Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BDS1 BAMS: Oral Morphology, Histology and Physiology > Embryology > Flashcards

Embryology Flashcards

1
Q

How soon after ovulation does fertilisation occur?

A

12-24 hours

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

How soon after fertilisation does implantation into the endometrium occur?

A

5 and a half to 6 days

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

What is a fertilised ovum termed?

A

A zygote

A diploid cell arises from the fusion of 2 haploid gametes

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

What is a morula?

A

A solid mass of cells

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

How many days following fertilisation does a blastocyst form?

A

6-10 days

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

What is a blastocyst?

A

A hollow ball of cells (inner cell mass and trophoblast surrounding it)

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

What are chorionic villi?

A

The exchanger between the placenta and the mother

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

How many days following fertilisation does a morula form?

A

4-6 days

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

How is the baby’s blood replenished?

A
  • From the mother’s blood via the placenta
  • Blood circulations do not mix, they are separated by a thin barrier
  • The barrier is permeable to most molecules (e.g. drugs) but not cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 2 layers of the bilaminar embryo?

A
  • Epiblast layer

- Hypoblast layer

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

Why is it risky for a Rh- mother to have a Rh+ baby?

A

Blood circulations may mix during birth, foetal blood enters maternal circulation. Mother raises antibodies against Rh+ blood. Can put mother’s future Rh+ babies at risk (haemolytic disease of the newborn)

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

What does the epiblast give rise to?

A

The embryonic ectoderm, mesoderm and endoderm

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

What does the hypoblast do?

A

Participates on formation of endoderm and extraembryonic mesoderm

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

At approx 10-12 days, the implanted trophoblast contains an embryo which has 2 layers. What is this embryo termed and what are the 2 layers?

A

Bilaminar embryo

Layers are the epiblast and the hypoblast

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

What are the 2 types of twins?

A
  1. Identical/paternal: 1 sperm, 1 egg. Zygote splits in 2. Shared placenta. Same genetic makeup.
  2. Fraternal: 2 sperm, 2 eggs . Separate placentas. Different genetic makeup.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The bilaminar embryo is a disc. it has no orientation or axis. What does the embryo develop during gastrulation?

A
  1. An axis
  2. The 3 embryonic cell layers: ectoderm, endoderm, mesoderm
  3. Formation of a primitive streak
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is the mesoderm formed?

A

Ectodermal cells are induced to differentiate and migrate through the primitive streak towards the hypoblast. These new cells are the mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is the endoderm formed?

A

Interaction between mesoderm cells and the hypoblast forms the endoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the embryo termed once is develops the 3 embryonic layers?

A

Trilaminar embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What happens during weeks 3-8 of embryo development?

A

The major organs develop from the 3 basic germ cell layers. This is termed organogenesis

21
Q

What is organogenesis?

A

The major organs develop from the 3 basic germ cell layers between weeks 3-8 of embryo development

22
Q

What is one of the first organs to be formed?

A

The central nervous system (CNS)

23
Q

What are somites?

A

Early formation of muscle

24
Q

When does the neural tube form?

A

19-20 days

25
Q

What is the neural tube?

A

The forerunner of the central nervous system

26
Q

What is a common neural tube defect?

A

Spida bifida - the neural groove persists. Folding does not occur.

27
Q

What is the neural crest derived from?

A

From ectoderm but has the characteristics of mesenchyme.

28
Q

What is the neural crest also known as?

A

Ectomesenchyme

29
Q

What does ectomesenchyme give rise to?

A

Structures in the head

30
Q

What occurs ~25 days after ovulation?

A

Embryo folds around the yolk sac, and some important organs appear (heart, liver, lungs)

31
Q

When is an embryo termed a foetus?

A

Week 9

32
Q

What is the 4th embryonic layer?

A

Ectomesenchyme

33
Q

What are stem cells?

A

Unspecialised cells (‘undifferentiated’) that can develop into more specialised cells

34
Q

Describe the potential of embryonic stem cells (ESCs)

A

Totipotent - can differentiate into any cell type

35
Q

Where are embryonic stem cells found?

A

The inner cell mass (ICM)

36
Q

Describe the potential of cells in the 3 germ layers

A

Pluripotent (more restricted in potential) - capable of giving rise to several cell types

37
Q

Describe the potential of adult stem cells

A

Multipotent

38
Q

What are induced pluripotent stem cells (iPSCs)?

A

Reprogramming differentiated cells to their undifferentiated state

39
Q

When does tooth development start?

A

6 weeks

40
Q

All body tissues develop from 3 primary embryonic layers. What are they?

A
  • Ectoderm: outer covering
  • Mesoderm: middle
  • Endoderm: inner lining
41
Q

Which tissues develop from the ectoderm?

A

Skin, mucous membranes of the mouth and anus, brain and spinal cord (CNS), tooth enamel

42
Q

Which tissues develop from the mesoderm?

A

Most connective tissues (dermis, tendons, cartilage, bone), muscle, blood vessels, kidney and urinary system, reproductive system, serous membranes

43
Q

Which tissues develop from the endoderm?

A

Alimentary canal (pharynx-rectum), respiratory system, parts of the urogenital system

44
Q

Which structures does the ectomesenchyme give rise to?

A
  • Most of the PNS: sensory and autonomic nerves
  • Melanocytes in skin
  • Adrenal medulla
  • Most of the mesenchyme in the head (muscles, connective tissues, most dental and periodontal tissues - EXCEPT enamel)
45
Q

Which dental and periodontal tissues are derived from the ectomesenchyme?

A

Dentine, cementum, pulp, periodontal ligament, jaw, jaw bones

46
Q

When during foetal development is the period of greatest sensitivity?

A

Weeks 3-12 (the first trimester)

Most developmental defects occur during this period

47
Q

The effects of developmental abnormalities depend on what?

A

When the changes occur i.e. what stage of development

48
Q

What usually happens if developmental abnormalities occur during the first 2 weeks of pregnancy?

A

Spontaneous abortion

49
Q

When is the period of ‘functional maturity’?

A

Weeks 13-39

BDS1 BAMS: Oral Morphology, Histology and Physiology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions