Deck 44: Survey of Embryonic Development

Question 1

The trophoblast cells of the blastocyst form the , which extends elaborate villi into the blood- filled sinusoids of the uterine wall.

A)chorion
B)allantois
C)yolk sac
D)amnion

Answer 1

A

Question 2

The placenta is formed by .

A)maternal and fetal tissues
B)fetal tissues
C)maternal tissues

Answer 2

A

Question 3

Implantation of the blastocyst in the uterine wall is complete by day after ovulation.

A)7
B)10
C)14
D)4

Answer 3

C

Question 4

Once fertilization has occurred, the activities of development begin. The first such activity is .

A)the formation of organ systems
B)cellular specialization
C)an increase in cell number

Question 5

Chorionic villi look like .

A)rings of chorionic canals in the uterine wall
B)fingers stuck into the uterine wall
C)feathery extensions of the chorion in the uterine wall
D)blood- filled channels in the uterine wall

Question 6

The decidua basalis and decidua capsularis are portions of the uterine wall. Which is(are)involved in formation of the placenta?

A)decidua capsularis
B)decidua basalis
C)both
D)neither

Question 7

Name the blood vessel that carries oxygen- rich blood to the fetus.

A)umbilical vein
B)fetal iliac arteries
C)umbilical artery
D)placental artery

Question 8

The function of cleavage is to .

A)form the organ systems
B)increase the number of cells forming the blastocyst
C)begin specialization of the cells to form specific tissues and organs

Question 9

What is true of the structure of the human placenta?

A)It is diffuse, with villi distributed over the surface of the chorion.
B)It forms a belt around the embryo.
C)It is disc- shaped.

Question 10

Fertilization .

A)is the final step to occur before implantation into the uterus
B)is the process of fusion of egg and sperm
C)is the process of providing nutrients to the embryo

Question 11

This cord attaches the embryo to the placenta.

A)allantois
B)yolk sac
C)abdominoplacental cord
D)umbilical cord

Question 12

Development progresses .

A)from the midline lateral to the body walls, then proximal to distal on the limbs
B)in rostral to caudal and proximal to distal directions
C)simultaneously upwards, outwards, and downwards from the trunk
D)from the head and the distal limbs towards the trunk

Question 13

This structure surrounds the early embryo and the fluid that fills it protects the embryo.

A)amnion
B)chorion
C)allantois

Question 14

The is the final product of cleavage.

A)trophoblast
B)blastocyst
C)gastrula
D)zygote

Question 15

What organs appear very early in development?

A)brain and heart
B)skeletal muscles
C)lungs and alimentary canal
D)kidneys and glands

Question 16

The three primary germ layers develop during this stage of human fetal development.

A)gastrula
B)blastula
C)cleavage

Question 17

The human blastocyst consists of two populations of cells with different functions. Select the correct match between population and its function.

A)trophoblast; becomes fetal amnion
B)inner cell mass (ICM); forms the embryo and three of the four extraembryonic membranes
C)inner cell mass (ICM); becomes fetal chorion
D)trophoblast; becomes yolk sac

Question 18

This portion of the blastocyst forms the embryo proper.

A)inner cell mass (ICM)
B)morula
C)zona pellucida
D)trophoblast

Question 19

During the process of implantation, the inner cell mass (ICM)gives rise to three embryonic membranes. Which of the following is not one of these membranes?

A)amnion
B)allantois
C)yolk sac
D)chorion

Question 20

In what region of the uterus does implantation usually occur (as indicated by the position of the placenta)?

A)anywhere in the body of the uterus
B)in the upper part of the uterus
C)close to the cervix

Question 21

All exchanges between mother and embryo occur .

A)through the amniotic fluid
B)through the allantois
C)across the chorionic membranes
D)as maternal and fetal blood mix in the placenta

Question 22

In the human, this germ cell layer gives rise to many of the organ systems, including the skeleton, skeletal muscles, walls of GI organs, urinary system, and circulatory system.

A)mesoderm
B)endoderm
C)ectoderm

Question 23

In humans, the yolk sac .

A)forms the human urinary bladder
B)is the site of origin for blood cells and primordial germ cells
C)is no longer a useful structure
D)passes nutrients to the embryo after digesting the yolk mass