Applied Embryology Flashcards

1
Q

Where does the process of fertilisation occur?

A

Fallopian tube

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

What happens once one sperm has entered the oocyte?

A

Oocyte becomes impenetrable to other sperm

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

What are the four steps in inplantattion?

A

Hatching
Apposition
Adhesion
Invasion

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

Briefly describe what happens in the apposition step of implantation.

A

First connection between blastocyst and endometrium.
Apposes to pinopodes (microvilli like structure) expressed on the receptive endometrium

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

Briefly describe what happens in the adhesion step of implantation.

A

Trophoblast of the blastocyst adheres to epithelial layer of endometrium
Embryonic tissue starts to secrete hCG

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

Briefly describe what happens in the hatching step of implantation.

A

Trophectoderm cells produce protease to dissolve the zona in preparation for the implantation

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

Briefly describe what happens in the invasion step of implantation.

A

Trophoblast proliferation, differentiation, crossing of the epithelial basement membrane and invasion of endometrial stroma to form placenta

->don’t get too hung up on this but could come up idk, depends on wording and stuff. I guess they could give five stages and ask ‘which of the following is NOT a step in the implantation process?’

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

Endometrium?

A

Lining of the uterus

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

After which stage of implantation would a pregnancy test show positive?

A

Adhesion

->due to secretion of hCG

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

What would happen if there was an inability for the blastocyst to hatch during implantation?

A

Infertility

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

What happens in the endometrium as it prepares to receive the embryo?

A

Stromal cell differentiation into decidual cells
Angiogenesis- new blood vessel formation
Increased macrophages, lymphocytes and decidual leukocytes (uterine NKC) for maternal immune tolerance

->these changes transform the endometrium to a vascular receptive tissue for the invasion of blastocysts

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

Is the placenta derived from foetal or mother tissues?

A

Fully developed from foetal tissues

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

Functions of the placenta?

A

Immunological barrier
Gas exchange
Nutrient exchange
Waste excretion
Endocrine functions*

->secretes hCG which maintains the pregnancy

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

What name is given to the changes in the endometrium as it prepares from the foetus?

A

Decidualization

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

Embryogenesis?

A

First eight weeks of embryo development post fertilisation

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

Briefly describe what happens in week 2-3 of embryogenesis.

A

Formation of bilaminar disc
Development of amniotic sac, yolk sac, extraembryonic mesoderm and chorionic cavity

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

Briefly describe what happens in week 3-4 of embryogenesis.

A

Bilaminar disc -> three germ layers (endoderm, mesoderm, ectoderm) through the process of gastrulation and neural tube formation

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

Briefly describe what happens in week 5-8 of embryogenesis.

A

Organogenesis

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

Two layers of the bilaminar disc?

A

Epiblast
Hypoblast

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

What does the epiblast go onto form?

A

Three germ layers

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

What does the hypoblast go onto form?

A

Extraembryonic mesoderm

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

List the derivatives of the ectoderm.

A

Epidermis
Central Nervous System
Peripheral Nervous System
Hair
Nails
Neuroendocrine organs (adrenal medulla, pituitary gland)
Enamel of teeth

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

List the derivatives of the mesoderm.

A

Dermis
MSK structures
Cardiovascular system
Kidneys
Ureters
Trigone of bladder
Gonads
Adrenal cortex

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

List the derivatives of the endoderm.

A

Lining of GIT
Parenchyma of liver
Pancreas
Thyroid
Parathyroid
Tonsils
Thymus
Bladder (excluding the trigone)
Urethra

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

The mesoderm divides into three major subunits. Name them.

A

Paraxial mesoderm
Intermediate mesoderm
Lateral plate mesoderm

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

Which part of the mesoderm does the urinary and repro system develop from?

A

Intermediate mesoderm

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

What are the two reasons why multiple pregnancies might occur (twins etc)?

A

Dizygotic- two or megs fertilising and implanting
Monozygotic- one embryo splitting

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

Which type of twins WON’T be identical?

A

Dizygotic

->two separate eggs being fertilised. In monozygotic, the twins will be identical as one egg is splitting

27
Q

Is it more common to have identical twins or non-identical twins?

A

Non-identical twins

28
Q

Are twins more likely in natural conception or fertility treatment e.g. IVF?

A

Fertility treatments

29
Q

Monochorionic?

A

Twins share one placenta

30
Q

Monoamniotic?

