Embryology 1&2

Question 1

What is embryology?

Answer 1

Study of the embryo

Question 2

Name the 3 phases of embryology

Answer 2

Pre-embryonic phase
embryonic phase
foetal phase

Question 3

What weeks does the pre embryonic phase occur?

Answer 3

0-3

Question 4

What weeks does the embryonic phase take place?

Answer 4

4-8 weeks

Question 5

What weeks does the foetal phase take place?

Answer 5

9-40 weeks

Question 6

What is a spermatogonium?

Answer 6

An early cell which will give rise to sperm and found in the gonads

Question 7

What is an oogonium?

Answer 7

An early cell in the production of an ovum and is found in the gonads

Question 8

How many sperm are formed in spermatogenesis?

Answer 8

4

Question 9

How many ovum are produced in oogenesis?

Answer 9

1 and 3 polar bodies

Question 10

Why can there not just be 1 sperm surrounding one ovum in fertilisation?

Answer 10

Must be 100’s of sperm surrounding the ovum to allow one to enter

Question 11

Where does fertilisation occur?

Answer 11

Distal end of the uterine tube

Question 12

What is the pro nucleus of a sperm and ovum?

Answer 12

The genetic material only

Question 13

When the pro nucleus of the ovum and sperm fuse what is formed?

Answer 13

Zygote

Question 14

What is a zygote?

Answer 14

The first cell

Question 15

Is a zygote diploid or haploid?

Answer 15

diploid

Question 16

Do you inherit your mitochondria from your mum or your dad?

Answer 16

Mum

Question 17

When a zygote divides a solid ball of cells is formed. What is this called?

Answer 17

Morula

Question 18

Give an example of a mitochondrial disease

Answer 18

Lebers hereditary neuropathy which leads to blindness

Question 19

Why does a cavity develop when the morula keeps on increasing in size?

Answer 19

Getting nutrition to the central core is difficult

Question 20

What are the cells that accumulate at one end called?

Answer 20

inner cell mass

Question 21

What are the outer lining of cells called?

Answer 21

trophoblast

Question 22

What is the structure arising from a morula called?

Answer 22

blastocyst

Question 23

When does a blastocyst form?

Answer 23

Day 5-6

Question 24

What is the main requirement for the blastocyst to be able to reach and implant in the uterus?

Answer 24

healthy ciliated epithelium

Question 25

Why does ectopic pregnancy occur?

Answer 25

The cilia are not functioning properly

Question 26

What exact structure does the blastocyst bury into in the uterine wall?

Answer 26

endometrium

Question 27

myometrium

Answer 27

the smooth muscle tissue of the uterus

Question 28

endometrium

Answer 28

inner epithelial layer of the uterus

Question 29

At around what day does the blastocyst bury into the endometrium?

Answer 29

about day 7

Question 30

What allows the blastocyst to bury into the endometrium?

Answer 30

The chorion

Question 31

What forms the chorion?

Answer 31

The trophoblast dividing into 2 layers of cells which forms the chorion

Question 32

What are the finger like structures on the chorion called?

Answer 32

chorionic villi

Question 33

Name the 3 things that the chorion does

Answer 33

implantation of blastocyst forms part of placenta Secretes HCG

Question 34

What is HCG used for?

Answer 34

To detect pregnancy

Question 35

Until what week does HCG increase until?

Answer 35

week 12

Question 36

What des HCG do?

Answer 36

Maintain the endometrium

Question 37

What is the decidua basalis?

Answer 37

Endometrium deep to implanted conceptus with maternal blood vessels

Question 38

What do the cells of the inner cell mass form?

Answer 38

The bilaminar disc

Question 39

What 2 compartments does the bilaminar disc seperate?

Answer 39

The amniotic cavity above and the yolk sac below

Question 40

What are the two parts of the bilaminar disc called?

Answer 40

The epiblast and the hypoblast

Question 41

By what week is the placenta matured by?

Answer 41

18-20 weeks

Question 42

In comparison to the fetus how much does the placenta weigh?

Answer 42

1/6

Question 43

State the 3 main functions of the placenta

Answer 43

Foetal nutrition Transport of waste and gases Immune properties

Question 44

What are the 2 parts of the placenta?

Answer 44

The maternal part and the foetal part

Question 45

Briefly describe the maternal part of the placenta

Answer 45

Decidua basalis of endometrium | Rough with maternal blood vessels

Question 46

Briefly describe the foetal part of the placenta

Answer 46

Smooth with foetal blood vessels and end of umbilical cord

Question 47

Name the 2 different types | Of twins

Answer 47

Fraternal and identical

Question 48

Which type of twins can run in families?

Answer 48

Fraternal

Question 49

What is the primitive streak?

Answer 49

Dipping in of cells of the epiblast - forms in the midline

Question 50

Once the primitive streak is formed what is also formed?

Answer 50

The axis of the embryo

Question 51

What is the term given to the formation of germ layers?

Answer 51

gastrulation

Question 52

Name the 3 germ layers

Answer 52

ectoderm mesoderm endoderm

Question 53

How is the notochord formed?

Answer 53

Cells from ectoderm sink down to form a solid tube

Question 54

How are the germ layers formed?

Answer 54

epiblast cells migrate down and displace the hypoblast

Question 55

What is the term given to the formation of the neural tube?

Answer 55

neurulation

Question 56

What induces ectodermal cells in the midline to form a neural tube?

Answer 56

The notochord

Question 57

What does the neural tube induce?

Answer 57

Mesoderm to thicken

Question 58

Name the 3 parts the mesoderm separates into

Answer 58

paraxial mesoderm intermediate plate mesoderm lateral plate mesoderm

Question 59

What does the lateral mesoderm split to give?

Answer 59

Somatic and splanchnic mesoderm

Question 60

What does the paraxial mesoderm give rise to?

Answer 60

somites

Question 61

What does the intermediate plate mesoderm give rise to?

Answer 61

Urogenital system (kidneys and reproduction)

Question 62

What does the lateral plate mesoderm give rise to?

Answer 62

Body cavity and coverings

Question 63

When do the lateral folds begin?

Answer 63

week 3

Question 64

What day does the heart start to beat?

Answer 64

day 24

Question 65

Where does the gut formation arise?

Answer 65

endoderm

Question 66

How many pairs of somites form?

Answer 66

43

Question 67

Name the 3 things that somites divide into

Answer 67

dermatome myotome sclerotome

Question 68

Dermatome give rise to..?

Answer 68

dermis of skin

Question 69

myotome give rise to...?

Answer 69

muscles

Question 70

sclerotome give rise to...?

Answer 70

bones including vertebrate

Question 71

What is teratology?

Answer 71

Study of when things go wrong during development

Question 72

Teratogens

Answer 72

environmental factors that cause abnormal development

Question 73

What causes congenital rubella syndrome?

Answer 73

contraction of german measles when pregnant

Question 74

Give some examples of environmental teratogens

Answer 74

drugs alcohol viruses radiation

Question 75

When is there a highest risk and sensitivity to teratogens?

Answer 75

week 3-8

Question 76

Give some examples of prenatal tests to diagnose malformations

Answer 76

anomaly ultrasound scan - 12 weeks blood test amniocentesis and chorionic villus sampling

Question 77

Give some examples of postnatal tests to diagnose malformations

Answer 77

hip stability fingers and toes hearing testes descent