1 and 2: development

Question 1

Mesoderm becomes what? (4)

Answer 1

gonads, kidneys, circulatory system, somites

Question 2

Gastrulation happens in what day of development?

Answer 2

16-18

you can start driving a car from 16-18, ‘gas’ time

Question 3

what direction in the bilaminar disk does the primitive streak form?

Answer 3

from caudal (tail end) to cranial.

Question 4

Where is hensen;’s node in relation to the primitive streak?

Answer 4

anterior to it

Question 5

Where do the cells that become mesoderm come from, and how do they migrate?

Answer 5

they come from the epiblast layer and they migrate, using the primitive streak, into the layer between the epiblast and hypoblast

Question 6

(in order of what develops first to what develops last,) name the five main parts/types of mesoderm:

Answer 6

extraembryonic mesoderm, lateral plate mesoderm, intermediate mesoderm
paraxial mesoderm,
notochord

Question 7

What days does neurulation BEGIN?

Answer 7

days 19-20

Question 8

what does the eem or extraembryonic mesoderm become?

Answer 8

amnion, yolksac, etc

Question 9

what does LPM, or lateral plate mesoderm become?

Answer 9

heart, vessel, gut wall

Love Plasma! Mmmmm! -says the vampire

Question 10

what does the IM, intermediate mesoderm become?

Answer 10

kidney, gonads

IM sports: drink lots of water and dont get hit in the balls

Question 11

what does the PM, paraxial mesoderm become?

Answer 11

skin, bone, muscle

PM nighttime “go to sleep and dont move a muscle”

Question 12

What part of the PM becomes dermis of skin?

Answer 12

dermatome (derma, skin)

Question 13

What part of the PM becomes skeleton (axial)?

Answer 13

sclerotome (sclera means white, and bones are white)

Question 14

What part of the PM becomes limb and axial muscles?

Answer 14

myotome (myo, muscle)

Question 15

somites develop in what day of development?

Answer 15

day 17, from paraxial mesoderm

Question 16

What Weeks does neurulation happen in?

Answer 16

Week 3-4,

my brain is mush at 3-4 pm

Question 17

what developmental week does folding happen in?

Answer 17

Week 4

Question 18

how many sets of somites will develop?

Answer 18

44 but you dont keep all of them

Question 19

What are the two parts of the LPM?

Answer 19

somatic and splanchnic mesoderm

Question 20

what does the somatic mesoderm become?

Answer 20

limb skeleton

soma means body, and you can move your body without limb skeleton. “it’s what makes your ‘soma’ tick!”

Question 21

What does the splanchnic mesoderm become? (4)

Answer 21

blood cells, heart (muscle), walls of GI (smooth muscle), and walls of respiratory system (smooth muscle)

“bleeding hearts always go with their gut! take a breather!”, explains nick. (splains nic)

Question 22

two main kinds of bone development?

Answer 22

intramembranous ossification and endochondral ossification (cartilage mediated)

Question 23

when does membranous ossification of neurocranium start and how long does it last?

Answer 23

9th week, (months 3-9 fetal period)

Question 24

What are the somite-like structures in the cervical region?

Answer 24

8 somitomeres that condense down to 4

Question 25

what do the somitomeres in the cervical region become? (3) and what innervates the structures?

Answer 25

occipital bone (partly), intrinsic mm. of the tongue, palatoglossus m., and it receives innervation from hypoglossal

Question 26

Neural crest cells contribute to the formation of the facial bones by first developing....what?

Answer 26

the branchial arches.

Question 27

the skull base is formed with what type of ossification?

Answer 27

endochondral ossification

Question 28

the skull (calvaria and not base) is formed with what kind of ossification?

Answer 28

intramembraneous ossification

Question 29

the frontal part of the skull is from what cell origins?

Answer 29

Neural crest cell

Question 30

the posterior portion of the skull is from what cell origin?

Answer 30

mesodermal origin

Question 31

the body and ramus of mandible is from what cell origin, and how is it formed?

