limbs developed from similar processes

Hence they have similar bone structure but different function

Question 2

How does limb development occur?

Answer 2

Limbs initially develop in neutral position

Upper limbs rotate 90 degrees laterally

Lower limbs rotate 90 degrees medially

Question 3

Upper extremity consists of

Answer 3

Pectoral girdle and upper limb

Question 4

Pectoral girdle consists of

Answer 4

Scapula and clavicle

Question 5

Upper limb consists of

Answer 5

Humerus, radius & ulna, carpals, metacarpals, and phalanges

Question 6

Description of clavicle

Answer 6

“Strut” between sternum and scapula that is the only bony attachment for the upper extremity

Question 7

Parts of the clavicle

Answer 7

Sternal end and acromial end

Question 8

Movements of the scapula

Answer 8

Biaxial: elevation/depression and abduction/adduction

Question 9

Where does the glenohumeral joint connect

Answer 9

Between head of the humerus and glenoid fossa of the scapula

Question 10

Characteristics of glenohumeral joint

Answer 10

Ball and socket joint that has multiaxial movement and is considered the most mobile joint in the body

Surrounded by ligaments and rotator cuff muscles

Question 11

Shoulder movements

Answer 11

Flexion-extension, abduction-adduction, medial rotation-lateral rotation, and circumduction

Question 12

Characteristics of the elbow joint

Answer 12

Found between trochlea of humerus and trochlear notch of ulna

Hinge joint that is uniaxial and stabilized by muscles and ligaments

Question 13

Elbow movements

Answer 13

Flexion-extension

Question 14

Characteristics of the radio-ulnar joint

Answer 14

Proximal and distal articulations

Angular ligament holds head of radius to radial notch of ulna

Allows for pronation-supination

Question 15

Carpal tunnel

Answer 15

Tunnel created by transverse carpal ligament has muscle tendons travel through with median nerve

Question 16

Carpal tunnel syndrome

Answer 16

Overuse of muscles in capable tunnel that causes tendons to swell and pinch median nerve, resulting in paresthesia or numbness of lateral hand and weakness in thumb movements

Question 17

Wrist movements

Answer 17

Radial deviation/ulnar deviation and flexion/extension

Question 18

Bones in palm

Answer 18

Metacarpals

Question 19

Bones in fingers

Answer 19

Phalanges

Question 20

Number of phalanges in thumb and digits

Answer 20

2 in thumb and 3 in digits 2-5

Question 21

Metocarpo-phalangeal movements

Answer 21

Condylar joint with biaxial movement via abduction/adduction and flexion/extension

Question 22

Interphalangeal movements

Answer 22

Hinge joint with uniaxial movement via flexion/extension

Question 23

Some Lovers Try Positions That They Can’t Handle

Answer 23

Scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate, hamate