Muscular System

Question 1

what are the two muscles that do not form from mesoderm?

Answer 1

• iris (neuroectoderm)

- esophagus ( not directly from mesoderm)

Question 2

what does the muscular system develop from

Answer 2

mesoderm

Question 3

what s derived from paraxial mesoderm which forms the somites

Answer 3

skeletal muscle

Question 4

what does smooth muscle differentiate from

Answer 4

visceral splanchnic mesoderm around the gut and from ectoderm

Question 5

arrector pili muscle has what origin?

Answer 5

ectoderm

Question 6

what is cardiac muscle derived from

Answer 6

visceral splanchnic mesoderm that surronds the heart tube

Question 7

what is the induction of myogenesis in mesenchymal cells carried out by?

Answer 7

Myo D

Question 8

what is the member of the family of myogenic regulatory factors that activates transcription of muscle specific genes

Answer 8

MyoD

Question 9

what is known to stimulate myogenic cells to begin expression of Myo D

Answer 9

Pax-3 and myf-5

Question 10

muscles from the head derive from how many somitomeres

Answer 10

7

Question 11

what are extraocular(eye) muscles derived from

Answer 11

somitomeres 1,2,3

Question 12

what are the cranial nerves that innervate the extra-ocular muscles

Answer 12

CN III
CN IV
CN VI

Question 13

what are tongue muscles derived from

Answer 13

occipital myotomes

Question 14

what are tongue muscles innervated by

Answer 14

CN XII

Question 15

what are trunk muscles derived from

Answer 15

myotomes in the trunk region

Question 16

what do the myotome in the trunk region split into?

Answer 16

• dorsal epimere

- ventral hypomere

Question 17

what does the epimere in the trunk become?

Answer 17

the extensor muscles of the neck and the vertebral column

Question 18

what are is the epimere innervated by ( extensor muscles of neck)

Answer 18

dorsal rami of spinal nerves

Question 19

what does the hypomere of the trunk region develop into

Answer 19

scalene, prevertebral, geniohyoid, infrahyoid, intercostal, and abdominal muscles

Question 20

what is the hypomere innervated by

Answer 20

ventral rami od spinal nerves

Question 21

what is the syndrome that is marked by partial or complete absence of abdominal musculature mostly involving the cells of the hypomere

Answer 21

Prune Belly Syndrome

Question 22

in prune belly syndrome what is seen about the abdominal wall

Answer 22

it is so thin that the organs are visible and can be palpated

Question 23

what is associated with malformations of the urinary tract, bladder, and urethral obstruction

Answer 23

prune belly syndrome

Question 24

accumulation of fluid in the abdomen of babies with prune belly syndrome results in

Answer 24

atrophy of the abdominal muscles

Question 25

what syndrome will you see that there is barley any linea alba and the muscles are missing, the umbilical cord will be very low as well

Answer 25

prune belly syndrome

Question 26

what is the group of inherited muscle diseases that cause progressive wasting and weakness

Answer 26

muscular dystrophies

Question 27

what is the most common muscular dystrophy

Answer 27

Duchenne's Muscular Dystrophy

Question 28

what age does Duchenne muscular dystrophy usually show

Answer 28

age 5

Question 29

what is the gene mutation for duchenne muscular dystrophy

Answer 29

dystrophin on the X chromosome

Question 30

what is the life expectancy of someone with ducheenes

Answer 30

age 20

Question 31

what makes boys with duchenne MS die

Answer 31

when the cardiac and respiratory muscles fail

Question 32

what muscle can easily be traumatized during birth and is associated with wryneck

Answer 32

sternocleidomastoid

Question 33

in what disease is the sternocleidomastoid abnormally shortened and causes the rotation and tilt of the head

Answer 33

Congenital Torticollis | Wryneck

Question 34

what can Wryneck be caused by

Answer 34

injury to the muscle during child birth and then a hematoma is formed and leads to fibrosis of the muscle, decreasing the movement

Question 35

what is the syndrome that is caused by the absence of a pectoralis major and is associated with the absence of the mammary gland in the breast, hypoplasia of the nipple or hypoplasia of the sternum and ribs

Answer 35

poland syndrome

Question 36

what is the max tanner stage of a young girl with Poland syndrome

Answer 36

3

Question 37

what develops from the myoblasts surrounding the developing bone

Answer 37

the muscles of the limb

Question 38

molecular signals from what induce Pax-3, Myf-5 in the somites

Answer 38

neura tube and notochord

Question 39

what participates in the regualtion of migration of the precursor myogenic cells

Answer 39

Pax-3

Question 40

what do smooth muscle fibers differentiate from

Answer 40

splanchnic mesenchyme

Question 41

what is the first sign of differentiation of smooth muscle

Answer 41

the development of elongated nuclei in spindle shaped myoblasts

Question 42

in skeletal muscle the cells fuse what about with smooth muscle

Answer 42

they remain multi nucleated

Question 43

what kind of innervation develops as smooth muscle proliferates

Answer 43

autonomic innervation

Question 44

what does cardiac muscle develop from

Answer 44

splanchnic mesoderm that is around the endothelial heart tube

Question 45

what do myoblasts adhere to one another by in cardiac muscle

Answer 45

intercalated discs

Question 46

what forms the conducting system of the heart

Answer 46

Purkinje Fibers

Question 47

what is characterized by the absence of the pectoralis minor and partial loss of the pec major. the nipple and areola will be absent r displaced this is coupled with syndactyly and brachydactyly

Answer 47

poland sequence

Question 48

what is it called when the fingers are fused

Answer 48

syndactyly

Question 49

what is it called when the fingers are short

Answer 49

brachydactyly

Question 50

what is the difference between poland syndrome and poland sequence

Answer 50

poland syndrome there is only an affect in the missing pec major in poland sequence the pec major is absent and there is anomaly of the limb development

Question 51

where should you look in the case of Poland sequence when you see syndactyly and brachydactyly?

Answer 51

the axilla area

Question 52

in what defect are the involved muscle replaced by fat or fiborus tissue and there is problem with one or all joints of the babies body

Answer 52

Arthrogryposis

Question 53

what are the joints that are the most commonly affected in Arthrogryposis

Answer 53

ankle and shoulder

Question 54

kids with spinal bifida and anomalies of motor horn cells can have what defect

Answer 54

arthrogryposis