Diagram of Placenta:

The placenta is a vital organ that develops during pregnancy and connects the developing fetus to the uterine wall. It provides the fetus with essential nutrients and oxygen while also removing waste products.

Structure of Placenta:
The placenta is a flat, circular organ that is typically 6-8 inches in diameter and about 1 inch thick. It consists of two main components:

1. Maternal Side: This side of the placenta is in direct contact with the uterine wall. It is covered by a smooth layer called the decidua basalis, which is formed by the modified cells of the uterus. The maternal side contains numerous blood vessels that supply oxygen and nutrients to the fetus.

2. Fetal Side: This side of the placenta is in direct contact with the fetus. It is covered by a thin membrane called the amnion, which surrounds the amniotic sac. The fetal side contains numerous chorionic villi, which are finger-like projections that increase the surface area for nutrient and gas exchange between the maternal and fetal blood.

Function of Placenta:
The placenta plays a crucial role in supporting fetal development and maintaining a healthy pregnancy. Its main functions include:

1. Nutrient and Gas Exchange: The placenta allows for the exchange of oxygen and nutrients from the maternal blood to the fetal blood. It also facilitates the removal of waste products, such as carbon dioxide, from the fetal blood to the maternal blood.

2. Endocrine Function: The placenta produces hormones that are essential for maintaining pregnancy. These hormones include human chorionic gonadotropin (hCG), progesterone, and estrogen, which help regulate various physiological processes during pregnancy.

3. Immune Protection: The placenta acts as a barrier, preventing harmful substances and pathogens from reaching the fetus. It also transfers maternal antibodies to the fetus, providing temporary immune protection after birth.

Diagram of Planira:

Unfortunately, there is no information available regarding "Planira." It is possible that it may be a term or subject that is not widely recognized or does not exist. Therefore, it is not possible to provide a diagram or detailed explanation for something that is not known or understood.