Embryology

Question 1

cell division

Answer 1

basis of growth

Question 2

patterning

Answer 2

how do cells know where they are

Question 3

cell specification/differentiation

Answer 3

stem cells and progenitors turning into the correct cell types

Question 4

morphogenesis

Answer 4

movement of cells/tissues to create anatomy

Question 5

oogenesis

Answer 5

begins in week 8 of life
when oogenia develop from primordial germ cells in the forming ovaries

Question 6

fertilisation

Answer 6

acrosome reaction is initiated around contact with zone pellucida and stimulates release of lytic enzymes that facilitate entry of the sperm head via membrane fusion

Question 7

morula

Answer 7

ball of cells that results from cleavage of the zygote

Question 8

morula to blastocyst

Answer 8

morula undergoes morphogenetic reorganisation to hollow out and form blastocyst
comprising inner cell mass, primitive endoderm and trophectoderm

Question 9

hatching from the zone pellucida

Answer 9

blastocyst hatches from zone pellucida
roughly 4 days post fertilisation
in advance of implantation

Question 10

implantation

Answer 10

involves binding to oligosaccharides in the uterine wall via L selectin receptors
reinforced by integral cell adhesion molecules

Question 11

L-selectin

Answer 11

stands for leukocyte
same molecule used by them to navigate vascular system

Question 12

what mediates invasion of endometrium

Answer 12

matrix metalloproteinases
secreted enzymes that lyse extracellular proteins

Question 13

what occurs at the same time as invasion (in implantation)

Answer 13

complex cellular morphogenesis gives rise to epiblast (B and C)
gives rise to future embryo
gastrulate to produce germ layers: ectoderm, mesoderm and endoderm

Question 14

spontaneous abortions

Answer 14

50% fertilised eggs are aborted
majority within first few weeks
often unrecognised or reflected in heavy/late menstruation
frequently characterised by chromosomal abnormalities

Question 15

how many ectopic pregnancies

Answer 15

1/90 pregnancies
11,000 per year

Question 16

symptoms of ectopic pregnancies

Answer 16

possible missed period
lower abdominal pain
vaginal bleeding
abnormal discharge
referred pain to shoulder
sudden sharp pain, dizziness, fainting, pallor

Question 17

diagnosis of ectopic pregnancy

Answer 17

pregnancy test
vaginal ultrasound
laparoscopy

Question 18

treatment for ectopic pregnancy

Answer 18

laparascopic surgery to terminate pregnancy
in case of rupture, abdominal surgery

Question 19

gastrulation

Answer 19

embryo undergoes process of gastrulation
creates the gut in animals
in humans the blastopore forms the anus and most h breaks through the anterior end to create a through gut