Tag: reproduction in humans
Questions Related to reproduction in humans
Which of the following structure is lacking from the placenta?
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Arteries
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Veins
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Smooth muscles
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Nerves
The placenta is an organ, that connects the fetus to the uterine wall. This allows the nutrient uptake, waste elimination and gas exchange via the mother's blood supply, fights against internal infection and produces hormones to support pregnancy. Placenta connects the fetus by an umbilical cord which contains two umbilical arteries and one umbilical vein. The placenta is encircled by a ring of smooth muscle cells.
The placenta does not have nerves.
Thus, the correct answer is option (D), 'Nerves'.
Which one of the following develops from the trophoblast?
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Placenta
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Allantois
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Epidermis of the skin
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Yolk sac
Trophoblasts are the cells forming the outer layer of a blastocyst, which provides nutrients to the developing embryo and it develops into a large part of placenta. Thus, trophoblasts are specialized cells of the placenta that plays an important role in embryo implantation.
Thus, the correct answer is option (A), 'Placenta'.
Foetus is nourished by
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Placenta
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Yolk
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Sertoli cells
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Phagocytosis
A placenta is formed from interdigitation of the trophoblast layer of the embryo and the endometrial lining during implantation. It facilitates the supply of oxygen and nutrients to the developing foetus and is also responsible for removal of carbon dioxide and excretory waste products of the foetus.
In simplest type of placenta, six barriers separate maternal blood from foetal blood. How many barriers are lost in human placenta?
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One
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Two
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Three
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Four
Attachment of foetus of placenta occurs through
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Chorda mesoderm
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Spinal cord
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Umbilical cord
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Notochord
In humans, the placenta is chorionic in nature. It attaches the foetus and the mother and is responsible for the nutrition and excretion and exchange of gases.
Extra structure which provides nutrition to embryo is
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Umbilicus
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Chorion
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Placenta
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Amnion
After implantation, finger-like projections appear on the trophoblast called chorionic Villi which are surrounded by uterine tissue and maternal blood. The chronic villi and uterine tissue become interdigitated with each other and jointly form a structural and functional unit between developing embryo that is foetus and maternal body called placenta. Placenta facilitate the supply of oxygen and nutrients to the embryo and also helps in removal of carbon dioxide in excretory waste materials produced by the embryo.
Metadiscoidal placenta is found in
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Humans
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Cow
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Pig
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Rabbit
The placenta in which the villi are restricted to a disk-shaped chorionic area on the ventral side of the embryo is known as the metadiscoidal placenta found in humans.
Which one is not a character of haemochorial placenta?
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$CO _2$ and excretory products pass from foetus to mother's body.
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$O _2$ and nutrients from mother's body enter the foetus.
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Chorion villi are covered by blood sinuses of mother.
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It protects foetus from mechanical shocks.
The haemochorial placenta is the type of placenta in which maternal blood is in direct contact with the chorionic villi which are covered by maternal blood and exchange of gases and nutrients from mother's blood and foetus takes place as observed in humans.
Which is not correct about placenta?
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It prevents passage of maternal IgG to foetus.
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It acts as foetal lung.
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It acts as foetal liver.
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It acts as endocrine gland.
Which of the following is not the function of placenta?
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Secretes oxytocin during parturition
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Facilitates supply of $O _2$ and nutrients to embryo
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Secretes estrogen
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Facilitates removal of $CO _2$ and waste products from embryo