Unit 10 ~Identify the organs of the gastrointestinal (GI) tract and the accessory organs of digestion. - Digestive tract, liver,pancreus, gallbladder and salivary gland ~Describe the general histology of the four layers of the gastrointestinal tract. (inner to outer) - 1. Mucosa - consists of 3 layers epithelium (secretory cells), lamina propria (connect tiss,BVess,Lympha,nervs), and muscularis mucosae (layers, smooth musc/elastic) - 2. Submucosa - dense irregular connect tiss, binds layers, submucosa nerve perplex - 3. Muscular layer - smooth muscles for mech digest (every direction) myenteric nerve perplex - Pacesetter cells: spot depolar - contraction wave - Peristalsis: rhythmic contractions (milk cow) - segmentation: muscles that do churning motion in Peristalsis - 4. Serosa - (visceral peritoneum) serous membrane in most of the GI tract has mucus to prevent friction/damage ~Describe the peritoneum and its folds. - 2 parts (Inside wall layer - Parietal peritoneum, around organ- serious (visceral peritoneum)) - Fluid between for lub (peritoneal fluid) - Mesenteries (folds): double-layer sheets of peritoneal membrane secrete serous fluid stabilize organs/vessels - Lesser Omentum: stomach/liver - greater: extend inferior to stomach/anterior surface of intestines (apron) - Mesentery proper - small intestine in place - Mesocolon - large intestine in place ~What controls gastric motility - Local: chemoreceptors/mechanoreceptors - pH, Volume, Stretch - Neural: Control digestive movement - swallowing - medulla oblongata - PSNS - acetylcholine stim gastric secretions/movements - Nerve plexus (ENS) - glands secrete muscles go -reflux (ENS) - Hormonal: enteroendocrine cells stim/inhibit digestion ~Describe the structure of the tongue. - Has Lingual papillae - projections - Frenulum - weird piece of skin below the tongue -stabilize/anchor ~Identify the location and histology of the salivary glands.
