Lecture 4 to 5

Question 1

What is the function of the chorion?

Answer 1

Outermost layer. Acting as a gas exchange surface

Question 2

What is the function of the amnion and where is it located?

Answer 2

The amnion surrounds the embryo. It is a fluid filled cavity, the primary function of the amnion is to act as a cushion providing favourable osmotic and ionic movement

Question 3

What is the allantois and what is its function?

Answer 3

It is a highly vascularsied structure delivering gases between the embryo and the outer surface layers- stores nitrogenous wastes in birds and reptiles

Question 4

Name the structure that is shown below:

Answer 4

Merkels diverticulum

Question 5

What are the three primary divisions of the brain?

Answer 5

Prosencephalon, Mesencephalon, Rhombencephalon

Question 6

What are the five primary divisions of the brain?

Answer 6

(most forward) Telencephalon to Diencephalon to Mesencephalon to the Metencephalon to the Myelencephalon

Question 7

How many brachial arches are there?

Answer 7

6 brachial arches exist, however the 5th one never develops

Question 8

Define the term brachial arches:

Answer 8

A series of externally visible tissue bands under the brain forming during embryological developement. Externally between the arches it is clefts that form, whereas internally it is pouches

Question 9

Whast forms from cleft one and pouch one?

Answer 9

External ear and the auditory tube

Question 10

What structure forms from pouch two?

Answer 10

Pouch two forms palantine tonsils

Question 11

What structures form from pouch 3-6?

Answer 11

Important endocrine glands

Question 12

What structure evolves from pharyngeal arch 1?

Answer 12

Merkels cartiladge

Question 13

What structure forms from pharyngeal arch 2?

Answer 13

Styloid process

Question 14

What structure forms from pharyngeal arch 3?

Answer 14

Hyoid Bone

Question 15

What structure forms from pharyngeal arch 4 and 5?

Answer 15

Thyroid cartilage and cricoid

Question 16

What happens the embryological developement condition of a cleft palate?

Answer 16

Typically occurs where the palantine processes and the incisor processes fail to meet up properly during embryological developement. The hard palate does not form and hence the animal will not be able to suckle.

Question 17

What occurs in the embryological condition of a cleft lip?

Answer 17

Forms as a result of a failure of fusion of the medial nasal prominences with the maxillary processes