Digestive System Part 2

Serosa. Which layer? Type of peritoneum? Type of CT covered with type of epithelium (term)? Two exceptions?

1. Outermost layer 2. Visceral peritoneum 3. Areolar CT covered by simple squamous epithelium (mesothelium) 4. Exceptions -Esophagus-> adventitia -Retroperitoneal organs->serosa and adventitia

Cephalic (reflex) phase. Prepares what? Length? Triggering? Innervation? Produces?

1. Prepares stomach for digestion 2. Short term (few minutes) 3. Triggered by aroma, sight, taste, thought of food. 4. ANS innervation 5. Produce more gastric juice

Structure that allows contents from esophagus to the stomach

Gastroesophageal sphincter

Not enough moisture mainted by the buccal glands is called?

Halitosis

Viral infection of parotid gland that can infect reproductive organs leading to miscarriage or sterility (term)

Mumps

What layer of the mucosa? -Effects on surface area (semi contracted all times which increases surface area)

Muscularis mucosa

Describe the stomach. Function? Location? Length? Width? Rugae?

Temporary storage tank. Upper left quadrant of peritoneal cavity. 15-25 cm in length and viable width. Rugae are folds/ridges that disappear when stomach is full.

Loose CT along outside of serous peritoneum only along organs that have a side not on side of serous peritoneum; outermost layer of the wall of a blood vessel (term)

Adventitia

Describe stomach wall. How many layers? Modification with epithelial layer (2)? Modification with Muscularis externa layer?

Contains all four alimentary canal layers. Epithelial layer has mucous cells that secrete alkaline mucous (protection from acid in stomach) and gastric pits/gastric glands that make gastric juice. Muscularis externa has an innermost oblique layer

Submucosal plexus of the enteric nervous system (function)

Controls contract of smooth muscle and secretion of glands

Interstinal phase. What happens to partially digested food? Gastrin? Reflex (term)? Pyloric sphincter? Inhibition (term)?

Partially digested food (chyme) enters small intestine, causes release of intestinal (enteric) gastrin. Duodenum fills/distends called enterogastric reflex. To stop food entry pyloric sphincter tightens. Enterogastrones inhibit gastric juice release.

The gastrointestinal tract/alimentary canal is made up of what structures (6)? What is its function?

1. Mouth 2. Pharynx 3. Esophagus 4. Stomach 5. Small intestine 6. Large Intestine *Carries food during its entire trip through body

Stomach wall layers (deep to superficial) (3)

1. Mucosa -Surface epithelium -Lamina propria -Muscularis mucosae 2. Submucosa 3. Muscularis externa -Oblique layer -Circular layer -Longitudinal layer

Layers of the gastrointestinal tract (4), innermost to outermost

1. Mucosa 2. Submucosa 3. Muscularis externa (aka muscularis) 4. Serosa *pattern holds true from the esophagus to the anal canal

Oral cavity. What membrane? Antibodies (term)? Continuous with what? Contains what structures (3)? Those structures associated with what (3)?

1. Mucous membrane -defensins (natural antibodies) 2. Continuous with oropharynx 3. Contains teeth/gums/ tongue -Bolus formation -Presence of papillae -"Tied tongue"

Sublayers of the stomach muscular is externa layer (3)

1. Oblique layer 2. Circular layer 3. Longitudinal layer

Pathway of food (3)

1. Oral cavity 2. Oropharynx 3. Laryngopharynx

Composition of saliva. Water content? Acidity/Basicity? Solutes (5)

1. 97-99.5% water 2. Slightly acidic (pH = 6.75-7.00) 3. Contains ions, mucus (mucin, concentrated mucus), enzymes, antibodies, and antimicrobials

1. Function of the mesentery 2. Two kinds of organs of the mesentery

1. Act like rope, hold intraperitoneal organs in place 2. Intraperitoneal and retroperitoneal organs

1. Lingual frenulum too short, "tied tongue" (term) 2. Space between teeth and lips 3. Range of lips

1. Ankyloglossia 2. Vestibule 3. Inferior portion of nose to inferior chin

Submucosa. Type of tissue? Connects what? Types of vessels? Type of fibers? Plexus?

1. Areolar CT 2. Connects mucosa to muscularis externa 3. Location of larger vessels 4. Rich with elastic fibers 5. Submucosal plexus of the enteric nervous system

Regulation of gastric secretion (3)

1. Cephalic (reflex) phase 2. Gastric phase 3. Intestinal phase

Functions of saliva (4)

1. Cleanses/rinses mouth 2. Dissolves food particles so that they can be tasted 3. Moistens food (bolus formation) 4. Begins chemical breakdown of food

Digestive processes of the stomach. What activity does it continue? Begins what degradation and how? Continued activity of ________? Only activity of stomach essential for life?

1. Continues the mechanical demolition begun in the oral cavity 2. Beginning of protein degradation-> HCl/pepsin 3. Continued activity of lingual lipase 4. Only activity of stomach essential for life -> activity of intrinsic factor

Mucosa layers (3), sublayers, and function (deep to superficial)

1. Epithelial layer -Protection -Secretion/absorption -Tight junctions 2. Lamina propria -Areolar CT -Blood vessels -Location of mucosa associated with lymphatic tissues (MALT: hold WBCs ready) 3. Muscularis mucosa -Effects on surface area (semi contracted at all times which increases surface area)

1. Where esophagus punctures through diaphragm (term) 2. Connecting esophagus and stomach (term)

1. Esophageal hiatus 2. Cardiac orifice

Regions of the stomach (7)

1. Fundus 2. Cardia 3. Greater curvature 4. Body (corpus) 5. Less curvature 6. Atrium 7. Pylorus

1. Breach of gel like mucosal barrier of stomach 2. Persistant damage to underlying tissue, can cause perforation, hemorrhage 3. Causes (2) and example

1. Gastritis 2. Gastric ulcers 3. Bacterial infection - helicobacter pylori and non steroidal anti-inflammatory drugs (NSAIDs) ex. aspirin can inhibit prostoglandins necessary for creation of alkaline mucus barrier.

