Embryology

Question 1

what is a functional disorder?

Answer 1

looks ok, doesn’t work well

Question 2

frequency of birth defect?

Answer 2

1:33 (live births only)

Question 3

what is the most common birth defect? frequency?

Answer 3

heart defect 1:200

Question 4

what is the second most common birth defect? frequency?

Answer 4

hypospadias male only

1:300

Question 5

how many cells is a morula?

Answer 5

16

Question 6

whats the diference between a blastocyst and blastocoele?

Answer 6

blastocoele has a cavity

Question 7

blastocyst has two types of cells?

Answer 7

outer trophoblast

inner cell mass

Question 8

What does the trophoblast form?

Answer 8

placenta

extraembryonic structures

Question 9

when does the blastocyst implant?

Answer 9

between 5-10 days

Question 10

inner cell mass splits to?

Answer 10

epiblast

hypoblast

Question 11

epiblast of hypoblast becomes the embryo?

Answer 11

epiblast

Question 12

what is gastrulation, where does it form?

Answer 12

epiblast’s formation of the 3 germ layers

Question 13

what layer does the lungs come from?

Answer 13

endoderm

Question 14

what layer does the heart come from?

Answer 14

mesoderm

Question 15

what layer does the pancreas/liver come from?

Answer 15

endoderm

Question 16

T/F? notochord comes from ectoderm?

Answer 16

Nope. mesoderm

Question 17

what’s the purpose of notochord?

Answer 17

induces ectoderm above it to form neural plate

Question 18

What forms neural crest?

Answer 18

cells at top of neural tube

Question 19

are the neural tube cells mobile?

Answer 19

yes, migrate away from wide range of structures

Question 20

melanocytes and dentine come from which tissue?

Answer 20

neural crest derivative

Question 21

most of the face comes from mesoderm?

Answer 21

Nope. neural crest

Question 22

example of neural crest defect?

Answer 22

cleft palate

Question 23

dermis comes from which germ layer?

Answer 23

mesoderm

Question 24

pleura peritoneum pericardium comes from which germ layer?

Answer 24

mesoderm

Question 25

whats the opposite of epithelial?

Answer 25

mesenchymal

Question 26

What is mesenchyme?

Answer 26

loose freely moving with Ct inbetween cells

Question 27

urogenital tract comes from which germ layer??

Answer 27

mesoderm

Question 28

3 areas of mesoderm?

Answer 28

paraxial (medial) intermediate lateral

Question 29

paraxial mesoderm forms what 3 things?

Answer 29

dermis of skin axial skeleton limb muscles

Question 30

intermediate mesoderm forms?

Answer 30

urogenital system

Question 31

lateral mesoderm forms?

Answer 31

heart | wall of gut/respiratory tissues

Question 32

what are somites? which germ layer do they come from?

Answer 32

mesoderm | swellings down paraxial mesoderm

Question 33

what is a somitomere?

Answer 33

pro-somite

Question 34

which pair do semitomere becomes independent somite?

Answer 34

8th pair

Question 35

somite splits into 2 things?

Answer 35

sclerotome (axial skeleton) | dermomyotome

Question 36

dermomyotome splits into?

Answer 36

dermatome | myotome

Question 37

where does the axial skeleton come from? vs. appendicular skeleton?

Answer 37

aial: sclerotome appendicular: lateral plate

Question 38

human 'gills' are called?

Answer 38

pharyngeal arches

Question 39

pharyngeal arches become?

Answer 39

jaw, face, ear, throat structures and glands

Question 40

when do limbs grow? what layer initates them?

Answer 40

end of 4 week | initiated by mesoderm

Question 41

limb field is what?

Answer 41

patch of mesoderm to make a free limb

Question 42

if remove whole patch vs. part of it?

Answer 42

whole=no limb | part of patch = compensation

Question 43

transplant free limb patch?

Answer 43

ectopic limb

Question 44

How thick is the ectoderm overlying limb bud? why is it significant?

Answer 44

one cell thick | easy to damage or split resulting in diplopodia or other defects

Question 45

how are digits developed?

Answer 45

hands and feet start as discs, sculpted by apoptosis

Question 46

what is syndactyly?

Answer 46

fused fingers

Question 47

what is the most common congenital limb abnormality? frequency?

