Embryology Final Exam-Digestive System

Front 1

Epithelial linings of respiratory and digestive tracts, as well as the pancreas are derivatives of which germ layer?

Back 1

endoderm

Front 2

What are derivatives of the endoderm?

Back 2

1) epithelial linings of resp. tract
2) " " " digestive tract
3) pancreas

Front 3

Which germ layer forms the lining of digestive and respiratory tract?

Back 3

endoderm

Front 4

Which tract buds from "this" tube from the liver, gall bladder and pancreas?

Back 4

digestive tract

Front 5

What is an outgrowth of the digestive tract?

Back 5

respiratory tract

Front 6

What bifurcates into two lungs?

Back 6

respiratory tract

Front 7

What is a common chamber in anterior region?

Back 7

pharynx

Front 8

What does the pharynx form?

Back 8

1) Tonsils
2) Thymus
3) paraThyroid glands

Front 9

What does the mesoderm form?

Back 9

1) skeletal muscle
2) blood cells
3) smooth muscle
4) cardio system
5) bones and cartilage
6) internal organs

Front 10

At the 4th week of development, what 3 parts develop?

Back 10

1) Foregut
2) Midgut
3) Hindgut

Front 11

What significant event occurs during the 4th week?

Back 11

1) 3 distinct portions of the portions extend the length of the embryo
2) They will contribute different components of the GI tract
3) Later, these three divisions are also defined by their vascular supply

Front 12

How is the large mid-gut generated?

Back 12

1) the lateral embryonic folding pinches off a pocket of the yolk sac
2) the 2 compartments continue to communicate through the vitelline duct

Front 13

T/F. The pharynx lies above the heart.

Back 13

False; the pharynx lies behind the heart.

Front 14

The respiratory tract will form from a ___________ arising "at this level".

Back 14

ventral bud

Front 15

Foregut

Back 15

1) oral cavity
2) pharynx (esophagus, trachea)
3) respiratory tract
4) stomach

Front 16

What is characteristic of the midgut?

Back 16

herniated

Front 17

Where is much of the midgut herniated?

Back 17

at the umbilicus external to the abdomen through development

Front 18

What is a key step in development of the midgut?

Back 18

the rotation of the midgut
-this must occur to place the GI tract in the correct abdominal position with its associated mesentry

Front 19

Why is important that the midgut is rotated during development?

Back 19

to place the GI tract in the correct abdominal position with its associated mesentry

Front 20

What does the GI tract differentiate into?

Back 20

1) oesophagus
2) stomach
3) duodenum
4) jejunum
5) iliem (small intestine)
6) colon (large intestine)

Front 21

What is the midgut?

Back 21

from beneath the stomach lies the initial portion of the small intestine, the duodenum, and associated pancreas

Front 22

What is the hindgut?

Back 22

1) distal transverse colon
2) descending colon
3) sigmoid colon
4) rectum
5) cloaca

Front 23

What is the cloaca? What does it differentiate into?

Back 23

1) the common urogenital sinus
2) an anterior urinary and posterior GI tract rectal component

Front 24

During early GI tract development, what 2 specialized regions develop?

Back 24

1) cranially (oropharyngeal membrane)
2) caudally (cloacal membrane)

Front 25

Picture of GI tract

Back 25

Name the following structures:
1) pharynx
2) pharyngeal arch arteries
3) Brain
4) Celiac trunk
5) septum transversum
6) spinal cord
7) superior mesenteric artery (SMA)
8) interior mesenteric artery
9) midgut
10) cloaca (caudal part of hindgut)
11) omphaloenteric duct

Front 26

When is the oral cavity formed?

Back 26

following the breakdown of the oropharyngeal membrane

Front 27

Where is the oral cavity formed?

Back 27

mainly by pharynx lying within pharyngeal arches

Front 28

The oral cavity contains what special fluid? Why? What happens later in development?

Back 28

1) amniotic fluid
2) because its the opening of the GI tract
3) it is swallowed

Front 29

Know 15.26 Dev biology

Back 29

know figure

Front 30

Label the following part of oral cavity:
1) salivary glands (parotid, submandibular, sublingual)
2) pharynx
3) tongue
4) esophagus

Back 30

see figure 14/38 pdf

Front 31

During the 3 and 4th weeks of human gestation, what happens to the foregut?

