BIOL373 UNIT 6B EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS GRADED A++
Where are long reflexes integrated
CNS
Where are short reflexes integrated
Gut in enteric nervous system
Long reflexes
- sensory info from GI tract to CNS
- feedforward reflexes in response to sight, smell, thought of food, effects emotion
- efferent limb always autonomic
Short Reflexes
- neurons in submucosal plexus receive signals from lumen
- regulate secretion
- Neurons in myenteric plexus regulate motility
Reflexes involving gut peptides
- can act locally (paracrine) or travel via blood (endocrine)
- have an effect on motility (i.e., altered peristalsis, gastric emptying)
- effects on both exocrine and endocrine secretion
- some can act on the brain
What are the parallels between the enteric nervous system and the CNS
, - intrinsic neurons that lie entirely within gut (similar to interneurons in CNS)
- release more than 30 different neurotransmitters and neuromodulators (similar to
molecules used in CNS)
- has glial supports (similar to astrocytes of CNS)
- diffusion barrier: capillaries surrounding ganglia are not very permeable (similar to
blood-brain barrier in CNS)
- acts as integrating center, gut function can be regulated without CNS
What was Pavlov's theory of endocrinology
Pancreas secretion was controlled by vagus nerve (thought to be neural)
What was Bayliss and Starling's theory of endocrinology
- They dissected all nerves surrounding pancreas and duodenum and put acid in the
duodenum, pancreas still secreted
- hypothesized that the acid caused a signal to be released from the duodenum into the
blood
What is secretin
Factors from intestine that stimulated pancreatic secretion, a hormone
General term for blood borne regulators
hormones
Families of Gut Hormones (3)
- Gastrin family: major targets are stomach (gastrin), intestine and accessory organs
(VIP)
- Secretin family: secretin, Vasoactive intestinal pepetide (VIP), gastric inhibitory peptide
COMPLETE SOLUTIONS GRADED A++
Where are long reflexes integrated
CNS
Where are short reflexes integrated
Gut in enteric nervous system
Long reflexes
- sensory info from GI tract to CNS
- feedforward reflexes in response to sight, smell, thought of food, effects emotion
- efferent limb always autonomic
Short Reflexes
- neurons in submucosal plexus receive signals from lumen
- regulate secretion
- Neurons in myenteric plexus regulate motility
Reflexes involving gut peptides
- can act locally (paracrine) or travel via blood (endocrine)
- have an effect on motility (i.e., altered peristalsis, gastric emptying)
- effects on both exocrine and endocrine secretion
- some can act on the brain
What are the parallels between the enteric nervous system and the CNS
, - intrinsic neurons that lie entirely within gut (similar to interneurons in CNS)
- release more than 30 different neurotransmitters and neuromodulators (similar to
molecules used in CNS)
- has glial supports (similar to astrocytes of CNS)
- diffusion barrier: capillaries surrounding ganglia are not very permeable (similar to
blood-brain barrier in CNS)
- acts as integrating center, gut function can be regulated without CNS
What was Pavlov's theory of endocrinology
Pancreas secretion was controlled by vagus nerve (thought to be neural)
What was Bayliss and Starling's theory of endocrinology
- They dissected all nerves surrounding pancreas and duodenum and put acid in the
duodenum, pancreas still secreted
- hypothesized that the acid caused a signal to be released from the duodenum into the
blood
What is secretin
Factors from intestine that stimulated pancreatic secretion, a hormone
General term for blood borne regulators
hormones
Families of Gut Hormones (3)
- Gastrin family: major targets are stomach (gastrin), intestine and accessory organs
(VIP)
- Secretin family: secretin, Vasoactive intestinal pepetide (VIP), gastric inhibitory peptide
