Digestive System Reviewer Flashcards

Flashcards based on the Digestive System Reviewer lecture notes.

What is Ingestion?

Process of food entering the body and chewing.

What is Peristalsis?

Involuntary waves of contraction and relaxation of longitudinal muscles in the organ wall that moves food.

What is mechanical digestion?

Mixing of food in the mouth (chewing).

What is chemical digestion?

Using enzymes to break down food.

What is Absorption?

Absorbing nutrients in the gastrointestinal tract.

What is Defecation?

Elimination of undigested and indigestible substances (stool or feces).

How long is the Alimentary Canal?

Approximately 9 meters (about 30 feet).

What is the function of the Mucous membrane (mucosa)?

Ability to produce mucus.

What is the Alimentary Canal?

Continuous, coiled canal 7 meters long, also known as the Gastrointestinal Tract (G.I.) or gut.

What is the Mouth (Oral Cavity)?

Part where food enters the digestive tract, a mucous membrane-lined cavity.

What is the function of Lips (labia)?

Protect the anterior opening of the mouth.

What is the function of Cheeks?

Forms the lateral wall of the mouth.

What is the hard palate?

Forms the anterior roof of the mouth.

What is the soft palate?

Forms the posterior roof of the mouth.

What is the Uvula?

Fleshy finger-like projection of the soft palate, extends below the back of the soft palate.

What is the Vestibule?

Space between the lips and cheeks externally and the teeth and gums internally.

What is the Oral Cavity?

Space where the teeth are contained.

What is the Tongue?

Muscle organ which occupies the floor of the mouth.

What are the hyoid bone and styloid processes?

Bony attachments to the tongue.

What is the Lingual Frenulum?

Fold of mucous membrane, secures the tongue to the floor of the mouth and limits its posterior movements.

What are the Palatine tonsils?

Found at the posterior end of the oral cavity, contains paired masses of lymphatic tissue.

What is the Lingual Tonsil?

Covers the base of the tongue just beyond.

What is the Pharynx?

From the mouth, the food passes here.

What is the Oropharynx?

It is posterior to the oral cavity.

What is the Laryngopharynx?

Continuous with the esophagus below; both are common passageways for food, fluids, and air.

What is the Esophagus?

Also known as gullet, runs from the pharynx through the diaphragm to the stomach, 25 cm (10 in) long, able to do peristalsis into the stomach.

What is Longitudinal (muscle fiber orientation)?

Muscle fiber orientation is vertical (lengthwise).

What is Circular (muscle fiber orientation)?

Muscle fiber orientation is horizontal (crosswise).

What is the Mucosa?

Moist innermost layer that lines the lumen of the organ.

What is the Lamina Propria?

Connective tissue layer of the mucosa.

What is the Submucosa?

Found underneath the mucosa, which contains blood vessels, never endings, lymph nodules, and lymphatic vessels.

What is the Muscularis externa?

Muscle layer typically made up of an inner circular layer and an outer longitudinal layer of smooth muscle cells.

What is the Peritoneum?

Comprises of the parietal and visceral peritoneum, and between those layer is the peritoneal cavity.

What is the Serosa?

The visceral peritoneum, is the outermost layer of the wall that consists of a single layer of flat serous fluid-producing cells.

What are Intrinsic nerve plexuses?

Network of nerve fibers that are part of the autonomic nervous system which also regulates the mobility and secretory activity of the GI tracts.

What is the Stomach's Composition?

C-shaped, found on the left side of the abdominal cavity, hidden by the liver and the diaphragm.

What is the cardioesophageal sphincter?

Gate through which food enters the stomach from the esophagus.

What is the Fundus?

Expanded part of the stomach lateral to the cardiac region.

What is the Body (of the stomach)?

Midportion of the stomach, it becomes the pyloric antrum as it narrows inferiorly.

What is the Pylorus?

Terminal part of the stomach (Last region of the stomach).

What is the Pyloric Sphincter (valve)?

Gate from the stomach to the small intestine.

What are the Rugae?

Found in the mucosa of the stomach, these are large folds of the stomach.

What is the Greater curvature?

The convex lateral surface of the stomach.

What is the Lesser curvature?

The concave medial surface of the stomach.

What is the Lesser omentum?

Double layer of peritoneum, extends from the liver to the greater curvature.

What is the Greater omentum?

Extension of the peritoneum, drapes downward and covers the abdominal organs like a lacy apron.

What is the Stomach mucosa?

Simple columnar epithelium, produces a protective layer of bicarbonate-rich alkaline mucus which protects the stomach from acid and digestion by enzymes.

What are the Gastric Glands?

Secretes gastric juice, smooth lining dotted with millions of gastric pits.

What is the Intrinsic factor?

Produced by the stomach cells which is needed in order for vitamin B12 to be absorbed in the small intestine.

What are the Chief Cells?

Produces protein-digesting enzymes, mostly pepsinogens.

What are the Parietal cells?

Produces HCl acid, makes the stomach contents acidic and activates enzymes.

What are the Enteroendocrine cells?

Produces hormones such as gastrin (important to the digestive activities of the stomach).

