development of the muscular system

Question 1

Myotome

Answer 1

Paraxial Mesoderm:

gives rise to all muscle except muscle in the eye

Question 2

Sclerotome

Answer 2

Paraxial Mesoderm:

gives rise to the axial skeletone and cartilage

Question 3

Dermatome

Answer 3

Paraxial Mesoderm:

give rise to dermis

Question 4

Somites divisions

Answer 4

myotome
sclerotome
dermatome

Question 5

Ventromedial part of the somite

Answer 5

Sclerotome

Question 6

Dorsolateral part of the somite

Answer 6

Dermatome

myotome

Question 7

what makes up the sclerotome

Answer 7

Cephalic Loose (upper)
Caudal dense (lower)
-packed mesenchymal cells

Question 8

how are vertebral bodies formed

Answer 8

caudal half of sclerotome travels down to the cephalic 1/2 of the sclerotome moving up

caudal dense: gives rise to transverse processes and half the body and superior artivular process

cephalic loose: gives rise to half the body and spinous process and the inferior articular process

Question 9

Nucleus pulposes

Answer 9

made from the notochord

Question 10

Annulus Fibrosus

Answer 10

made from the fribrous tissue from the sclerotome

fibrocartilage

Question 11

Ribs are mad from:

Answer 11

sclerotome cells that grow from the costal processes of thoracic vertebrae

costal cartilage also from sclertome

Question 12

sternum derived from:

Answer 12

develops from the somatic layer of the lateral plate mesoderm

made from ribs and then medially join from either side

Question 13

what are hox genes

Answer 13

help give rise to the shape of the bones in the vertebrae

Question 14

Hox 4/5 give rise to:

Answer 14

cervical vertebrae

Question 15

Hox 6 give rise to:

Answer 15

Ribs and thoracic

Question 16

Hox 9 give rise to:

Answer 16

floating ribs

Question 17

Hox 10 give rise to:

Answer 17

lumbar vertebrae

Question 18

Hox 11 give rise to:

Answer 18

sacral vertebrae

Question 19

Caudalization and examples

Answer 19

gain of function

transforms the vertebrae to look similar to the vertebrae below

Hox 6 in the cervical region to look like thoracic and have ribs

hox 10 in the thoracic cregion to look like lumbar vertebrae

Question 20

Cranialization and examples

Answer 20

loss of function

vertebrae look like the ones above them

Hox4 loss gives rise to c2-C5 looking like C1

Hox 5 loss makes c3-t2 to look like C2

Hox 10 loss makes Lumbar to look like thoracic vertebrae

Question 21

Cervical rib

Answer 21

abnormality where there is a rib in the cervical region and contributes to thoracic outlet syndrome

subclavian artery or brachial plexus is compressed usually occurs in the inferior trunk can cause hand issues

Question 22

Pectus Carinatum

Answer 22

sternum protrusion

Pigeon chest

happens at puberty

Question 23

Pectus Excavatum

Answer 23

funnel chest
can displace heart
can exercise intolerance

Question 24

two regions of Myotome

Answer 24

Epimere and hypomere

Question 25

Epimere

Answer 25

gives rise to epiaxial muscles
innervated by posterior rami

ex: intrinsic muscles on the back

dorsal on the dermomyotome

form extensor muscles and vertebral column

Question 26

Hypomere

Answer 26

gives rise to hypaxial muscles
gives rise to flexors of the trunks and into the limbs

innervated by ventral rami

ventral on the dermomyotome

cervical myotome
thoracic myotome
lumbar myotome
sacrococcygeal myotome

Question 27

limb myoblasts

Answer 27

hypomere
Dorsal: posterior compartments extensors and innervated by terminal branches of the posterior cord

Ventral: anterior compartments, flexors and pronators
innervated by the terminal branches of the lateral and medial cords

Question 28

Poland syndrome

Answer 28

improper migration of the hypoaxial

absence of pectoralis major and minor and sometimes loss of trapezius, serratus anterior, pamaris longus

syndactyly: webbing of fingers
ipsilateral breast hypoplasia
absence of 2 to 4 ribs

Question 29

Prune belly syndrome

Answer 29

abnormal migration of the hypoaxial muscles and the abnormality migration of the intermediate mesoderm

partial or complete absence of the abdominal musculature

cryptochidism: failure of one or both testes to descend

malformation of the urinary tract and bladder
urethral obstruction