Module 8 - embryology

Question 1

What is the result of mitosis?

Answer 1

two identical cells

Question 2

What is the result of meiosis?

Answer 2

four different cells with 23 chromosomes each

Question 3

What is a zygote?

Answer 3

fertilization to implantation (2 weeks)

Question 4

What is a morula called when it becomes hollow?

Answer 4

blastocyst

Question 5

What are the two parts of a blastocyst?

Answer 5

trophoblast, inner cells

Question 6

the trophoblast becomes what?

Answer 6

the placenta

Question 7

When is the embryo stage?

Answer 7

2-8 weeks

Question 8

inner mass of the blastocyst differentiates into three germ layers in embryo stage. what are they called?

Answer 8

ectoderm - nervous tissue, epidermis, epithelial tissue
endoderm - lining of digestive and respiratory tracts, larynx, trachea, bronchi, lungs
mesoderm - connective tissues, cartilage, muscle, ears, kidneys

Question 9

What is the time period of a fetus?

Answer 9

8 weeks to birth

Question 10

when can a fetus start to survive outside of the womb?

Answer 10

26 weeks

Question 11

what are the three enlargements on the end of the neural tube?

Answer 11

forebrain - prosencephalon
midbrain - mesencephalon
hindbrain - rhombencehalon

Question 12

What does the neural crest become?

Answer 12

PNS

Question 13

What do cells do during development of brain?

Answer 13

proliferation through mitosis, migration, differentiation, myelinization, synpatogenesis

Question 14

What is spina bifida?

Answer 14

spinal cord, surrounding nerves, and/or spinal column fail to develop correctly during the first 28 days of gestation

Question 15

what are the types of spina bifida?

Answer 15

myelomeningocele - sac containing an abnormally formed spinal cord protrudes from newborn’s back
meningocele - born with sac protruding from back
spina bifida occulta - bones in spinal column fail to develop normally - nerves usually normal