A

Twins share one smniotic sac

->this occurs is >5% of twin cases

31
Q

Dichorionic?
Diamniotic?

A

Separate placenta
Separate amniotic sacs

32
Q

What is the most common combo of placenta/amniotic sacs in twins?

A

Monochorionic
Diamniotic

->one placenta, two amniotic sacs, this occurs when the early embryo implants in the womb and then splits. If it splits before implanting in the womb, the two foetus have their own placenta.

33
Q

Okay recap
Monozygotic vs dizygotic?

A

Monozygotic- one zygote splits, identical twins
Dizygotic- two zygotes, non-identical twins

34
Q

Part of the urinary system (kidney and ureter) and reproductive system develop from what part of the intermediate mesoderm?

A

Urogenital ridge

35
Q

Which develops first, urinary or repro system?

A

Urinary

36
Q

Where do the gonads develop from?

A

Gondadal ridge

->gonads are originally indifferent, develop later into a testis or ovary

37
Q

What does the Y chromosome contain which determines the production of a teste rather than an ovary?

A

SRY- sex -determining region Y

38
Q

RECAP- why does their have to be a testicular descent?

A

Scrotal sack needs to be at a different temperature to the rest of the body for proper spermatogenesis to take place

39
Q

Name the two sets of genital ducts.

A

Mesonephric duct
Paramesonephric duct

40
Q

The presence of what determines which genital duct develops and which recesses?

A

AMH

->anti- =Mullerian hormone

41
Q

In males, the presence of AMH means which genital duct develops?

A

Mesonephric duct develops, paramesonephric duct recesses

->M=male

42
Q

When the mesonephric duct develops, what name do this ducts now have?

A

Wolffian ducts

->forms the trigone of the bladder in males and females

43
Q

What do the Wolffian ducts do?

A

Drain the menephros into the cloaca

44
Q

What do the Wolfferian ducts forms in males?

A

Epididymis
Vas deferens
Seminal vesicles

->only able to form these under the effect of testosterone.

45
Q

What happens as the Wolffian ducts regress in females?

A

Remnants might remain as opoophoron, paraophoron (small cystic structures lateral to ovary) and garters duct cyst (benign lesions on the lateral vaginal wall).

46
Q

What happens to the paramesonephric duct in females?

A

Grow medially and fuse, forming the uterus and 2/3 of vagina
Unfused portions give rise to fallopian tubes

47
Q

If the paramesonephric ducts give rise to the upper 2/3 of the vagina, what forms the lower 1/3?

A

Urogenital sinus

48
Q

The paramesonephric ducts fuse with the urogenital sinus at the sinus tubercle to form what?

A

Hymen

49
Q

What forms the clitoris in females?

A

The genital tubercle

50
Q

What forms the labia minora in females?

A

Urogenital folds

51
Q

What forms the labia majora in females?

A

Labioscrotal folds

52
Q

Micropenis is a male reproductive tract anomaly. What has happened?

A

Genital tubercle does not fully elongate

53
Q

Hypospadias is a male reproductive tract anomaly. What has happened?

A

Urethral development problem causing opening to be abnormally located

54
Q

In what condition may there by absence of vas deferens in males?

A

Cystic fibrosis

55
Q

Cryptochordism?

A

Absent or undescended testicles

56
Q

How common are female reproductive tract anomalies?

A

Common, 4-7% of women

57
Q

What are the three reasons why uterine anomalies can happen?

A

Underdevelopment
Fusion defect
Resorption defect

58
Q

Give examples of two uterine anomalies which can occur due to underdevelopment.

A

Uterine agenesis
Unicornuate uterus

59
Q

Give examples of two uterine anomalies which can occur due to fusion defects.

A

Didelphys uterus
Bicornuate uterus

60
Q

Give examples of two uterine anomalies which can occur due to resorption defects.

A

Separate uterus
Arcuate uterus

61
Q

Which investigation is used to identify uterine anomalies?

A

3D Ultrasound

62
Q

List some of the congenital female anomalies which aren’t to do with the uterus.

A

Vaginal septa
Imperforate hymen
Vaginal agenesis

63
Q

Name a syndrome in which is common for their to be female reproductive anomalies.

A

MKRH syndrome

64
Q

What happens in Mullerian agenesis syndrome?

A

Full female reproductive tract but parts or all of the uterus or vagina will be absent

65
Q

What can these reproductive anomalies have an effect on?

A

Fertility
Urinary function

66
Q
A