Canine Thoracic Limb Osteology

Four topographic regions of the thoracic limb

1.) thoracic girdle

2.) brachium

3.) antebrachium

4.) manus

Two bones of the thoracic girdle

1.) scapula

2.) clavicle

In the dog, the clavicle is _____________

vestigial

Function of clavicle

acts as a tendon in the dog; small piece of cartilage that doesn't serve much purpose

What does the clavicle turn into as it regresses?

clavicular intersection

clavicular intersection

Divides the brachiocephalicus into two parts; deep edge of a fibrous plate where the vestigial clavicle is connected

Joint between the humerus and scapula

glenohumeral joint

Three borders of the scapula

1.) cranial

2.) cadual

3.) dorsal

cranial border of scapula

border that faces the head

caudal border of scapula

border that faces the tail

dorsal border of scapula

border that faces the dorsal midline/back

Two angles of the scapula

1.) cranial

2.) caudal

cranial angle of scapula

where the cranial border meets the dorsal border

caudal angle of scapula

where the dorsal border meets the caudal border

Six structures of the lateral scapula

1.) spine

2.) supraspinous fossa

3.) infraspinous fossa

4.) acromion process

5.) supreglenoid tubercle

6.) glenoid cavity

Spine of scapula

ridge on the lateral side of the scapula that divides it in half

Supraspinous fossa of scapula

fossa in front of the spine

Infraspinous fossa of scapula

fossa behind the spine

Acromion process of scapula

the distal end of the spine where it thickens

Supraglenoid tubercle of scapula

distal end of the cranial border; origin of biceps brachii

Glenoid cavity of scapula

ventral end of scapula that articulates with the humerus

Structure of the medial surface of scapula

subscapular fossa

subscapular fossa

makes up most of the medial side of scapula; attachment for subscapularis

Three structures of the ventral surface of scapula

1.) acromion

2.) supraglenoid tubercle

3.) glenoid cavity

Bone of the brachium

humerus

Head of the humerus

articulates with glenoid cavity of scapula; located at the proximal end of humerus

Body of the humerus

shaft of humerus

Condyle of the humerus

articulates with ulna and radius; located at the distal end of the humerus

Four structures of the proximal humerus

1.) head

2.) greater tubercle

3.) lesser tubercle

4.) intertubercular groove

greater tubercle of humerus

located at the lateral prospect of the head

lesser tubercle of humerus

located at the medial prospect of the head

intertubercular groove of humerus

groove between the lesser and greater tubercles; where the tendon of the biceps brachii sits

Seven structures of the distal humerus

1.) medial epicondyle

2.) lateral epicondyle

3.) trochlea

4.) capitulum

5.) supratrochlear foramen

6.) radial fossa

7.) olecranon fossa

medial epicondyle of humerus

bump on the medial aspect of the condyle

lateral epicondyle of humerus

bump on the lateral aspect of the condyle

Which two parts of the humerus articulate with the radius and ulna?

trochlea and capitulum

trochlea of humerus

located medially on the cranial surface; articulates with both the radius and ulna

capitulum of humerus

located laterally on the cranial surface; articulates with the radius

supratrochlear foramen of humerus

hole above the trochlea

radial fossa of humerus

depression on the cranial aspect

olecranon fossa of humerus

depression on the caudal aspect

Instead of the supratrochlear foramen, the cat has the _______________ foramen

supracondylar foramen

supracondylar foramen of the cat

foramen located on the distal medial surface of the humerus

What passes through the supracondylar foramen of the cat?

brachial artery and median nerve

Two bones of the antebrachium

1.) radius

2.) ulna

Joint of the humerus and radius/ulna

cubital/elbow joint

Joint of the radius/ulna with the carpus

antebrachiocarpal joint

Function of the radius

principle weight bearing bone of the forearm

Two parts of the radius

1.) head

2.) trochlea

What comes off the trochlea of the radius?

styloid process

styloid process

process towards the thumb; covers the medial aspect of the carpus

Four structures of the ulna

1.) olecranon

2.) anconeal process

3.) trochlear notch

4.) styloid process

olecranon of ulna

proximal part of the elbow; located caudally and forms point of the elbow

olecranon tuber of ulna

a palpable tuber on the proximal aspect of the ulna

anconeal process of ulna

associated with the supratrohclear foramen of the humerus; point that goes through the foramen to stabilize the elbow joint

anconeal process is a common site of ______________

fracture

trochlear notch of ulna

half moon structure on the cranial aspect of ulna; what articulates with the condyle of the humerus to form the elbow joint

styloid process of ulna

located on the distal lateral end of ulna

The radius is __________ to the ulna proximally

cranial

The radius is __________ to the ulna distally

medial

Three bones of the manus

1.) carpus

2.) metacarpus

3.) phalanges

There are _______ rows of carpus bones

two

antebrachiocarpal joint

between radius and ulna and proximal row of carpal bones

mid-carpal joint

between the proximal and distal rows of carpal bones

carpometacarpal joint

between the distal row of carpal bones and the metacarpus

metacarpophalangeal joint

between the metacarpus and proximal phalanges

Two rows of the carpal bones

1.) proximal row

2.) distal

How many proximal carpal bones are there?

3

Three proximal carpal bones from medial to lateral

1.) radial carpal bone

2.) ulnar carpal bone

3.) accessory carpal bone

How many distal carpal bones are there?

four

Four distal carpal bones from medial to lateral

1.) first carpal bone

2.) second carpal bone

3.) third carpal bone

4.) fourth carpal bone

How many metacarpal bones are there?

five

Five metacarpal bones from medial to lateral

1.) first metacarpal bone

2.) second metacarpal bone

3.) third metacarpal bone

4.) fourth metacarpal bone

5.) fifth metacarpal bone

Each digit is composed of ________ phalanges

three

Three phalanges of the each digit

1.) proximal phalanx

2.) middle phalanx

3.) distal phalanx

Five digits from medial to lateral

1.) first digit

2.) second digit

3.) third digit

4.) fourth digit

5.) fifth digit

In the first digit, there is no ___________ phalange

middle

Three parts of each phalange

1.) base

2.) body

3.) head

The base of each phalange is at the _________ end

The head of each phalange is at the _________ end

proximal

distal

proximal interphalangeal joint

joint between proximal and middle phalanges

distal interphalangeal joint

joint between middle phalanges and distal phalanges

Four parts of the distal phalanx

1.) base

2.) extensor process

3.) ungual crest

4.) ungual process

extensor process of distal phalanx

where the extensor tendons for the extensor muscles insert

ungual crest of distal phalanx

Thin shelf around proximal portion of the claw

ungual process of distal phalanx

piece of bone that is in the claw; covered by corium (dermis)