Module 7.2 Regulation of Digestive Functions Flashcards
Within the digestive system, motility and secretion are regulated to maximize digestion and absorption.
This regulation occurs by what four mechanisms?
- autonomous smooth muscle function,
- enteric nervous system (ENS) activity,
- extrinsic innervation, and
- digestive hormones
Autonomous smooth muscle contains ____\_(also called ____\_ of_______)
Autonomous smooth muscle contains pacemaker cells (also called interstitial cells of Cajal)
What is the function of pacemaker cells in the Autonomous smooth muscle?
to generate slow-wave potentials
What is the purpose of the slow-wave potentials generated by autonomous smooth muscle?
Slow-wave potentials generate action potentials that cause smooth muscle to contract
Digestive system pacemaker cell activity:
(Top) Autonomous smooth muscle pacemaker cells generate ______\_that, upon reaching threshold, produce ______\_.
(Bottom) The strength of the corresponding smooth muscle contraction varies with the _____\_ of the action potentials.
Digestive system pacemaker cell activity:
(Top) Autonomous smooth muscle pacemaker cells generate slow-wave potentials that, upon reaching threshold, produce action potentials.
(Bottom) The strength of the corresponding smooth muscle contraction varies with the frequency of the action potentials.
The degree of depolarization of the slow-wave potentials is dependent on ___\_, ___\_, and ___\_ factors
The degree of depolarization of the slow-wave potentials is dependent on mechanical, neural, and hormonal factors
The frequency of the slow-wave potentials is called the _________\_, which varies in different regions of the digestive tract
The frequency of the slow-wave potentials is called the basic electric rhythm (BER), which varies in different regions of the digestive tract
The ENS is composed of the ____\_and ____\_ and the associated neurons
The ENS is composed of the submucosal plexus and myenteric plexus and the associated neurons
The neurons of the submucosal plexus and myenteric plexus of the Enteric Nervous System (ENS) include
- __________ neurons,
- _______, and
- _______ neurons
The neurons of the submucosal plexus and myenteric plexus of the Enteric Nervous System (ENS) include
- afferent sensory neurons,
- interneurons, and
- efferent neurons
In the Enteric Nervous System (ENS), the efferent neurons __________ cells, __________ cells, and __________ cells.
In the Enteric Nervous System (ENS), the efferent neurons innervate smooth muscle cells, endocrine cells, and exocrine cells.
What is the function of the Enteric Nervous System (ENS)?
To coordinate digestive system activity independent of the central nervous system (CNS)
Extrinsic innervation to the digestive system is mediated through the __________\_
Extrinsic innervation to the digestive system is mediated through the autonomic nervous system (ANS)
Overall, an increase in sympathetic nervous system activity decreases digestive system activity,
whereas an increase in parasympathetic nervous system activity increases digestive system activity
Overall, an increase in sympathetic nervous system activity decreases digestive system activity, (fight or flight)
whereas an increase in parasympathetic nervous system activity increases digestive system activity (rest and digest)
Parasympathetic nervous system activity is primarily mediated by the ____\_ nerve, which is cranial nerve ten (CN X)
Parasympathetic nervous system activity is primarily mediated by the vagus nerve, which is cranial nerve ten (CN X)
_______ ______\_ nerve fibres also form part of the ENS
Postganglionic parasympathetic nerve fibres also form part of the ENS
The digestive hormones are secreted from the _____\_ cells of the digestive tract
The digestive hormones are secreted from the endocrine cells of the digestive tract
What are four digestive hormones?
- gastrin,
- cholecystokinin (CCK),
- secretin, and
- glucose-dependent peptide (GIP)
Regulation of digestive function is coordinated through _______\_
Regulation of digestive function is coordinated through reflex pathways
What are the three types of receptors contained in the walls of the digestive tract?
The walls of the digestive tract contain three types of receptors:
- chemoreceptors
- mechanoreceptors
- osmoreceptors
The afferent information received by the three types of receptors in the digestive tract wall is relayed through long reflex pathways to the ___\_or is relayed through short reflex pathways to the _____\_.
Efferent information is then sent out to _____\_cells, _____\_ cells, or _____\_ cells.
The afferent information received by the three types of receptors in the digestive tract wall is relayed through long reflex pathways to the CNS or is relayed through short reflex pathways to the ENS.
Efferent information is then sent out to smooth muscle cells, endocrine cells, or exocrine cells.
Regulation of digestive system function by reflex pathways.
