Introduction Chapter 1 Flashcards Preview

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Flashcards in Introduction Chapter 1 Deck (31):
1

what are the three developmental stages of the embryo ?

early development, embryonic stage and the fetal period. early development is 1-16 days, and the embryonic stage is usually weeks 3-8

2

What developmental stage is the period of greatest sensitivity ?

the embryonic stage or weeks 3 to 8

3

What is a malformation ?

errors that occur during the formation of structures mostly in organogenesis during the embryonic stage

4

What occurs in the period of early development ?

fertilization, implantation, growth, formation of trilaminar embryo and the placenta and the determination of the body exes (where the head, tail, left and right are)

5

What stages involves the formation of the organs and body parts in development or organogenesis

the embryonic period

6

During the fetal period or after 9 weeks, the increase in length of the fetus is _________ where as the increase in weight is not __________. It is greatest __________.

uniform, not uniform, prior to birth

7

What organs are still susceptible during the fetal period and subject to malformations ?

eyes, ears, brain, palate, teeth and the external genitalia

8

What is the definition of an anomaly?

something that is readily visible and can interfere with normal function or note detected until after death from natural causes (examples are horseshoe kidney(doesn't impact function though, and cleft palate that does impact function

9

what are the four types of congenital abnormalities

malformations, disruptions, deformations, and dysplasia

10

malformations

they occur duirng organogenesis and result in abnormal structure

11

disruptions

result form external influences that cause alterations of completely formed structures

12

deformations

abnormal form resulting from mechanical force such as a club foot

13

dysplasia

abnormal organization of cells into tissue (sacrococcygeal teratoma)

14

genetic factors contribute to what percent of congenital abnormalities

28%

15

environmental agents contribute to what % of congenital abnormaliteis

3 to 4%

16

multifactorial (ie environmental and genetic) contribute to what % of congenital abnormalities

20-25%

17

agenesis

absence of an organ

18

aplasia

cells to form an organ never formed

19

association

anomalies ocurring together without determined cause

20

atresia

absence of an opening or lumen

21

syndrome

group of anomalies occuring together with a common cause

22

teratogen

substance affecting migration, proliferation, or interaction of cells which results in congenital abnormalities

23

primordial germs cells are responsible for forming the_______--

epiblast which gives rise to the ectoderm

24

primitive sex cords

supporting cells plus the undifferentiated germ cells (they are neither male or female yet)

25

what are the supporting cells of the female pgc's?

follicular cells

26

what are the supporting cells of the male pgc's?

sertoli cells

27

genital ridges

areas where the gonads are going to form

28

What are the four steps in spermiogenesis?

lose the cytoplasm, condense the nucleus, neck and tail, acrosome addition

29

what is the function of FSH

to stimulate the development of ovarian follicles and the production of estrogen

30

what is the function of LH

serves as a trigger for ovulation and stimulates the production of progesterone

31

What is the G0 phase of the cell cycle??

dead end stage for cells that are highly speciliazed and don't futher divide later. not all cells go through all of the stages of the cell cycle