Embryogenesis and Fetal Period Flashcards Preview

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Flashcards in Embryogenesis and Fetal Period Deck (72)
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1

neurulation

ectoderm thickens and becomes known as the neural place

2

what happens on day 22 in reference to the neural plate

it begins to fold inward and makes contact with four occpital somites and the first cervical somites

3

what day does the cranial neuropore close

24 or 25

4

what day does the caudal neuropore close

26 or 27

5

the fusion of the neural folds results in the formation of what ?

neural tube

6

neural crest cells

really important, lose attachment to neural tube and form a lot of things

7

what are some examples of neural crest derivatives

parasympathetic ganglia of 3,7, 9 and 10, sensory ganglia of central nervous sytem of 5, 7, 9 and 10 and the autonomic doral root ganglia

8

surface ectoderm gives rise to what ?

epidermis, hair, nails, cutaneous, mamary glands, anterior pituitary gland, enamel of teeth, internal ear, and lens of eye

9

mesoderm immediately laterally to the notochord form cylindrical bodies called ___________

paraxial mesoderm

10

mesoderm just laterally to the notochord forms_________

intermediate mesoderm

11

futherest lateral to the notochord forms _____-

lateral plate mesoderm

12

paraxial mesoder

axial skeleton, volutary musclulatur and part of the dermis

13

intermediate mesoderm

form the urinary system and parts of the genital system

14

lateral plate mesoderm

will split into two layers splachnic mesoderm (associated with endoderm) and somatopleuric mesoderm (associated with the ectoderm)

15

the paraxial mesoderm helps form the first ________-

somite on day 20

16

how many pairs of somites are there ?

37 pairs

17

the endoderm of the embryo contributes to what structure ______________

yolk sac

18

endoderm derivatives

epithelial lining of GI tract, allantois, epithelium of repiratory tract, bladder, urethra, tympanic cavity and auditory tube, parenchyma of thyroid, parathyroid, liver and pancreas, stroma cells of the tonsils and the thymus

19

when is the fetal period

9th week til birth

20

characteristics of weeks 9-12

liver is major site of erythropoeisis, and the external genitals can be distinguished male or female

21

weeks 13-16

sites of ossification are evident, eye movements and the eyes are facing forward

22

weeks 17-20

primary ovarian follicles are formed and testes are descending

23

weeks 21-25

period of weight gain, blink and startle reflexes, surfactant is beginning to be secreted into the lungs

24

weeks 26-29

lungs are capable of breathig, CNS is capable of breathing and body temperature, spleen is still making blood cells but by 28 weeks blood formation shifts to the bone marrow

25

weeks 30-34

pupillary light reflex is present, fat is still accumulating

26

weeks 35-38

finish period involves final preparations of tissues important to the outside world

27

for the first 12 weeks of developent what is the major blood producing organ

yolk sac

28

for weeks 12-30 what organ is the major blood producing organ and weeks 12-24

liver, spleen

29

by week 30 what is the major hemopoietic organ

bone marrow

30

what is amniocentesis ?

sampling of the amnioc fluid to test for genetic disorders (must pass through chorion and amnion to get the sample)