Embryology Final-Skeletal System

Front 1

Each somite differentiates into which two parts?

Back 1

1) sclerotome-ventromedial part; vertebrae and ribs
2) dorsolateral part-dermomyotome; myoblasts

Front 2

What does the ventromedial part in embryonic origin differentiate into?

Back 2

the vertebrae and ribs

Front 3

What does the dorsolateral part in embryonic origin differentiate into?

Back 3

myoblasts (or pre-muscle cells)

Front 4

What does mesodermal cells give rise to?

Back 4

mesenchyme

Front 5

What is mesenchyme?

Back 5

A mesh work of loosely organized embryonic CT

Front 6

How does bone/cartilage develop?

Back 6

1) mesodermal cells--> mesenchyme, a mesh work of loosely organized embryonic CT
2) Ossification occurs later-->bone

Front 7

What are the two types of cartilage growth?

Back 7

1) interstitial growth
2) appositional growth

Front 8

Which type of cartilage growth occurs mainly in immature cartilage?

Back 8

interstitial

Front 9

Which type of cartilage growth forms small groups of cells?

Back 9

interstitial growth, forms isogenic groups

Front 10

Where does appositional cartilage growth occur?

Back 10

in the perichondrium (chondrogenic layer)

Front 11

What are the two main forms of ossification?

Back 11

1) Intramembranous
2) Endochondrial

Front 12

Which type of ossification forms both the skull and the bones of the face?

Back 12

intramembranous

Front 13

Which type of ossification is used by the majority of the skeleton (axial and appendicular)?

Back 13

Endochondrial

Front 14

What are the two major systems of bone?

Back 14

1) axial
2) appendicular

Front 15

Which bone system consists of the skull, ribs, and sternum?

Back 15

axial

Front 16

Which bone system consists of shoulders, pelvis, limbs (a total of 126 bones)?

Back 16

appendicular

Front 17

Describe the three bone cell types.

Back 17

1) chondrocyte-mesenchymal origin
2) osteoblast-mesechymal origin
3) osteoclast-monocytic origin

Front 18

Which bone cell type is of monocytic origin?

Back 18

Osteoclast

Front 19

specialized form of ossification form a mesenchymal membrane?

Back 19

intramembranous ossification

Front 20

What is Rickets?

Back 20

1) a disease occurring mainly in children who have vitamin D deficiency
2) deficiency causes disturbances of ossification of epiphysial cartilage plates
3) limbs are shortened and deformed (severe bowing of limbs)

Front 21

How many births are affected by achondroplasia?

Back 21

1/15,000

Front 22

T/F. Achondroplasia is autosomal recessive disorder.

Back 22

FALSE; it is an autosomal dominant disorder.

Front 23

Which type of bone formation occurs in mesenchyme?

Back 23

Intramembranous ossification

Front 24

What are the types of bone forming cells?

Back 24

1) osteoprogenitor cells
2) osteoblast
3) osteocyte

Front 25

Which bone-forming cells form periosteum and endosteum?

Back 25

osteoproenitor cells

Front 26

Which bone-forming cells secrete bone matrix and differentiate into osteocytes?

Back 26

osteoblast

Front 27

What bone-forming cells is a mature bone cell embedded into matrix?

Back 27

osteocyte

Front 28

type of bone formation occurs in mesenchyme that has formed a membranous sheath

Back 28

intramembranous ossification

Front 29

the majority of the skeleton is formed by what ossification process?

Back 29

endochondral ossification

Front 30

_____ derived from the bone collar replace cartilage matrix with a matrix rich in ____________, leading to bone formation.

Back 30

1) osteoblasts
2) type I collagen

Front 31

How many ossification centers are there?

Back 31

primary, secondary

Front 32

Where does early ossification usually occur?

Back 32

at the ends of long bone

Front 33

When does limb ossification begin?

Back 33

at the end of the embryonic period

Front 34

What does limb ossification usually induce in the mother?

Back 34

high demands on the maternal supply of calcium and phosphorous; mothers are supposed maintain good levels for their health and the baby's

Front 35

Distinguish the diaphysis vs. the epiphysis at birth.

Back 35

Diaphysis-largely ossified
Epihphysis-still cartilage

Front 36

Upon completion of growth, _________ is replaced by spongy bone

Back 36

epiphysial cartilage plate; this unites the epiphyses and diaphysis; no further elongation of bones occurs (20 years)

Front 37

At what age does no further elongation occur

Back 37

20 years old

Front 38

asymmetric growth impairment of vertebral bodies

Back 38

scoliosis

Front 39

brittle bone syndrome

Back 39

osteogenesis imperfecta, caused by abnormal collagen type 1

Front 40

What are some vertebra abnormalities?

Back 40

spina bifida, klippel-feil syndrome

Front 41

What are some rib abnormalities?

Back 41

accessory rib-extra rib cervical or lumbar uni or bilateral
short rib polydactyly syndrome
pigeon chest-rib overgrowth
funnel chest-sternum depression and lower costal cartilages

Front 42

What are some causes of the small face in fetuses?

Back 42

1) lack of air sinuses
2) small jaw
3) underdeveloped facial bones

Front 43

Differentiate between the three different types of muscle tissue.

Back 43

1) smooth muscle-originate from undifferentiated mesenchymal cells
2) skeletal muscle-originate from paraxial mesoderm
3) cardiac muscle-originate from prechordal splanchnic mesoderm

Front 44

In smooth muscle, what do mesenchymal cells differentiate into?

Back 44

myoblast, which contain a few filaments --> cells which will differentaite into mature smooth muscle cells

Front 45

the region of the somite that contributes skeletal muscle to the embryo body

Back 45

myotome

Front 46

What happens to musculoskeletal mass by the end of puberty?

Back 46

it doubles

Front 47

spinal nerve generally refers to what?

Back 47

a mixed spinal nerve, which carries motor, sensory and autonomic signals between the spinal cord and the body

Front 48

How many left-right pairs of spinal nerves do humans have?

Back 48

30

Front 49

each somite pair gives rise to what?

Back 49

a group of skeletal muscles supplied by a specific segmental spinal nerve

Front 50

Where does the muscle arise from? Where does the spinal nerve arise from?

Back 50

specific somite; specific level of spinal cord