Back 31

the foregut divides into esophagus and respiratory diverticulum

Front 32

Label parts of partitioning of foregut

Back 32

1) foregut
2) pharynx
3) trachea
4) lung buds

Front 33

Describe the process of canalization.

Back 33

1) by week 5: endoderm in GI tract wall grows to occlude (totally block)
2) week 6-8: this tissue degenerates, reforming a hollow gut tube (recanalization)
3) abnormalities in this process can lead to duplications or stenosis
4) end of week 8: GI tract endoderm tube is a tube once again

Front 34

What is recanalization?

Back 34

hollow, then solid, then hollow again

Front 35

When and how does the stomach form?

Back 35

1) during week 4, the tube will dilate, forming an enlarged lumen in the tube. This is where the stomach will form.
2) Dorsal border grows more rapidly ventral, which establishes the greater curvature of the stomach.
3) The second 90-degree rotation occurs on the longitudinal axis establishing the adult orientation of the stomach.

Front 36

What is duodenum/pancreas rotation?

Back 36

1) The initial portion of the GI tract tube is the duodenum, which initially lies in the midline within the peritoneal cavity
2) Along with the pancreas, the duodenum undergoes rotation to become a retroperitoneal structure.

Front 37

What becomes a retroperitoneal structure?

Back 37

the duodenum and attached pancreas

Front 38

What is the junctional region?

Back 38

Internally, it is where the foregut meets the midgut

Front 39

How does the liver form?

Back 39

1) the transverse septum arises at an embryonic junctional site
2) externally, the junctional region is where the ectoderm of the amnion meets the endoderm of the yolk sac
3) Internally, the junctional region is where the foregut meets the midgut
4) the mesenchymal structure of the transverse septum provides a support within which both blood vessels and liver begin to form

Front 40

What does the liver bud differentiate to form?

Back 40

1) hepatic diverticulum
2) hepatic primordium
3) generates gall bladder, which then divides into R/L hepatic buds

Front 41

What are the three connecting stalks to the liver bud?

Back 41

1) hepatic duct
2) cystic duct
3) bile duct

Front 42

How does the pancreas form?

Back 42

1) at the foregut/midgut junction, the septum tranversum generates 2 pancreatic buds
2) the dorsal bud arises first and generates most of the pancreas
3) the ventral bud arises beside the bile duct and forms only part of the head
4) Both fuse to form the pancreas

Front 43

What does the pancreas arise from?

Back 43

1) hepatic diverticulum
2) duodenum
3) differentiate to establish specific cells for endocrine and exocrine function

Front 44

How does the spleen form?

Back 44

1) mesoderm within the dorsal mesogastrium form a long strip of cells adjacent to the forming stomach above the developing pancreas
2) spleen's haematopoietic function is lost with embryo development and lymphoid precursor...

Front 45

Much of the midgut is herniated where? When?

Back 45

umbilicus; external to abdomen through development; until week 11

Front 46

What is the expanded terminal part of the hindgut?

Back 46

cloaca; it's an endoderm-lined chamber that is in contact with the surface ectoderm

Front 47

WWhat is the surface ectoderm that is in contact with the cloaca?

Back 47

cloacal membrane

Front 48

What is the wedge of mesenchyme that divides the cloaca into dorsal and ventral parts?

Back 48

urorectal septum

Front 49

What are the two parts of the cloaca?

Back 49

1) rectum
2) urogenital sinus ventrally

Front 50

Describe cloaca development.

Back 50

1) Cloaca divides into 2 parts by week 7 (rectum, urogenital sinus ventrally)
2) by week 8: anal membrane ruptures, bringing the distal digestive tract into communication with the amniotic cavity

Front 51

What are some lumen abnormalities?

Back 51

1) atresia
2) stenosis
3) duplication

Front 52

What is a lumen abnormalities?

Back 52

abnormalities that impact the continuity of the GI tract lumen

Front 53

What is the abnormality that results in the interruption of the lumen?

Back 53

atresia

Front 54

What is the abnormality that causes the narrowing of the lumen?

Back 54

stenosis

Front 55

What is the abnormality that causes the incomplete recanalization resulting in parallel lumens?

Back 55

duplication