Development of the fertilized ovum

Question 1

Menarche

Answer 1

Beginning of menstruation

Occurs at about age 11 - 15 years

Question 2

Climacteric

Answer 2

a period of years during which the woman’s ability to reproduce gradually declines

Question 3

Menopause

Answer 3

the final menstrual period

Question 4

Phases of ovarian cycle

Answer 4

Follicular, ovulation and luteal

Question 5

Phases of menstrual cycle

Answer 5

Menstrual, proliferative, secretory

Question 6

What does FSH do?

Answer 6

Stimulate the follicles in the ovary to mature.

Once it matures it becomes the graafian follicle

Question 7

What does LH do?

Answer 7

Causes the graafian follicle to release the ovum

Question 8

Stages of fetal development

Answer 8

1. Morula
2. Blastocyst
3. Embryonic disk
4. Gastrulation

Question 9

Morula

Answer 9

Solid mass of cells resulting from cleavage after 3 days

Question 10

Blastocyst

Answer 10

Ball of cells formed from morula after 5 days

Question 11

Embryonic disk

Answer 11

Inner mass of cells of blastocyst

Question 12

Gastrulation

Answer 12

Embryo composed of three tissues:
Ectoderm, mesoderm and endoderm

Question 13

Ectoderm

Answer 13

Outer layer which gives rise to the nervous system and outer layers of integumentary system

Question 14

Mesoderm

Answer 14

Middle layer

Muscles, organs of circulation, reproduction, excretion and skeleton are derived from it

Question 15

Endoderm

Answer 15

Inner layer

Gives rise to the lining of the digestive tube and organs derived from it

Question 16

Four weeks

Answer 16

The four-chambered heart beats, sending blood through simple vessels.

Intestines, liver, pancreas, lungs, and limb buds can be
seen.

The embryo is about 1/5
inch long.

Question 17

Eight weeks

Answer 17

At this stage, the face and neck take shape, the back straightens, and fingers and toes can be differentiated clearly.

The embryo starts to move.

It is now around 1 to 1-1/5 inch in length.

Question 18

Monozygotic twins

Answer 18

A single fertilized egg, or zygote, forms an embryo that splits into two. Each develops into a fetus.

The two have the same genes and sex and share one placenta. They look alike and are known as “identical”
twins

Question 18

Dizygotic twins

Answer 18

Two eggs are released and both are fertilized.

Two zygotes form, implant, and develop, resulting in the birth of dizygotic (or fraternal) twins.

Question 18

Trophoblast

Answer 18

forms early embryo, fetal membranes and placenta after five to seven days

Question 19

Embryo

Answer 19

the developing human from fertilisation to the eighth week of pregnancy

Question 20

Placental functions

Answer 20

IRENE

I - Immune
R - Respiratory
E - Endocrine
N - Nutritional
E - Excretory

Question 21

Function of membranes and amniotic fluid

Answer 21

• Protection from trauma

• Maintenance of temperaturr

• Amniotic fluid allows free movement of the fetus

• Allows for fetal growth and prevents body parts sticking to the membranes

• Allows fetus to prepare for swallowing and breathing when baby is born

• Fetus helps maintain fluid volume by swallowing and passing it out as urine

Question 22

Human chorionic gonadotropin

Answer 22

Maintains corpus luteum until week 12

Secreted by placenta

Question 23

Estrogen/progesterone

Answer 23

Source: Corpus luteum/placenta

Stimulate and maintain uterine lining, inhibit FSH and LH, ihibit uterine contractions, enlarge reproductive organs

Question 24

Estrogen/progesterone

Answer 24

Source: Corpus luteum/placenta

Stimulate and maintain uterine lining, inhibit FSH and LH, ihibit uterine contractions, enlarge reproductive organs

Question 25

Human chorionic somatomammotropin

Answer 25

Human placental lactogen

Source: placenta

Mammary gland development, insulin sparing effects in mother, weak GH type effect

Question 26

Human chorionic thyrotropin

Answer 26

Source: placenta

Increases size/activity of maternal thyroid and parathyroid glands

Question 27

Aldosterone

Answer 27

Source: adrenal cortex

Increase fluid retention