Additional notes on branchial anatomy

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Myomeres are segmentally arranged blocks of muscle
Form somites, each forms:
- sclerotome: vertebral skeleton
- dermotome: skin
- myotome: skeletal muscle.
- neurosome: territory supplied by a spinal nerve

At head end, get branchial segmentation
- 6 folds, with mesoderm in middle, ectoderm outside and endoderm inside.
- pouch infold externally forms branchial cleft
- endoderm folding internally forms pharyngeal pouch
- mesoderm here has sphlanchnic, not somatic properties.
- (these muscles tend to be covered with mucous membranes or near a mucocutaneous border)
- each retains a nerve supply (not spinal; cranial).

Effectors of a special group of reflexes.
- e.g. swallow and cough reflexes.
- visceral reflexes, e.g. glandular secretions.

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