L1: Intro to GIT Physiology Flashcards
What are each of these layers of the GIT
Outmost layer when tissue is outside the peritoneum (e.g. upper Oesophagus)?
Adventitia
Loose Connective Tissue
Outmost layer when tissue is within the peritoneal cavity (e.g. Stomach)
Serosa
lubrication function
Innervation of the GIT?
EXTRINSIC (Autonomic nervous system)
- Sympathetic Nervous System
- Parasympathetic Nervous system
INTRINSIC (Enteric Nervous System)
- Myenteric Nerve Plexus (Auberbach’s Plexus)
- Submucosal Nerve Plexus (Meissner’s Plexus)
Location/Role of Meissner’s Plexus?
Also known as?
Located in Submucosa (Regulates Secretion/Blood Flow)
Submucosal Plexus
Location/Role of Auerbach’s Plexus?
Also known as?
Located in Muscularis externa. Between longitudinal and circular layers!! (Regulates Motility)
Distance of Ganglia from Target
(Sympathetic vs. Parasympathetic)
Differing roles of Submucosal Plexus and Myenteric Plexus?
Submucosal = Meissner’s
Myenteric = Auerbach’s
Sphincter muscles receive basal tone from ________ fibers
Sympathetic FIbers
Synmpathetic Innervation maintains continence
Salivary Glands are under what kind of control?
Neural
Stomach is under what kind of control?
Neural and Hormonal
Pancreas is under what kind of control?
Neural and Hormonal
Parasympathetic vs. Sympathetic Nervous System in Digestion?
Parasympathetic Nervous System in Digestion:
- Secretory Cells: Chrolinergic, M1 (Gastric Acid), M3
- Motility: Stimulatory (M1/M3) (Long/Short Reflexes)
Sympathetic Nervous System in Digestion:
- Secretory Cells: Alpha Adrenoreceptors (Vasoconstriction)
- Motility: Inhibitory (Sphincters are exception (maintains continence))