Anatomy Block 2: Development Of Musculosckeletal System

Front 1

When embryonic connective tissue tissue (mesenchyme) differentiates into bone directly, it is considered ______
This is seen mainly in the _____

Back 1

-Intramembranous ossification
-skull

Front 2

When embryonic connective tissue tissue (mesenchyme) differentiates into a hyaline cartilage model of bone, it is considered ________
Hyaline cartilage model then turns into _______

Back 2

-endochondral ossification
-bone

Front 3

The skeletal and muscular system develop mainly from the (ectoderm, mesoderm, endoderm) of the embryo

Back 3

mesoderm

Front 4

During development, the mesoderm differentiates into what three parts on each side of the midline neural tube and notochord (from medial to lateral)

Back 4

-paraxial mesoderm
-intermediate mesoderm
-lateral plate mesoderm

Front 5

The _____ is a thickened band of mesoderm on each side of the neural tube. This becomes segmented into paired blocks of _____ which differentiate into spinal

Back 5

-paraxial mesoderm
-somites

Front 6

The somite differentiates into what 4 parts and what do these turn into?

Back 6

1) sclerotome (ventromedial) - contributes to vertebral column
2) epimere (dorsomedial myotome) - intrinsic back muscles
3) hypomere (dorsolateral myotome) - muscle of limbs and body wall
4) dermatome - skin

Front 7

_____ migrate medially to surround the neural tube and notochord to form 2 adjacent vertebrae

Back 7

sclerotome

Front 8

Describe how sclerotomes form a vertebrae:
Also, how are intervertebral discs formed?

Back 8

-caudal half of one sclerotome and cephalic half of sclerotome below form body of vertebra
-intervertebral discs form between these formed halves

Front 9

During development, _____ bridge the intervertebral discs

Back 9

-myotomes

Front 10

_____ results when half a vertebra is missing, which results in scoliosis

Back 10

hemivertebra

Front 11

Spina bifida is a defect in the ______

Back 11

vertebral arches of adjacent vertebrae

Front 12

______ is protrusion and/or defect of the spinal cord
______ is when the defect is not apparent and is covered by hair and/or pigmented skin

Back 12

-spina bifida systica
-spina bifida occulta

Front 13

Lateral plate mesoderm is divided into two layers by development of ______
What are these two divisions and what do they contribute to?

Back 13

-intraembryonic cavity

1) Somatic/parietal mesoderm - ventral and lateral body walls
2) Splanchnic/visceral mesoderm - gastrointestinal, respiratory, and other systems

Front 14

Somatic mesoderm migrate to form upper and lower _____ at approximately opposite segments of _____ and _____ respectively

Back 14

-limb buds
-C5-T1 and L2-S3

Front 15

Somatic mesoderm cells form _____ that undergo _______

Back 15

-hyaline cartilage models
-endochonral ossification (give rise to bones of limbs)

Front 16

The ______ is a thickened ectoderm at the distal border of limb bud. This induces adjacent mesoderm to _____ while the more proximal mesoderm ______

Back 16

-apical ectodermal ridge (AER)

-remain undifferentiated and proliferate rapidly *progress zone*
-condenses and differentiates into hyaline cartilage models of bone

Front 17

Bone first starts to appear in the embryo at about ____ weeks and primary ossification centers are present by ____ week

Back 17

-8
-12th

Front 18

In 6-week-old embryos, the termal portion of the limb flatten to form _____

Back 18

handplates and footplates

Front 19

Mesenchyme at handplates and footplates condense to form ______ and between these, the cells undergo ______ to separate fingers and toes from each other

Back 19

-digital rays
-programmed cell death

Front 20

During the ____ week, the upper limbs rotates laterally and lower limbs rotate medially 90 degrees

Back 20

7th

Front 21

Total absence of one or more extremity is ____ while partial absence is _____
This could be caused by maternal digestion of _____

Back 21

-amelia
-meromelia

-thalidomide

Front 22

Extra fingers or toes is _____

Back 22

polydactyly

Front 23

Abnormal fusion of fingers and toes is _____
This is due to _____

Back 23

-syndactyly
-failer of apoptosis between digital rays

Front 24

The skull is divided into what two parts?

