Pelvic Limb 2 Flashcards
Which phalanx is the longest?
P1
What is the relative size of P2?
1/2 the length of P1
What is the shape of P3?
Looks like the hoof
Where is the bony ridge of P1, what inserts here, and what does it outline?
On the palmar/plantar aspect;
Several ligaments terminate here;
Outlines the triangular area
What is the triangular area of P1 outlined by?
bony ridge
Where are the extensor processes of P2 and P3 located and what inserts on them?
On the dorsal surface;
digital extensor tendons
Where are the flexor tuberosities/surfaces located and what inserts on them?
Proximal aspect of palmar/plantar P2, navicular bone, and P3;
Digital flexor tendons
What are the solar foramina of P3 joined by and what pass through here?
Joined by solar canal;
terminal branches of the digital arteries pass thru
How many proximal sesamoids does the horse have?
2 per foot
How many distal sesamoids does the horse have?
1 per foot (navicular bone)
Where is the sagittal ridge located?
On the distal aspect of the 3rd metacarpal/tarsal
Where is the sagittal groove located?
On the proximal aspect of P1
What two articular surfaces of the distal limb are described as a “lock and key” mechanism and what does it do?
The sagittal ridge and sagittal groove;
Restricts range of motion to flexion and extension
What is present at the fetlock joint that helps to limit the range of movement to flexion and extension?
robust collateral ligaments
What does the bony ridge of the ox’s fused 3rd and 4th MC/MTs divide?
divides bone into 2 medullary cavities
How many proximal sesamoids does the ox have?
4 per foot (2 per digit)
How many distal sesamoids does the ox have?
2 per foot (1 per digit)
What two MT/MC bones are fused in the rmt?
3rd and 4th MC/MTs
What is the cannon bone in the horse?
3rd MC or MT
What are the splint bones of the horse?
2nd and 4th MCs or MTs
What is the long pastern bone of the horse?
P1
What is the short pastern bone of the horse?
P2
What is the coffin bone of the horse?
P3
What is another name for the 3rd MC or MT of the horse?
cannon bone
CANNOT use this term on the exam!
What is another name for the 2nd and 4th MC/MT of the horse?
splint bones
CANNOT use this term on the exam!
What is another name for P1 in the horse?
long pastern bone, proximal phalanx
What is another name for P2 in the horse?
short pastern bone, middle phalanx
What is another name for P3 in the horse?
coffin bone, distal phalanx
What are the 3 distal limb joints called (common names)?
fetlock, pastern, coffin
What are the 3 distal limb joints called (anatomic names)?
metatarso(carpo)phalangeal, proximal interphalangeal, distal interphalangeal
From cranial to caudal, what is the order of the crus muscles (craniolateral grp) in the rmt?
- Cranial tibial (small at proximal aspect of crus)
- Peroneus tertius
- Long digital extensor (deep to PT)
- Peroneus longus
- Lateral digital extensor
- Flexor hallucis longus (deep digital flexor)
- Soleus
- Gastrocnemius
From cranial to caudal, what is the order of the crus muscles (craniolateral grp) in the horse?
- Cranial tibial
- Long digital extensor
- Peroneus tertius (deep to LoDE; not a true muscle)
- Lateral digital extensor
- Flexor hallucis longus (deep digital flexor)
- Soleus
- Gastrocnemius
In the pig, what is the origin and insertion of the lateral digital extensor muscle of the pelvic limb?
O: lateral tibial condyle/lateral collateral ligament
I: lateral digits
In the pig, what is the origin and insertion of the peroneus tertius muscle?
O: extensor fossa of distal femur (same as LoDE)
I: metatarsal/tarsal bones
In the ox, what is the origin and insertion of the peroneus tertius muscle?
O: extensor fossa of distal femur
I: metatarsal/tarsal bones
In the ox, what is the origin and insertion of the long digital extensor muscle?
O: extensor fossa of distal femur
I: digits
What pelvic limb muscle does the rmt have, but is absent in the horse?
Peroneus longus
In the horse, what does the tendon of the lateral digital extensor join with?
The tenson of the long digital extensor at the proximal part of the cannon bone
What innervates the craniolateral group of crus muscles?
common peroneal n.
What innervates the caudal group of crus muscles?
tibial n.
In the dog, what is the origin and insertion of the cranial tibial muscle?
O: lateral tibial condyle/tibial tuberosity
I: MT and/or tarsal bones
In the dog, what is the origin and insertion of the long digital extensor muscle?
O: extensor fossa of distal femur
I: digits
In the dog, what is the origin and insertion of the peroneus longus muscle?
O: lateral tibial condyle/lateral collateral ligament
I: MT and/or tarsal bones
In the dog, what is the origin and insertion of the gastrocnemius muscle?
O: distal femur
I: calcanean tuber
In the dog, what is the origin and insertion of the superficial digital flexor muscle in the pelvic limb?
O: supracondylar fossa of distal femur
I: calcanean tuber and digits
In the dog, what is the origin and insertion of the deep digital flexor muscle in the pelvic limb?
O: proximal tibia
I: P3 (all domestic animals)
In which large animal is the soleus muscle the largest?
pig
What is the triceps surae?
The soleus muscle + 2 heads of gastrocnemius (pig only)
What two muscles of the equine crus share an origin?
long digital extensor and peroneus tertius
What two muscles “sandwich” the peroneus tertius distal to their origins in the horse?
Long digital extensor - laterally
Cranial tibial - medially
What are the 3 bellies of the deep digital flexor in the pelvic limb?
- Flexor hallucis longus = lateral digital flexor
- Long digital flexor = medial digital flexor
- Caudal tibial head of DDF
What two tendons of the DDF fuse, where and what structure do they pass over as a common tendon?
Lateral digital flexor and cranial tibial heads fuse proximally and pass over the sustentaculum tali
What tendon of the DDF joins the other two at the cannon region, and what structure does it pass over?
medial digital flexor; passes over the medial malleolus
What is the origin and insertion for the accessory/check ligament in the horse?
O: fascia overlying the tarsal bones
I: joins tendon of DDF to insert on P3
Which limb has a larger check ligament?
thoracic
Where does the superficial digital flexor muscle begin?
deep to the gastrocnemius
What is the course of the SDF tendon in the pelvic limb?
Changes course in mid-crural region - wraps around the gastrocnemius tendon medially and becomes superficial on the plantar aspect
Where does the superficial digital flexor tendon insert on the pelvic limb?
tuber calcanei, distal P1, proximal P2
What structure runs through where the SDF splits into 2 limbs?
DDF tendon
