Term
| What are the 2 parts of the digestive system |
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Definition
The alimentary canal and the accessory organs |
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Term
| Describe the alimentary canal. |
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Definition
a tube that is considered to be outside the body. It extends from mouth to anus. About 7x the person's height.
Includes mouth, pharynx, esophagus, stomach, small intestine, and large intestine. |
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Term
| Describe the accessory organs. |
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Definition
Assist with digestion but are not part of the tube
Include tongue, teeth, salivary glands, liver, gall bladder, and pancrease |
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Term
| Describe the location of the digestive organs |
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Definition
Most found in the abdominal cavity
Lined by a the peritoneum
perietal peritoneum lines the abdominal pelvic cavity
viseral peritoneum covers the surface of most of the digestive organs
The space between the layers is peritoneal cavity, filled with peritoneal fluid
This reduces friction. |
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Term
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Definition
Fused double layered extensions of the peritoneum that connect the the viseral and parietal layers.
Support organs and hold stored fat. |
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Term
| Define retroperitoneal and give examples. |
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Definition
Organs located posterior to the peritoneum.
Ex: Kindeys, spinal cord |
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Term
| Describe the mucosa of the digestive system in general. |
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Definition
Made of either stratified squamous or simple columnar epithelium
Inferior to the epi is the lamina propria
Inferior to the lamina propria in the muscularis mucosa. |
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Term
| What is the lamina propria? |
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Definition
A loose conective tissue layer that supports the epithelium
May include blood vessels, nerves, lymph, and glands. |
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Term
| What the musularis mucosa? |
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Definition
| 2 thin smooth muscle layers that control the shape of the lumen. |
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Term
| Describe the submucosa of the digestive system in general. |
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Definition
Made of dense irregular connective tissue
May have a submucosal plexus- a network of nerve fibers along the edge. |
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Term
| Describe the muscularis externa of the general digestive system. |
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Definition
two layers inner and outer, used for peristalsis
inner is circular smooth muscle
outer is longitudinal smooth muscle |
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Term
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Definition
Outer most layer
A serous membrane continuous with the viseral peritoneum. |
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Term
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Definition
Outer most layer
Composed of colligen fibers which achors the organs to another part of the body. |
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Term
| What are the 6 essential activities of the GI tract? |
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Definition
Ingestion
Propulsion
Mechanical digestion
Chemical digestion
Absorption
Excretion |
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Term
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Definition
| the process of taking food into the digestive system |
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Term
| Define propulsion and name 2 types. |
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Definition
Moving of food thru the digestive tube.
Deglutition and peristalsis. |
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Term
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Definition
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Term
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Definition
| Wave like motion that pushes material thru the digestive tube. |
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Term
| Define Mechanical Digestion and name 4 types. |
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Definition
Breaking food into smalled pieces
Mastication, mixing with tongue, churning in stomach, and segmentation. |
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Term
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Definition
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Term
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Definition
Contraction on non-adjacent muscle segments that mixes food
Occurs in the small intestine. |
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Term
| Define chemical digestion |
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Definition
| chemical process that uses enzymes to break down food macromolecules into "monomers" that are small enough to absorb. |
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Term
| What enzymes break down protiens? |
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Definition
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Term
| What enzymes break down startch? |
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Definition
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Term
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Definition
| The transport of digested materials into the blood or lymph. |
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Term
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Definition
The elimination of indigestable from the body in the form of feces. |
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Term
| How does the digestive system mantain homeostasis? |
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Definition
Mechanoreceptors and Chemoreceptors in the walls of the GI tract monitor conditions.
They respond to stretch, osmolarity, pH, substrates, and end products of digestion.
When stimulation cause the GI tract to secretes digestive juices, hormones, and muscle contrations |
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Term
| What is the enteric nervous system? |
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Definition
| The neural network in and around the GI tract |
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Term
| What are the 2 parts of the enteric nervous system, what are their locations, and functions? |
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Definition
1. Outer Plexus- located between the smooth muscle layer and the externa, Controls muscle contraction.
2. Inner Plexus- located in the submucosa, stimulates glands |
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Term
| Name and describe the 2 types of enteric reflexes. |
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Definition
Short Reflexes- integrated in the GI tract, act locally, work even in para or quadrapeligics.
