|
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
|
 Hip
and Thigh of the Rat (Rattus norvegicus)
Photos and text by Yu Jin Kim and Ana Panduro
Dissection:
Skin around the thigh was removed in order to reveal some of the thigh
muscles. The skin came off very easily, but fascia that was left on the
muscles was very thin and it was hard to separate it from the muscles.
Once the fascia was removed it was much easier to see the muscles. After
we identified all the superficial muscles and took pictures, we cut the
gluteus maximus and biceps femoris muscles on their insertions and reflected
them in order to see the deep muscles. Unlike the superficial muscles,
the deep muscles were not invested in fascia and it was easier to identify
the muscles.
Overview
of hip & thigh:
The rat has a short forelimb and hindlimb compared to its body size.
However, its hindlimbs are much bigger than the forelimbs, and its leg
muscles are much larger than its arm muscles. Some of the superficial
muscles that can be found in the lateral side of hip and thigh area are
biceps femoris, gluteus maximus and tensor fascia lata. The two heads
of a biceps femoris in the rat, caput pelvis and caput vertebralis, are
very well distinguished. Some other mammals have two heads of biceps
femoris that appear to be one muscle. Also Rattus norvegicus has
a very large tensor fasciae latae. Muscles such as vastus lateralis,
adductor magnus, and semimembranosus are deep to the muscles mention above
(biceps femoris, gluteus maximus and tensor fasciae latae). Muscular structure
of hip and thigh of a rat most resembles the beaver. Although the opossum
and the rat have similar body size they have different muscular features
due to their different locomotion. The way bones are arranged differs
as well because they walk differently. Femur of the opossum makes a bigger
angle with the pelvic bone than the femur of the rat and it gives more
side-to-side movement when opossums walk. Also opossums have less spinal
fluctuation that the rat when they move.
Muscles
of the hip & thigh:
Superficial muscles of the hip and thigh
|
muscles
|
origin
|
insertion
|
action
|
|
tensor fasciae latae
|
tuber coxae and spinous processes of all sacral vertebrae
|
third trochanter of the femur and the fascia lata
|
flexion of the hip
|
|
biceps femoralis
|
spinous process of S4
|
lateral epicondyle of the femur
|
flexion of the stifle and abduction of the limb
|
|
gluteus maximus
|
tuber coxae and spinous processes of all sacral vertebrae
|
third trochanter of the femur and the fascia lata
|
flexion of the hip
|
|
gluteus medius
|
wing of the ilium and from the sacral vertebrae by means of an
aponeurosis
|
dorsal and distal to the greater trochanter
|
extension of the hip
|
|
vastus lateralis
|
greater and third trochanter
|
tibial tuberosity
|
extends the stifle and draws the limb forward
|
|
vastus medialis
|
neck of the femur
|
tibial tuberosity
|
extends the stifle and draws the limb forward
|
|
vastus intermedius
|
cranial aspect of the femur
|
tibial tuberosity
|
extends the stifle and draws the limb forward
|
|
rectus femoris
|
one head from a tubercle cranial and another head from the ventral
side of the body of the ilium
|
tibial tuberosity
|
extends the stifle and draws the limb forward
|
|
gracilis
|
cranial part from symphysis pelvis and caudal part from caudal
end of pelvic symphysis and ramus of the ischium
|
tibial crest
|
adduction of the limb and flexion of the stifle
|
|
adductor femoris
|
acetabular ramus of the pubic bone and close to its origin it
splits into the adductor magnus and adductor brevis
|
adductor magnus inserts into entire length of shaft of femur and
adductor brevis inserts into third trochanter
|
extension of the hip and adduction of the limb
|
|
pectineus
|
iliopectineal eminence and pectin pubis
|
medially on the shaft of the femur
|
flexion of the hip and adduction of the limb
|
|
semimembranosus
|
lateral head from the transverse process of the first coccygeal
vertebra and the sciatic tuberosity and medial head from the sciatic
tuberosity
|
medially on the proximal end of the tibia
|
flexes the stifle and draws the limb backward
|
|
semitendinosus
|
spinous processes of the last sacral and first coccygeal vertebrae
|
medial aspect of the tibia
|
extension of the hip and flexion of the stifle joint
|
Deep hip flexors and extensors
|
muscles
|
origin
|
insertion
|
action
|
| |
sacral vertebrae
|
dorsal and distal to the greater trochanter
|
extension of the hip
|
|
gluteus minimus
|
dorsal and lateral surface of the ilium
|
greater trochanter
|
extension of the hip
|
|
obturator internus
|
pelvis
|
trochanteric fossa
|
outward rotation of the limb
|
|
quadratus femoralis
|
caudal border of the ischium
|
shaft of the femur distal to the lesser trochanter
|
rotates the limb outward and draws it backward
|
|
gemellus inferior
|
dorsal edge of the ischium
|
trochanteric fossa
|
outward rotation of the limb
|
|
obturator externus
|
rim of the obturator foramen
|
trochanteric fossa of the femur
|
adducts the limb and rotates it outward
|
|
