Embryology

Question 1

what is embryology? (2)

Answer 1

• study of embryonic development
• development and implementation of structures that compose the human anatomy

Question 2

what is teratology?

Answer 2

study of abnormal embryonic and fetal development

Question 3

what is the anatomical position? (3)

Answer 3

• Body is upright
• Arms at the side
• Palms forward

Question 4

what are anatomical planes?

Answer 4

Perpendicular cardinal planes to transect the human body

Question 5

(anterior, posterior, right, left, superior, inferior):

1. Sagittal planes separate the ___ and ___ (between the two ____)
2. frontal (coronal) planes separate the ___ and ___ (like cutting ____
3. transverse (horizontal) planes separates the ___ and ___ (____ to the body)

Answer 5

1. right; left sides; hemispheres
2. anterior; posterior; loaf of bread
3. superior; inferior; perpendicular

Question 6

what is the clinical definition of embryology?

Answer 6

embryonic and fetal development of the prenatal development

Question 7

what is the importance of embryology?

Answer 7

importance of understanding the embryological causes of birth defects (teratology)

Question 8

how long does fertilization take, when and how does it occur?

Answer 8

• takes 24hr
• beginning of pre-embryonic period
• when spermatozoon and oocyte contact and unite to form the zygote

Question 9

what is an oocyte?

Answer 9

cell in the ovary that can undergo meiotic division to form an ovum

Question 10

what is the cleavage of the zygote and what initiates it?

Answer 10

• consists of repeated mitotic division of the zygote
• metabolic activation

Question 11

what is the clinical relevance of the fertilization of a zygote?

Answer 11

defect in the molecular and physical sequences cause the death of a zygote

Question 12

what does each cleaved zygote contain?

Answer 12

• blastomere (which gets further divided)
• zona pellucida that surrounds the blastomere

Question 13

what does the blastomere stand for?

Answer 13

mother of blastocyst

Question 14

what are all the stages of zygote cleavage and when do they occur?

Answer 14

2-cell stage = 30hr
4-cell stage = 40hr
8-cell stage = 60hr
12-32-cell stage = 3-4 days

Question 15

what happens at 8-cell stage of zygote cleavage?

Answer 15

compaction (cells are tightly aligned against each other, better cell interaction)

Question 16

what happens at cell stages 12-32 of zygote cleavage? (3)

Answer 16

• enters the uterus
• zona pellucida disappears by day 4
• morula stage on day 4

Question 17

T/F: during the morula stage, the zygote is the size of a small berry

T/F: the embryo increases in size as it gets cleaved

Answer 17

TRUE; FALSE