Lecture 4: Equine Pelvic Limb pt 2 (Exam 1) Flashcards
What muscle create the round rump in equine
- large gluteal muscles
- the caudal thigh (hamstring) muscles
Caudal thigh muscles have what type of heads
vertebral heads
What do the gluteal muscles do
Collectively act to extend, abduct, & medially rotate the limb @ the coxal joint
What do the coudal thing (aka hamstring) muscles do
Collectively act in extension of the coxal joint & flexion of the stifle joint when it is not bearing weight
Label the following:
What is the origin & insertion of the superficial gluteal m
- O: Tuber coxae & gluteal fascia
- I: Third trochanter
What is the origin & insertion of the middle gluteal m
- O: Gluteal surface of the ilium, tuber coxae, & sacrosciatic ligament
- I: Greater trochanter (cd part) & the proximal femur btw/ the greater & third trochanters
Label the following:
T/F: the accessory gluteal muscle is considered to be a part of the middle gluteal m
F: This deeper muscle is often considered a seperate muscle
What is the trochanteric bursa
Where the middle gluteal tendon of insertion passes over the cranial part of the greater trochanter
What is the origin & insertion of the deep gluteal m
- O: Body of the ilium & ischiatic spine
- I: Greater trochanter (cranial part)
Label the following:
What is the common PELVIC origin of all the caudal thigh muscles
Tuber ischii
What is the origin of the biceps femoris
- Sacrum
- sarcosciatic ligament
What is the more proximal vertebral origins of the semitendinosus
- Sacrosciatic ligament
- Caudal vertebrae
What is the vertebral origin of the semimembranosus
Caudal-most edge of sacrosciatic ligament
List the muscles that make up the caudal thigh
- Biceps femoris
- Semitendinosus
- Semimembranosus
Label the following:
- 1 = Biceps femoris
- 2 = Semitendinosus
- 3 = semimembranosus
What are the insertions of the 3 parts of the bicep femoris
- patella & lateral patellar ligament
- cranial border of the tibia (lateral aspect)
- Crural fascia & tuber calcanei via common calcanean tendon
Label the insertions of the following
- 1 = patella & lateral patellar ligament
- 2 = Cranial border of the tibia (lateral aspect)
- 3 = Crural fascia & tuber calcanei via common calcanean tendon
Where does the semitendinosus insert
- Cranial border of the tibia (medial aspect)
- Tuber calcanei via the common calcanean tendon
Where does the semimembranosus insert
- Medial epicondyle of the femur
- Medial collateral ligament of the stifle
Label A, B, & C
What nerve supplies the vertebral heads of the biceps femoris & semitendinosus mm
Caudal gluteal nerve
What nerve supplies the pelvic head of the biceps femoris, semitendinosus, & the sememembranosus mm
Sciatic n
Label A & B
- A = semitendinosus muscle
- B = Biceps femoris m.
What muscles doe the cranial gluteal nerve supply
- Tensor fasciae latae m
- Deep gluteal muscle
- Middle gluteal muscle
- Superficial gluteal m
What muscles does the caudal gluteal nerve supply
- Middle gluteal muscle
- Superficial gluteal muscle
- Biceps femoris m
- Semitendinosus m
Label A - C
- A = Superficial gluteal muscle
- B = Middle gluteal m
- C = Tensor fasciae latae m
OI of the sartorius m
O: Psoas fascia & tendon
I: Medial aspect of stifle
OI of the Gracilis
O: Pelvic symphysis via symphyseal tendon
I: Medial aspect of stifle & cranial border of the tibia
OI of Adductor m
O: Ventral surface of the pubis & ischium; symphyseal tendon
I: Caudal aspect of the medial epicondyle of the femur
OI of Pectineus
O: Margin of pubis (pecten)
I: Medial surface of the femur
What muscles does the obturator nerve supply motor function to
- Gracillis
- Adductor
- Pectineus
What muscle is innervated by the saphenous nerve
Sartorius
Label the following A - D
- A = Sartorius m
- B = Pectineus
- C = Gracilis
- D = Adductor
Label A & B
A = Sartorius
B = Gracilis
Label the following:
A = Iliopsosas
B = Sacrosciatic ligament
C = Pectineus
D = Adductor
What muscle forms the caudal border and which one forms the cranial border of the femoral triangle
- Caudal border: Pectineus m
- Cranial border: Sartorius m
What nerve emerges from the iliopsoas m
Femoral n
What nerve passes through the obturator foramen
Obturator n
What nerve innervates the sartorius m
Saphenous n
Label the following:
- A: Femoral n
- B: Obturator n
- C: Obturator n
What muscles are lateral rotators of the hip (the ones in equine are the same as in a canine)
- External obturator
- Internal obturator
- Gemelli
- Quadratus femoris
Where do the lateral rotators of the hip insert
- Trochanteric fossa
- Trochanteric crest of the femur
Label A & B:
- A = External obturator m
- B = Quadratus femoris m
Describe the internal obturator m
- A pelvic floor muscle dorsal to the obturator foramen
- The tendon of insertion passes over the lesser ischiatic notch
Describe the crainal & caudal gemelli
- Originates from the ischium
- Ventral to the lesser ischiatic notch
- Appears to be two identical muscles on either side of the internal obturator tendon
Describe the quadratus femoris
- Originates from the ventral aspect of the ilium
- Inserts on trochanteric crest of the femur
Label the following including the purple, yellow, & orange arrows
- A: Trochanteric fossa
- B: Trochanteric Crest
- C: Lesser ischiatic notch
- Purple: Cranial & Caudal gemelli m
- Yellow: Internal obturator
- Orange: Quadratus femoris
What is the action of the quadriceps femoris muscle group
Extend the stifle