Long Reflexes- integrated in the CNS, cordinate activities that go along the GI tract. |
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Term
| Describe Enteroendocrine cells/glands |
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Definition
| Cells in the GI tract that make and release 18+ hormones. |
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Term
| Describe a few local mechanisms. |
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Definition
Local messangers like prostaglandins and histamine.
Effects segmentantion of the GI tract
It is a local response |
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Term
Describe the location of the mouth. |
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Definition
| It is defines by the hard and soft palates, the cheeks, the tongue, the lips, and the oral pharynx. |
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Term
| What are the functions of the mouth? |
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Definition
Ingestion
Mastication/ mechanical digestiion
Chemical digestion of startch with salivary amylase
Propulsion |
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Term
| What are the 5 parts of the mouth and what are their functions? |
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Definition
Labia (lips)- keep in food and speech
Palate- closes nasopharynx during swallowing, and help in repositioning food.
Uvula
Teeth- Tear/grind food
Tongue- aids in speech (saying consanants), mixes and moves food. |
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Term
| What is the location of teeth and what are the types of teeth, how many of each type? |
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Definition
Found in the gum covered margins of the maxilla and mandible.
incisors (8)
cuspids/canine (4)
bicuspids (8)
molars (12) |
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Term
| Describe the crown, neck, and root of the tooth. |
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Definition
Crown- the visible part of the tooth
Neck- part of tooth that goes into the gum
Root- part of tooth in the bone |
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Term
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Definition
| the mineralized matrix (calcium phosphate) that makes up the tooth. |
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Term
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Definition
The big space in the crown of the tooth. |
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Term
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Definition
| tube/tunnel that goes from the pulp cavity to the end of the tooth and contains nerves and blood vessels. |
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Term
| What is the apical foramen? |
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Definition
| The enterance/exit of the root canal |
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Term
| What is the alveolus (as it applies to teeth)? |
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Definition
| The boney socket for the teeth |
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Term
| What is the gomphosis/periodontal ligament? |
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Definition
| The articulation between the tooth and alveolus |
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Term
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Definition
| Covers the dentin of the tooth root |
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Term
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Definition
| Covers the dentin of the tooth crown |
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Term
| Name and describe 3 parts on the tongue. |
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Definition
extrinsic muscles- their origin is outside of the tongue.
intrinsin muscle- their origin is inside the tongue.
lingual frenulum- the piece of tissue that holds the tongue to the floor of the mouth. |
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Term
| Describe the histology of the mouth |
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Definition
Has a musosa that is made of stratified squamous epithelium.
There are not 4 layers yet. |
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Term
| Describe the location and function of the pharynx. |
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Definition
In the back of the throat. Goes from the nasal cavity to the latynx.
Serves as a passage way for food and air. |
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Term
| What are the 4 parts of the pharynx? |
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Definition
Nasopharynx
Oropharynx
Laryngopharynx
Palatine tonsils- located in the lateral walls of the throat. |
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Term
| Describe the Histology of the pharynx. |
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Definition
Stratified squamous epithelium
No 4 layers yet |
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Term
| Describe the location and function of the esophagus. |
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Definition
10-12" long muscular tube posterior to the trachea, that pierces the diaphragm at the esophageal hiatus.
passage way for food |
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Term
Name and describe the parts of the esophagus. |
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Definition
Cardiac orifice- opening between the esophagus and the stomach had a sphincter that keeps acid in stomach
Hiatal hernia- the portion just above the diaphragm. |
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Term
| Describe the histology of the esophagus. |
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Definition
4 layers start here
stratified squamous epithelium
long folds in the mucosa and submucosa
skeletal muscle at top, sm muscle at bottom. |
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Term
| Describe the location of the stomach |
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Definition
inferior to the diaphram in the up left quadrant
about 10" long
holds .5 mL empty and 1.5 mL full |
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Term
| What are the functions of the stomach? |
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Definition
Mechanical digestion
Chemical digestion
absortion of some lipid soluble materials (ex asprin & alcohol)
holding area
secretion of intrinsic factor (needed to absorb vit B12)
Making and propulsion of chyme |
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Term
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Definition
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Term
What are the openings of the stomach and where are they located. |
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Definition
Cardiac orafis and sphincter- located at the top of the stomach.
