Brainscape's Knowledge GenomeTM

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


See full index

Tissues of the Body > Embryology > Flashcards

Embryology Flashcards

1
Q

What is the most critical period of pregnancy and why?

A

Embryonic period

All the major structures and systems are formed

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

Why is week 3 called the ‘week of 3s’?

A

3 cavities form (amniotic, yolk and chorionic) and 3 germ layers form in trilaminar disk (ectoderm, mesoderm, endoderm)

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

Define gastrulation

A

The process of establishing the 3 germ layers and hence the origin of all tissues of the body. Also setting the axes.

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

What does the primitive streak do?

A

Drives and coordinates gastrulation

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

Where is the primitive node located?

A

At the cranial end of the primitive streak

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

Where does the primitive streak appear?

A

The dorsal surface of the epiblast

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

In which direction does development proceed?

A

Cranial to caudal

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

How are the 3 germ layers formed?

A

By migration and invagination: epiblast divides and migrates up to edges of primitive streak, some new cells push through epiblast layer to create a new layer.

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

What defines the phylum Chordata?

A

Having a notochord

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

What is the notochord for?

A

basis of axial skeleton, drives formation of nervous system (drives neurulation), defines the midline and has an important signalling role

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

Define the axes in an embryo

A

Anterior - towards head
Posterior - towards feet
Dorsal - back
Ventral - front

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

Which tissues are derived from the ectoderm?

A

Organs and structures that maintain contact with the outside world.
Eg. Nervous system, epidermis

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

Which tissues are derived from the mesoderm?

A

Supporting tissues

Eg. Muscle, cartilage, bone, vascular system

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

Which tissues are derived from the endoderm?

A

Internal structures

Eg. Epithelial linings, parenchyma of glands

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

What is situs inversus?

A

A congenital birth defect that means that the body is the mirror image of what it should be.
This results from immobile cilia during the embryonic period but has no associated morbidity.

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

How do monozygotic and dizygotic twins arise?

A

Monozygotic - a single fertilised oocyte

Dizygotic - 2 fertilised oocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is teratogenesis?

A

The process through which normal embryonic development is disrupted.

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

Name some teratogenic agents

A

Thalidomide, Rubella, Alcohol and Therapeutic drugs (eg. Warfarin)

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

How is the neural plate formed?

A

The notochord releases signals that affect the ectoderm. The ectoderm thickens and forms a slipper-shaped neural plate.

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

How is the neural tube formed?

A

The edges of the neural plate elevate out of plane and curl towards each other forming a tube.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where is the paraxial mesoderm?

A

Around the notochord and neural tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the two types of lateral plate mesoderm?

A

Somatic and splanchnic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does somatic mesoderm go on to form?

A

Connective tissues of limbs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does splanchnic mesoderm go on to form?

A

Smooth musculature, connective tissues and vasculature of gut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are somites?

A

The organisation of paraxial mesoderm into segments. The segments appear in craniocaudal sequence at 3 pairs per day.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where does dermomyotome form and what will it become?

A

Dorsally

Skin and muscle tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What happens to the myotome?

A

It proliferates and migrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What happens to the dermatome?

A

It disperses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What does the segmentation organisation of the mesoderm give rise to?

A

Repeating structures

Eg. Vertebrae, ribs, intercostal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What innervates the epimere?

A

Dorsal branch of spinal nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What innervates hypomere?

A

Ventral branch of spinal nerve

32
Q

What is a dermatome?

A

A strip of skin supplied by a single spinal nerve

33
Q

What is a myotome?

A

A muscle/group of muscle supplied by a single spinal nerve

34
Q

What does the paraxial mesoderm go on to form?

A

Vertebral column and ribs, Dermis and Muscles

35
Q

What does the intermediate mesoderm go on to form?

A

Urogenital system

36
Q

What will the buccopharyngeal membrane be?

A

The future mouth

37
Q

What are the two steps of embryonic folding and what is each step driven by?

A

Cephalocaudal folding (head and tail) - driven by neural tube

Lateral folding - driven by somites

38
Q

Why does embryonic folding occur?

