embryogenesis & development

Question 1

What is gastrulation?

Answer 1

The process of the development of the 3 germ layers, known as the trilaminar disc

Question 2

What are the 3 layers of the trilaminar disc?

Answer 2

Ectoderm (on top) , mesoderm (in middle), endoderm (on bottom)

Question 3

What are the tissue derivatives of the ectoderm?

Answer 3

neural ectoderm: brain, spinal cord
non-neural ectoderm: epidermis, hair, nails

Question 4

What are the tissue derivatives of the mesoderm?

Answer 4

muscle, blood vessels, connective tissue, bones, reproductive organs

Question 5

What are the tissue derivatives of the endoderm?

Answer 5

digestive tract & organs, respiratory tract and associated glands

Question 6

What is teratogenesis?

Answer 6

The process by which congenital malformations are produced in an embryo or foetus, due an event that interferes with the process of development of a tissue or organ

Question 7

What stage of gestation are embryos most vulnerable to teratogens?

Answer 7

Week 3-8 - when embryogenesis is occuring

Question 8

What is neurulation?

Answer 8

The process of the formation of the neural tube, which is the precursor to the central nervous system

Question 9

What is the process of neural tube formation (neurulation)?

Answer 9

Following gastrulation, a portion of the ecotderm becomes the neural plate. The lateral edges of the plate converge to form nerual folds. The folds come together to form the neural tube, which closes from the centre to the ends. The areas that are last to close are called the anterior and posterior neuropores.

Question 10

What are some possible developmental defects that can occur to the GI system?

Answer 10

Omphalocele, Hirschprung’s disease, Meckel’s diverticulum, Fistula

Question 11

What are some possible developmental defects that can occur to the heart?

Answer 11

Atrial/ventricular septal defect, narrowed aorta, closure of pulmonary artery, tetralogy of Fallot

Question 12

What are some possible developmental defects that can occur to the lungs?

Answer 12

Fistula, herniation

Question 13

What are some possible developmental defects that can occur to the genitalia?

Answer 13

Ambiguous genitalia, infertility

Question 14

What are some possible developmental defects that can occur to the kidneys?

Answer 14

Horseshoe kidney, pelvic kidney, renal agenesis