- Integument - Nervous System - Proctodeum - Stomoteum

- Muscles - Muscle walls - Connective tissue - Bones

- Lining of the gut - Gut derived organs

- Double layer of peritoneum formed by splanchnic mesoderm - Functions to connect organs to the body wall

Exam #4: Abdominal Cavity Embryology Flashcards by Jonathan Kallevang

Ectoderm

Integument
Nervous System
Proctodeum
Stomoteum

How well did you know this?

Not at all

Perfectly

What is the proctodeum?

Primary lining of the anus

How well did you know this?

Not at all

Perfectly

What is the stomodeum?

Secondary lining of the mouth

How well did you know this?

Not at all

Perfectly

Mesoderm

Muscles
Muscle walls
Connective tissue
Bones

How well did you know this?

Not at all

Perfectly

Endoderm

Lining of the gut

- Gut derived organs

How well did you know this?

Not at all

Perfectly

When does the embryo form a primitive gut tube?

4 weeks

How well did you know this?

Not at all

Perfectly

What is the primitive gut tube connected to?

Yolk Sac

How well did you know this?

Not at all

Perfectly

What is the yolk sac? What are the functions of the early yolk sac?

Yolk sac provides the fetus with nourishment prior to implantation (2-3weeks)
Hematopoesis prior to development of the liver

How well did you know this?

Not at all

Perfectly

What connects the primitive gut tube to the yolk sac?

Yolk stalk or omphalocentric duct (future umbilical cord)

How well did you know this?

Not at all

Perfectly

Describe the contents of the foregut.

Stomodeum–>Proximal 1/3 of the duodenum

Celiac Trunk
Pharyngeal pouches

How well did you know this?

Not at all

Perfectly

Describe the contents of the midgut.

Distal 2/3 of duodenum–> proximal 2/3 of colon

Superior mesenteric artery (SMA)
Yolk stalk

How well did you know this?

Not at all

Perfectly

Describe the contents of the hindgut.

Distal 1/3 of colon–>proctodeum

Inferior mesenteric artery
Allantois (waste sac)

How well did you know this?

Not at all

Perfectly

What is recanalization?

Hollowing out of the primitive gut tube

How well did you know this?

Not at all

Perfectly

What can an error in recanalization produce?

Stenosis (narrowing) or atresia (complete blockage)

How well did you know this?

Not at all

Perfectly

What is a mesentery?

Double layer of peritoneum formed by splanchnic mesoderm

- Functions to connect organs to the body wall

How well did you know this?

Not at all

Perfectly

What are the three remnants of the ventral mesentery?

1) Lesser Omentum
2) Falciform Ligament
3) Coronary Ligament

How well did you know this?

Not at all

Perfectly

Lesser Omentum

Sheet of mesentery from the liver to the stomach & duodenum

Falciform Ligament

Attaches the liver to the ventral body wall

Coronary Ligament

Attaches the liver to the diaphragm

What is the definition of intraperitoneal & what organs are intraperitoneal?

Organs suspended in the mesentery

Stomach
Spleen
Transverse Colon

What is the definition of primarily retroperitoneal & what organs are primarily retroperitoneal?

Organs that have always been external to the peritoneum

Esophagus
Rectum
Anal canal
Kidneys

What is the definition of secondarily retroperitoneal & what organs are secondarily retroperitoneal?

Organs initially develop in the mesentery but end behind the mesentery after folding & rotation

Distal 2/3 of the duodenum
Ascending & descending colon

What is the mnemonic for all of the retroperitoneal organs?

SADPUCKER

Suprarenal glands
Aorta (& Vena Cava) 
Duodenum (Distal 2/3)
Pancreas
Ureters
Colon (Ascending & Descending) 
Kidneys 
Esophagus 
Rectum

List the organs of the foregut.

Pharynx
Esophagus
Stomach
Proximal 1/3 of the duodenum

Outpocketings

Pharyngeal pouches
Lower respiratory system
Liver
Pancreas
Gallbladder

Describe the development of the esophagus.

Tracheal-esophageal fold splits into two tubes, the esophagus & trachea

Esophageal atresia

Complete blockage of the esophagus

Polyhydramnios

Abnormal build up of amniotic fluid; an indication of esophageal atresia - Fetus "drinks" amniotic fluid - Esophageal atresia= unable to "drink" & increase in amniotic fluid that is not being recycled

Describe the development of the stomach.

- Dorsal border grows faster than the ventral border-->greater & lesser curvatures - Rotates 90 degrees CLOCKWISE along the longitudinal axis - Lesser curvature moves right - Greater curvature moves left

Describe the location of the right & left vagus nerves in relation to the stomach.

Vagus nerves run alongside the stomach - Right vagus ends on the dorsal surface - Left vagus ends on the ventral surface

Describe the development of the pancreas.

Pancreas forms from two buds; dorsal &ventral - Dorsal bud elongates as the ventral remains same - Fuse together b/c of stomach rotation

What is an annular pancreas?

When there are two ventral pancreatic buds that form & fuse around the gut tube-->strangulation of the intestines

What is special about the embryology of the spleen?

It is NOT an endodermal derivative; rather, it is a mesoderm derivative (outpocketing of the dorsal mesentery)

List the organs of the midgut.

- Distal 2/3 of the duodenum - Cecum - Appendix - Ascending colon - Proximal 2/3 of the transverse colon (to left colic flexure)

Describe the development of the midgut.

Midgut rotates COUNTER-clockwise around the SMA - Elongates & forms as U-shape w/ SMA as axis & Yolk stalk as apex - End of rotation cecum descending into right lower quadrant - Causes secondarily retroperitoneal configuration

Non-rotation

- Intestine does NOT rotate as it re-enter the abdomen - Causes duodenal obstruction - Can lead to midgut volvulus i.e. catastrophic twisting of the midgut

Reversed Rotation

Midgut rotates CLOCKWISE instead of COUNTER-CLOCKWISE

Subhepatic Cecum & Appendix

Cecum adheres to the inferior surface of the liver

List the organs of the hindgut.

- Distal 1/3 of the transverse colon - Descending colon - Sigmoid colon - Rectum - Anal canal Outgrowths - Urinary bladder - Urethra

Urorectal Septum

- Divides the allantois & yolk sac | - Separates cloaca into urogenital membrane & anal membrane

What is the significance of the pectinate line?

``` Above= endoderm w/ pressure & stretch receptors Below= ectoderm w/ pain receptors ```