Equine Thoracic Limb Block 3

shoulder

scaplar region

point of shoulder

greater tubercle of humerus (boney prominence)

brachium

arm

antebrachium

forearm

carpus

“knee”

metacarpus

metacarpal, cannon

fetlock

ankle; metacarpophalangeal joint

pastern

pastern

coronet

junction of skin with hoof

hoof

hard outer covering

chestnut

vestigial structure of carpal pad in the carpal region

ergot

level of fetlock, vestigial structure of metacarpal pad

digit

pastern, coronet, and hoof

withers

inter-scapular region (T1-T8 spinous processes)

shoulder joint

glenohumeral joing

elbow joint

cubital joint

carpal joint

knee

fetlock joint

ankle

pastern joint

proximal interphalangeal joint

coffin joint

distal interphalangeal joint

flexion makes angle

more acute

extension makes angle

more obtuse

flexor surface of shoulder joint

caudal aspect

flexor surface of elbow joint

cranial surface

flexor surface of carpal joint

palmar surface

flexor surface of fetlock joint

palmar surface

flexor surface of pastern joint

palmar surface

flexor surface of coffin joint

palmar surface

What happens to the scapular cartilage as an animal gets older?

it ossifies

What is the serrated face an attachment for?

Serratus ventralis sling

What originates on lateral epicondyle?

extensors of carpus and digit

What originates on medial epicondyle?

flexors of carpus and digit

Olecranon tuberosity

point of the elbow

What is special about ulna in horse?

fused to radius and not fully developed, vestigial

What is the synonymous structure of the abductor pollicus longus of canine in the horse?

extensor carpi obliquus

Proximal row of carpal bones

radial carpal, intermediate carpal, ulnar carpal, and accessory carpal

Distal row of carpal bones

second carpal, third carpal, fourth carpal, first carpal (may or may not be present)

metacarpal bone II common name

medial splint bone

metacarpal bone III common name

cannon bone

metacarpal bone IV common name

lateral splint bone

sagittal ridge ends

proximal end = base, distal end = head of cannon

What is the difference between the medial and lateral splint bones?

medial is longer than lateral splint

Where are proximal sesamoid bones?

level of fetlock joint

Extensor process of P3 is the insertion of what?

common digital extensor

Palmar process of P3 is attachment area of what?

hoof cartilage

Another name for navicular bone

distal sesamoid bone

What is parietal sulcus on P3 for

for entrance of arteries into hoof

solar canal

site of anastomosis for lateral and medial digital arteries

Flexor surface is site of insertion for what?

deep digital flexor tendon

Where is cartilage of hoof palpable?

above top of hoof

flexion of neck moves…

head towards ground

extension of neck moves…

head up

contraction of muscles on right side of neck move…

head to the right

Thoracic girdle

boney structure of skeleton that attaches limb to trunk

Innervation of rhomboideus cervicis

cervical spinal nerve

Innervation of serratus ventralis cervicis

long thoracic nerve

Innervation of trapezius

CN XI

Innervation of latissimus dorsi

thoracodorsal nerve

Innervation of brachiocephalicus

CN XI

Innervation of Omotransversarius

CN XI

Innervation of serratus ventralis thoracis

long thoracic nerve

What is the extra 4th pectoral muscle in the horse?

subclavius

Innervation and action of supraspinatus

suprascapular nerve, extend shoulder

Innervation and action of infraspinatus

suprascapular nerve, adduct shoulder

Innervation and action of deltoideus

axillary nerve, flex shoulder

Innervation and action of teres minor

axillary nerve, flex shoulder

Innervation and action of triceps brachii long head

radial nerve, flex shoulder and extend elbow

Innervation and action of triceps brachii lateral head

radial nerve, extend elbow

Innervation and action of brachialis

musculocutaneous nerve, flex elbow

Innervation and action of biceps brachii

musculocutaneous nerve, flex elbow

Innervation and action of subscapularis

subscapular nerve, adduct shoulder

Innervation and action of teres major

axillary nerve, flex shoulder

Innervation and action of coracobrachialis

musculocutaneous nerve, adduct limb and flex shoulder

Innervation and action of triceps brachii medial head

radial nerve, extend elbow

Innervation and action of tensor fasciae antebrachii

radial nerve, extend elbow

lacertus fibrosus

central tendon in biceps muscle and inserts on extensor carpi radialis, helps lock limb in place

Innervation, origin, and action of extensor carpi radialis, common digital extensor, lateral digital extensor, ulnaris lateralis, and extensor carpi obliquus

radial nerve, lateral epicondule of humerus, extend carpus and digits

Innervation, origin, and action of deep digital flexor, flexor carpi radialis, and flexor carpi ulnaris

median and ulnar nerve, medial epicondyle of humerus, flex carpus and digits

Proximal check ligament

accessory ligament of SDF

distal check ligament

accessory ligament of DDF

suspensory ligament

palmar aspect of cannon bone, from interosseous muscle

What tendons and ligaments can you feel in the horse?

lacertus fibrosus, SDF, accessory of SDF, DDF, accessory of DDF, and suspensory ligament

What locks P3 inside hoof wall?

interdigitation of primary and secondary laminae

Artery pathway

1. Axillary

   1. suprascapular

   2. subscapular

      1. caudal circumflex humeral

      2. thoracodorsal

   3. cranial circumflex humeral

2. Brachial

   1. deep brachial

   2. bicipital

   3. collateral unlar

   4. transverse cubital

   5. common interosseous

      1. cranial interosseous

      2. caudal interosseous

3. median

   1. deep antebrachial

   2. proximal radial

4. medial palmar

   1. medial digital

   2. lateral digital

5. arcus terminalis

What artery is the principal blood supply to the digit?

Medial palmar artery

Which artery is the last branch of the axillary artery?

Cranial circumflex humeral artery

Which arteries anastomose in the axillary artery region>

caudal circumflex humeral artery and cranial circumflex humeral artery

Which artery is the last branch of brachial artery?

common interosseous artery

rete carpi dorsale formation

spider web like netowrk of arteries on dorsum of carpus formed by transverse cubital and cranial interosseous arteries

rete carpi dorsale gives rise to…

medial dorsal metacarpal and lateral dorsal metacarpal

What does the deep antebrachial artery supply?

caudomedial muscles of antebrachium

What does the proximal radial artery supply?

carpal joint

When does median artery become medial palmar artery?

After it passes through carpal canal

Where is the arcus terminalis?

in the solar canal of P3

on lateral side of limb, palmar branch of median artery fuses with collateral ulnar artery to form…

lateral palmar artery

Lateral palmar artery fuses with lateral digital artery to form…

deep palmar arch

on medial side of limb, radial artery comes from median artery at same level of palmar branch of median artery to supply…

deep palmar arch

Deep palmar arch gives rise to…

medial palmar metacarpal artery and lateral palmar metacarpal artery

medial and lateral palmar metacarpal arteries fuse to empty into…

lateral digital artery

Which vein connects the cephalic and brachial veins?

Median cubital vein