Answer 31

neural crest cell origin, intramembraneous ossification

Question 32

the condyle, coronoid, and symphysis of the mandible is from what cell origin, and how is it formed?

Answer 32

neural crest cell origin, endochondral ossification

Question 33

when does the the lip fusion occur? (mid facial development)

Answer 33

weeks 4-5 | usually dinner is at five and you gotta have lips before you eat dinner at 5

Question 34

consequences of Fetal Alcohol Syndrome?

Answer 34

Cleft lip and palate

Question 35

failure of neural tube closure causes?

Answer 35

anencephaly, exencephaly, spina bifida

Question 36

When does human limb development begin?

Answer 36

5 weeks (finishes up at 8 weeks), you can see limb buds at 31-32

Question 37

limbs develop from what mesoderm? (2)

Answer 37

paraxial and lateral plate mesoderm

Question 38

limb bones and connective tissue comes from what mesoderm?

Answer 38

lateral plate mesoderm

Question 39

limb bones form by what kind of ossification?

Answer 39

endochondral ossification

Question 40

What signaling causes interdigit area (webbing) to go away through apoptosis?

Answer 40

BMP signaling

Question 41

What must occur to correctly orient the lower limbs?

Answer 41

limb torsion, (because lower limbs grow outward but they have to face forward)

Question 42

Type of myoblast that can actually divide and can aid in repair?

Answer 42

satellite cells

Question 43

What protein is expressed after limb bud outgrowth and localizes to the AER?

Answer 43

Fgf8

Question 44

What happens if you remove AER?

Answer 44

limb development arrests at the stage it was removed

Question 45

Digit identity is patterned by what protein?

Answer 45

SHH

Question 46

How is Anterior posterior (pinky to thumb) patterning of digits regulated?

Answer 46

SHH is more concentrated towards the posterior of limb bud which causes pinky development, and the decreasing concentration leads to the more anterior digits. Pinky (v),.... index (ii) and thumb (i)

Question 47

insufficient apoptosis signaling in digit formation leads to?

Answer 47

syndactyly (fused digits)

Question 48

Dorso-ventral patterning of limb is regulated by?

Answer 48

Dorsally: WNT-7a and "radical fringe" expressed which induces LMX-1 in the mesoderm. Ventrally: Engrailed-1 expression inhibits wnt7a and r-Fng. AER is the border between the two.

Question 49

What molecular signals distinguish forelimb from hindlimb?

Answer 49

upper limb/forelimb: TBX5 | lower/hindlimb: TBX4

Question 50

what genes act as switches and control pattern formation during development?

Answer 50

Homeotic/HOX genes (it's the reason why limbs form at the correct axial level)

Question 51

How is HOX code used for limb patterning?

Answer 51

Proximo-distal patterning

Question 52

knock out of Hox11d leads to ?

Answer 52

no radius or ulna

Question 53

What is amelia and what causes it?

Answer 53

failure of developing an entire limb, caused by loss of AER and FGF8 signaling

Question 54

How does thalidomide (drug) affect limb development?

Answer 54

it prevents limb angiogenesis in the proximal limbs so it "withers away" and no limb forms

Question 55

What is phocomelia and what causes it?

Answer 55

partial loss of limb, caused by FGF/HOX/angiogenesis (thalidomide) disruption

Question 56

what is polydactyly, and what causes it?

Answer 56

duplication of digits, caused by disrupted Shh/Gli3 function, usu Auto Dominant but Auto Rece. with ellis van creveld syndrome

Question 57

What inheritance is Ellis van creveld?

Answer 57

Auto Recessive

Question 58

Common signs of Ellis van creveld sydrome?

Answer 58

DENTAL DEFECT skeleton defect polydactyly

Question 59

Prune belly sign?

Answer 59

no abdominal muscles

Question 60

Cause of torticollis or wry neck?

Answer 60

Sternocleidomastoid muscle too short