Week 1 Flashcards
What does the digestive system consist of primarily?
Gastrointestinal Tract
GI tract works in cooperation with
Accessory organs
Parts of upper GI tract
Mouth, pharynx, esophagus, stomach
Lower GI tract = bowels
SI, LI, Rectum, Anus
Accessory organs of Digestive System
LV, GB, Pancreas (hepatobilliary)
retroperitoneal organs
kidney, ureters, rectum, ascending and descending colon, parts 2, 3, 4 duodenum, head, neck, body of pancreas, suprarenal gland, abdominal aorta, inferior vena cava
intraperitoneal organs
stomach, part 1 duodenum, jejunum, ileum, cecum, appendix, transverse colon, sigmoid colon, LV, GB, tail of Pancreas.
thick band of doubled up peritoneum
mesentery, mesogastrium
mucosal layers of GI tract
** Ephitelium**
* Single innermost layer
* Organized into villi and crypts
* Absorptive, secretory, endocrine function
** Lamina Propria**
* Connective tissue
* Small blood vessels, glands, nerves,
lymphatic vessels
** Muscularis Mucosa**
Smooth muscle ~ contracts mucosa into
fold
Four layers of GI tract
- Mucosa
- Submucosa
- Muscularis Externa
- Serosa
Layers of Submucosa
- Submucosa*
- Connective tissue layer
- Large blood vessels, glands,
lymphatics - Submucosal (Meissner’s) Plexus ~
part of enteric nervous system à
secretory activity
Layers of Muscular Externa
- Muscularis Externa
- Inner Layer à Circular Muscle
- Outer Layer à Longitudinal
Muscle - Myenteric nerve plexus à
motoric activity
Layers of Serosa Layer
- Serosa
- Outermost layer
- Connective tissue layer and
epithelial cells - Autonomic nerve fibers synapse
on target cells and enteric nerve
plexus
Neurotransmitter of sympathetic GI response
NE (Norepinephrine)
What does NE do in GI?
Reduce motility, reduce secretions, constrict sphincters
Neurotransmitters of Parasympathetic GI activity
ACh (acetylcholine), VIP (vasoactive intestinal peptide), GRP
ACh does what in GI activity
increase motility, increase secretions
VIP does what in Gi activity?
Decrease sphincter constriction
GRP does what?
stimulates G cell Gastrin
three salivary glands
Parotids -> Serous, less viscous, parasympathetic
Sublinguals and Submantibulars -> mostly Mucin, viscous, sympathetic
what is TMJ
temporomandibular joint
what is deglutition?
swallowing
other name for Lower Esophageal Sphincter?
cardiac sphincter
Sequence of swallowing
Timed nerve reflexes in swallowing
Cranial Nerve V, IX, X, XII ~ timed
events in swallowing
Areas of stomach
Cardiac Sphincter (LES), Fundus, Body, Antrum, Pyloric Sphincter (pylorus)
small intestine
pyloric sphincter to large intestine, 20 feet, Duodenum, Jejunum, Ileum
Review the digestive hormone process
Mostly about regulating pH
Three phases of control of gastric secretions
cephalic phase
Gastric phase
Intestinal phase
cephalic phases
Gastric phase
Intestinal phase
what is MMC
migrating motor complex
what stimulates MMC?
fasting
How often does MMC happen during fasting?
every 90-120 minutes
where and how does absorbtion of vitamin B12 happen?
distal ilium by intrinsic factors
