Lecture 16: Branching Morphogenesis

Question 1

Types of glands (secretion)

Answer 1

1. Serous
2. Mucous
3. Seromucous

Question 2

Serous vs mucous secretion

Answer 2

H2O based vs glycoprotein based secretions

Question 3

Types of glands (structure)

Answer 3

1. Unicellular
2. Multicellular
   -Simple tubular
   -Branched compound

Question 4

Secretory unit shapes

Answer 4

1. Tubular
2. Alveolar (pit-like)
3. Tubulo-alveolar
4. Acinar

Question 5

Types of ducts

Answer 5

1. Striated
2. Intercalated
3. Pancreatic (special centroacinar cell)

Question 6

Major salivary glands and their secretion types

Answer 6

1. Parotid (serous)
2. Submandibular (mixed seromucous, 90/10)
3. Sublingual (mixed seromucous, 50/50)

Question 7

Stages of lung development

Answer 7

1. Embryonic
2. Pseudoglandular
3. Canalicular
4. Saccular
5. Alveolar

Question 8

Other salivary glands

Answer 8

Minor mucous salivary glands and serous von Ebner’s glands (tongue)

Question 9

Pancreatic branching

Answer 9

2 trunks form separate dorsal and ventral buds of foregut endoderm

Question 10

Pancreatic excretory ducts

Answer 10

Duct of Wirsung (ventral bud) and Duct of Santorini (dorsal bud)

Question 11

Endocrine pancreas cells

Answer 11

Endocrine pancreas = islets of Langerhans
α cells -> glucagon
β cells -> insulin
γ cells -> somatostatin

Question 12

Pancreatic progenitor lineages

Answer 12

1. Tip cells (exocrine acini)
2. Trunk cells (ducts, endocrine cells)

Question 13

Zollinger-Ellison syndrome

Answer 13

Gastrin producing islet cell tumor; gastrinoma

Question 14

Lung branching

Answer 14

Trachea -> segmental bronchi -> bronchioles -> alveoli

Question 15

Salivary gland branching

Answer 15

Excretory ducts -> interlobular -> intralobular -> striated -> intercalated -> acinar cells

Question 16

Pancreatic branching

Answer 16

Excretory ducts (Wirsung, Santorini) -> interlobular -> intralobular -> intercalated -> centroacinar -> acinar cells

Question 17

Mammary gland branching

Answer 17

Lactiferous ducts -> interlobular -> intralobular -> terminal ductules -> alveolar cells

Question 18

Kidney development stages

Answer 18

1. Pronephros
2. Mesonephros
3. Metanephros

Question 19

Kidney branching

Answer 19

Ureters -> major then minor calyces -> collecting duct -> collecting tubules -> nephron

Question 20

Pancreatic EMT

Answer 20

Trunk cells delaminate (EMT) from the ducts to form islets in mesenchymal tissue

Question 21

MET events in kidney

Answer 21

1. MET from intermediate mesoderm to mesonephric/paramesonephric ducts (to form collecting ducts)
2. Induction of metanephric mesenchyme into nephron by metanephric tissue cap via MET

Question 22

Pronephros

Answer 22

First kidney development stage. Located in dorsal/superior coelomic cavity and drains directly into the cavity. Originates the mesonephric duct.

Question 23

Mesonephros

Answer 23

Second developmental kidney. Forms internal glomeruli to connect with mesonephric duct

Question 24

Metanephros

Answer 24

Final, most caudal developmental kidney. Mesonephric duct branches into ureteric bud and collecting tubule/duct.
Metanephric induction of loop of Henle occurs.
Vasculogenesis to form glomeruli and vasa recta occurs.

Question 25

Formation of renal corpuscle

Answer 25

Vascular supply forms a capillary bed which punches into the primitive renal tubule