All of this head motion must be executed by epaxial musculature if the pectoral girdle is reduced or lost, which requires a strong anchor and lever for force transmission.
The axial musculature of all vertebrates consists of two principal masses, the epaxial and hypaxial muscles.
If a salamander is to swim straight, the action of these muscle fibers must be balanced by muscle fibers dorsal to the vertebral centra, presumably in the epaxial musculature.
That study demonstrated that in anesthetized birds, resting on their sternum, one of the epaxial muscles (the longissimus dorsi) was consistently active during inspiration.
To the best of my knowledge, this tendon insertional pattern represents a unique morphological construct for cetaceans, mammals that lack connections between epaxial muscles and pelves.
Definition of epaxial in US English:
epaxial
adjectiveɛˈpæksiəleˈpaksēəl
Anatomy Zoology
Situated on the dorsal side of an axis.
〔剖，动〕轴上的
epaxial muscles
轴上肌。
Example sentencesExamples
If a salamander is to swim straight, the action of these muscle fibers must be balanced by muscle fibers dorsal to the vertebral centra, presumably in the epaxial musculature.
That study demonstrated that in anesthetized birds, resting on their sternum, one of the epaxial muscles (the longissimus dorsi) was consistently active during inspiration.
The axial musculature of all vertebrates consists of two principal masses, the epaxial and hypaxial muscles.
To the best of my knowledge, this tendon insertional pattern represents a unique morphological construct for cetaceans, mammals that lack connections between epaxial muscles and pelves.
All of this head motion must be executed by epaxial musculature if the pectoral girdle is reduced or lost, which requires a strong anchor and lever for force transmission.