Functions Of The Placenta: Nutrition, Respiration, Hormones, And Waste Removal

Functions Of The Placenta: Nutrition, Respiration, Hormones, And Waste Removal

Question 1. Ovulation.
Answer:

Ovulation Definition:

• It is the process by which the graffian follicle in the ovary ruptures and the ovum is released into the abdominal cavity.
• It occurs on the 14th day of menstrual cycle.

Ovulation Process:

Ovulation Significance:

• Pregnancy can be prevented by determining the ovulation time.

Ovulation Hormonal regulation:

• Prior to ovulation, large amount of LH is secreted.
• This LH is important for ovulation.

Question 2. Functions of placenta.
Answer:

1. Nutritive function.

• The various nutritive substances, electrolytes and hormones required for fetal development diffuse from the mother’s blood into fetal blood through placenta.

2. Excretory function.

• All the metabolic waste products from fetal blood passes to mother’s blood through placenta.

3. Respiratory function.

• Placenta acts as respiratory organ as the fetal lungs are non-functioning.
• Oxygen from mother’s blood is received by fetal blood and carbon dioxide from fetal blood is diffuse into maternal blood through placenta.

4. Endocrine function.

• Placenta secretes five hormones.
  1. Human chorionic gonadotrophin (HCG).
     • It is formed by placenta immediately after implantation of the fertilized ovum.
     • It is responsible for preservation and secretory activity of corpus luteum.
     • It stimulates the interstitial cells of leydig to secrete testosterone.
  2. Human chronic somatomammotrophin (HCS).
     • It is lactogenic.
     • It has a small amount of growth stimulating activity.
     • Causes enlargement of mammary glands.
     • Reduces peripheral utilization of glucose.
  3. Estrogen.
     • Enlarges uterus for accommodating fetus.
     • Enlarges breast and develops ductal system.
     • Facilitates passage of fetus through the birth canal at the time of labor.
  4. Progesterone.
     • Inhibits the contraction of uterine muscle in the pregnant uterus.
     • Causes enlargement of breast and develops its ductal sysem.
  5. Relaxin – helps in labor.