Composite muscle
From Infogalactic: the planetary knowledge core
Composite or hybrid muscles are those muscles which have more than one set of fibers but perform the same function and are usually supplied by different nerves for different set of fibers.[1][2]
Examples
- Adductor magnus
- Biceps femoris: Its long head is supplied by the tibial part of sciatic nerve, whereas the short head is supplied by the common peroneal nerve. This reflects the composite derivation from the flexor and extensor musculature.
- Pectineus: Its anterior set of fibers are supplied by the femoral nerve, whereas posterior set of fibers are supplied by the obturator nerve.
- Quadriceps femoris
- Flexor digitorum profundus: Its radial half of is supplied by the median nerve and the ulnar half is supplied by the ulnar nerve.
- Iliopsoas: It is a composite muscle performing flexion at the hip.
- The tongue is a composite muscle made up of various components like longitudinal, transverse, horizontal muscles with different parts innervated having different nerve supply.
- Digastric muscle: Its anterior belly is supplied by nerve to mylohyoid (a branch of trigeminal nerve). The posterior belly is supplied by the facial nerve.
Commonly confused
Certain muscles are commonly confused with composite muscles which they are not. Examples are:
- Rectus femoris
- Omohyoid
- Occipitofrontalis
- Ligament of Trietz
- Sternocliedomastoid (has two heads, not bellies)
References
- Cunningham's text book of anatomy (old edition)
