Mod 1: Embryology

Question 1

Embryo

Answer 1

Weeks 3-8
Gastrulation
Neurulation
Head, tail fold

Question 2

Fertilization time

Answer 2

Beg week 1

Question 3

Implantation time

Answer 3

End week 1

Question 4

Bilam germ disc time

Answer 4

End week 2

Question 5

Gastrulation time

Answer 5

Week 3

Question 6

Head tail fold time

Answer 6

Weeks 4-5

Question 7

Immature fetus

Answer 7

Weeks 9-25

Question 8

Premature fetus

Answer 8

Weeks 26-36

Question 9

Full term fetus

Answer 9

Weeks 37-38

St dev 12 days

Question 10

Congen malform: zygote

Answer 10

Prenatal death

Question 11

Congen malform: 3-14 weeks

Answer 11

Major morph malformation

Question 12

Congen malform: 15-28 weeks

Answer 12

Minor abnormalities and functional deficits

Question 13

Full term

Answer 13

38 weeks or 266 days

St dev 12 days

Question 14

End of first trimester

Answer 14

All major organ sys

Length of Palm

Question 15

Second trimester

Answer 15

Long as hand

50% survival at 22 weeks

Question 16

Female infertility

Answer 16

Occlusion of uterine tube lumen

Question 17

Male infertility

Answer 17

Low sperm count

Question 18

Meningocele

Answer 18

Herniation of membranes around sc

Question 19

Menungomyelocele

Answer 19

Herniation of membranes and sc

Question 20

Surface ectoderm becomes

Answer 20

Epithelium
Hair
Nails
Cutaneous and mammary glands

Question 21

Neuroectoderm becomes

Answer 21

Neural tube–> CNS

Neural crest –> dorsal root ganglia and nerves, pigment cells

Question 22

Paraxial mesoderm

Somites form:

Answer 22

Muscles of trunk and limbs
Axial skeleton bone and cartilage (except head)
Connective tissue

Question 23

Lateral plate mesoderm forms

Answer 23

Skelton of limbs

Connective tissue of muscles and viscera

Question 24

Zygote

Answer 24

Weeks 1-2
Fertilization
Implantation
Bilam germ disc

Question 25

Differentiation of mesoderm into what layers?

Answer 25

Paraxial Intermediate Lateral

Question 26

First evidence of limb buds on what day? | Major features of limbs present by...?

Answer 26

first evidence: day 26 (end of 4th week) | major features: end of 8th week

Question 27

Carnegie stages

Answer 27

standardized set of embryonic stages based on appearance of structures during development

Question 28

Forelimb or hindlimbs develop earlier? how much earlier?

Answer 28

Forelimbs precede by 1-2 days | (both forelimbs and hindlimbs present by 28 days

Question 29

What tissue initially forms limb bud?

Answer 29

somatic lateral plate mesoderm (helps form body wall) covered with ecotoderm

Question 30

What levels does forelimb/hindlimb develop?

Answer 30

Forelimb: caudal, cervical (C4-T2 -- about same as brachial plexus) Lower limb: lumbar and upper sacral (L2-S3)

Question 31

Limb bud elongates in what direction?

Answer 31

proximal --> distal

Question 32

When do hand and foot plates form?

Answer 32

hand plates: 6th week | foot plates: 7th week

Question 33

Describe formation of digital rays? | When?

Answer 33

mesenchyme in plates condenses to form digital rays proliferation and apoptosis -- fingers and toes by end of week 8

Question 34

Chondrification Osteogenesis Endochondral ossification

Answer 34

Chondrification (5 w): development of cartilaginous precursor which will later undergo osteogenesis to form bone (7 w) Endochondral ossification: develop primary ossification centers to replace cartilage

Question 35

When do secondary ossification centers form?

Answer 35

birth

Question 36

What genes/TF's in limb development are highly conserved across animals?

Answer 36

Hox (gene) | TBX 4 and 5 (transcription factors)

Question 37

Haploinsufficiency

Answer 37

patients have one working copy of gene (mutations in both copies would be lethal) -- why diff from animal models

Question 38

Phenocopies

Answer 38

malformations have diff causes, but have same physical result

Question 39

Unilateral deformation of limb suggests what cause?

Answer 39

pressure on limb | if genetic, would likely be bilateral

Question 40

What measures used to determine age of fetus?

Answer 40

``` Crown Rump Length (1st trimester) 2nd and 3rd trimesters: Head circumference/diameter abdominal circumference femur length foot length ```

Question 41

Viability

Answer 41

ability of fetus to survive in extrauterine environment

Question 42

Immature infants | Premature infants

Answer 42

immature: fetuses with extremely low birth wt (less than 500 g) -- don't survive premature: fetuses with very low birth wt (b/w 1500-2500 g) -- survive with complications

Question 43

When does fetus reach 500 g? | 1500g?

Answer 43

500g: week 23 1500g: week 29

Question 44

Premature deaths due to

Answer 44

incomplete differentiation of CNS and resp sys

Question 45

Factors influencing fetal growth

Answer 45

maternal fetal environmental

Question 46

Primary source of maternal substrate for fetal growth

Answer 46

maternal glucose | fetal insulin used for metabolism of glucose

Question 47

What stimulates fetal growth? | post natal growth?

Answer 47

Fetal: insulin-like growth factor | Post-natal: human growth hormone (IGF later becomes human growth hormone)

Question 48

IUGR | What causes it

Answer 48

``` Itraunterine growth retardation (low birth wt) smoking alcohol drugs poor nutrition poor fetoplacental bloodflow/placental dysfunction genetic factors twins ```

Question 49

What period is most suceptible to factors causing problems?

Answer 49

embyronic

Question 50

Malformation

Answer 50

errors in genetic programming/tissue formation

Question 51

Deformation

Answer 51

forced into abnormal shapes

Question 52

Disruptions

Answer 52

targeted, localized insult

Question 53

Syndrome

Answer 53

group of anomalies occuring together with common cause

Question 54

Perinatology

Answer 54

assess health of fetus and newborn (26 wks - 4wks old)

Question 55

Methods for assessing health of fetus

Answer 55

``` ultrasound fetoscopy CT MRI xrays (amniography, fetography) amniocentesis (vest after wk 12) -- collect alpha fetoprotein, genetic disorders alpha fetoprotein assay sex chromatin analysis cell culture chorionic villus sampling percutaneous umbilical cord blood sampling ```