Question

Placenta in the cat is
A. zonary
B. deciduate
C. discoidal
D. hemochorial

Answer 1

Hint: Placenta forms a link between the fetus and mother. The placenta of most carnivores is the same.

Complete Answer:
- The placenta is a temporary membranous vascular organ that develops in females during pregnancy.
- It is expelled after childbirth. The placenta forms a link between the fetus and mother.
- It is not only the physical attachment but also forms the physiological connection between the fetus and mother.
- The placenta is implanted in the wall of the uterus. It is connected to the fetus by the umbilical cord, which contains blood vessels and connective tissue.
- The navel or umbilicus is the site of attachment of the placenta in the center of the anterior abdomen of the fetus.

Functions of Placenta:
- Important nutritive substances, electrolytes, and hormones necessary for the development of a fetus diffuse from the mother’s blood into fetal blood through the placenta.
- Metabolic waste products and other waste products from the fetal bodies are excreted into the mother’s blood through the placenta.
- Fetal lungs are non-­functioning and the placenta forms the respiratory organ for the fetus. The oxygen for the fetus is received by diffusion from the maternal blood and carbon dioxide from fetal blood diffuses into the mother’s blood through the placenta.
- Placenta also secretes hormones. Hormones secreted by the placenta are Human chorionic gonadotropin, Estrogen, Progesterone, Human chorionic somatomammotropin, Relaxin.

In carnivores like dogs and cats, the zonary placenta is present. Zonary placenta means the fetus is completely circled by the placenta. Here placenta forms a complete band around the fetus.

So, the correct answer is zonary.

Note: Cat gives birth 5-8 kittens at a time. Every fetus has its own placenta to nourish it. So, the cats (or other carnivores also) have more than one placenta during a single pregnancy.