Comparative Osteology Flashcards
List 2 things that differentiate the scapula in relation to the dog
- scapular cartilage prominent in ungulates
- acromion absent in equine and swine
Why is slope important in equine conformation?
Defines the reach of the stride
What is characteristics of an equine humerus?
- Intertubercular groove with intermediate tubercle
- Greater and lesser tubercles with cranial and caudal parts
- Prominent deltoid tuberosity and brachialis groove
- absent supratrochlear foramen
A greater tubercle that is shaped like a wave and a humerus with no intermediate tubercle is from which species?
Ruminants
What is the primary weight bearing bone in the antebrachium?
Radius, medial side
What is characteristic of the equine ulna?
Reduced in the horse and completely fused
Describe the ulna in ruminants
Slender and discernable
What is it called when there is incomplete fusion proximally of the radius and ulna?
Interosseus space
True or false: the lateral styloid process develops separately in the horse but fuses in adults
true
List the 3 cursorial specializations
- Plantigrade
- Digitigrade
- unguligrade
List the bones of the proximal row of the carpus from medial to distal
Radial, Intermediate, ulnar, accessory
List the distal row of the equine carpus
Carpal bones I-IV
How many carpal bones does the horse have?
7 or 8 ; carpal bone 1 is inconsistent
How many carpal bones in the ruminants?
6
How many carpal bones in the pig?
8
List a special characteristic of the ruminant carpus
Carpal bones II and III are fused; I is missing
What is the anatomical name for the “cannon” bone
Metacarpal III
What runs in the metacarpal tuberosity?
Extensor carpi radialis
The condyle of the metacarpus articulates with __________ and the _________________ on P1
Sesamoids and intermediate groove
Which MC are the splint bones?
MC II and IV
What are the splint bones fused to the cannon bone by?
Interosseous ligaments
In ruminants, which MC are fused?
III and IV
The vestigial bone in ruminants is _________.
MC V
Which carpal bone rests entirely on the medial splint bone?
Carpal bone II
Where does Carpal IV rest in equines?
MC III and IV
Why are MC II lesions more common than MC IV?
Because the downward force distribution is concentrated on the medial side
Which phalanx forms the articulation with the distal cannon bone?
Proximal phalanx
What is another name for the proximal phalanx?
Long pastern or P1
Describe the location of the proximal sesamoids in relation to the phalanges
They are on the palmar surface of the fetlock joint
Which joint of the distal limb is a common site for fractures?
Fetlock joint
The short pastern is the _________ phalanx.
Middle
The coffin bone is also known as which phalanx?
Distal
The navicular bone is which bone when speaking anatomically?
Distal sesamoid
What is the articulation of the short pastern the coffin and the navicular bone called?
Distal interphalangeal joint
What is the clinical relevance of the Distal sesamoid bone?
Navicular syndrome
Which digits are weight bearing in the ruminant?
3 and 4
Which digits are non weight bearing in ruminants?
2 and 5
What is the common term for digits 2 and 5 in ruminants?
Dewclaws
Describe the phalanges in pigs
4 complete digits, but 2 and 5 are non-weight bearing
Describe a difference in ruminants sesamoids
There are duplicated
The shoulder joint is also known as the _________________ joint.
Glenohumeral
What type of joint is the glenohumeral joint?
Ball and socket
True or false: the shoulder joint has collateral ligaments
False
Describe the function of the glenohumeral joint
Flex and extend
What type of joint is the cubital joint?
Hinge joint
Describe the location of the ligaments in relation to the center of rotation of the cubital joint
Caudal to the center of rotation
List the two ligaments associated with the elbow joint
Lateral and medial collateral ligaments
The superficial and deep collateral ligaments are lateral or medial?
Lateral
There is a short __________ division and a long _________ division of the medial collateral ligaments.
Short caudal, long cranial
What is another name for the carpus that’s technically not correct?
Knee
List the 3 joints of the carpus
- radiocarpal/antebrachiocarpal
- midcarpal
-carpometacarpal
Describe the 2 divisions of the lateral and medial collateral ligaments of the carpus joints
Superficial and deep
Which carpal joint compartment has the most movement?
Radiocarpal (60-90%)
Describe the movement in the midcarpal joint compartment
~40% movement
Which 2 joint compartments of the carpus communicate?
Midcarpal and carpometacarpal
Describe movement in the carpometacarpal compartment
No movement
What supports the carpus caudally?
- palmar carpal ligament
- Flexor tendons held in place by flexor retinaculum
The accessory ligament of the SDFT (proximal check) supports the carpus ____________
Proximally
What supports the carpus distally?
The accessory ligament of the DDFT (distal check)
The fetlock/ankle joint is called the ______________
Metacarpophalangeal joint
What bones make up the fetlock joint?
MC III and proximal phalanx
The metacarpophalangeal joint is a ________ joint.
Hinge
List the ligaments associated with the metacarpophalangeal joint
Lateral and medial collateral ligaments
Which ligament attaches the sesamoids to the other bones?
The lateral collateral sesamoidean ligament
List the interphalangeal joints
- proximal
- distal
The pastern join it is a ______ joint
Hinge
The coffin joint is what type of joint?
Saddle joint
How much body weight is carried in the thoracic limb?
~60%
The first conceptual spring of the thoracic limb is from where to where?
Proximal part of the limb (shoulder to elbow)
List the structures that make up the suspensory apparatus
- suspensory ligament
- proximal sesamoids
- distal sesamoidean ligaments
What is the clinical term for the interosseus muscle in horses?
Suspensory ligament
What is a structure that is also present in the suspensory apparatus that holds things in place?
Flexor manica
List the sesamoidean ligaments
- intersesamoidean ligament
- straight sesamoidean
- oblique sesamoidean
- cruciate sesamoidean
Which sesamoidean ligaments goes to the proximal end of middle phalanx?
Straight sesamoidean
Which sesamoidean ligament goes to the palmar surface of proximal phalanx?
Oblique sesamoidean
Which ligament attaches the navicular bone to the coffin bone?
Navicular impar ligament
Which ligaments go superficial to the SDFT and DDFT
Annular ligaments