Chapter 29: Human Development

Question 1

Oxygen, Carbon dioxide, nutrients, and wastes cross the placenta by the process of ________.

Answer 1

diffusion

Question 2

What structures arise from the mesoderm?

Answer 2

• dermis
• gonads
• skeletal muscles

Question 3

Bone loss that is severe enough to compromise physical health and activity is known as?

Answer 3

osteoporosis

Question 4

The period from fertilization through the 12th wk is known as the __________.

Answer 4

first trimester

Question 5

List the correct order of gestational stages.

Answer 5

1. preembryonic stage
2. embryonic stage
3. fetal stage

Question 6

What are the functions of the amniotic fluid?

Answer 6

• protect fetus from trauma
• allow development of the lungs
• protect fetus from temp fluctuations

Question 7

What are the 3 features of a blastocyst?

Answer 7

blastocoel, trophoblast, and embryoblast.

Question 8

What is the w blastocoel?

Answer 8

the outer layer of cells?

Question 9

What is the trophoblast?

Answer 9

hollow internal cavity of cells

Question 10

What is the embryoblast?

Answer 10

the cell mass within blastocyst.

Question 11

What is a zygote?

Answer 11

a single-celled fertilized egg

Question 12

The process by which a blastocyst attaches to the lining of the uterus is called?

Answer 12

implantation

Question 13

What structures arise from the endoderm?

Answer 13

• Digestive glands
• epithelium of the digestive tract
• parathyroid gland

Question 14

Name the stages of developing organism that occur during the preembryonic stage.

Answer 14

1. zygote
2. cleavage
3. morula
4. blastocyst

Question 15

What structures arise from the ectoderm?

Answer 15

• central nervous system
• salivary glands
• epidermis
• portions of the reproductive tract

Question 16

The function of the____________ is to protect the embryo from trauma, infection, and temp fluctuations, allow freedom of movement, and allow development of the lungs.

Answer 16

Amniotic Fluid

Question 17

What stage begins 16 days post-conception, after the three germ layers have developed?

Answer 17

embryonic

Question 18

The stage of ________ is complete when the blastomeres form 3 primary germ layers.

Answer 18

Embryogenesis

Question 19

Some structures that arise from the mesoderm include:

Answer 19

• dermis
• skeletal muscle
• gonads

Question 20

What primary germ layer gives rise to most of the epithelium of the digestive and respiratory tracts adn the mucosal epithelium of urinary bladder and urinary tract?

Answer 20

endoderm

Question 21

When does the embryonic stage begin?

Answer 21

When the 3 germ layers are first present, at about 16 days

Question 22

Sperm remain viable for ___ days after ejaculation.

Answer 22

6