Pelvic Limb 1 Flashcards
What is the fastest animal?
cheetah
How fast do cheetahs run?
65 mph
Can run 25 feet 3 times per second
How can cheetahs run as fast as they do?
They have a flexible lumbar spine, so their pelvic limbs can be brought cranial to the point of the shoulder
What function does the cheetah’s long tail have?
Acts as a rudder to maintain control and balance at full speed
What is the brachium homologous to on the pelvic limb?
thigh
What is the antebrachium homologous to on the pelvic limb?
crus
What is the carpus homologous to on the pelvic limb?
tarsus
What is the metacarpus homologous to on the pelvic limb?
metatarsus
What is the manus homologous to on the pelvic limb?
pes
What are the bones of the brachium/thigh?
humerus/femur
What are the bones of the antebrachium/crus?
radius and ulna/tibia and fibula
What are the bones of the carpus/tarsus?
carpals/tarsals
What are the bones of the metacarpus/metatarsus?
metacarpals/metatarsals
What are the bones of the digits called generally?
phalanges
What is plantigrade?
entire manus or pes contacts the ground
What are examples of plantigrade animals?
Man, armadillo, primate, bear
What is digitigrade?
Body weight is carried by the digits
What are examples of digitigrade animals?
coyote, dog, cat, cheetah
How many of the fastest animals are digitidrage?
4/10
What is unguligrade?
“Hoofed” animals, carries weight to ground through a single phalanx (P3) for each digit
What are examples of unguligrade animals?
pronghorn, horse, ox, pig, goat, sheep
How are limb modifications related to efficiency of locomotion?
As the length of the MT/MC region increases, so does efficiency
(plantigrade < digitigrade < unguligrade)
How many of the fastest animals are unguligrade?
6/10
How long can a cheetah maintain its speed?
for 300 yds
How fast can a pronghorn run a marathon?
35-40 min
How fast is the record marathon time for a human?
2 hours
What % of weight is on the thoracic and pelvic limbs?
60% thoracic, 40% pelvic
What is the thoracic limb used for?
steering and shock absorption
What is the pelvic limb used for?
motor - main limb driving the animal forward
What feature of the thoracic limb allows for shock absorption?
synsarcosis
What happens in the limb as you move distally?
- Restricted range of movement
- Only flexion and extension (no supination or pronation)
- More efficient in forward movement
- Reduction in # of bones
- Digits disappear
- Some bones fuse, some never develop
What about the horse’s stride at a gallop allows for support of trunk and steering?
Thoracic limbs are staggered/slightly offset, allows for staying on course
What two animals have the greater trochanter and the head of the femur at the same level?
dog and pig
What is the relationship bt the greater trochanter and head of the femur in the horse and rmt?
The greater trochanter is more dorsal than the head of the femur
What is unique about the greater trochanter of the femur of the horse?
It has cranial and caudal parts
What feature of the femur is unique to the horse, where is it located, and which way does it project?
3rd trochanter - located mid-shaft - projects laterally
What feature of the femur do the dog and pig have that the rmt and horse do not?
neck
Which trochlear ridge of the femur is larger in the horse and ox only?
medial
What is special about the sartorius of the rmt?
It has 2 tendinous cords off of the ventral aspect of the ilium
What is special about the adductor muscle in the rmt?
It is often fused with the semimembranosus muscle
In both horse and rmt, what does the cranial gluteal n. innervate?
tensor fascia lata m.
In both horse and rmt, what does the femoral n. innervate?
- Rectus femoris
- Vastus lateralis
- Vastus intermedius
- Vastus medialis
- Sartorius
- Part of the pectineus
In both horse and rmt, what does the obturator n. innervate?
- Gracilis
- Adductor
- Part of the pectineus
In the RMT only, what does the tibial n. innervate?
- Semimembranosus
- Semitendinosus
- Part of the gluteobiceps
In the RMT only, what does the caudal gluteal n. innervate?
Part of gluteobiceps
superficial gluteal and vertebral head of biceps femoris
How many adductor muscles can be seen in the horse?
2
In the HORSE only, what does the tibial n. innervate?
PELVIC part of:
- Semimembranosus
- Semitendinosus
- Biceps femoris
In the HORSE only, what does the caudal gluteal n. innervate?
VERTEBRAL part of:
- Semimembranosus
- Semitendinosus
- Biceps femoris
What are the patellar ligaments present in the horse and ox?
lateral, intermediate, and medial
What is the orientation of the origins of the patellar ligaments?
They are divergent, with the medial and intermediate ligaments having the greatest space bt their origins
How many patellar ligaments does the dog have?
1
Where do the patellar ligaments insert?
tibial tuberosity
What is the main contributing vessel to the pelvic limb?
external iliac a.
What does the deep femoral a. supply?
proximal limb
What are the branches of the deep femoral a.?
- Pudendoepigastric trunk
2. Medial circumflex femoral
What are the branches of the femoral a.?
- Superficial circumflex iliac - carnivore only
- Lateral circumflex femoral
- Saphenous
- Descending genicular
- Proximal caudal femoral
- Middle caudal femoral
- Distal caudal femoral –> only one that is ALWAYS present in the horse and ox!
What artery marks the transition from femoral a. to popliteal a.?
distal caudal femoral
What are the 2 bones of the crus, and which one is larger and weight-bearing?
tibia (larger and weight-bearing) and fibula - tibia is medial, fibula is lateral
What does the fibula look like in the horse and what does it form?
Fuses with the tibia distally to form the lateral malleolus
What can be seen as a separate center of ossification in the crus of the foal?
The lateral malleolus/distal fibula - where the tibia and fibula fuse
What does the fibula look like in the rmt?
Only a small part of the fibular head remains
What does the distal part of the rmt fibula remain as?
malleolar bone
How many tarsal bones does the dog have?
7
How many tarsal bones does the pig have?
7
How many tarsal bones does the ox/rmt have?
5
How many tarsal bones does the horse have?
6
How are the tarsal bones numbered?
from medial to lateral
What is the orientation of the trochlea of the talus in the horse?
oblique
What bones are fused in the rmt tarsus?
2nd + 3rd tarsal bones
Central tarsal bone + 4th tarsal bone
What bones are fused in the horse tarsus?
1st and 2nd tarsal bones
What other bone does the trochlea of the talus receive in the horse?
cochlea of the tibia
What happens when the hock of the horse flexes?
The distal limb drifts in a lateral direction due to the oblique nature of the talus and its articulation with the cochlea of the tibia
What is a ray?
A metacarpal/metatarsal + the phalanges
How many complete rays does the human have?
5
How many phalanges does ray #1 in the human have?
2
What is ray #1 in the dog?
dew claw - usually only present in the thoracic limb (if present in pelvic it is incomplete)
How many complete rays does the pig have?
4 (#2-5)
Which rays of the pig are dew claws?
2 and 5
What rays of the pig are weight bearing?
3 and 4
How many complete rays does the rmt have?
2 (#3 and #4)
What rays are the dew claws in the rmt?
2 and 5 - on plantar aspect - usually remnants of the rays
How many complete, weight-bearing rays does the horse have?
1 (#3)
What are rays # 2 and #4 in the horse called?
splint bones - they are remnants of MCs/MTs
