Chapter 24: The Digestive System Flashcards
(175 cards)
1
Q
Digestive System
A
Consists of a group of organs that break down the food we eat into smaller molecules that can be used by body cells.
2
Q
Tonus
A
Sustained contraction
3
Q
Accessory Digestive Organs
A
Include: teeth, tongue, salivary glands, liver, gallbladder and pancreas.
4
Q
Digestive System 6 Basic Processes
A
- Ingestion
- Secretion
- Motility:
- Digestion
- Absorption
- Defecation
5
Q
Layers of the GI Tract
A
4 layers
Deep to Superifical
4.Mucosa: 3 thin layers, epi, lamina propria (contains vessels where nutrients are absorbed), and muscularis mucosea.
3. Submucosa: contains some blood and lympathic vessels
2. Muscularis (contains skeletal muscle and smooth muscle)
1. Serosa (secretes fluid) /adventita (lines esophagus) : also called visceral peritoneum
6
Q
Epi of Mouth, Pharynx, Esophagus and Anal Canal
A
Mainly nonkeratinized strained squamous epi.
Serves a protective function.
7
Q
Epi of Stomach and Intestines
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Simple columnar epi.
Functions in secretion and absorption.
8
Q
Enteroendocirne Cells
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Endocrine cells
Secrete hormones
9
Q
Lamina Propria
A
Found in the mucosa layer
Areolar CT containing blood and lymphatic vessels that are routes by which nutrients absorbed into the GI tract reach other tissues in the body.
10
Q
Muscosa Associated Lympathic Tissue (MALT)
A
Contains in lamina propria.
Are prominent lymphatic nodules
Contain: immune system cells that protect against disease.
11
Q
Muscularis Mucosae
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Thin layer of smooth muscle fibers
The mucous membrane of the stomach and small intestines for many small folds.
Folds increase surface area for digestion and absorption.
12
Q
Submucosa
A
Areolar connective tissue that bind the mucosa to the muscularis.
Contains: many blood vessels and lymphatic vessels that receive absorbed food molecules.
13
Q
Muscularis of Mouth, Pharynx and superior/middle parts of Esophagus.
A
Contains:
skeletal muscles that produce voluntary swallowing, forms the external anal sphincter.
Smooth muscles in 2 sheets, helps breaks down food, mix digestive secretions and propel it along the tract.
14
Q
Serosa
A
Function: secretes lubricating fluid
Superficial layer that is suspended in the abd cavity.
A serosa membrane composed of areolar CT and simple squamous epi.
15
Q
Adventitia
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Single layer of areolar CT in esophagus.
Esophagus lacks serosa.
16
Q
Myenteric Plexus
A
Or plexus of Auerbach
Located between the longitudinal and circular smooth muscle layers of the muscularis.
17
Q
Submucosa Plexus
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Apart of the ENS.
Found within the Submucosa.
18
Q
ENS of GI.
A
Enteric nervous system, brain of the GI tract.
Wall of the GI tract contains 2 major types of sensory receptors.
1. Chemoreceptors: respond to certain chemical in the food present in the lumen.
2. Mechanoreceptors: are activated when food distends the wall of the GI organ.
19
Q
Gastrointestinal Reflex Pathway
A
Neurons of the ENS that regulate GI secretions and motility in response to stimuli present in the lumen of the GI tract.
20
Q
Peritoneum
A
Largest serous membrane of the body.
Consists of a layer of simple squamous epi (mesothelioma) with underlaying supporting layer areolar CT.
Divided into:
1. Parietal peritoneum-lines wall of abd
2. Visceral peritoneum-covers some of the organs
21
Q
Peritoneal Cavity
A
Slim space containing lubricating serous fluid that is between the parietal and visceral portion of the peritoneum.
22
Q
Ascites
A
Accumulation of several liters of fluids.
23
Q
Retroperitoneal
A
Organs that lie on the posterior abd wall and are covered by peritoneum on their anterior surfaces and they are not in the peritoneal cavity.
Includes: kidney, ascending and descending colon, duodenum and pancreas.
24
Q
Mouth
A
The oral or buccal cavity.
Formed by the creeks, hard and soft palates and tongue.