A

To: create an inside and an outside, create a opening for the umbilical cord, draw the amniotic sac around the embryo and create a new cavity within the embryo.

39
Q

When is the pre-embryonic period?

A

The first 2 weeks

40
Q

When are pregnancy weeks calculated from?

A

The date of the last menstrual period.

41
Q

Where is the oocyte usually fertilised?

A

In the ampulla

42
Q

Where is the ideal site for implantation?

A

Posterior uterine wall

43
Q

What is the uterus lined with?

A

Glandular epithelium

44
Q

How long is an oocyte viable for?

A

1 day

45
Q

How long are sperm viable for?

A

Up to 3 days

46
Q

When does cleavage begin?

A

30 hours after fertilisation

47
Q

What is the zona pellucida?

A

A glycoprotein shell that surrounds the zygote immediately after fertilisation to exclude the sperm and prevent polyspermy.

48
Q

What is the result of the first cleavage?

A

2 blastomeres of equal size

49
Q

How does compaction occur?

A

The morula secretes tissue fluid and collects to create a cavity. The cells get pushed to one side.

50
Q

What is another name for the inner cell mass?

A

Embryoblast

51
Q

What is another name for the outer cell mass?

A

Trophoblast

52
Q

Why does the blastocyst hatch?

A

So it is free to enlarge and interact with the uterine surface to implant.

53
Q

What 2 layers does the outer cell mass split into?

A

syncytiotrophoblast and cytotrophoblast

54
Q

What 2 layers does the inner cell mass split into?

A

epiblast and hypoblast

55
Q

Which is the top layer of the bilaminar disc?

A

Epiblast

56
Q

What does the change from histiotrophic to haemotrophic mean?

A

Changes from relying of simple tissue diffusion to relying on the maternal blood supply

57
Q

What is an ectopic pregnancy?

A

Implantation occurring at another site than the uterine body.
Can very quickly become life threatening due to haemorrhage.

58
Q

What is placenta praevia?

A

Implantation in the lower uterine segment. There is risk of haemorrhage due to enlargement of the foetus. Will always require a C section.

59
Q

What is the connecting stalk?

A

A column of mesoderm that will be the umbilical cord.

60
Q

How does the amniotic sac form?

A

From spaces within the epiblast

61
Q

How does the primitive yolk sac form?

A

Formed by the hypoblast lining of the blastocyst.

62
Q

How does the secondary yolk sac form?

A

Forms within the primitive yolk sac

63
Q

When is the embryonic period?

A

Weeks 3-8

64
Q

What has happened by the end of the fourth week?

A

nervous system has started to form, segments have appeared and the embryo has folded so that everything is in the right place

65
Q

What are the hypomere and epimere?

A

The ventral and dorsal parts of the myotome.

Epimere = dorsal. Hypomere = ventral

66
Q

What is the sclerotome?

A

The hard tissue section that gives rise to bones eg. Vertebrae and ribs

67
Q

How do the vertebrae develop in the sclerotome?

A 
Medial = vertebral body
Lateral = vertebral arch
68
Q

How do the ribs develop in the sclerotome?

A 
Medial = proximal rib
Lateral = distal rib
69
Q

What arises from the dermomyotome?

A

Dermis and muscles

70
Q

How do the muscles develop in the dermomyotome?

A 
Medial = back muscles
Lateral = ventral body wall muscles and limb muscles
71
Q

What are neural crest cells?

A

A temporary group of cells unique to vertebrates that arise from ectoderm. They give rise to a diverse cell lineage.

72
Q

What is a nucleus pullout and what is it formed from?

A

It is the inner core of the vertebral disc that is jelly-like but has collagen fibres so can withstand compression. It arises from the notochord.

73
Q

How does the chorionic cavity form?

A

From spaces within the extra embryonic reticulum and mesoderm.

74
Q

What is the intra embryonic coelum?

A

The space between the splanchnic and somatic mesoderm that forms from the separation of the lateral plate mesoderm.

75
Q

What is the future anus called?

A

Cloacal membrane

76
Q

When does gastrulation occur?

A

Week 3

Tissues of the Body (12 decks)

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