Thoracic Limb Lecture

Question 1

Name parts of the thoracic girdle.

Answer 1

Scapula, clavicle (in remnants)

Question 2

What does the shoulder region include?

Answer 2

scapulohumeral joint

Question 3

What does the brachium region include?

Answer 3

humerus

Question 4

What does the elbow region include?

Answer 4

humeroradioulnar joint

Question 5

What does the antebrachium region include?

Answer 5

radius and ulna

Question 6

What does the manus region include?

Answer 6

carpus, metacarpus, digits (phalanges, sesamoids)

Question 7

What is synsarcosis?

Answer 7

the attachment of the thoracic limb to the body via the extrinsic muscles

Question 8

What is the sling muscle?

Answer 8

serratus ventralis

Question 9

What muscles transfer the weight of the head, neck, and cranial aspect of the trunk to the thoracic limb?

Answer 9

serratus ventralis and pectoral mm

Question 10

What percentage of an animals weight is transferred to the thoracic limb during the stance phase?

Answer 10

60%

Question 11

Where do all of the of the extrinsic attach?

Answer 11

head, neck, and/or trunk

Question 12

What major movements are the extrinsic muscles involved in?

Answer 12

protraction (advancement) and retraction of the limb

Question 13

What are intrinsic muscles and, in general, where do they attach?

Answer 13

muscles with the limb itself, both attachments of the muscle will be to bones of the thoracic limb

Question 14

What is the name of the shoulder joint and what is its function?

Answer 14

Glenohumeral joint; allows movements in multiple planes and has less developed ligaments –> more muscles around it to perform complex movements and stabilize it

Question 15

What is the name and function of the elbow joint?

Answer 15

Humeroradioulnar joint; allows flexion and extension only, has strong collateral ligaments; 2 main muscle groups with opposing actions

Question 16

What is the name and function of the carpus joint?

Answer 16

metacarpophalangeal joint; allow flexion and extension primarily, have collateral ligaments; 2 main muscle groups with opposing actions

Question 17

What are the names and functions of the joints of the phalanges?

Answer 17

proximal and distal interphalangeal joints; allow flexion and extension primarily, have collateral ligaments; 2 main muscle groups with opposing actions

Question 18

Where do the extensors of the carpus and digits orginate from?

Answer 18

Lateral supracondylar crest and lateral epicondyle of the humerus

Question 19

What is ECLU?

Answer 19

craniolateral muscles of the antebrachium; begins on the cranial aspect of the antebrachium and moves laterally

Extensor carpi radialis, Common digital extensor, Lateral digital extensor, Ulnaris lateralis

Question 20

Where do the flexors of the carpus and digits originate?

Answer 20

medial epicondyle of the humerus

Question 21

What is the function of the caudomedial muscles of the antebrachium? What are they?

Answer 21

flex the carpus and/or digits

Flexor carpi ulnaris; superficial digital flexor; deep digital flexor; flexor carpi radialis

Question 22

What is the function of the craniolateral muscles of the antebrachium?

Answer 22

extend the carpus an the digits

Question 23

What do tendons of the digital flexor muscles pass through?

Answer 23

carpal canal

Question 24

Explain the boundaries of the carpal canal.

Answer 24

dorsal border: palmar carpal ligament
lateral border: accessory carpal bone
palmar border: flexor retinaculum

Think of it as a triangle

Question 25

Where are interossei muscles located?

Answer 25

On the palmar aspect of the metacarpal bone of each digit

Question 26

What does the tendon of each interosseus muscle contain?

Answer 26

Two sesamoid bones

Question 27

How does a cat retract and contract its claws?

Answer 27

Relaxation of the DDF results in elastic recoil of the dorsal elastic ligament, resulting in the hyperextension of the distal interphalangeal joint

Contraction if the DDF protracts the claw

Question 28

What are the parts of the paw pads?

Answer 28

Carpal pad, metacarpal pads, and digital pads