GI

Question 1

What are the 4 digestive organs in the GI system and what are the 2 accessory organs?

Answer 1

Digestive = oesophagus, stomach, small intestine, large intestine
Accessory = pancreas and liver

Question 2

What are the three stages of mechanical breakdown?

Answer 2

Prehension
Mastication
Motility (movement of the gut

Question 3

Which enzyme is found in saliva and what does it breakdown?

Answer 3

Amylase that breaks down carbohydrates

Question 4

What type of saliva is produced in ruminants, what is the pH alkaline?

Answer 4

Mainly serous saliva

pH is alkaline to buffer the forestomach for fermentation

Question 5

What happens to HCO3 and PO4 secretion during eating and ruminating?

Answer 5

HCO3 secretion increases and PO4 secretion decreases, this is because there is a higher flow rate

Question 6

Regulation of saliva is under neural control, how would the sympathetic nervous system influence saliva?

Answer 6

It would reduce production in the fight or flight response

Question 7

Compare the pH in the stomach compared to the small intestine

Answer 7

Stomach = pH 2

Small intestine = pH 6/7

Question 8

What provides insulation in pigs despite their lack of hair?

Answer 8

Subcutaneous fat - adipose in the superficial fascia

Question 9

What is the role of the cutaneous trunci muscle?

Answer 9

It is a skin twitch e.g. horses

Question 10

What are the 4 muscles that comprise the abdominal wall?

Answer 10

External abdominal oblique
Internal abdominal oblique
Transverse abdominal
Rectus abdominis

Question 11

What separates the left and right sides of the Rectus abdominis muscle?

Answer 11

Linea alba

Question 12

How does the arrangement of the tendons passing by the rectus abdominis affect the strength and flexibility of the abdomen?

Answer 12

Cranial - split evenly above and below providing high strength but low flexibility
Mid - more flexible decreased strength
Caudal - all below, weakest arrangement but highest flexibility

Question 13

As an embryo, part of the yolk sac is taken into the body, what does this go on to form?

Answer 13

The gut

Question 14

What do the foregut, midgut and hindgut differentiate into?

Answer 14

Foregut differentiates into pharynx, oesophagus, stomach and initial duodenum
Midgut differentiates into rest of duodenum, jejunum, ileum, caecum, ascending / transverse colon
Hindgut differentiates into descending colon and rectum

Question 15

What do the liver and pancreas arise from?

Answer 15

Endodermal diverticulum

Question 16

What are the 3 arteries supplying the abdomen?

Answer 16

Celiac artery
Cranial mesenteric artery
Caudal mesenteric artery

Question 17

What is the type of peritoneum that dictates where an organ stays within the abdominal cavity?

Answer 17

Connecting peritoneum

Question 18

What do the mesentery, omentum, fold and ligament peritoneum connect?

Answer 18

mesentery = bowel to body wall
omentum = stomach to something
fold = connects bowel organs
ligament = non GI organs to body wall

Question 19

What is the peritoneal cavity?

Answer 19

The potential space between the parietal and visceral peritoneum

Question 20

What are the names of the 4 lobes of the liver?

Answer 20

Left, right, caudate and quadrate

Question 21

What are the attachments of the peritoneal?

Answer 21

coronary ligament, triangular ligaments, and round/falciform ligament

Question 22

What are the 3 areas of the stomach?

Answer 22

Fundus, corpus, pylorus

Question 23

What are 2 roles of the greater omentum?

Answer 23

Attaches stomach to spleen

Provides a surface area for white blood cells to quickly get to areas in the abdomen

Question 24

Where would you find the spleen and what is it’s main role?

Answer 24

Left side of the abdomen

Blood reservoir

Question 25

What is the duodenum? Which 2 ducts empty into it?

Answer 25

The first part of the small intestine | Exit of bile duct and accessory duct

Question 26

What are the 3 peritoneal attachments of the duodenum?

Answer 26

Mesoduodenum Duodeno-colic fold Hepato-duodenal ligament

Question 27

How many lobes are there in the pancreas, in which direction do these lobes run?

Answer 27

- Right lobe running in the cranio-caudal direction | - Left lobe running medio-laterally

Question 28

Which part of the small intestine has the greatest proportion?

Answer 28

Jejunum

Question 29

What are the 3 parts of the colon?

Answer 29

Ascending, transverse and descending

Question 30

What do the sensory cells in the GI tract detect?

Answer 30

Wall stretch, nutrient conc, metabolite conc, osmolarity, pH, irritation

Question 31

What are digestive processes coordinated by?

Answer 31

Neural regulation and hormonal regulation

Question 32

Which nervous systems produce 1) short and 2) long reflex arcs?

Answer 32

1) enteric NS | 2) autonomic NS

Question 33

What do short reflex arcs enable?

Answer 33

The GI tract to have extensive control of its activities that can act independently to the rest of the body

Question 34

Which relfexes co-ordinate activity between different parts of GI tract? Give an example

Answer 34

Entero-enteric reflexes | Mastication stimulates release of saliva, gastric juice, pancreatic juice and bile

Question 35

Describe the 3 phases of regulation

Answer 35

1) Cephalic phase - pertains the head, e.g. anticipation of food 2) Gastric phase - pertains the head 3) Intestinal phase

Question 36

What are the 3 theories of the regulation of appetite

Answer 36

Glucostat - levels of glucose CCK theory - level of CCK Lipostat theory - level of fat

Question 37

What are the 4 types of contraction that allow food to move through the GI system?

Answer 37

1) Segmental - mixes lumen contents 2) Peristalsis 3) Anti-peristalsis 4) Mass movement - empties entire sections of the GI tract

Question 38

Where are pacemaker cells in the GI system located?

Answer 38

between circular and longitudinal smooth muscle