embryology

Question 1

Define conceptus/ fertilistation

Answer 1

End of week 3

Question 2

What is the time period for an embryo?

Answer 2

Weekk 4-8

Question 3

What is the time period of a foetus?

Answer 3

Week 9 to birth

Question 4

Define gametogenesis

Answer 4

germ cell formation (oogenesis > oocyte, spermatogenesis > spermatozoa)

Question 5

Define fertilisation

Answer 5

fusion of sperm and oocyte to form the ZYGOTE

Question 6

Cleavage ?

Answer 6

period of rapid cell division

Question 7

Gastrulation?

Answer 7

formation of germ layers (Ecto (outer) Meso (middle) Endo (inner) –derm)

Question 8

Formation

Answer 8

– embryonic folding (gut tube within skin/body wall)

Question 9

Organogenesis –

Answer 9

formation of organs and organ systems (continues to develop during foetal period)

Question 10

How development of the embryo is regulated?

Answer 10

Genetic, Epigenetic (preferential expression of either the maternal or the paternal copy of a gene), environmental.

Question 11

Describe fertilisation to trilaminar

Answer 11

Fertilisation takes place at the ampulla
Sperm binds to the zona pellucida glycoprotein. Acrosomal enzymes released from sperm head digest its way into egg. Egg and sperm plasma membrane fuse and sperm contents enter egg. Sperm entry triggers completion of meiosis 2 and release of cortical granules by oocyte.

Cleavage- the zygote (sperm + oocyte) undergoes series of mitotic divisions which leads to many daughter cells called blastomeres.

When there are 8 cells compaction takes place so that the zygote becomes a Blastocyst.

Implantation should take place at the middle or upper uterine wall.
Can take place at the ovary, ampulla, and uterine tube (ECTOPIC)
Gastrulation formation of the germ layers. 2 layers become 3.
Cells migrate through the primitive streak.

Question 12

What is in the mesoderm, ectoderm and endoderm?

Answer 12

Ectoderm – epidermis of skin, Nervous System
Mesoderm – subdivided (into three parts)
Endoderm – lining of gut tube, lining of respiratory tract

Question 13

What are some abnormalities of development?

Answer 13

The embryo is most at risk of defects occurring during weeks 3 – 8

Interatrial septum separates the right from the left atrium in the adult heart and that incomplete closure of the embryonic foramen ovale in the septum leads to an atrial septal defect (ASD).

The interventricular septum separates the right from the left ventricle in the adult heart. Know that incomplete closure leads to a ventricular septal defect (VSD).

Abnormalities affecting the adult heart:

• transposition of the great vessels (where aorta emerges from right ventricle, and pulmonary trunk from left)
• tetralogy of Fallot (pulmonary stenosis, right ventricle hypertrophy, VSD, overriding aorta)

Question 14

What is a systematic review?

Answer 14

Systematic Review – review of evidence on a clearly formulated question that uses systematic and explicit methods to identify, select and critically appraise relevant primary research.

Question 15

Meta-Analysis

Answer 15

– a statistical analysis that combines the results of multiple scientific studies.

Question 16

Randomised Controlled Trial

Answer 16

• People are allocated at random to receive one of several clinical interventions. One of these interventions is the standard of comparison or control. The control may be a standard practice, a placebo (dummy treatment), or no intervention at all. RCTs seek to measure and compare the outcomes after the participants receive the interventions. Because the outcomes are measured, RCTs are quantitative studies.

Question 17

Phases of Clinical Trials

Answer 17

Phase I – Clinical Pharmacology (dosage, safety)
Phase II – Initial Clinical Assessment (likely effectiveness, common adverse effects)
Phase III – Randomised Controlled Trial
Phase IV – Post marketing surveillance (less common adverse effects)

Question 18

Incidence rate:

Answer 18

No. of new cases of a disease occurring in a population during a specific period of time/
No. of persons exposed to risk of developing the disease during that period of time

Question 19

Prevalence Rate:

Answer 19

No. of cases of a disease present in population at specific point in time /
No. of persons at risk of having disease at that point in time

Question 20

What is the work system in the SEIPS framwork?

Answer 20

tools+ tech, organization, person, tasks, internal environment

Question 21

What correctly explains the difference between

foetal and adult haemoglobin?

Answer 21

Foetal haemoglobin has gamma subunits instead of beta subunits, causing
it to have a higher affinity for oxygen than adult haemoglobin

This is why infants with some congenital heart defects can be
asymptomatic until they are weeks old, when foetal haemoglobin is lost.

Question 22

What is the

a) Ductus arteriosus
b) Ductus venosus
c) Foramen ovale
d) Ligamentum arteriosum

Answer 22

The ductus arteriosus connects the pulmonary
trunk to the aorta in the foetal circulation and closes to form the ligamentum arteriosum three weeks after birth.
The ductus venosus allows oxygenated blood
from the placenta to bypass the hepatic circulation.

The foramen ovale shunts oxygenated blood from the right atrium to the left atrium, bypassing the
pulmonary circulation.

Question 23

What is placed in the centre of the SEPSIS framework?

Answer 23

Person(s)

Question 24

When are the germ layers formed?

Answer 24

They are formed during gastrulation

Question 25

Which cell population is the fatal part of the placenta derived?

Answer 25

trophoblast