Test 3 Flashcards
Which one, flexors or extensors, are responsible for weight bearing?
Flexors
If extensors are damaged, what do the flexors do to the action of the distal limb?
They overwhelm it
Loss of _______ function produces several abnormalities both posture and gait
flexors
Lining of the joint capsule that makes synovial fluid?
synovial membrane
Areas of joint that are free to distend somewhat are _______
joint pouches
This ligament runs from the prepubic tendon, up over the acetabular ligament, and to the head of the femur
accessory ligament of the hip
Why does the horse have an accessory ligament of the hip?
Helps hold the head of the femur in the acetabulum d/t the weight of the abdominal viscera pulling on the accessory ligament
Name the patellar ligaments of the horse
- medial
- middle (intermediate)
- lateral
Which ligament of the horse is analogous to the patellar ligament of the dog?
Middle patellar ligament
What forms the locking mechanism for the stifle?
medial and middle patellar ligaments, patella, and medial trochlear ridge
T/F: The dog has divisions of the articular surfaces of the trochlea and patella like the horse does
FALSE.
The dog lacks these divisions
Where do the 3 patellar ligaments of the horse insert?
Tibial tuberosity
T/F: Locking of the equine stifle is an active process
true
What are the synovial joints in the stifle? (3)
- medial femorotibial
- lateral femorotibial
- femoropatellar
The cruciate ligaments and menisci are in the ___________ joint space
femorotibial
What percentage of the time do the femoropatellar and medial femorotibial joints communicate?
80%
What percentage of the time do the femoropatellar and lateral femorotibial joints communicate?
20%
T/F: The two femorotibial joints usually don’t communicate with each other
True
What holds the patella in the trochlear groove of the femur while the joint is moving?
femoropatellar ligaments
There are several tarsocrural joint pouches. What are they? Which is the biggest compartment?
- lateroplantar
- medioplantar
- dorsomedial - biggest
The collateral ligaments of the tarsus are actually both _____ and _____ collateral ligaments
long and short
These are important joint stabilizers when the leg is “in flight”
collateral ligaments of the tarsus
________ is responsible for the “snap” function of the tarsus
medial collateral ligament
_________ involves fibrous bands which attach to the distal femur and to the tarsus/metatarsus
Reciprocal Apparatus
Reciprocal apparatus - Cr. side
peroneus terius
reciprocal apparatus -Cd. side
- SDF
- fibrous band in the gastrocnemius
When the stifle flexes, the hock _______
flexes
When the stifle extends, the hock _______
extends
When the stifle is fixed in position, the hock is
fixed also
T/F: The reciprocal apparatus is the same thing as the stay apparatus
FALSE!!
It is a component of the stay apparatus
What does the stay apparatus allow the horse to do?
stand with minimal muscular effort required to keep limb joints from collapsing
How does the horse lock its patella?
pulling it up and medially
How does the horse unlock its patella?
pulling it up and laterally
What anatomical structures lock the stifle and hock?
The patella and patellar ligaments lock the stifle
The hock is locked d/t the relation of the reciprocal apparatus
If the stifle is locked, the hock is also fixed in _______
extension
How can a “locked” patella be fixed?
- backing the horse
- sometimes need to physically push patella off its ridge
- severe case = cut medial patellar ligament
If the case of locked patella is severe enough and the patella cannot be unlocked, what can be done? Why is this a last option?
Cut medial patellar ligament
- no longer able to use passive locking mechanism
- causes malignment of patella and other issues
Function of the suspensory ligament?
support the fetlock (and digit somewhat)
Where is the suspensory ligament located?
palmar/plantar side of metacarpus/metatarsus
The suspensory ligament in the horse is entirely a ligamentous structure. Is that the case in dogs?
No, is a muscle in dogs
Is the suspensory ligament palpable?
yes, especially distally
Where does the suspensory ligament originate?
plantar/ palmar aspect of MTIII or MCIII
Where does the suspensory ligament insert?
on each proximal sesamoid bone
The suspensory ligament also has ___________ that attach to the extensor tendon
medial and lateral extensor branches
What do the distal sesamoidean ligaments do?
anchor proximal sesamoids to the first two phalanges
What is a (nearly) pathognomonic sign of suspensory ligament lameness
Post legged confirmation = hyperextension of the metatarsophalangeal joint
This artery on the hindlimb of the horse is palpable, can be used to take a pulse, and measure blood pressure under general anesthesia
dorsal metatarsal artery III
The sciatic nerve divides into the
- common peroneal
- tibial
The common peroneal divides into the
- superficial branch
- deep branch
The tibial divides into the
- medial plantar
- lateral plantar
T/F: Forelimbs have dorsal nerves
FALSE!!!
They DO NOT have dorsal nerves
X-rays are named for where the beam is ______ to where the beam is ______
COMING ; GOING
In a radiograph, ________ at the top is standard orientation
proximal
In a dorsal palmar projection, what can be better seen?
Edges will be better detailed - Med. and Lat. edges in this view
How is the x-ray beam in DLPM-O?
From: Dorsolateral
To: Palmaromedial
How is the x-ray beam in DMPL-O?
From: Dorsomedial
To: Palmarolateral
The ________ is sometimes also known as the knee and is comparable to the human wrist
carpus
Which carpal bone is an inconsistent finding in most horses?
Carpal bone 1