Anatomy- how do our intestines work?

Question 1

How is the inner layer of smooth muscle in the intestine wall arranged?

Answer 1

Circularly

Question 2

How is the outer layer of smooth muscle in the intestine wall arranged?

Answer 2

Longitudinally

Question 3

Which cavities are contained within the abdominal cavity?

Answer 3

The peritoneal cavity and the retroperitoneum.

Question 4

name the 9 regions of the abdomen.

Answer 4

Right and left hyperchondrium, epigastric, Right and left lumbar/flank, umbilical, right and left inguinal/iliac fossa, pubic.

Question 5

What is muscle guarding?

Answer 5

The involuntary contraction of anterolateral abdominal wall muscles to protect a damaged organ. It is a sign which alerts doctors to a pathology in the abdominal cavity.

Question 6

What are the abdominal organs?

Answer 6

The liver
the terminal oesophagus
The stomach
The gallbladder
The pancreas
Most of the intestines (part of the small intestines hang inferiorly into the pelvic cavity)
The kidneys
The adrenal glands

Question 7

What is the pelvic part of the lower GI tract?

Answer 7

Rectum, anal canal and anus

Question 8

What are the foregut organs?

Answer 8

the oesophagus to the mid duodenum including the liver, spleen, gallbladder and half of the pancreas

Question 9

What are the midgut organs?

Answer 9

The mid duodenum to the proximal 2/3 of the transverse colon and half of the pancreas

Question 10

What are the hindgut organs?

Answer 10

The distal 1/3 of the transverse colon to the proximal half of the anal canal.

Question 11

How many layers of skeletal muscles are in the anterolateral abdominal wall?

Answer 11

3

Question 12

Where is the retroperitoneum?

Answer 12

In the abdominal cavity, posterior to the peritoneum

Question 13

What is an intraperitoneal organ?

How mobile is it?

Answer 13

An organ which is almost completely covered with visceral peritoneum. It is not in the peritoneum. It is minimally mobile.

Question 14

What is a retroperitoneal organ?

Answer 14

It is located in the retroperitoneum and only has visceral peritoneum on its anterior surface.

Question 15

What is an organ with a mesentery?

How mobile are these organs?

Answer 15

An organ which is covered in visceral peritoneum and is suspended from the posterior abdominal wall by a mesentery, which is an organ’s double layer of visceral peritoneum.
The organs are highly mobile.

Question 16

What are often contained within the mesenteries?

Answer 16

Arteries, veins, nerves and lymphatics passing between the intestines and the retroperitoneum.

Question 17

What can cause peritonitis?

Answer 17

Blood, pus or bowel contents in the peritoneal cavity

Question 18

Where in the abdominal cavity does the inferior vena cava ascend?

Answer 18

In the retroperitoneum

Question 19

Where in the abdominal cavity does the abdominal aorta descend?

Answer 19

In the retroperitoneum

Question 20

What are the three midline branches of the abdominal aorta and which organs do they supply?

Answer 20

1. The coeliac trunk- supplies the organs of the foregut
2. The superior mesenteric arery- supplies the organs of the midgut
3. The inferior mesenteric artery- supplies the organs of the hindgut

Question 21

Which vein drains the organs of the hindgut?

Where does it drain the blood to?

Answer 21

The inferior mesenteric vein. It drains the blood into the splenic vein.

Question 22

Which vein drains the organs of the midgut?

Where does it drain the blood to?

Answer 22

The superior mesenteric vein. It drains the blood into the hepatic portal vein.

Question 23

Which vein drains the organs of the foregut?

Where does it drain the blood into?

Answer 23

The splenic vein. It drains the blood into the hepatic portal vein.

Question 24

What are the two venous systems of the liver?

Describe the passage of blood through the liver via these venous systems.

Answer 24

The portal venous system (the hepatic portal vein) and the systemic venous system the IVC and the SVC).
The hepatic portal vein carries venous blood from the portal venous system to the liver. The liver then passes the blood to the IVC via the hepatic veins to return to the heart.

Question 25

Describe the lymphatic drainage of the foregut organs.

Answer 25

The foregut structures drain their lymph via nodes located along the splenic artery towards the coeliac nodes located around the origin of the coeliac trunk.

Question 26

Describe the lymphatic drainage of the organs of the midgut.

Answer 26

The midgut structures drain their lymph via nodes located along the superior mesenteric artery, towards the superior mesenteric nodes located around the origin of the superior mesenteric artery.

Question 27

Describe the lymphatic drainage of the organs of the hindgut.

Answer 27

The structures of the hindgut drain their lymph via nodes located along the inferior mesenteric artery, towards the inferior mesenteric artery nodes, located around the origin of the inferior mesenteric artery.

Question 28

Name a sphincter made of skeletal muscle.

Answer 28

The external anal sphincter.

Question 29

What kind of pain is caused by an obstruction?

What causes this pain?

Answer 29

Colickly pain. This is caused by increased peristalsis proximal to the obstruction to try and dislodge it.

Question 30

What sort of control is the smooth muscle in the wall of the GI tract under?

Answer 30

Autonomic control

Question 31

What is the name of the folds in the stomach?

Answer 31

Rugae

Question 32

Name a disease in which the villi of the small intestine are damaged.

Answer 32

Coeliac disease

Question 33

Is the internal anal sphincter made of smooth or skeletal muscle?

Answer 33

Smooth muscle

Question 34

Where is the anus located?

Answer 34

The perineum

Question 35

What is it called when drugs reach the liver via the portal venous system and are slightly metabolised there?

Answer 35

First pass metabolism

Question 36

What is the name for the specialised lymphatic capillaries found in the capillary beds of the villi of the small intestine into which some digested fat molecules are absorbed?

Answer 36

Lacteals