What muscle comprise the quadriceps femoris
- Rectus femoris
- Vastus lateralis
- Vastus medialis
- Vastus intermedius
Where do the muscles of the quadriceps femoris group insert
- Patella
- Tibial tuberosity
How do the quadriceps femoris muscle group attach to the patella & tibial tuberosity
By patellar ligaments
Label the following:
- A = Quadriceps femoris m
- B = Medial patellar ligament
- C = Medial collateral ligament of the stifle
- D = Medial meniscus
Label the following:
- A = Patella
- B = Tibial tuberosity
- 1,2, & 3 = Patellar ligaments
Where does the rectus femoris originate
From the body of ilium (rectus femoris area), craniodorsal to the acetabulum
What muscle in the quadriceps femoris muscle group is the only one that crosses the hip joint
Rectus femoris m
T/F: the rectus femoris flexes the hip
True
Where do the vastus muscles originate from
The proximal aspect of the femur
What muscle is the black star on
Rectus femoris m
Describe the Cranial Tibial m in large animals
- it is not the most superficial muscle of the crus
- Located deep to the other craniolateral mm
- Sits right against the tibia
Describe the fibularis (peroneus) tertius m in equine
- Fibrous band in the horse
- not found in the dog
Describe the Fibularis (peroneus) longus m in equine
Not present in the horse
Describe the soleus m in equine
- Very small but still present in large animals (& in the cat)
- Not present in dogs
- Contributes to common calcanean tendon
Label the following:
- 1 = Cranial tibial m
- 2 = Fibularis (peroneus) tertius m
- 4 = Soleus m
Describe the long and lateral digital extensor
- Are equivalent to common & lateral digital extensor mm of the thoracic limb
- Equine lateral digital extensor tendon joins the tendon of the long digital extensor
Describe the DDF & SDF mm in equine
- Similar to the thoracic limb
- DDF has medial & lateral heads (AKA medial digital flexor & lateral digital flexor mm)
T/F: the gastrocnemius & popliteus mm are different in all species
False they are all similar
Label the following:
- 5a: long digital extensor mm
- 5b: Lateral digital extensor
- 6: Digital flexors
- 7: Gastrocnemius & popliteus mm
What is the collective action of the cranial muscle of the crus
Flexion of the hock
What nerve innervates the cranial muscles of the crus
Common fibular n
Label the following:
- A = Cranial tibial m
- B = Long digital extensor m
- Peroneus tertius
What is the origin & insertion of the cranial tibial m
- O: lateral condyle of the tibial
- I: Dorsal tendon on the metatarsal tuberosity & Medial tendon inserts on the fused tarsal 1 & 2 bones
What is the black star on
Metatarsal tuberosity
What is the blue star on
Fused tarsal bones 1 & 2
What is cunean bursa & where is it located
- A bursa affiliated w/ the medial tendon of the cranial tibial m
- Located btw/ the cunean tendon & the underlying medial collateral ligament of the tarsal joints
Describe the peroneus (fibularis) tertius including the origin & insertion
- Origin: extensor fossa of the femur (in common w/ the long digital extensor m)
- Insertion via 2 tendons: Dorsal tendon (tarsal bone 3 & metarsal bone 3) & lateral tendon (Calcaneus & trasal bone IV)
- Passes through the extensor groove of the tibia
- Forms a tunnel through which the tendon of the cranial tibial m passes
What are the blue X’s on
The calcaneus & tarsal bone IV
What are the Black X’s on & what muscle/ tendons are highlighted in yellow
- X’s = Tarsal bone 3 & Metatarsal bone 3
- Yellow: Peroneus (fibularis) Tertius
What is the origin of the long digital extensor
- Extensor fossa of the femur (has this in common with the long peroneus tertius m)
- Passes through the extensor groove of the tibia
What is the origin of the lateral digital extensor
The lateral collateral ligament of the stifle
Where do the tendons of the long & lateral digital extensor unite
@ the level of the metatarsus distal to the metatarsal (distal) extensor retinaculum
What is the insertion & action of the the long & lateral digital extensors
- I: Extensor process of the distal phalanx 3
- A: Flexes the hock & extends digit
What nerve innervates the long & lateral digital extensor
Common fibular n
Label the following:
What tendons make up the crural (proximal) extensor retinaculum
- Long digital extensor tendon
- Peroneus tertius tendon
- Cranial tibial tendon
What tendon makes up the tarsal (middle) extensor retinaculum
Long digital extensor tendon
What tendons make up the metatarsal (distal) extensor retinaculum
- long digital extensor tendon
- Lateral digital extensor tendon
Label the following:
- A = Crural (proximal) extensor retinaculum
- B = Tarsal (middle) extensor retinaculum
- C = Metatarsal (distal) extensor retinaculum
Label A - C
- A = Crural (proximal) extensor retinaculum
- B = Tarsal (middle) extensor retinaculum
- C = Metatarsal (distal) extensor retinaculum
Where can the short digital extensor be seen
Label the following:
What is the collective action of the caudal muscles of the crus
Extension of the hock
What nerve innervates the caudal muscles of the crus
Tibial n
Label the following:
What it the origin & insertion of the Gastrocemius & Soleus muscle
- O: Lateral supracondylar tuberosity of the femur (lateral head of the gastrocnemius), the medial supracondylar tuberosity of the femur (medial head ot the gastrocnemius), & the fibula (soleus)
- I: Calcaneal tuber
Label the green & blue arrows along with “A”
- Green arrows: Gastrocnemius m.