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Cheeks
Form the lateral walls of the oral cavity.
Covered by skin and mucous membrances.
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Lips
Are freshly folds surrounding the opening of the mouth.
Contains the orbicularis oris muscle and are covered by skin and muscles membranes.
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Labial Frenulum
Midline fold of mucous membrane. Attaches the inner surface of each lip to its corresponding gum.
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Oral Vestibule
Oral cavity
Is the space bounded externally by the cheeks and lips and internally by the guns and teeth.
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Oral Cavity Proper
The space that extends from the gums and teeth to the faucets.
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Fauces
The opening between the oral cavity and the oropharynx.
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Palate
Wall or septum that separates the oral ca its from the nasal cavity and forms the roof of the mouth.
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Hard Palate
Anterior portion of the roof of the mouth.
Formed by the maxillae and palatine bones.
Covered by the mucous membrane.
Forms a bony partition between the oral and nasal cavities.
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Soft Palate
Forms posterior portion between the oropharynx and nasopharynx.
Lined with mucous membrane.
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Palatoglossal Arch
Extends to the side of the base of the tongue.
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Palatopharyngeal Arch
Posteriorly extends to the side of the pharynx.
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Major Salivary Glands
Accessory organ that produces a fluid to soften food
Most saliva is secreted by this gland.
Lies beyond the oral mucosa, into ducts that leads to the oral cavity.
3 major glands;
1. Parotid gland
2. Submandibular glands
3. Sublingual glands
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Parotid Gland
Located inferior and anterior to the ears.
Between the skin and Masseter muscle.
Secretes saliva into the oral cavity via parotid duct.
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Parotid Duct
Duct that pierces the buccinator muscle to open into the vestibule opposite the second maxillary molar tooth.
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Submandibular Glands
Found in the floor of the mouth.
Medial and partly inferior to the body of the mandible.
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Submandibular Ducts
Run under the mucosa on either side of the midline of the floor of the mount and enter the oral cavity proper lateral to the lingual frenulum.
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Sublingual Glands
Are beneath the tongue and superior to the submandibular glands.
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Lesser Sublingual Ducts
Open into the floor of the mouth in the oral cavity proper.
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Composition of Saliva
99.5 % water
0.5 % solutes
Amount solutes: ions- Na, K,Cl, bicarbonate and phosphate.
Only slightly acidic (pH 6.35-6.85)
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Function of Saliva
Water in saliva provides a medium for dissolving foods so they can be tasted by gustatory receptors so that digestive reactions can occur.
Help remove waster molecules from the body.
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Salivary Amylase
Enzyme that is activated by Cl ions in saliva.
Starts the breaks down of starch in the mouth into maltose, maltotriose and a-dextrin.
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Salivation
Secretion of saliva
Controlled by the ANS.
Average 1000-1500mL daily.
Parasympathetic stimulation promotes continuous secretion of a moderate amount of saliva.
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Tongue
Accessory digestive organ composed of skeletal muscle covered with mucous membranes.
Forms floor of the oral cavity.
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Extrinsic Muscle of the Tongue
Originate outside the tongue and insert tinpot the CT of the tongue.
More tongue from side to side and in and out to maneuver food for chewing.
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Intrinsic Muscle of the Tongue
Originate in and insert into CT within the tongue. Alter shape and size of tonic for speech and swallowing.
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Lingual Frenulum
A fold of mucous membrane in the midline of the undersurface of the tongue.
Attached to the gloom of the mouth and aids in lifting the movement of the tongue posteriorly.
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Papillae
Covers the dorsum and lateral surfaces of the tongue.
Are projections of lamia proprioception converted with stratified squamous epi.
Contains taste buds.
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Lingual Glands
Found in lamina propria of the tongue.
Secretes both muscular and watery serous fluid that contains an enzyme lingual lipase.
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Lingual Lipase
Enzyme that acts on 30% of dietary triglycerides and converts them to simpler fatty acids and diglycerides.
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Teeth
Accessory digestive organs located in sockets of the alveolar processes of the mandible and maxillae.
Has 3 major regions:
1. Crown
2. Root
3. Neck
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Gingivae
Gums.