What is the Chyme?

Term referred to as food after being processed in the stomach, resembling heavy cream.

What is the Ileocecal Valve?

Valve between the Ileum and Cecum.

What is the Small intestine?

Muscular tube extending from the pyloric sphincter to the large intestine.

What is the Hepatopancreatic ampulla?

Flask-like formed by the main pancreatic and bile ducts at the duodenum.

What is the Duodenal papilla?

Passageway of the bile and pancreatic juice to enter the duodenum.

What is the Bile?

Fluid released by the liver for digestion.

What are the Microvilli?

Referred to as the brush border; tiny projections of the plasma membrane of the mucosa cells. They bear brush border enzymes that complete the digestion of proteins and carbohydrates in the small intestine.

What are the Villi?

Fingerlike projections of the mucosa that give it a velvety appearance and feel, much like the soft nap of a towel.

What is the Lacteal?

Rich capillary bed and a modified lymphatic capillary found in each villus.

What are the Circular folds (plicae circulares)?

Deep folds of both mucosa and submucosa layers, and they do not disappear when food fills the small intestine.

What are the Peyer’s Patches?

Local collections of lymphatic tissue found in the submucosa.

What is the major function of the Large intestine?

To dry out indigestible food residue by absorbing water and to eliminate these residues from the body as feces.

Why is the appendix a potential trouble spot?

ideal location for bacteria to accumulate and multiply in the large intestine.

What is the right colic (or hepatic) flexure?

Turning point of the Ascending colon.

What is left colic (or splenic) flexure?

turning point of the colon as it descends.

What is the Sigmoid colon?

S–shaped colon that is found in the pelvis.

What is the function of External anal sphincter?

The anal canal has an external voluntary sphincter composed of skeletal muscle.

What is the function of Internal involuntary sphincter?

An internal involuntary sphincter formed by smooth muscles.

What is the function of the Teeth?

The teeth tear and grind the food, breaking it down into smaller fragments.

What are Deciduous teeth?

First set of teeth, also called baby teeth or milk teeth, 20 teeth.

What are Permanent Teeth?

Second set of teeth, enlarge and develop, the roots of the milk teeth are reabsorbed.

What are Incisors?

These are teeth for cutting.

What are Canines?

Fang-like canines are for tearing and piercing.

What are Premolars?

Between the molars in the back of your mouth and your canine teeth.

What are Molars?

Have broad crowns with round cusps (tips) and are best suited for grinding.

What is the Crown (of a tooth)?

Enamel covered, is the exposed part of the tooth above the gingiva or gum.

What is the Enamel?

Hardest substance in the body (tooth) and is fairly brittle because it is heavily mineralized with calcium salts.

What is the Root (of a tooth)?

Covered by a substance called cementum, which attaches the tooth to the periodontal membrane (ligament).

What is the Dentin?

Bonelike material, underlies the enamel and forms the bulk of the tooth.

What is the Pulp cavity?

Contains a number of structures (connective tissue, blood vessels, and nerve fibers) collectively called the pulp.

What is the Root Canal?

Provides a route for blood vessels, nerves, and other pulp structures to enter the pulp cavity of the tooth.

What are the Parotids glands?

Lie anterior to the ears and empty their secretions into the mouth.

What are the Submandibular and sublingual glands?

Empty their secretions into the floor of the mouth through tiny ducts.

What is the Salivary amylase?

Clear serous portion of the saliva, an enzyme, a bicarbonate–rich juice that begins the process of starch digestion in the mouth.

What is the location of the Pancreas?

Lies posterior to the parietal peritoneum, hence its location is referred to as retroperitoneal.

What is the function of the Pancreatic enzymes?

Are secreted into the duodenum in an alkaline fluid that neutralizes the acidic chyme coming in from the stomach.

What is the Endocrine function of the Pancreas?

Produces hormones insulin and glucagon.

What is the Liver?

Largest gland in the body, produces bile.

What is the location of the liver?

Located under the diaphragm and almost completely covers the stomach.

What is the Falciform ligament?

Delicate mesentery cord, suspends the liver from the diaphragm and abdominal wall.

What is the Bile?

Yellow-to-green, watery solution containing bile salts, bile pigments, cholesterol, phospholipids, and a variety of electrolytes.

What is the function of the Bile salts?

Emulsify fats by physically breaking large fat globules into smaller ones, thus providing more surface area for the fat-digesting enzymes to work on.

What is the function of the Gallbladder?

Remove excess water in the bile to make it concentrated.

What is the Cystic duct?

This duct helps the bile to get stored in the gallbladder, when food digestion is not present.

What is Food ingestion and breakdown?

Once food is placed in the mouth, mechanical and chemical digestion begin.

What is Physical Breakdown of food?

Food is physically broken down into smaller particles by chewing.

What is Chemical Breakdown of food?

As the good mixes with saliva, salivary amylase, begins the digestion of starch, converting it to maltose.

What is Stimulation of saliva?

Production of saliva is triggered when food enters the mouth, even simple pressure of anything put into the mouth and is chewed, will trigger the release of saliva.