- Blue arrow: Soleus m.
- A: Supracondylar tuberosities
What is the OIA of the SDF
- O: Supracondylar fossa of the femur
- I: Calcaneal tuber; eminences (medial & lateral) on the palmar & distal aspect of the proximal phalanx & proximal aspect of the middle phalanx
- A: Extension of the hock, flexion of the fetlock & pastern joints, & conteracts flexion (buckling forward) of pastern joint when the weight bearing
T/F: There is a proximal check ligament in the hindlimb
False there is no proximal check ligament
OIA of the DDF
- O: lateral condyle of tibia & caudal proximal surface of the tibia
- I: Flexor surface of the distal phalanx
- A: Extension of the hock & flexion of all digital joints
Describe the semilunar line
A line that partitions the solar surface of P3 into a flat part (planum cutaneum) & a flexor surface where the tendon of the DDF m inserts
Label the following:
- A = Popliteus m.
- B = Medial digital flexor m.
- C = Lateral digital flexor m.
- D = Deep digital flexor m.
What are the synovial structures of the digital flexor muscles
- Calcanean bursae
- Tarsal sheath
- Digital sheath
Describe the calcanean bursae
- Is found SQ btw/ the skin & the SDF tendon
- Found subteninous located deep to the SDF tendon where it passes over the point of the hock
Describe the tarsal sheath
Surround the lateral digital flexor tendon from ~ 2 - 3 inches proximal to the medial malleolus to a quarter of the way down the metatarsus
Describe the digital sheath
- Surrounds the tendons of the SDF & DDF proximal & distal to the fetlock
- Extends from the distal quarter of the cannon bone (MT 3) to the middle of the short pastern bone (P2)
What are the major components of the reciprocal apparatus
- the SDF m
- The peroneus tertius m
Describe the reciprocal apparatus
- Converts the limb into a pantograph (femur & metatarsus move in parallel)
- Links the action btw/ the stifle & the hock
Reciprocal apparatus: If the stifle flexes what happens
- There is a pull on the PT which causes the hock to flex in
Reciprocal apparatus: If the stifle extends what happens
There is a pull on the SDF which causes the hock to extend in reciprocation
Describe the Passive stay
- If the stifle can be locked in extension then the hock will lock in extension as well
- Uses fibrous comonents to conserve muscle energy by using the patellar locking mechanism
Describe the patellar lock mechanism
- The patella is pulled onto the resting surface of the tubercle of the medial trochlear ridge by the quadriceps femoris m.
- The medial & intermediate patellar ligament (along w/ the parapeatellar firbrocartilage & patella) form a loop around the medial trochlear ridge
- the medial rotation of the patella locks it in place on the resting surface
Describe upward fixation of the patella
- A clinical condition in which the patella becomes lock on the trochlear resting surface
- Commonly known as stifled horse
What is the common cause of stifled horse
Neuromuscular disorders or spasms of the medial thigh muscles
How can a temporary lock of the patella on the trochlear resting surface be broken
- By startling a horse into sudden movement
- Forcing the horse to walk backwards
T/F: A persistent lock of the patella on the trochlear resting surface may require surgical intervention
True
What results in peg leg
Upward fixation of the patella preventing flexion of the hock
Describe the vertebral head in the middle gluteal muscle
Extends as far as the cranial lumbar vertebra
What is the muscle that is considered a part of the DDF, describe it
- Caudal tibial m
- Has a small belly & long thin tendon that passes over the sustentaculum tali in combo w/ the lateral digital flexor tendon