Back 24

-neurocranium - encloses, protects brain
-viscerocranium - forms skeletal face

Front 25

Neural crest cells is unique because:

Back 25

it is ectoderm that gives rise to skeletal and connective tissues that only occurs in anterior portion of head and neck

Front 26

The anterior portion of the skull develops from _____ and the posterior portion of skull develops from ______

Back 26

-paraxial mesoderm (red)
-neural crest cells (blue)

Front 27

The skull develops partly by ____ ossification and partly by _____ ossification

Back 27

-intramembranous
-endochondral

Front 28

The flat bones forming the sides and roof of the neurocranium are the _____ which develops ______
The roof (skullcap) is the _____

Back 28

-cranial vault
-intramembranously
-calvaria

Front 29

The cranial base of the neurocranium is called the _______ because it develops mainly by _____

Back 29

-chondrocranium
-endochondral ossification

Front 30

The _____ are important sites for growth of the skull, which undergo _____ growth
____ are wider areas where two or more bones meet

Back 30

-sutures
-appositional growth

-fontanelles

Front 31

The _____ is the soft spot on a baby's head

Back 31

anterior fontanelle

Front 32

_____ is premature closure of one side of patients coronal and lambdoid sutures

Back 32

plagiocephaly

Front 33

_____ is premature fusion of the sutures which causes restricted growth and compensatory overgrowth on remaining open sutures

Back 33

craniosynostosis

Front 34

Most common craniosynostosis is ____, which is narrowing of the skull from premature sagittal suture

Back 34

scaphocephaly

Front 35

Craniosynostosis can results from ____ such as growth constraint of the fetal head by uterine malformation or triplet pregnancies. This usually results in a ____ forehead

Back 35

-mechanical factors
-wedge shaped

Front 36

Mutations in _____ have been shown to cause syndromes involving craniosynostosis and limb deformities

Back 36

fibroblast growth factor receptors (FGFRs)

Front 37

_____ is the most common, nonfatal form of dwarfism
This results in what type of features?

Back 37

-achondroplasia

-large cranial fault
-small midface (due to abnormal chondrocranial growth)
-short and bowed extremities
-short fingers

Front 38

Skeletal muscle develops from the _____ of the ______

Back 38

somites of the paraxial mesoderm

Front 39

The hypomere (dorsolateral region of somites) is innervated by the _____ of spinal nerves

Back 39

anterior rami

Front 40

The epimere (dorsomedial region of somites) is innervated by the ____ of spinal nerves

Back 40

posterior rami

Front 41

The _____ divisions of the anterior rami innervate the flexor compartments of the upper extremity (musculocutaneous, median, and ulnar nerve)
The _____ divisions of the anterior rami innervate the extensor compartments of the extremities (radial nerve)

Back 41

-anterior
-posterior

Front 42

The _____ are innervated by the anterior rami and migrate to the superficial back muscles

Back 42

hypomere

Front 43

Skeletal muscles are (uninucleated/multinucleated)

Back 43

multinucleated

Front 44

Skeletal muscle fibers are formed by the fusion of percursor cells called ____
These form long multinucleated _____ and synthesis of contractile proteins

Back 44

-myoblasts
-myotubes

Front 45

Skeletal muscle fibers differentiate into different types largely due to:

Back 45

-properties that innervate them

Front 46

What are the three types of muscle fibers?

Back 46

-slow oxidative (SO) (more numerous in postural muscles)
-fast oxidative glycolytic (FOG) - intermediate
-fast glycolytic (FG)

Front 47

Partial or complete absence of the abdominal musculature results in _____
This usually results in urinary tract obstruction, which causes ______ which compresses the lungs resulting in _____

Back 47

-prune belly syndrome

-oligohyramnios
-pulmonary hypoplasia