Covers the alveolar processes.
Extended slightly into each socket.
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Periodontal Ligament
Lines socket of teeth.
Consists of dense fibrous CT that anchors the teeth to the socket walls and acts as a shock absorber during chewing.
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Crown of Teeth
Visible portion above the level of the gums.
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Roots of Teeth
Embedded in each socket is 1-3 roots.
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Neck of Teeth
Is the constricted junction of the crown and root near the gum line.
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Dentin
Forms the majority of the tooth.
Consists of calcified CT that gives the tooth its basic shape and rigidity.
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Enamel
Covers the dentin.
Consists primarily of calcium phosphate and calcium carbonate.
Is harder than bone.
Also protects against acids that can easily dissolve dentin.
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Pulp Cavity
Enlarged part of space that encloses tooth.
Lies within the crown and is filled with pulp.
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Pulp
A CT containing blood vessels, nerves and lympathic vessel.
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Root Canals
Narrow extension of the pulp cavity. Run through the root of the tooth.
Each root canal has an opening as its bases called apical foramen.
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Apical Foramen
Openings at the base of a root canal.
Where Blood vessels (nourish) lympathic vessles (protection) and nerves (sensation) enter a tooth.
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Endodontics
Branch of dentistry that is concerned with the prevention, diagnosis and treatment of diseases that affect the pulp, root, periodontal ligament and alveolar bone.
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Orthodontics
Is a branch of dentistry that is concerns with the prevention and correction of abnormally aligned teeth.
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Periodontics
Is a branch of dentistry concerned with the treatment of abnormal conditions of the tissues immediately surrounding the teeth.
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Dentitions
2 sets of teeth in human. Replaced by bicuspids.
1. Deciduous: falling out teeth, appear at 6 months until 20 are present. Lost between 6-12 years
2. Permanent: replace deciduous teeth. 32 teeth, appear between 6 year to adulthood.
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Mastication
Mechanical digestion in the mouth from chewing in which food is manipulated by the tongue, grinded by the teeth and mixed with saliva.
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Enzymes that Contribute to Chemical Digestion
2 enzymes
1. Salivary amylase: secreted by salivary glands, breaks down starch.
2. Lingual lipase: secreted by lingual glands. Breaks down triglycerides.
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Pharynx
Or throat
A funnel shaped tube that extends from the internal nares to the esophagus posteriorly and to the larynx anteriorly.
Composed of skeletal muslce and lined my mucous membrane.
Divided into 3 parts:
nasopharynx: only respiration
oropharynx: both respiration and digestive function
Laryngopharynx: both resp and digestive function
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Esophagus
Is a collapsible muscular tube, about 25 cm long.
Lies posterior to the trachea.
Begins at the larynxopharynx, passes through inferior part of the neck and enters the mediastinum anterior to the vertebrae column.
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Esophageal Hiatus
Opening in the diaphragm where esophagus pierces.
Ends in superior portion of the stomach.
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Histology of the Esophagus
Mucosa: consists of nonkeratinized stratified squamous epi.
Muscularis Mucosae: smooth muscle
Muscularis: superior third of esophagus is skeletal muscle, and the rest is smooth muscle.
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Sphincters of Esophagus
1. Upper esophageal sphincter (UES): consists of skeletal muscle
2. Lower esophageal (cardiac) sphincter (LES): consists of smooth muscle and is near the heart.
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Physiology of the Esophagus
Secretes mucus and transport food into the stomach.
Does not produce enzymes and does not carry on absorption.
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Deglutition
Act of swallowing, 3 stages.
The movement of food from the mouth into the stomach.
Facilitated by the secretion of saliva and mucus.
Involves the mouth, pharynx and esophagus.
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Deglutition (Swallowing) Stages
1. Voluntary stage: bonus is passed into the oropharynx
2. Pharyngeal stage: involuntary passage of the bolus through the pharynx into the esophagus.
3. Esophageal stage: involuntary passage of the boules through the esophagus into the stomach.
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Deglutition Center
Medulla Oblongata
Food bolus stimulates receptors in the oropharynx and sends impulses to this center and to lower pons of the brain stem.
