Mcb 135K Aging Of The Gi Tract Lecture

Front 1

What are the major goals of the GI tract?

Back 1

Provide organism with nutritive substances, vitamins, minerals, fluids

Front 2

What are the four major functions of the GI tract?

Back 2

1) Digestion.
2) Absorption.
3) Mobility.
4) Secretion.

Front 3

What are the signs of aging teeth?

Back 3

-Yellowish brown discoloration (from staining by beverages, tobacco, bacteria)
-Recession of pulp from crown
-Narrowing of root canal
-Roots become brittle and fracture easily
-Odontoblasts (secrete dentin) become irregular and discontinuous
-Pulp calcification
-Osteoporosis of mandibular and maxillary bones contributing to tooth loss
-Gum recession and infection (peridontitis).

Front 4

What might be causes of disturbances to deglutition (the act of swallowing) AKA dysphagia?

Back 4

1) Increased incidence of non-peristaltic contraction.
2) Failure of lower esophageal sphincter to relaxation.
3) Reduced amplitude of peristaltic contractions.

Front 5

What is GERD?

Back 5

A reflux of stomach acid into the esophagus.

Front 6

What are some signs of GERD?

Back 6

1) Decreased esophageal clearance.
2) Increased gastric secretion.
3) Decreased lower esophageal sphincter pressure.
4) Decreased emptying of stomach and/or increased gastric pressure.

Front 7

What is the one main treatment used to treat GERD?

Back 7

H2 receptor blockers.

Front 8

What are the major functions of the stomach?

Back 8

-Food reservoir
-Digestion of food
-Secretion of gastric juice with digestive enzyme, mucus, hydrochloric acid
-Secretion of hormones gastrin, glucagon, somatostatin, vasoactive intestinal polypeptide (VIP)
-Secretion of intrinsic factor
necessary for Vitamin B12 absorption & maturation of RBCs

Front 9

What are the functions of VIP? (Vasoactive Intestinal Polypeptide)

Back 9

1) Stimulate intestinal secretion of water and electrolytes.
2) Relaxes intestinal smooth muscle.
3) Inhibit gastric acid secretion.
4) Dilates peripheral blood vessels.

Front 10

What are the factors influencing the incidence/severity of H. pylori infection?

Back 10

-Virulence of infection
-Genetic characteristics
-Environmental co-factors (non-steroidal anti-inflammatory drugs e.g. aspirin, others)

Front 11

Three types of managements of peptic ulcers are ____, _______, and _______.

Back 11

1) Dietary.
2) Pharmacologic.
3) Surgery.

Front 12

What are the major factors in maintaining optimal functioning of the SI?

Back 12

1) Anatomic integrity.
2) Normal gastrointestinal secretions.
3) Coordinated gastointestinal motility.
4) Normal intestinal transport.
5) Adequate intestinal blood supply.
6) Normal defense mechanisms against toxic injurious agents (bacteria, injury, drugs).

Front 13

What are the major causes of decreased intestinal absorption?

Back 13

1) Changes in villus shape.
2) Increase of collagen.
3) Mitochondrial changes.
4) Prolonged replication time of cells.
5) Decreased villus motility.
6) Inadequate blood supply.
7) Impaired water barrier restricting diffusion and transport.
8) Permeability changes.

Front 14

What are the mechanisms of decreased intestinal calcium absorption with aging?

Back 14

1) Decrease in intake of vitamin D (poor nutrition).
2) Decrease vitamin D conversion in skin (reduced exposures to sunlight).
3) Decreased vitamin D metabolism (hepatic) and activation (renal).
4) Decreased cellular binding (decreased receptors).

Front 15

What are the major functions of the liver?

Back 15

1) Bile formation.
2) Carbohydrate storage and metabolism.
3) Regulation of lipid metabolism.
4) Manufacture of plasma protein.
5) Urea formation.
6) Ketone body formation.
7) Metabolism of steroid & polypeptide hormones.
8) Detoxification of many drugs and toxins.

Front 16

What are the signs of the aging liver?

Back 16

1)Atrophy after 60 years and greater after 80 years.
2) Cell size variable.
3) Increased collagen.
4) Alteration in hepatic cell degeneration/ regeneration cycle.
5) Alterations in mitochondrial number.
6) Decrease in ER and decreased ability to metabolize drugs.

Front 17

What are the major functions of bile?

Back 17

1) Emulsification of lipids.
2) Activation of enzymes for degradation of lipids.
3) Excretion of cholesterol.
4) Conjugation of bilirubin to water soluble products.
5) Neutralization of acid delivered to duodenum from stomach.
6) Excretion of drugs, heavy metals, environmental toxins.

Front 18

The hormone ghrelin that regulates appetite also triggers activity where?

Back 18

Hypothalamus, the part of the brain involves in both learning and memory.