Embryology Flashcards

1
Q

Define Embryology

A

Study of the origin and development of an organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How long is the “fetal” age?

A

38 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How long is the “gestational” age?

A

40 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How long and what defines the “embryonic” period?

A

First 8 weeks

All major organs formed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How long and what defines the “fetal” period?

A

Remaining 30 weeks

Organs grow larger and increase in complexity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define Ovulation

A

Egg released into the peritoneal cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define Fertilization

A

Occurs as egg travels down the fallopian tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define Zygote

A

The cell that forms when the ova and sperm fuse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define Cell Division

A

Begins immediately as the zygote travels down the fallopian tube and into the uterus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What occurs during the first week after conception?

A

Zygote divides repeatedly
Daughter cells = blastomeres
Morula
Blastocyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define Morula

A

Solid cluster of 12-16 blastomeres at about 72 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When occurs on day 4 post conception?

A

Morula enters uterus and takes up fluid becoming a blastocyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Types of Cells in the Blastocyst Stage

A

Inner cell mass

Trophoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define Inner Cell Mass

A

Forms the embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define Trophoblast

A

Layers of cells surrounding the cavity which helps form the placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What occurs on day 6 post conception?

A

Implantation of the zygote

17
Q

What occurs during implantation?

A

Tropholast erodes uterine wall

18
Q

Three Primary Germ Layers

A

Ectoderm
Endoderm
Mesoderm

19
Q

The ectoderm and endoderm form what?

A

Sheets of epithelial tissue

20
Q

The mesoderm forms what?

A

Mesenchyme tissue

21
Q

Define Gastrulation

A

Invagination of epiblast cells

22
Q

When does the endoderm form?

A

Days 14-15

23
Q

When does the mesoderm form?

24
Q

What occurs during days 16-18?

A

Epiblast cells invaginate
Migrate anteriorly with endoderm cells
Rod defining body axis formed
Notochord is future site of vertebral column

25
Define Neurulation
Formation begins of spinal cord and brain
26
What occurs during neurulation
Neural plate to neural groove to neural tube
27
What are the three regions of the mesoderm?
Somites: beginning of vertebral bones Intermediate mesoderm Lateral plate: forms cavity
28
When does the neural tube close?
Starts at the end of week 3 and completes at end of week form
29
What is the somatic mesoderm opposed to?
Ectoderm
30
What is the splanchnic mesoderm opposed to?
Endoderm
31
What is between the somatic mesoderm and splanchnic mesoderm?
Coelom
32
What serous cavities form from the coelom?
Peritoneal Pericardial Pleural
33
Major Derivatives of the Ectoderm
Epidermis, hair, nails, glands of skin Brain & spinal cord Neural crest: sensory nerve cells, nervous structures, pigment cells, portions of skeleton, blood vessels in H&N
34
Major Derivatives of the Endoderm
Epithelial lining and glands of digestive and respiratory tracts
35
Major Derivatives of the Mesoderm
``` Nucleus pulposus Vertebrae & ribs Dermatomes Trunk & limb musculature Kidneys Gonads Parietal serosa Ventral body dermis CT of limbs Wall of digestive & respiratory tracts Visceral serosa Heart Blood vessels ```
36
When does the heart start pumping?
4 weeks to 1 month
37
When Does Organogenesis Occur?
Weeks 3-8
38
What occurs during organogenesis?
Stem cell populations established for each organ | MOST gross structural birth defects are induced
39
What is the significance of organogenesis?
Mother MUST avoid environmental, dietary, and drug exposure during this period