The return impulses cause the soft palate and uvula to move upward to close of nasopharynx preventing food to move into the nasal cavity.
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Peristalsis
A profession of coordinated contractions and relaxations of the circular and longitudinal layers of the muscularis, pushed the bolus onward.
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Stomach
J-shaped enlargement of the GI tract directly inferior to the diaphragm in the abdomen.
Connects the esophagus to the duodenum.
Has 4 main regions:
1. Cardia: surrounds the opening of the esophagus.
2. Fundus: rounded portion superior to and to the left of the cardia.
3. Body: large central portion, inferior to fundus.
4. Pyloric part: divisible into 3 parts: pyloric antrum-connects to the body, pyloric canal-leads to third region, pylorus-connects to the duodenum.
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Function of Stomach
1. Mixes saliva, food and gastric juice to form chyme.
2. Serves as reservoir for food before release into small intestine.
3. Secretes gastric juice which contains HCL, pepsin, intrinsic factor and gastric lipase.
4. Secretes gastric into blood.
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Rugae
Larges folds formed when the stomach is empty.
Allows for greater distention for food storage.
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Pyloric Sphincter
Smooth muscle sphincter.
The pylorus communicated with the duodenum via this sphincter.
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Lesser Curvature
Concave medial border of the stomach
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Greater Curvature
The convex lateral boarder of the stomach.
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Surface Mucous Cells
Surface of the mucosa of the stomach is a layer of simple columnar epi cells.
Contains lamina propria and Muscularis mucosae.
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Gastric Glands
Columns of secretory cells that are formed by epi cells that extend down into the lamina propria.
Secretions from this gland flow into gastric pits and then into the lumen of stomach.
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Gastric Pits
Gastric glands that open in the bottom of narrow channels in the stomach.
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3 Types of Glands contained in Gastric Glands
Contain 3 types of exocrine glands that secrete products into the stomach:
1. Mucous neck cells: secrete mucous
2. Parietal cells: produce intrinsic factor
3. Chief cells: secrete pepsinogen.
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G Cells of Gastric Gland
Secretes a hormone that promotes production of hydrochloride acid.
Type of enteroendocrine cell.
Located in the pyloric antrum.
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Propulsion
The ability of the GI tract to move material along it’s length
Peristaltic wave that moves gastric contents from body to the stomach down the antrum.
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Retropulsion
The pyloric sphincter remains almost closed.
Most food particles that remain too large to fit through the sphincter, they are forced back into the body of the stomach.
Causing another round of propulsion.
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Chyme
The net results of propulsion and retropulsion.
Gastric contents are mixed with gastric juice and are reduced to a soupy liquid.
Once the food particles are small enough and become chyme they pass through the pyloric sphincter cause it gastric emptying.
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Gastric Emptying
Is a slow process
About 3 mL of chyme moves through the pyloric sphincter at a time.
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Proton Pumps
Powered by H+ - K+ ATPases
Actively transports H+ into the lumen while bringing K+ ions into the parietal cell.
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Parietal Cells
Secrete hydrochloric acid
H+ and CL- separately into the stomach lumen to create this acid.
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Carbonic Anhydrase
Enzyme
Plentiful in partial cells.
Catalyzes the formation of carbonic acid ( H2CO3) from water and co2.
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HCL Secretion by Parietal Cells
Can be stimulated by several sources:
1. ACh relased by parasympathetic neurons
2. Gastric secreted by G cells
3. Histamine, which is a paracrine substance released by mast cell in the nearby laminate propria. This acts to enhance the effect of ACh and gastric.
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Pepsin
The only proteolytic (protein digesting) enzyme in the stomach.
Secreted by chief cells.
Most affect in very acidic enviroment of the stomach pH 2. Become inactive at a higher pH.
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Pepsinogen
Inactive form of secreted pepsin.
Can not digest proteins in the chief cells.
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Gastric Lipase
Another enzyme found in the stomach.
Acts to spits triglycerides in fat molecules into fatty acids and monoglycerides.
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Pancreas
Retroperitional gland.
Produces pancreatic lipase.
About 12-15 cm long and 2.5 cm think.
Lies posterior to the greater curvature of the stomach.