Answer 47

congenital hip dislocation due to malformed acetabulum | 1:500

Question 48

What is amelia? meromelia? caused by?

Answer 48

absent or reduced limbs. Thalidomide

Question 49

what forms the epithelial lining of liver, pancreas?

Answer 49

ENDODERM!

Question 50

What is the Coelom?

Answer 50

holds the viscera

Question 51

Where does coelom come from?

Answer 51

split in lateral mesoderm

Question 52

what does the lateral mesoderm divide into? what do the two become?

Answer 52

splanchnic mesoderm: viscera | somatic mesoderm: muscle

Question 53

describe the folding formation of the coelom?

Answer 53

pulls toether like a bag pull string in 3D

Question 54

Where does the lumen of gut come from?

Answer 54

pinched off from the yolk sac during the coelom folding (tube within a tube)

Question 55

what is the stomodeum? | proctodeum?

Answer 55

membrane covering future mouth and anus

Question 56

ectoderm meets endoderm when what happens to the oral plate?

Answer 56

when it breaks = oral cavity

Question 57

what is the cloacal membrane?

Answer 57

anus seal where ectoderm and endoderm meet

Question 58

What is the allantois?

Answer 58

in body stalk, used to be nitrogenous waste storage in animals

Question 59

what is between allantois and hind gut? what does it do?

Answer 59

urorectal septum that divides rectum from urogenital tract

Question 60

what gives rise to bladder and urogenital tract?

Answer 60

allantois

Question 61

how many pharyngeal pouches form?

Answer 61

4

Question 62

where does most of the heart come from?

Answer 62

lateral splanchnic mesoderm

Question 63

how is the heart developed?

Answer 63

from two endocardial tubes fused together

Question 64

how do you get 4 chambers of heart in embryo?

Answer 64

folding of two fused tube

Question 65

where does heart muscle comes from? germ layer.

Answer 65

mesoderm

Question 66

what's the most common congenital heart defect?

Answer 66

ventricular septal defects

Question 67

congenital heart defect issue in utero?

Answer 67

Nope. usually immediately post birth

Question 68

does the foramen ovale allow left to righ flow of blood?

Answer 68

No. it shouldn't

Question 69

Foregut supplied by?

Answer 69

coeliac artery

Question 70

midgut supplied by?

Answer 70

superior mesenteric

Question 71

hindgut supplied by?

Answer 71

inferior mesenteric

Question 72

describe GIT growth pattern.

Answer 72

lengthens>haipin rotate around axis>elongation>more folding>herniation of GIT

Question 73

When does herniaion of GIT happen?

Answer 73

week 6-7

Question 74

When does GIT retract back into cavity?

Answer 74

week 9

Question 75

What is omphalocele?

Answer 75

no retraction of herniation of GIT

Question 76

retraction but failure to seal wall is?

Answer 76

umbilical hernia

Question 77

frequency of omphalocoele?

Answer 77

1:25 000

Question 78

viscera comes from which germ layers?

Answer 78

initially endoderm which interacts with mesoderm

Question 79

Situs invertus frequency?

Answer 79

1: 10 000

Question 80

What determines left and right in blastocyst?

Answer 80

via primitive groove and cilia that generate right to left current

Question 81

If cilia in primitive node don't work, are you guaranteed to get situs invertus?

Answer 81

Nope 50/50 change

Question 82

intermediate mesoderm forms what system?

Answer 82

urogenital system

Question 83

genital or urinary system forms first?

Answer 83

urinary

Question 84

what are the 3 kinds of kidneys that develop?

Answer 84

pronephros mesonephros metanephros

Question 85

kidney from which germ layer?

Answer 85

mesoderm

Question 86

what happens to mesonephric duct in males?

Answer 86

reused and attaches to testes to become the vas deferens

Question 87

kidneys migrate from where to where?

Answer 87

inferior to superior

Question 88

ureters start off where?

Answer 88

mesonephros at bladder

Question 89

penis forms by fusion of?

Answer 89

urogenital folds

Question 90

what happens when urogenital folds don't fuse completely?

Answer 90

hypospadiasis: urethra at base of penis

Question 91

all major organogenesis complete by?

Answer 91

3 months: first trimester