Pyloric orafis and sphincter- located at the bottom of the stomach. |
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Term
| Name and describe the curvatures of the stomach. |
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Definition
The greater curvature is on the outer edge.
The lesser curvature is on the inner edge. |
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Term
| Name and describe the location of the stomach regions. |
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Definition
Cardiac- connects to the esophagus
Fundus- superior portion
Body
Pyloric- thick muscular portion that connects to the small intestine. |
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Term
What are omentums? Name and describe them. |
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Definition
Messentaries that connect the stomach to other organs.
Lesser omentum- connects the lesser curvature to the liver.
Greater omentum- connects the greater curvature to the small intestine. |
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Term
| Describe the mucosa of the stomach. |
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Definition
Simple columnar epithelium with goblet cells
Has gastric pits with gastric glands
Lamina propria, which has enteroendocrine cells |
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Term
| What are the gastric glands that are found in the fundus and body of the stomach? |
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Definition
Mucous neck cells- toward the top, make mucous.
Parietal cells- make HCL and intrinsict factor
Cheif cells- make pepsinogen |
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Term
| What is the function of the glands in the cardiac and pyloric regions of the stomach? |
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Definition
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Term
Where are the enteroendocrine glands located in the stomach and how are the activated? |
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Definition
found in the lamina propria
Activated by pH, stress, and local factors. |
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Term
| Describe the submucosa and muscularis exteran of the stomach. |
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Definition
Submucosa- nothing special
Muscularis esterna- has 3 layers instead of 2. |
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Term
Describe the small instestine
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Definition
| A muscular tub, small in diameter, takes up most of the peritonial cavity, about 12 dead |
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Term
Describe the function of the small intestine
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Definition
Finishes mechanical and chemical digestion Main site of food absorption Propulsion |
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Term
Describe the 3 sections of the small intestine
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Definition
The first 12 inches that connects to stomach is the duodenum Middle 8 ft is the jejunum The last 12 ft connects to the large intestine ileum |
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Term
What is the hepatopancreatic ampulla (of Vater)
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Definition
| An opening into the duodenum, where secretions from the liver and pancrease are secreted. |
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Term
| Describe the small intestine mesentary |
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Definition
A fan shapd mesentary contain blood vessel, nerves, ect.
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Term
Describe the mucosa of the small intestine and it's specializations.
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Definition
Simple columar epithelium with specializations for absortion, lots of goblet cells, and enteroendrine cells. Villi- finger like projections of the mucosa, increases surface area. Microvilli- tiny finger like projections of the plasma membrane, increases surface area. Circular folds- folds in both the mucosa and submucosa, slows the movement of chyme by making it swirl, increases time for absorption. Crypts of Leiberkuhn- spaces in between the villi
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Term
Describe the specializations of the submucosa of each part of the small intestine.
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Definition
Duodenum has Brunner's glands- it releases alkaline secretions. Jejunum has no specaliztions. Ileum has Peyer's patches- aggrigations of lymph tissue |
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Term
Describe the location and functions of the large intestine.
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Definition
Muscular tube that extends from the small intestine to the anus. Reabsorption of water. Propulsion and elimination of feces. Mass movement/peristalsis- long slow waves of contraction over large areas.
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Term
Describe the cecum and the appendix
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Definition
Cecum- 1st part of the large intestine, a dead end sac that connects to the small intestine. Where the ileocecal sphincter is. The appendix is a finger like sac filled with lymph tissue and bacteria.
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Term
| Name the parts of the large intestine in the order that food goes through them beginning at the colon. |
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Definition
Ascending colon ---> transverse colon ---> descending colon ---> sigmoidal colon ---> rectum ---> anal canal ---> anus, an opening with sphincters |
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Term
Describe the mucosa of the large intestine.
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Definition
Simple columnar with lot of goblet cells, no villi, almost no cells secreting digestive enzymes.
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Term
| What are the specializations of the muscularis in the large intestine. |
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Definition
Teniae coli- bands of muscle Haustra- pockets/ puckers in the large intestine. |
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Term
What is the histology of the anus?
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Definition
Stratified squamous epithelium. Internal anal sphincter is smooth muscle, involuntary. External anal sphincter is skeletal muscle, voluntary.
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