Consists of:
1.head: expanded portion of the organ neatly the curve of the duodenum
2. body: central; superior or and to the left of the head
3. tail: tapering
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Pancreatic Duct
Or duct of Wirsung
Carries fluid rich in bicarbonate ions
Is the large, major of the two ducts in the pancreas.
Joins the pancreatic duct to the common bile duct from the liver and gallbladder and enters the duodenum.
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Hepatopancreatic Ampulla
Dilated common ducts where the pancreatic duct enters the duodenum.
Opens on an elevation of the duodenal mucosa.
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Major duodenal Papilla
Duodenal mucosa, lies about 10 cm inferior to the pyloric sphincter of the stomach.
Used for passage of pancreatic juice and bile into the duodenum.
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Sphincter of the Hepatopancreatic Ampulla
Regulated mass of smooth muscle that surround the ampoule.
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Accessory Duct
Other major duct of the pancreas.
Leads from the pancreas and empties into t he duodenum superior the Hepatopancreatic ampulla.
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Acini
99% of small clusters of glandular epi cells that make up the pancreas.
Constitutes the exocrine portion of the organ.
Cells within are a mixture of fluid and digestive enzymes called pancreatic jucie.
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Pancreatic Islets
The remains in 1% of clusters.
Form the endocrine portion of the pancreas.
Secretes hormones glucagon, insulin and somatosin.
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Pancreatic Jucie
1200-1500 mL of clear, colorless liquid that is produced by pancreas.
Consisting of mostly liquid, water, salts, sodium bicarbonate (makes juice alkaline 7.1-8.2 pH)and enzymes.
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Pancreatic Amylase
Acts on glycogen and starch digesting enzymes in pancreatic juice.
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Protein Digesting Enzymes in Pancreas
Trypsin; inactive form trypsinogen
Chymotrypsin
Carboxypeptidase
Elastase
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Pancreatic Lipase
Enzyme that digests Lipids, fatty acids, monoglycerides during digestion.
Principal triglyceride digesting enzyme in adults.
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Ribonuclease
Nucleic acid digesting enzymes
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Deoxyribonuclease
Enzyme that digest RNA and DNA into nucleotides.
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Trypsin Inhibitor
Protein secreted by pancreatic acinar cells that combines with any trypsin formed in the pancreas or pancreatic juice will block its enzymes actively.
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Liver
Accessory organ produces a fluid that functions to emulsify deity fats.
Heaviest gland of the body, completely covered by visceral peritoneum.
Receives blood from: hepatic portal vein and hepatic artery (least nutrient rich)
Weights 1.4 kg or 3 it’s in average adult.
Inferior to the diaphragm and occupies most of the right hypochondriac and part of the epigastric regions of abdominopelvic cavity.
Two principals lobes:
1. Right lobe: large
2. Left lobe: smaller
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Gallbladder
Main Function: stores and concentrates the bile produced by the liver
Pear shaped sac that is located in a depression of the posterior surface of the liver.
Hangs from the anterior inferior margin of the liver.
Parts of gallbladder:
1. Fundus: projects inferior beyond the inferior boarder of the liver
2. Body: central portion
3. Neck: tapered portion.
.
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Ligaments of the Liver
1. Falciform ligament: fold of mesentery
2. Ligamentrum teres: free boarder of the Falciform ligament, remnant of the umibical vein of the fetus.
3. Coronary ligaments: narrow extension of the parietal peritoneum that suspends the liver from the diaphragm.
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Hepatocytes
Major functions cells of the liver
Perform metabolic, secretory, and endocrine fucntion.
Contains: specialized epi cells 80% of volume of the liver.
Forms: hepatic laminae. Complex three dimensional arrangements.
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Bile Canaliculi
Small ducts between hepatocytes that collect bile produced by the hepatocytes.
Bile passes into bile duct ulcers and then bile ducts.
Bile ducts merge and eventually from the larger right and left hepatic ducts which unite and exit the liver as the common hepatic duct.
Common hepatic duct joints the cystic duct from the gallbladder to form the common bile duct.
From here bile enters the duodenum.
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Hepatic Sinusoids
Highly permeable blood capillaries between rows of hepatocytes that receive O2 rich blood from branches of the hepatic artery and nutrient rich DO2 blood from branches of the hepatic portal vein.
