Introduction Chapter 1

Question 1

what are the three developmental stages of the embryo ?

Answer 1

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

Question 2

What developmental stage is the period of greatest sensitivity ?

Answer 2

the embryonic stage or weeks 3 to 8

Question 3

What is a malformation ?

Answer 3

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

Question 4

What occurs in the period of early development ?

Answer 4

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)

Question 5

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

Answer 5

the embryonic period

Question 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 __________.

Answer 6

uniform, not uniform, prior to birth

Question 7

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

Answer 7

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

Question 8

What is the definition of an anomaly?

Answer 8

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

Question 9

what are the four types of congenital abnormalities

Answer 9

malformations, disruptions, deformations, and dysplasia

Question 10

malformations

Answer 10

they occur duirng organogenesis and result in abnormal structure

Question 11

disruptions

Answer 11

result form external influences that cause alterations of completely formed structures

Question 12

deformations

Answer 12

abnormal form resulting from mechanical force such as a club foot

Question 13

dysplasia

Answer 13

abnormal organization of cells into tissue (sacrococcygeal teratoma)

Question 14

genetic factors contribute to what percent of congenital abnormalities

Answer 14

28%

Question 15

environmental agents contribute to what % of congenital abnormaliteis

Answer 15

3 to 4%

Question 16

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

Answer 16

20-25%

Question 17

agenesis

Answer 17

absence of an organ

Question 18

aplasia

Answer 18

cells to form an organ never formed

Question 19

association

Answer 19

anomalies ocurring together without determined cause

Question 20

atresia

Answer 20

absence of an opening or lumen

Question 21

syndrome

Answer 21

group of anomalies occuring together with a common cause

Question 22

teratogen

Answer 22

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

Question 23

primordial germs cells are responsible for forming the_______–

Answer 23

epiblast which gives rise to the ectoderm

Question 24

primitive sex cords

Answer 24

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

Question 25

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

Answer 25

follicular cells

Question 26

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

Answer 26

sertoli cells

Question 27

genital ridges

Answer 27

areas where the gonads are going to form

Question 28

What are the four steps in spermiogenesis?

Answer 28

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

Question 29

what is the function of FSH

Answer 29

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

Question 30

what is the function of LH

Answer 30

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

Question 31

What is the G0 phase of the cell cycle??

Answer 31

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