All aspects of the GI processes are controlled by neural, hormonal and paracrine controls, specific control systems include
The autonomous function of the enteric nervous system (ENS)
Integrated within in the CNS
May originate in or outside of the GI tract
Feedforward & emotional reflexes are initiated and integrated entirely outside the GI tract
Integrated in the enteric nervous system
Initiated by changes in pH, distension, osmolarity, products of digestion
Submucosal plexus contains the sensory neurons
Afferent information to ganglia
Efferent information to submucosal and myenteric plexuses for control of secretion, motility and growth
Peptides released by the GI tract may act:
Act on accessory organs, other parts of the GI tract or the brain
Secreted into the lumen or extracellular fluid
Lumenal signals bind to apical epithelial receptors
ECF signals act in the immediate vicinity of secretion
Peptides alter secretion and motility
Alter behaviour related to eating
Allows for the autonomous behaviour of the digestive system
CNS control is not required for digestive functioning
Commonalities between ENS and CNS:
Intrinsic neurons – similar to interneurons of CNS
Extrinsic neurons – composed of autonomic neurons
Neurotransmitters and neuropeptides
Nonadrenergic and noncholinergic receptors - same as adrenergic and cholinergic in CNS
Glial support cells – similar to astrocytes in CNS
Diffusion barrier – cells around capillaries in the ganglia are tight, just as the capillaries in the brain, forming the BBB
ENS acts as its own integrating centre, just as the CNS does
Stimulus-CNS-Vagus nerve-ANSSalivary glands-salivary amylase & lingual lipase
Enteric Nervous system-increased gastric secretions and motility
Stores food; digests into chyme
Digestion of proteins, formation of chime in ileum
Controlled entry of chyme into ileum
Concentration of waste and digestion in colon
kianamaiart
discoholicmusic
dailybridgerton
prguitarman
theartofmadeline
dededos
annaxmalina
jacobvanloon
gummygunk