|
Shoulder
Brachium
Antebrachium
Facial
and Masticatory Muscles
Thorax
and Heart
Brain
Body
Wall
Hip
and Thigh
Shank
and Foot
Digestive
System
Urinary
and Reproductive Systems
Hip
and Tail
|
 Shank
and Foot of the Rat (Rattus norvegicus)
Photos and text by Ana Panduro and Yu Jin Kim
Dissection:
We started to peel rest of the skin off that was left on the leg from
last week’s lab on hip and thigh. Skinning process got tough as we got
near the foot because of the thick tendons at the ankle and at the bottom
of the foot. It was very hard to see the muscles that on the bottom of
the foot because it was covered with tendons and also because they were
they thin and small.
Overview of hind foot:
Rattus norvegicus has a short leg compared to its body size.
Muscles are small and short as well but they are well developed. Its
foot on the other hand is very long and lean. Shape of the muscles most
resembled the other rodent in the class, the beaver. It differed very
much from the cat, rabbit, fetal pig and the opossum, which have long
lean muscles. This difference can be explained with different bone structure.
One interesting feature of leg of a rat is that its tibia and fibula
are fused together. Also, Rattus norvegicus can rotate its foot
to certain extent but not as much as scansorial mammals, such as opossums
or squirrels, which can rotate their foot 180° for their
unusual locomotion.
Muscles of the hind foot:
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muscles
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origin
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insertion
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action
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extensors
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tibialis anterior
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lateral condyle and tibial tuberosity
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proximally on the medial side of Mc1
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flexion of the tarsus and inversion of the foot
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extensor digitorum longus
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lateral epicondyle of the femur
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distal phalanx of the second, third, fourth, and fifth digits
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extension of the digits
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extensor digitorum brevis
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lateral to the calcaneus
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second phalanx of the second and third digit
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extension of the second and third digits
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peroneus longus
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lateral surface of the head of the fibula
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proximally on Mc1
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flexion of the tarsus and eversion of the foot
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peroneus brevis
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head of the fibula
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proximally on the lateral side of Mc5
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flexion of the tarsus
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flexors
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gastrocnemius
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epicondyle of the femur
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tuber calcaneus as part of the common calcaneal tendon
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extension of the tarsal joint
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soleus
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head of the fibula
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fuses with gastrocnemius tendon at the tuber calcaneus
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extension of the tarsus
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flexor digitorum longus
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caudal face of the tibia
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distal phalanx of each of the five digits
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flexion of the digits
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flexor digitorum brevis
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distally at the tarsus
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distal phalanx of each of the five digits
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flexion of the digits
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tibialis posterior
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fibular condyle and proximal end of the tibia
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medial cuneiform bone
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outward rotation and inversion of the foot
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rotator
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popliteus
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muscular fossa and lateral condyle of the femur
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medially on the proximal third of the tibia
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flexion of the stifle and pronation of the crus
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