Delivers blood into central vein.
From the central vein that flows into the hepatic veins.
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Stellate Reticuloendothelial Cells
Present in hepatic sinusoids that are fixed phagocytes.
Destroy worn out white and red blood cells, bacteria and other foreign matters in the venous blood draining from the GI tract.
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Portal Triad
Formed by bile duct, branch of the hepatic artery and branch of hepatic vein.
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Anatomical and Function Units of Hepatocytes, Bile Duct System and Hepatic Sinusoids
1. Hepatic Lobule: functional unit of liver, hexagon shaped.
Contains central vein and radiating out are rows of hepatocytes and hepatic sinusoids located at the 3 corners.
2. Portal Lobule: emphasizes the exocrine function of the liver, that is bile secretion. Triangle shaped
Bile duct of portal triad is the center of the portal lobule.
3. Hepatic Acinus: smallest structure, preferred structural unit of the liver. Oval mass that includes portions of 2 neighboring hepatic lobules.
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Cystic Duct
Contractions of the smooth muscle fibers ejects its contents of the gallbladder into this duct.
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Bile
Produced by the hepatocytes of the liver.
About 800-1000mL.
Yellow, brownish or liver green liquid.
Aids in digestion and absorption of fats.
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Bilirubin
Principal Bile Pigment.
Derived from heme.
Is secreted into the bile and eventually broken down in the intestines.
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Sterocbilin
Once bile breaks down its products becomes this.
Gives feces their normal brown color.
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Emulsification
The breakdown of large lipids globules into a suspension of small lipid globules.
Create a large surface area that allows pancreatic lipase to more rapidly digest triglycerides.
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Small Intestine
Most digestion and absorption of nutrients occurs in this long tube.
Due to this structure is specially adapted for these functions.
Provides large surface area for digestion and absorption.
Begins at the pyloric sphincter of the stomach and coils ending at the large intestine.
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3 Regions of the Small intestine
1. Duodenum: shortest, retroperitoneal. Forms a c shape. Starts at the pyloric sphincter of stomach and merges with jejunum. 12 ft
2. Jejunum: means empty. 3 ft.
3. Ileum: the longest and final region.
6 ft long, joins large intestine at a smooth muslce sphincter called ileocecal sphincter.
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Histology of Small intestine
4 layers
Mucosa, Submucosa, muscularis (contains skeletal muscle), serosa.
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Functions of the Small Intestine
1. Segmentations mix chyme with digestive juice and bring food into contact with Mucosae for absorption, peristalsis propels chyme through small intestine.
2. Completes digestion of carbohydrates, proteins and lipids. Begins and completes digestion of Nucleic acids.
3. Absorbs about 90% of nurses rent and water that pass through the digestive system.
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Absorptive Cells
Found in epithelium of small intestine that contain enzyme that digest food and possess microvilli that absorb nutrients in small intestinal chyme.
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Goblet Cells
Also present in epithelium of small intestine.
Secrete mucus.
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Intestinal Glands
Cells that line the deep crevices in the mucosa of small intestine.
Secrete intestinal jucie.
Contain planets cells and enteroendocrine cells.
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Paneth Cells
Secrete lysozyme which is a bacterial enzyme that is capable of phagocytosis.
Also have a role in regulating the microbial population in the small intestine.
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Types of Enteroendocrine Cells found in Intestinal Glands of small Intestine
S cells, CCK cells and K cells which secrete the hormones secretin, cholecystokinin (CCK) and glucose dependent insulinotropic peptide.
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Lamina Propria of Small Intestinal Mucosa
Contains areolar connective tissue
Has an abundance of mucosa associated lymphoid tissue (MALT).
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Solitary Lympathic Nodules
Are most numerous in the distal part of the ileum.
Groups of lymphatic nodules are known as: aggregated lymphatic follicles or peyers pathes, are also present in the ileum.
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Duodenal Glands or Brunners Glands
Secrete an alkaline mucus that helps neutralize gastric acid in the chyme.
Found in the Submucosa of the duodenum.
