Exam 2 - Lecture 32 (Digestive & Respiratory System)

Question 1

What 2 things support intestinal development?

Answer 1

1. Elongated dorsal mesentery

2. Cranial mesenteric artery

Question 2

From what does the cecum form?

Answer 2

As an evagination of the caudal limb of the intestinal loop

Question 3

What happens during physiological herniation of the intestine during development?

Answer 3

Developing intestine moves out of the embryo into the yolk sac

Question 4

How many degrees does the cranial limb of the developing intestinal tract move and what does it form?

Answer 4

270 degrees; root of mesentery

Question 5

What closes the cloaca?

Answer 5

cloacal membrane

Question 6

What divides the cloaca?

Answer 6

Urorectal septum

Question 7

Where does the urorectal septum form?

Answer 7

Junction of hindgut and allantois (urogenital sinus)

Question 8

Which way does the cloaca divide?

Answer 8

Caudally

Question 9

What does the urorectal septum divide the cloaca into?

Answer 9

anal membrane and urogenital membrane

Question 10

What are the 3 steps to cloacal separation?

Answer 10

1. Urorectal septum moves towards cloaca to divide it
2. Septum fuses with the cloacal membrane
3. Formation of anal membrane and urogenital membrane

Question 11

What are the 4 malformations of the intestinal tract?

Answer 11

1. Intestinal stenosis
2. Intestinal atresia
3. Atresia ani
4. Urorectal fistula

Question 12

What is intestinal stenosis?

Answer 12

Narrowing of intestines

Question 13

What is intestinal atresia?

Answer 13

Section of intestine disappears

Question 14

What is atresia ani?

Answer 14

Anal membrane doesn’t break down

Question 15

What is a urorectal fistula?

Answer 15

Abnormal connection between rectum and urogenital system where the septum failed to divide.

Question 16

What do the pharyngeal arches give rise to as a whole?

Answer 16

pharynx and part of the face

Question 17

What 4 things can you find in the pharyngeal arches?

Answer 17

1. Aortic arch
2. Cartilage rod
3. Nerve (cranial)
4. Muscle

Question 18

The 1st pharyngeal arch gives rise to CN # __?

Answer 18

V (trigeminal n.)

Question 19

What bones does the 1st pharyngeal arch give rise to?

Answer 19

Mandible, maxilla, incus, malleus

Question 20

What muscles does the 1st pharyngeal arch give rise to?

Answer 20

Muscles of mastication and rostral digastricus

Question 21

The 2nd pharyngeal arch gives rise to CN # __?

Answer 21

VII (facial n.)

Question 22

What bones does the 2nd pharyngeal arch give rise to?

Answer 22

Hyoid bones and stapes

Question 23

What muscles does the 2nd pharyngeal arch give rise to?

Answer 23

Muscles of facial expression and caudal digastricus

Question 24

The 4th and 6th pharyngeal arches give rise to CN # __?

Answer 24

X (Vagus n.)

Question 25

What cartilage do the 4th and 6th pharyngeal arches give rise to?

Answer 25

laryngeal

Question 26

What muscles do the 4th and 6th pharyngeal arches give rise to?

Answer 26

``` 4th = cricothyroideus 6th = intrinsic laryngeal muscles ```

Question 27

The caudal laryngeal nerve is a terminal branch of the _____.

Answer 27

Recurrent laryngeal nerve

Question 28

What does the left recurrent laryngeal nerve wrap around in the thoracic cavity?

Answer 28

Ligamentum arteriosum

Question 29

What does the right recurrent laryngeal nerve wrap around in the thoracic cavity?

Answer 29

R subclavian a.

Question 30

What causes cleft lip?

Answer 30

Medial nasal and maxillary processes don't meet

Question 31

What causes cleft palate?

Answer 31

Secondary palates fail to meet each other, and can also fail to meet with the primary palate

Question 32

What part of the palates become the hard palate?

Answer 32

Rostral 1/3

Question 33

What part of the palates become the soft palate?

Answer 33

Caudal 2/3

Question 34

What is another name for cleft lip?

Answer 34

Cheiloschisis

Question 35

What is another name for cleft palate?

Answer 35

Palatoschisis

Question 36

At what timepoint does the secondary palate close?

Answer 36

Outside of the critical period

Question 37

In which direction does the trachea separate from the esophagus?

Answer 37

Caudal --> cranial

Question 38

What does early lung development deal with?

Answer 38

Large airway conduction (NOT gas exchange!!)

Question 39

When are the majority of alveoli produced?

Answer 39

Postnatally

Question 40

What part of the lungs increases in mass in order for them to grow?

Answer 40

mesodermal part

Question 41

Why is it important for the SA of the lungs to increase when they expand in the fetus?

Answer 41

Important for drawing fluid away by lymphatic vessels

Question 42

What are the 3 lung malformations?

Answer 42

1. Pulmonary hypoplasia 2. Tracheal hypoplasia 3. Tracheoesophageal fistulas

Question 43

What is pulmonary hypoplasia?

Answer 43

Underdevelopment of lung

Question 44

What is tracheal hypoplasia?

Answer 44

Underdevelopment of trachea

Question 45

What is a tracheoesophageal fistula?

Answer 45

Abnormal connection between the esophagus and trachea