Early Embryonic Development Quiz

What is the primary function of the trophoblast during implantation?

To secrete enzymes for penetrating the endometrium

Which extraembryonic membrane is responsible for forming the primitive gut?

Yolk sac

What is the name of the space filled with amniotic fluid that absorbs shocks?

Amniotic cavity

Which germ layer forms the muscles and bone tissue?

Mesoderm Signup and view all the answers

During which day range does the implantation process typically complete?

7-14 days after fertilization Signup and view all the answers

What is the primary function of the extraembryonic membranes?

To provide nutrients and oxygen to the fetus Signup and view all the answers

During which stage of embryonic development do the three germ layers form?

During the gastrula stage Signup and view all the answers

What is the term for the process by which the embryo implants into the uterine lining?

Implantation Signup and view all the answers

What is the structure that develops from the trophoblast and serves as the interface between the mother and the fetus?

Placenta Signup and view all the answers

What is the number of chromosomes present in the secondary oocyte formed after meiosis I?

23 Signup and view all the answers

How long are secondary oocytes viable for after ovulation?

24 hours Signup and view all the answers

What is the role of prostaglandins in the fertilization process?

They cause reverse peristalsis of the uterus and uterine tubes Signup and view all the answers

What is the result of the fusion of the sperm and ovum nuclei during fertilization?

Formation of a zygote Signup and view all the answers

What is the approximate time it takes for a sperm to reach the uterine tubes?

1 hour Signup and view all the answers

What is the number of chromosomes present in a zygote?

46 Signup and view all the answers

What is the primary function of the placenta during embryonic development?

To facilitate the exchange of materials between embryonic and maternal blood Signup and view all the answers

What embryonic tissue and maternal tissue combine to form the placenta?

Chorion and endometrium Signup and view all the answers

During which week of embryonic development do the rudiments of all organs become present?

7th week Signup and view all the answers

What is the primary method of material exchange between embryonic and maternal blood in the placenta?

Diffusion Signup and view all the answers

What is the term for the developing offspring during the 3rd-8th week of development?

Embryo Signup and view all the answers

What stimulates the release of oxytocin from the posterior lobe of the pituitary?

Fetus head pushing against the cervix Signup and view all the answers

What is the result of higher blood oxytocin levels during labor?

More intense and frequent uterine contractions Signup and view all the answers

What is the purpose of Pitocin in labor?

To induce uterine contractions Signup and view all the answers

How long does the second stage of labor typically last?

Less than an hour Signup and view all the answers

What occurs during the third stage of labor?

Delivery of the placenta Signup and view all the answers

What causes the uterus to decrease in size after birth?

Continued contractions of the uterus Signup and view all the answers

What helps prevent alveolar collapse in the newborn's lungs?

Surfactant Signup and view all the answers

What is the purpose of clamping and cutting the umbilical cord?

To separate the newborn from the placenta Signup and view all the answers

What stimulates the respiratory rhythmicity center in the newborn?

Increased blood CO2 levels Signup and view all the answers

Why is the first breath difficult for the newborn?

Because the lungs are collapsed Signup and view all the answers

What is the primary function of progesterone during pregnancy?

Suppress GnRH release Signup and view all the answers

What is the role of relaxin during pregnancy?

Develop placental blood vessels Signup and view all the answers

What triggers the formation of action potentials during the first stage of labor?

Cervical stretching Signup and view all the answers

What is the primary function of estrogens during pregnancy?

Stimulate mammary gland development Signup and view all the answers

What is the typical duration of the first stage of labor?

6-12 hours Signup and view all the answers

What is the primary function of the hormone hCG produced by the trophoblast and chorion?

Maintains the corpus luteum for the first 10 to 12 weeks of development Signup and view all the answers

During which week of development does the placenta take over the role of producing estrogens and progesterone?

12 weeks Signup and view all the answers

What is the approximate weight of the fetus by the 20th week of development?

460 grams (1 lb) Signup and view all the answers

What is the purpose of vernix caseosa?

To protect the skin from the digestive and urinary wastes in the surrounding amniotic fluid Signup and view all the answers

During which weeks of development does the fetus reach infant proportions?

21-29 weeks Signup and view all the answers