Gastrointestinal

Question 1

What is the role of the palate?

Answer 1

Separates the mouth from the nasal passages, allowing breathing and chewing simultaneously

Question 2

What is the role of the uvula during eating?

Answer 2

Seals of the nasal passages during swallowing

Question 3

What are the functions of the tongue?

Answer 3

Guides food

Speech

Swallowing

Taste buds

Question 4

Describe the pharynx

Answer 4

Common passageway for respiratory and digestive systems

Tonsils on side walls - lymphoid tissue

Question 5

Where are the salivary glands located?

Answer 5

Parotid - below ear, over the masseter

Submandibular - under lower edge of mandible

Sublingual - floor of mouth under tongue

Question 6

What are the functions of saliva?

Answer 6

Lubrication

Solvent (taste)

Antibacterial

Digestion of complex carbohydrate (amylase)

Neutralization of acid (bicarbonate)

Facilitates suckling of infant (fluid seal)

Question 7

Which peptide hormones are secreted by the duodenum?

Answer 7

Gastrin - G cells

Cholecystokinin - I cells

Secretin - S cells

Motilin - M cells

Glucose-dependent insulinotropic peptide (GIP), incretin - K cells

Glucagon-like peptide-1 (GLP-1), incretin - L cells

Question 8

Which peptide hormones are secreted by the jejunum?

Answer 8

Cholecystokinin - I cells

Motilin - M cells

Glucose-dependent insulinotropic peptide (GIP), incretin - K cells

Glucagon-like peptide-1 (GLP-1), incretin - L cells

Question 9

What type of receptors do the peptide hormones secreted by the small intestine act on?

Answer 9

G-protein coupled receptors

Question 10

What are the control mechanisms for secretion of succus entericus?

Answer 10

Increase secretion

Distension/irritation

gastrin

CCK

secretin

parasympathetic

Decrease secretion

sympathetic

Question 11

What does the succus entericus contain?

Answer 11

Mucus (from goblet cells)

Aqueous salt (crypts)

no digestive enzymes

Question 12

What membrane proteins does secretion of the succus entericus involve?

Answer 12

Na+/K+ ATPase

Na+/K+/2Cl- co-transporter

Chloride channel

Question 13

What is the BER and what triggers it?

Answer 13

Basic Electrical Rhythm

Interstitial cells of Cajal - pacemaker cells

Question 14

How is the chyme mixed in the small intestine?

Answer 14

Segmentation - chopping movements back and forth created by contraction of circular muscle

Question 15

What triggers segmentation in the empty ileum?

Answer 15

Gastroileal reflex - gastrin released from stomach

Question 16

What is the Migrating Motor Complex?

Answer 16

Perilstalsis occuring between meals every 90-120 minutes

Strong peristaltic contraction from stomach to ileocaecal valve

which clears the small intestine of undigested debris, mucus and sloughed epithelial cells

Question 17

What triggers the Migrating Motor Complex?

Answer 17

Motilin

Question 18

What suppresses the Migration Motor Complex?

Answer 18

Gastrin

CCK

Question 19

Why might macrolide antibiotics such as erythromycin cause GI disturbance?

Answer 19

They mimic the action of motilin

Question 20

What are the contents of pancreatic juice?

Answer 20

Digestive enzymes

aqueous NaHCO^₃-

Question 21

Which pancreatic cells secrete digestive enzymes?

Answer 21

Acinar cells

Question 22

Which pancreatic cells secrete bicarbonate solution?

Answer 22

Duct cells

Question 23

How are enzymes stored in the acinar cells of the pancreas?

Answer 23

Zymogen granules

Question 24

Which proteases are secreted in proform by the pancreas?

Answer 24

trypsin(ogen)

chymotrypsin(ogen)

(pro)carboxypeptidase

Question 25

Which enzyme, released by duodenal mucosal cells, catalyses the activation of trypsin from trypsinogen?

Answer 25

enterokinase

(and then trypsin autocatalyses further conversion)

Question 26

Which enzyme catalyses the activation of chymotrypsinogen and procarboxypeptidase?

Answer 26

trypsin

Question 27

As well as proteases, which other digestive enzymes are secreted by the pancreas?

Answer 27

pancreatic amylase

pancreatic lipase