Question

what is the function of a placenta​

Answer 1

Answer:

The placenta is an organ that develops in your uterus during pregnancy. This structure provides oxygen and nutrients to your growing baby and removes waste products from your baby's blood.

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Answer 2

Answer:

The placenta is an organ that is used as the site of the exchange. It provides nutrients and oxygen to the developing fetus and removes the waste products from the fetus. It develops in the uterus during pregnancy. It develops from 2 separate individuals, both the mother and the fetus.

Explanation:

Important functions performed by the Placenta are as follows:-

1. It stores important nutrients like proteins, calcium, iron, carbohydrates which are released into the blood of the fetus when required.
2. It permits nutrients and oxygen to diffuse into fetal blood from the maternal blood while Carbon dioxide and waste diffuse out from fetal blood into maternal blood. The placenta is connected with the fetus through a structure called the umbilical cord. It is usually 2cm in width and 50-60cm in length. It consists of 1 umbilical vein that carries nutrients and oxygen obtained from the intervillous spaces of the mother into the fetus and 2 umbilical arteries that carry deoxygenated fetal blood to the placenta.  
3. From the 3rd month through the remaining part of the pregnancy, the placenta produces progesterone and estrogen at high levels.
4. It also secretes Relaxin Hormone which was previously secreted by the corpus luteum. Relaxin helps in dilating the uterine cervix during labor and also increases the flexibility of pubic symphysis and ligaments of the sacrococcygeal and sacroiliac joints.
5. CRH or Corticotropin-releasing hormone is the hormone found recently to be produced by the placenta. Secreted at about 12 weeks and increases till the end of pregnancy. It is the part of the "clock" that determines the timing of birth. CRH also increases the secretion of cortisol which is required for the maturation of fetal lungs.
6. Placenta also acts as a protective barrier. It contains a structure called the chorion. which surrounds the embryo and the fetus later on. The chorion is responsible for protecting the embryo and fetus from the immune responses of the mother and performs various other functions in the following ways-

• It blocks the production of antibodies(produced by the mother) by secreting the proteins.
• It suppresses the normal immune response in the uterus by promoting the production of T-lymphocytes
• It also produces hCG or Human chorionic gonadotropin into the blood. In turn, the corpus luteum is stimulated by the hCG to continue the production of progesterone and estrogen (required to prevent menstruation and for the continuation of attachment of the embryo and fetus with the lining of the uterus).
• Chorion also secretes estrogen after the first 3 or 4 weeks of pregnancy and progesterone by the 6th week.
• Another hormone produced by the chorion of the placenta is hCS or human chorionic somatomammotropin. (also called human placental lactogen or hPL) It is released at high levels after 32 weeks and later remains constant. It increases protein synthesis which helps in enhancing maternal growth, it also helps in preparing mammary glands for lactation and it also regulates certain aspects of metabolism in fetus and mother. E.g. decreasing the levels of glucose used by the mother, and making it available to the fetus.