ANS & GI Systems
20
THE AUTONOMIC NERVOUS SYSTEM
• Introduction to the adrenal medulla and to
the stress response: autonomic nervous
system, endocrine / neural components
• catecholamines: synthesis, secretion,
receptors, mechanism of action, general
hormonal effects
• sympathoadrenal roles: intermediary
metabolism, thermogenesis, CV, respiratory, link to stress
• pheochromocytoma as main endocrine
pathology: a possible role for medullary
peptides
ANS & GI Systems
GASTROINTESTINAL HORMONE SYSTEM
• Introduction to the endocrinology of the
GI tract: neurogenic components,
endocrine components and regulatory
mechanisms. Enteroendocrine cells,
hormone families, hormones of the GI
tract and their neuroendocrine control.
• GI hormones: Gastrin / CCK family:
gastrin, CCK; Secretin family: secretin,
VIP, GIP, GLP; PP family: PPY, peptide YY,
NPY; Other GI hormones: neurotensin,
galanin, GRP, motilin, TRH, CGRH, SS,
enkephalins, endorphins, SP.
• Neuroendocrine control of food intake
• Pathologies associated with GI hormones
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19
The ANS and the GI Systems
Autonomic Nervous System
The sympatho-adrenal system as a faster neuronal and a relatively slower
endocrine component. Both are involved in the stress response.
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Autonomic Nervous System
Cas biosynthesis occurs in the cytosol and in the secretory
vesicle. Cortisol controls PNMT biosynthesis and thus Epi.
Autonomic Nervous System
Typical responses after stimulation of adrenal medulla
To visualize the stress response imagine the gazelle running
away from the lion
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Autonomic Nervous System
S
E
Adrenoreceptors are seven transmembrane
domain receptors (GPCR)
Autonomic Nervous System
The sympathoadrenal control is involved in blood preassure
homeostasis and intermediary metabolism
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Autonomic Nervous System
S
E
The hyperglycemic effect of epinephrine is
controlled by several organs & processes
Gastrointestinal Hormones
GI hormones are clustered into families having similar / overlaping
functions
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Gastrointestinal Hormones
The gastrin / CCK family and the secretin / VIP family (includes
GIP & GLP) have major roles in gastric / duodenal interactions
Gastrointestinal Hormones
Control of GI function by hormones /
metabolites
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Gastrointestinal Hormones
Leptin, an adipocyte hormone, inhibits food
intake & promotes energy expenditure
Some pathologies involved in
disfunction of the GI system
The ANS and the GI Systems
Page 7
The ANS and the GI Systems
structure
a)
b)
Which, increase
or decrease?
function
How do
you know?
c)
Parts to total?
d)
Two feedbacks and
an absolute
requirement?
Next week question
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