Embryology

Question 1

What do you call the top and tail of an embryo?

Answer 1

Cranial and caudal

Question 2

What do you call the front and back of an embryo?

Answer 2

Ventral and dorsal

Question 3

What is a transverse plane of an embryo?

Answer 3

When you cut through an embryo across the waist

Question 4

What is a sagittal section of an embryo?

Answer 4

When you divide the embryo into right and left halves

Question 5

What is the coronal section of an embryo?

Answer 5

When you divide the embryo into ventral and dorsal

Question 6

What is the difference between fertilisation age and menstrual age?

Answer 6

Menstrual age is measured from the first day of your last cycle - easy to identify
Fertilisation age used by embryologists - measured from fertilisation

Question 7

When is the early development stage of pregnancy?

Answer 7

0-3 weeks

Question 8

When is the embryonic (organogenesis) period of pregnancy?

Answer 8

3-8 weeks

Question 9

When is the foetal period of pregnancy?

Answer 9

8-38 weeks

Question 10

How many births in the UK have birth defects?

Answer 10

1 in 44

Question 11

What percentage of birth defects are diagnosed prenatally/ at birth ?

Answer 11

Prenatally - 60%
At birth - 30%

Question 12

What are the possible causes of congenital defects?

Answer 12

[put in picture of pie chart]

Question 13

What conditions are caused by aneuploidy?

Answer 13

Patau syndrome
Edward syndrome
Down syndrome

Question 14

What are teratogens?

Answer 14

Environmental causes of birth defects

Question 15

What are 5 examples of teratogens?

Answer 15

Infectious agents
Chemical agents
Physical agents
Maternal disease
Deficiency

Question 16

Between what weeks of pregnancy are teratogens at the most risk of producing a congenital defect?

Answer 16

3-8 weeks (because this is during the embryonic/ organogenesis period)

Question 17

What are infectious teratogens?

Answer 17

Toxoplasmosis
Other (hepatitis B, syphilis)
Rubella
Cytomegalovirus
Herpes simplex virus

Question 18

What is toxoplasmosis?

Answer 18

It is a parasite
Found in cat faeces and raw meat
Causes congenital malformations

Question 19

`What is rubella and how does it affect pregnancy?

Answer 19

Infection that passes over placenta during first 3 months of pregnancy
Causes congenital malformations

Question 20

What is cytomegalovirus and how does it affect pregnancy?

Answer 20

Virus that crosses the placenta
Infection via bodily fluids
Causes congenital malformations

Question 21

What is herpes and how does it affect pregnancy?

Answer 21

Varicella zoster virus - chickenpox
Most dangerous between 13-20 weeks
Causes congenital malformations

Question 22

Which congenital malformations does toxoplasmosis cause?

Answer 22

Inflammation of retina
Hearing loss
Enlarged liver/spleen
Hydrocephaly
Microcephaly

Question 23

Which congenital malformations does rubella cause?

Answer 23

Cloudy cornea
Intellectual disability
Microcephaly
Heart defects

Question 24

Which congenital malformations does cytomegalovirus cause?

Answer 24

Inflammation of retina
Enlarged liver/spleen
Mineral deposits on the brain [insert pic]
Microcephaly
Psychomotor impediments

Question 25

Which congenital malformations does herpes simplex virus cause?

Answer 25

Segmental skin loss Limb hypoplasia Microcephaly Visual defects

Question 26

What is Zika virus and how does it affect pregnancy?

Answer 26

Spread by mosquitos, bodily fluids Causes a fever/ rash/ joint pain/ red eyes Causes congenital malformations

Question 27

Which congenital malformations does Zika virus cause?

Answer 27

Microcephaly Severe cognitive disabilities

Question 28

What is thalidomide and how does it affect pregnancy?

Answer 28

It was developed in Germany in the 1950s as a morning sickness drug Caused shortened or absent limbs Now used to treat leprosy and HIV

Question 29

How does alcohol affect pregnancy?

Answer 29

It is a chemical teratogen Causes growth problems, intellectual disability, impaired motor ability and coordination Facial characteristics - small eyes, thin upper lip More alcohol consumed during pregnancy means increased problems

Question 30

How does radiation affect pregnancy?

Answer 30

It is a physical teratogen Causes cell death or chromosome changes Affects central nervous system Causes congenital malformations (microcephaly, cognitive disability, bone cancer risk)

Question 31

How can maternal disease such as uncontrolled maternal diabetes affect pregnancy?

Answer 31

Causes congenital malformations such as Macrosomia (really big baby) Ventricular septal defects Spina bifida Renal agenesis

Question 32

How dos folic acid deficiency affect pregnancy?

Answer 32

Malformations in the central nervous system Causes congenital malformations such as spina bifida, anencephaly (neural tube doesn’t form)

Question 33

Label the features of the sperm [insert pic]

Question 34

Label the features of the oocyte [insert pic]

Question 35

Label the development of the ovum [insert pic]

Question 36

What is the role of LH?

Answer 36

It increases the permeability of blood vessels local to the antrum. The antrum gets larger LH activates proteases that snip off tissue around the Graafian follicle Oocyte erupts from Graafian follicle (Ovulation)

Question 37

What are the first 4 stages in fertilisation?

Answer 37

Capacitacion of sperm Acrosome reaction Formation of zygote Fusion of pronuclei

Question 38

Where does fertilisation usually take place?

Answer 38

In the ampulla of the uterine tube

Question 39

How do the oocytes get into the uterine tube?

Answer 39

The fimbriae sweep them in

Question 40

How do the sperm know where and when to go in the uterus?

Answer 40

Oocyte produces chemoattractants which attract sperm

Question 41

Describe the steps in capacitation

Answer 41

Acrosome releases enzymes that allow sperm to penetrate the zona pellucida Sperm initiates cortical reaction Zona pellucida becomes impermeable

Question 42

What is the process of cells dividing during the first 4 days of fertilisation called?

Answer 42

Cleavage

Question 43

When does a zygote become a morula?

Answer 43

When it reaches 16-32 cells

Question 44

Describe the structure of the morula

Answer 44

Inner cell mass (embryoblasts) Outer cell mass (trophoblasts) Pocket of fluid which pushes embryoblasts to one size

Question 45

What organ systems do the ectoderm, mesoderm and endoderm end up forming?

Answer 45

Ectoderm - nervous system Mesoderm - musculoskeletal and cardiovascular system Endoderm - respiratory tract, GI tract, bladder, liver, pancreas and glands