Ageing Gastrointestinal System

Question 1

What are the functions of the gastrointestinal tract (GI)?

Answer 1

Ingestion
Secretion
Mixing and Propulsion
Digestion
Absorption
Defecation

Question 2

What age related decines occur within the GI tract?

Answer 2

Slightly reduced smooth muscle tone and motility

Reduced neuroendocrine control and secretary activity

Question 3

In regards to general ageing and digestion, what are most age related changes associated with?

Answer 3

diseases such as cancer or diabetes
atrophic gastritis and helicobacter pylori infections
poor nutrition (vitamin D deficiency affecting Ca absorption)

Question 4

What GI tract problems are more common in the elderly?

Answer 4

Dysphagia (difficulty swallowing), diarrhoea, constipation
Gum disease, reduced immunity
Altered drug metabolism in the GI tract and liver

Question 5

What is Dysphagia?

Answer 5

Swallowing difficulty

Question 6

What regulates mouth, tongue and throat movements?

Answer 6

Peripheral motor neurons

Question 7

What is peristalsis?

Answer 7

The spontaneous pacemaker activity and autonomic nervous

system reflexes regulate GI tract motility

Question 8

What is the role of parasympathetic nerves in digestion?

Answer 8

Promote motility via Acetylcholine

Question 9

What is the role of sympathetic nerves in digestion?

Answer 9

Inhibit motility via adrenaline and noradrenaline

Question 10

What is the location of enteric neurons and how many are there approximately?

Answer 10

100 million neurons and runs the entire length of the gut

Question 11

What are the sub sytems of the enteric nervous system?

Answer 11

Sub-mucosal plexuse

Myenteric plexuse

Question 12

What is another name for the sub-mucosal

Answer 12

Meissners plexus

Question 13

What is the role of the sub mucosal sub system in the enteric nervous system?

Answer 13

Sensory neurons respond to distension / stretch, pain,
acidity and nutrients
Motor neurons regulate muscularis mucosa contraction, vasoconstriction and secretions

Question 14

What is an alternate name for the myenteric plexus?

Answer 14

Auerbach’s plexus

Question 15

What is the main roll of the myenteric plexus?

Answer 15

regulates the frequency and strength of gastrointestinal contractions via several methods

Question 16

What neurons and NTs are involved in myenteric plexus activities

Answer 16

(+) and (-) refer to increased of decreased action

Enteric neurons: 5HT +,
histamine +, opiates -

parasympathetic postganglion neurons: Musc ACh +

sympathetic postganglionic neurons: Adrenergic -

Question 17

What ganglia acts on the enteric system and what NT is used?

Answer 17

parasympathetic ganglia: nicotinic ACh +

Question 18

What is the average volume of secretions that are added to the GI tract daily?

Answer 18

7000ml

150ml excreted

Question 19

What glands secrete saliva?

Answer 19

Parotid
Submandibular
Sublingual
Buccal

Question 20

What molecules are found in saliva?

Answer 20

alkaline bicarbonate
mucous
amyalse
lysozyme

Question 21

What are related changes occur in relation to saliva excretion?

Answer 21

Volume saliva decreases but concentrations remain the same

Question 22

What neurological conditions are associated with decreased saliva volume?

Answer 22

Stroke
Myasthenia gravis, Parkinsons disease
Alzheimer’s disease

Question 23

What are phases of swallowing?

Answer 23

Buccal phase
Pharyngeal phase
Esophageal phase

Question 24

What are the two types of contractions in the intestines?

Answer 24

Peristaltic (directional)

Segmental (localised)

Question 25

What is one age related change that occurs during ageing?

Answer 25

constipation, mainly effects older women

Question 26

What hormones cause gastric contraction?

Answer 26

Gastrin | Histamine

Question 27

What regulates motility and acid secretion?

Answer 27

Pavlov reaction Neural reflexes and gastrin / histamine release Hormone feedback

Question 28

How do gastrosecretions and general changes occur during ageing?

Answer 28

Significantly less HCO3 is secreted Peptic ulcer disease is increased

Question 29

How are gastric pit secretions changed during ageing

Answer 29

Normal ageing shoud not effect acid secretions

Question 30

What is the purpose of intrinsic factor and how is it effected by age?

Answer 30

Assists in vitamin B12 absorption abd should not be effected by age

Question 31

What stomach disease is more common in the elderly and what is the the mechanism?

Answer 31

Atrophic gastritis | Reduces HCl, pepsin and intrinsic factor secretion due cell loss

Question 32

How does ageing effect pancreas secretions?

Answer 32

Ageing has minor effects on secretions but type 2 diabetes is more prevalent

Question 33

What is the purpose of gastric inhibitory peptide?

Answer 33

inhibits gastrin release when chyme has left the stomach

Question 34

How does ageing effect nutrient absorption?

Answer 34

May slow down but does not change effectiveness

Question 35

What is the cause of Megaloblastic anemia?

Answer 35

Vitamin B12 deficiency

Question 36

What is the cause of a peptic ulcer?

Answer 36

Helicobactor pylori infection of gastric mucosae Non-steroidal anti-inflammatory drugs (aspirin) Hypersecretion of HCL

Question 37

Questions

Answer 37

Provide examples to support the following statement: most age-related changes the gastrointestinal tract are associated with disease, infections and poor nutrition Describe ageing related changes that affect the gastrointestinal tract