Resulted in a loss of many branchiometric muscles. The epibranchial and hypobranchial are the dorsal and ventral muscles associated with the head region as well as to the trunk region, but that perform functions associated with jaw and tongue movement. These muscles are also used in speech and sound production in tetrapods. Homologies between the bronchial and hypobranchial muscles of several different vertebrate taxa are shown in the table in your handout. The axial musculature associated with the trunk can function either in locomotion or breathing.
Axial musculature begins as myotomes separated by myosepta.
In fishes, the trunk muscles remain divided into folded muscle segments or myomeres that are divided into myosepta. These muscles contract alternately to produce an undulating motion that propels the fish through the water. Such outgrowths are called the myotomic buds to the appendages. These muscle masses later differentiate into multiple muscle groups depending on the type of organism. However, when we discuss the appendicular muscles, we will refer to whether the muscles originated from the dorsal or ventral muscle groups of the embryo.