1. Gastric juice regurgitates into esophagus through gastroesophageal sphincter (term) 2. Chronic heart burn 3. Esophageal lined by stratified squamous but converted to simple columnar (found in stomach) 4. The protrusion (or herniation) of the upper part of the stomach into the thorax through a tear or weakness in the diaphragm

1. Heart burn 2. Gastroesophageal reflux disease (GERD) 3. Barrett's esophagus 4. Hiatal hernia (esophageal hiatus)

Digestive system processes (6)

1. Ingestion 2. Propulsion (swallowing/peristalsis) 3. Mechanical digestion (teeth/tongue) 4. Chemical digestion 5. Absorption (small intestine) 6. Defecation (rid of things you can't digest)

Muscularis Externa (aka Muscularis). Two layers and the type of plexus?

1. Inner circular layer of smooth muscle -Sphincters 2. Outer longitudinal layer of smooth muscle 3. Myenteric plexus of the enteric nervous system

Histology of pharynx. Inner layer (type of cell)? Two outer layers?

1. Inner stratified squamous epithelium layer (mucous production) 2. Two layers of smooth muscle (inner longitudinal, outer circular)-> responsible for deglutition (swallowing)

What phase? 1. Partially digested food enters small intestine; enterogastric reflex 2. Prepares stomach for digestions 3. Stretch sensitive cells; pH regulation

1. Intestinal phase 2. Cephalic (Reflex) phase 3. Gastric phase

Salivary glands (2) and their function

1. Intrinsic salivary glands (buccal glands): mixed throughout mucus membrane 2. Extrinsic salivary glands 3. Control of salivation -Buccal glands: maintains moisture -Extrinsic salivary glands: parasympathetic stimulation

Extrinsic salivary glands (5) and three anatomical structures

1. Maxilla 2. Submadibular duct 3. Sublingual gland (2) 4. Mandible 5. Submandibular gland (2) 6. Parotid gland (2) 7. Parotid duct 8. Masseter muscle

Gastric phase pH regulation cycle (8)

1. Meal enters stomach 2. Protein utilizes H ions from HCl 3. pH rises 4. Stimulates release of gastrin 5. Stimulates release of gastric juice 6. Enables pepsin function 7. Protein digested, pH decreases 8. Stomach empty

What gastrointestinal tract layer? 1. Areolar CT; location of larger vessels and submucosal plexus 2. Visceral peritoneum, areolar CT covered by simple squamous epithelium

1. Submucosa 2. Serosa

Two plexuses of the enteric nervous system and their functions

1. Submucosal plexus: control of mucosal glands/smooth muscle 2. Myenteric plexus: segmentation/peristalsis

Sublayers of the stomach mucosa layer (3)

1. Surface epithelium 2. Lamina propria 3. Muscularis mucosae

Accessory digestive organs (6)

1. Teeth 2. Tongue 3. Salivary glands 4. Liver 5. Gallbladder 6. Pancreas

Parts of the peritoneum (5)

1. Visceral peritoneum 2. Parietal peritoneum 3. Peritoneal cavity 4. Serous fluid 5. Mesentery

Describe gastric juice. pH? Contents (4)? Functions of mucosal barrier (3)?

1.5-3.5. Contains: -Mucus -H and Cl ions to make HCl (produced by parietal cells) -Pepsinogen (only enzyme produced by stomach, need HCl to become pepsin) -Intrinsic factor that allow absorption of vitamin B12 which is important for erythropoeisis. Function of mucosal layer: -Bicarbonate mucous (helps neutralize) -Tight junctions -Quick turnover of damaged cells.

Describe the esophagus. How long? What carries food after deglutition (term)? How many layers? Collapsable? Gastroesophageal sphincter function? Diaphragm function?

Aprox. 24 cm long. Peristalsis following deglutition. Contains all four alimentary canal layers. Collapsable. The gastroesophageal sphincters opens/closes to allow food into stomach-> prevent acid reflux. The diaphragm reinforces muscle that closes gastroesophageal sphincter

Where is the myenteric plexus of the enteric nervous system located?

Between the circular and longitudinal layer

Semi autonomous nervous system of the alimentary canal (capable of reflex activities without communication with the CNS) (term)

Enteric nervous system -More than 100 million neurons (more than the spinal cord)

What layer of the mucosa? -Protection -Secretion/absorption -Tight junctions

Epithelial layer

Gastric emptying. Rate? Depends on? How does it empty (term)?

Every 4 hours. Dependent of food movement through the duodenum: liquid vs solid, and fatty meal. Peristaltic waves.

What layer of the mucosa? -Areolar CT -Blood vessels -Location of mucosa associated with lymphatic tissues (MALT)

Lamina Propria

Gastric phase. Length? Type of cells? pH regulation?

Last 3-4 hours. Stretch sensitive cells detect distention. pH regulation is a negative feedback loop.

Two layers of serous membrane fused back to back (term)

Mesentery

Which portion of the pharynx is not part of the digestive system?

Nasopharynx (superior most portion of the pharynx)

Digestive system works to maintain homeostasis ________ (location) the body

Outside

Serous membrane that lines the inside of the abdominopelvic cavity and covering the surface of the abdominopelvic organs (term)

Peritoneum

Structure that allows contents from the stomach to enter into the small intestine

Pyloric sphincter

Inner circular layer of smooth muscle in the muscularis externa (term)

Sphincter