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Circular Folds
Or plicae circulares
Are folds of the mucosa and Submucosa of the small intestine.
They are per ent ridges about 10 cm long.
Begin at the proximal portion of the duodenum and ends at the midpoint of the ileum.
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Villi
Present in the small intestine.gives it a velvety appearance.
Are hair like projections of the mucosa that are 0.5-1 mm long.
The large amount of villi increases the surface area of the epi for absorption and digestion.
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Lacteal
A lymphatic capillary found in each vili.
Nutrients absorbed by the epi cells covering the villus pass through the lacteal to enter blood or lymph.
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Motility
mixing and propulsion,
Pocess of the smooth muscles layer to churn and movement of food through GI tract.
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Injection
Primary process of the mouth
involves taking foods and liquids into the mouth.
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Absorption
Primary function of the villi and small intestine
passage of digested products from GI tract into blood and lymph.
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Secretion
Cells within the walls of the GI tract and accessory digestive organs secrete a total of about 7 L of water, acid, buffers and enzymes into the lumen of the tract.
Stimulates the secretion of bile
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Digestion
Primary function of the stomach
mechanical and chemical breakdown of food.
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Defecation
Elimate on of feces from GI tract.
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Why do Emotions such as Anger or Fear Slow DIgestion
They stimulate the sympathetic nerves that supply the GI tract
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Great Omentum: Peritoneal Folds
Largest, drapes over transverse colon and coils of the small intestine
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Falciform Ligament: Peritoneal Fold
Attaches the liver to the anterior abd wall and diaphragm.
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Lesser Omentum: Peritoneal Fold
Anterior folds in the serosa of stomach and duodenum. Connects the stomach and duodenum to the liver
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Mesentery: Peritoneal Fold
Fan shaped fold, binds the jejunum and ileum of the small intestine to the posterior abd wall.
Contains adipose tissues and contributes to larger fold in obese people.
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Mesocolon Peritoneal Fold
Two separate folds.
Bind to transverse colon and sigmoid colon of large intestine to abd wall.
Carries blood and lymphatic vessels to the intestines.
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Fundus
Food can stay in the fundus for 1 hour before being mixed with gastric juices.
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Round Ligament
Structure found on the liver and is a remnant of the umbilical cord in a fetus.
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Functions of the Liver
1. Conversation of carbohydrates
2. Protein metabolism
3. Phagocytosis
4. Shortage of vitamins
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Chymotrypsin
Pancreatic enzyme that acts on peptide bonds.
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Secretin
A hormone that functions to counteract the effect of gastric acid in the small intestine
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Cholecystokinin
Hormone that is stimulated by high levels of dietary fat in the small intestine.
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Hydrochloric Acid
Digestive aid that is produced by the stomach
Begin digestion by denaturing protein
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Ileocecal Sphincter
Structure that regulate the floe of material into the colon
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Large Intestine Function
1. Mechanical digestion
2. Chemical digestion
3.Absorption
4. Feces formation
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Primitive Gut
Forerunner of the GI tract
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Lactase
Enzyme produced in the intestines.
Produces both glucose and galactose products.
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Maltese
Enzyme produced in the intestines.
Produces only glucose.
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Hepatitis
Disorder of the liver that can result from virus, drugs and chemical like alcohol.
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Peptic Ulcers
Disorder of the stomach.
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Gastrointestinal Organs
Continuous of mouth and ends with the anus.
Includes;
Mouth
Pharynx
Esophagus, stomach, small intestines, large intestines.
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Major Peritoneal Folds
1. Greater Omentum: the longest peritoneum fold. Drapes over transverse colon and small intestine like an apron. Has 4 layers. Consists of adipose tissue and lymph nodes.
2. Falciform ligament: attached the liver to the anterior abd wall and diaphragm.
3. Lesser Omentum: arises as an anterior fold in the serosa of the stomach and duodum, connects them to the liver.
4. Mesentery: fan shaped, binds to small intestine and post anterior wall. Most massive fold, contributes to large abd in obese people. Double layered structure contains blood and lymphatic vessel and node.
5. Mesocolon: t separate folds binds the transverse color and sigmoid colon to abd wall.
Carries blood and lymphatic vessel to intestine.
