Embryology

Question 1

embryology

Answer 1

study of the embryo, prenatal development, intrauterine development, and gestation

Question 2

duration of embryology development for mother

Answer 2

40 weeks

Question 3

duration of development from the conceptus

Answer 3

38 weeks

Question 4

why there is there a difference between gestation periods for mother and baby?

Answer 4

mothers is dated by first day of last period which is 2 weeks from ovulation and fertilization

Question 5

periods of development 1-2 weeks

Answer 5

conceptus: zygote, morula, and blastocyst

Major event: fertilization, implantation, mitosis

not suceptible to teratogens at this time

Question 6

periods of development 3-8 weeks

Answer 6

name: embryonic period conceptus: embryo Major event: organgenesis

major abnormalities can occur during this tims

Question 7

periods of development 9-38 weeks

Answer 7

name: fetal period conceptus: fetus Major event: growth maturation

minor abnormalities can occur during this time

Question 8

development starts with _____ cells

Answer 8

pluripotent; undifferentiated

Question 9

each step is ____ by a message from a neighboring cell which can only occur if cell two has the receptors to perceive the inductive message

Answer 9

induced

Question 10

teratogens are responsible for _____ % of congenital abnormalities

Answer 10

7-10%

Question 11

teratogen

Answer 11

is a agent or factor that causes congenital abnormalities; environmental, chemical, radiation, medication, drug, or toxin

Question 12

what precent of abnormalities are due to an unknown cause ?

Answer 12

50-60%

Question 13

what % of abnormalities are due to multifactor inheiritance?

Answer 13

20-25%

Question 14

what % of abnormalities are due to Chromosomal aberrations?

Answer 14

6-7%

Question 15

what % of abnormalities are due to Mutant Genes?

Answer 15

7-8%

Question 16

when dose gastrulation occur?

Answer 16

3rd week

Question 17

what occurs during grastulation?

Answer 17

the formatoin of three layers the ectoderm, endoderm, and mesoderm

Question 18

mitosis of epiblast at __________ forms new cells leading to formation of 2 new layers ______ and _____

Answer 18

primitive streak; mesoderm and endoderm

Question 19

Ectoderm

Answer 19

outer layer of skin and teeth, nervous system

Question 20

mesoderm

Answer 20

muscle, bone, connective tissues, blood and blood vessels, deeper layer of skin

Question 21

Endoderm-

Answer 21

epithelial lining of GI and respiratory tract

Question 22

Somite formation definition

Answer 22

formation of horizontal body segments from the mesoderm

Question 23

somite formation occurs from caudal/cranial to caudal/cranial

Answer 23

from cranial to caudal

Question 24

each somite divides forming….

Answer 24

dermatome –> skin dermis, myotome –> muscle and sclerotome –> bone

Question 25

how many somites are there?

Answer 25

35-37

Question 26

what four proccesses occur during the 3rd week?

Answer 26

1. gastrulation 2. somite formation 3. neurulation 4. trilaminar embryo

Question 27

what is the main evemt occuring in week 4?

Answer 27

organogenesis, folding: longitudinal and transverse, germ layer differentiation, pharyngeal arches, heart, 4 limbs begin to develop

Question 28

Caudal/cranial --\> Caudal/cranial distal/Proximal --\> distal/Proximal

Answer 28

cranial --\> caudal proximal --\> distal

Question 29

fetus breaths amniotic fluid and excretes into the amniotic fluid but this dose not cause \_\_\_\_\_\_

Answer 29

defecation

Question 30

there **is/is not** mixing of fetal blood in the womb

Answer 30

there is not

Question 31

-Placenta is highly ______ and formed by the embryo exchanges 1. waste 2. gas 3. nutrition therefore acting as \_\_\_\_\_, \_\_\_\_, and \_\_\_\_\_\_

Answer 31

vascular; kidney, lungs, and GI tract

Question 32

Malformation

Answer 32

abnormality that occurs 3-8 weeks

Question 33

Deformation

Answer 33

abnormality secondary to extrinsic disruption after embryonic period

Question 34

Sequence

Answer 34

multiple abnormalities developing in a sequence

Question 35

Syndrome

Answer 35

multiple abnormalities not developing in a certain sequence

Question 36

Mesenchyme

Answer 36

aggregates of undifferentiated cells mostly made of mesoderm

Question 37

Longitudinal Folding

Answer 37

cranial and caudal ends fold ventrally, moves heart from cranial into new thorax and it begins to beat

Question 38

Transverse Folding

Answer 38

lateral sides fold ventrally, creates the GI tract, creates body cavities called coelom, germ layers begin forming structures

Question 39

Major congenital abnormalities are most likely to arise during developmental weeks ___________ to ___________ .

Answer 39

3;8

Question 40

1.The inner cell mass gives rise to the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_, whereas the trophoblast gives rise to the _________________ .

Answer 40

fetus; placenta

Question 41

1.Growth and maturation of organs is the major event during developmental weeks __________ to __________ .

Answer 41

9;38

Question 42

1.Implantation of the conceptus into the uterus begins during developmental week _________ .

Answer 42

1

Question 43

1.Formation of the GI tract takes place by _________________ folding during developmental week ___________ .

Answer 43

transverse; 4

Question 44

Answer 44