Reproduction in Humans II

Question 1

Placenta

Answer 1

The intimate connection established between the foetal membrane and uterine wall is known as placenta

Question 2

What do the two parts of the placenta develop from

Answer 2

Foetal part- develops from the chorionic villi
Maternal part- Develops from the endometrium

Question 3

Which hormones production does placenta take over

Answer 3

Placenta takes over the production of progesterone around 8-12 weeks of pregnancy

Question 4

Antibody that can cross placental barrier

Answer 4

IgG- Immunoglobulin G

Question 5

Functions of placenta

Answer 5

1. Oxygen and nutrients diffuse through the walls of the chorionic villi and reach the foetus
2. Carbon dioxide and waste products are eliminated throught he umbilical cord by the process of diffusion into the maternal circulation
3. Produces hormones, acts as an interface, protection, excretory organ, nutrition, respiratory organ

Question 6

Major landmarks of human embryonic development-
One month/4 weeks

Answer 6

Heart is formed

Question 7

Major landmarks of human embryonic development-
Two months/8 weeks

Answer 7

Limbs and digits formed

Question 8

Major landmarks of human embryonic development-
Third month/12 weeks (FIRST TRIMESTER)

Answer 8

1. All major organs start development
2. Limbs and external genital organs well developed

Question 9

Major landmarks of human embryonic development-
Fourth month/16 weeks

Answer 9

Digestive system and teeth well developed

Question 10

Major landmarks of human embryonic development-
Fifth month/20 weeks

Answer 10

First movement of foetus and hair on head

Question 11

Major landmarks of human embryonic development-
Sixth month/24 weeks (SECOND TRIMESTER)

Answer 11

1. Eyelids separate
2. Eyelashes are formed
3. Body is covered with fine hair

Question 12

Major landmarks of human embryonic development-
Seventh month/28 weeks

Answer 12

Lungs and immune system well developed

Question 13

Major landmarks of human embryonic development-
8th month/32 weeks (THIRD TRIMESTER)

Answer 13

Testes descend into scrotal sac in a male child

Question 14

Major landmarks of human embryonic development-
Ninth month/36 weeks

Answer 14

Foetus is fully developed and ready for delivery

Question 15

Parturition

Answer 15

The act of expelling the full term foetus from the mother’s uterus at the end of gestation is terms as parturition

Question 16

Gestation period

Answer 16

The time from conception to birth

Question 17

Lactation

Answer 17

The secretion and ejection of milk by mammary glands is termed as lactation

Question 18

WHat are the hormones that initiate lactation

Answer 18

PRH- Prolactin releaseing hormone
Secreted by the hypothalamus

Prolactin- released from the anterior pituitary gland

Question 19

Oxytocin- where + fn

Answer 19

Hormone released from posterior pituitary gland

• Stimuate smooth muscles of the uterus to contract to facilitate parturition
• Induces the ejection of milk from mammary glands

Question 20

What is colostrum

Answer 20

Colostrum in the first milk that is secreted from the mammary gland after parturition

Colostrum contains IgA- Immunoglobulin A (secretory antibody) which provides neonatal immunity to the newborn baby

Question 21

Briefly describe the structure of the ovarian follicle

Answer 21

The ovarian follicle carries a large, centrally placed ovum surrounded by several layers of granular cells (follicular granulosa)

Question 22

Graafian follicle

Answer 22

1. Tertiary follicle changes into mature follicle called Graafian follicle
2. Secondary oocyte forms a new membrane called zona pellucida surrounding it which is released from the ovary by ovulation

Question 23

Corpus luteum

Answer 23

1. After extrusion of the ovum what remains of the Graafian follicle is called corpus luteum
2. The corpus luteum grows for a few days and if the ovum is fertilized and pregnancy results, it continues to grow
3. But if the ovum is not fertilized the corpus luteum persists for only about 14 days during which period it secretes progesterone

Question 24

What happens to the corpus luteum if fetilization occurs

Answer 24

1. Does not degenerate
2. Grows continuously and produces progesteron which is necessary to support pregnancy