Muslce System Flashcards
What is the somite division that develops the muscles and skin?
Dermamyotome
what is the the process of muscle formation called?
Myogenesis
Which layer doe the muscular system develop from?
Mesoderm
What are the 3 classifications of muscle?
Skeletal, Smooth/Visceral, Cardiac
What is skeletal muscle derived from?
Myotomes of somites, Mesenchyme of brachial arches, and mesenchyme of the limbs
What are the two divisions of skeletal muscle?
1) the small dorsal division or epimre
2) large ventral division or hyopmere
What is formed from the Epimer?
extensor musculature of the vertebral column and the dorsal primary rami
What is formed from the hypomers?
muscles of the limbs and body wall and the ventral primary rami
What is an example of change in direction of the muscle fibers during development?
- Latissimus dorsi (migration of whole muscle)
- Rectus abdominus (fusion of successive myotomes)
- sternohyoid (longitudinal splitting of the myotome)
- Oblique and transvers abdominals (tangential splitting of myotomes)
- Tensor Fascia Lata (Degeneration of myotomes)
What are some of the muscles that form from the hyopmers in the cervical region?
- Scalenes
- part of trap
- part of SCM
- infrahyoid
What muscles develop from the hypomers in the thoracic region?
- Intercostals
- Transverse Throacis
What muscles develop from the hyopmere in the abdominal region
- psoas (major and minor)
- quadratus lumborum
- external/internal transverse abdominus
- rectus abdominus
What is the significance of the ribs developmentally?
They allow the muscles of the chest wall to maintain their segments
T/F: The nerves remain within the muscles even though the muscles will change direction.
True
T/F: The muscle origin and insertion will change as the muscles change direction.
False. The origin and insertions of the muscles will stay the same even though the muscle ill change diection
What muscles form from the 1st arch?
Teh muscles of mastication
- temporalis
- masseter
- pterygoid
- myelhyoid
- Ant. belly of digastric tensor tempani
- tensor veli palatini
What muscles form from the 2nd arch?
The facial muscles
- orbicularis oculi
- obiculris oris
- risorius
- platysma
- occipitalis
The muscle that develops from the 3rd arch
stylo-paryngeal muscle
The muscles that develop from the 4th and 6th arch
- laryngeal
- palateine muscles
- part of SCM
- part of trap
The innervation of the 1st brachial arch
Trigiminal nerve (CN V)
Innervation of 2nd brachial arch
Facial N. (CN VII)
Innervation of 3rd Brachial arch
Glossopharyngeal N. (CN IX)
Innervation of the 4th and 6th brachial arch
Vagus N. (CN X) and Hypoglossal N. (CN XII)
What do the limb buds originate from?
Muscular Mesenchyme
The extensors muscles develop from which mesenchymal group?
Dorsal Group
The flexor muscles develop from which mesenchymal group?
Ventral Group
What does the smooth muscle derived from?
Splanchinic Mesoderm. Except the smooth muscle of the iris which develop from the neuroectoderm
The cardiac musculature develops from which layer?
Splamchinc Mesoderm
