Development

Question 1

Syngamy

Answer 1

“syn”= getting together

When the sperm enters the egg

Question 2

What happens to keep another sperm out after one has entered to fertilize the egg?

Answer 2

1) Calcium is released to stimulate the granule release

2) Results in a change in electrical charge and granules release to block the entry of another sperm

Question 3

What is a segmentation nucleus composed of?

Answer 3

Contains a haploid female pronucleus and haploid male pronucleus; diploid zygote w/ 46 chromosomes)

Question 4

Yolk Sac

Answer 4

• extraembryonic membrane
• the early site of blood formation
• has cells that migrate to the gonads to create germ cells

Question 5

Amniotic sac

Answer 5

• extraembryonic membrane

- forms by the 8th day and eventually surrounds the developing embryo and eventually the fetus and fills with fluid

Question 6

Amniotic fluid

Answer 6

• comes from the mother’s plasma
• as the baby’s excretory system develops, it urinates into the fluid to add volume
• protects the baby from shock, maintains correct body temperature and keeps tissues from sticking to the amniotic sac

Question 7

Amniocentesis

Answer 7

14-16 weeks; ejection of amniotic fluid via ultrasound

• Used to determine whether or not there are genetic abnormalities
• Risk: Miscarriage (up to 0.5%)

Question 8

How are chromosomes organized?

Answer 8

Ordered by size; largest is #1 and smallest is #22

*#23 is the sex chromosome

Question 9

Chorionic villus sampling

Answer 9

Similar to amniocentesis, but at 8 weeks
*Risk: Miscarriage (1-2%)
Transcervical- intravaginally
Transabdominal- ejection in abdominal region

Question 10

Allantois

Answer 10

CRUCIAL
An outpouching of the yolk sac that collects liquid waste from the embryo and allows gas exchange
*The vessels later become the umbilical cord

Question 11

Toxoplasma gondii (congenital toxoplasmosis)

Answer 11

Protozoan that cross the placenta and cause damage

Question 12

What damage is caused by toxoplasma gondii?

Answer 12

Enlarged liver and spleen, diarrhea or vomiting, eye damage from inflammation of parts of the eye, feeding problems, hearing loss, jaundice, abnormal brain function

Question 13

Congenital Rubella Syndrome

Answer 13

Caused by rubella virus; leads to deafness, microphthalmia, cataracts, mental retardation, hepatomegaly, micrognathia (small jaw)

Question 14

Placenta previa

Answer 14

1/250 pregnancies; “placenta previous to the baby”

*The woman can’t go into labor b/c the high pressure would result in a lot of bleeding

Question 15

Teratogens

Answer 15

Chemicals or agents that cause developmental anomalies

Question 16

Thalidomide

Answer 16

A drug/tranquilizer used for morning sickness
Problem: given during the 1st trimester and results in “flipper” limbs, interference in development and differentiation of growing tissue for the child

Question 17

Impact of Cigarette Use

Answer 17

*Nicotine: a vasoconstrictor that cuts down on blood supply
Low infant birth weight, higher fetal and infant mortality rate following birth (SID), cardiac abnormalities, cleft lip and palate

Question 18

Fetal Alcohol Syndrome

Answer 18

Low infant birth weight, slow growth in utero and after delivery, small head, facial irregularities, heart defects, limb defects, genital defects

Question 19

Morning sickness

Answer 19

Term: Emesis gravidarum

Hyperemesis gravidarum: type where nothing can be held down and it becomes very dehydrating

Question 20

Placenta abruptio

Answer 20

Placenta tearing away from the uteral wall prior to labor

Question 21

Relaxin

Answer 21

Hormone produced by ovaries to soften the disc of the pubic symphysis during labor so the hip bones can spread to allow the passage of the baby’s head