Anatomy Excercise 38 Digestive System Lab Flashcards
Digestive Terms
Two Major Parts
Digestive Tract and Accessory Organs
Digestive Tract
A long tube that runs from the mouth and the anus and comes into contact with food and the breakdown products of digestion.
What is another name for the digestive tract? What is it commonly called?
Alimentary canal and commonly called the “food tube”.
Organs of the Digestive Tract
Esophagus, Stomach, Intestines, Colon, Rectum and Anus.
Why are accessory organs important?
They secrete many substances necessary for digestion, yet these organs do not come in direct contact with food.
Examples of Accessory Organs
Pancreas, Gallbladder, Liver and Salivary Glands
Functions of the Digestive System
- Ingestion of Food
- The Physical Breakdown of Food
- The Chemical Breakdown of Food
- Food Storage
- Food and Water Absorption
- Vitamin Synthesis
- The Elimination of Indigestible Material
Oral Cavity (Mouth)
Starts as the opening surrounded by lips, or labia.
Labial Frenulum
A membranous structure that keeps the lip adhered to the gums, or gingivae.
Gingivae
Gums
Hard Palate
Composed of the palatine processes of the maxillae and palatine bones.
Form the roof of the oral cavity, and the floor of the chin is the inferior border.
Soft Palate
Composed of connective tissue and a mucous membrane.
Form the roof of the oral cavity, and the floor of the chin is the inferior border.
Uvula
At the posterior border of the oral cavity, a small, grapelike structure suspended from the posterior edge of the soft palate.
Helps prevent food and liquid from moving into the nasal cavity during swallowing,
Oropharynx
Posterior border of the oral cavity.
What type of tissue is the Oral Cavity lined with?
Nonkeratinized Stratified Squamous Epithelium
One of the major muscles of the tongue is ___________.
Genioglossus
What is the tongue important for?
Speech, Taste, the Movement of Food toward the Teeth for Chewing, and Swallowing.
Acts like a piston to propel food to the oropharynx.
Oropharynx
The space behind the oral cavity.
What holds on the tongue down?
Held down to the floor of the mouth by a thin mucous membrane called the Lingual Frenulum.
Papillae
Raised areas, on the tongue.
Foliate Papillae
Leaf-shaped.
Fungiform Papillae
Mushroom-shaped.
Filiform Papillae
Thread-like.
Circumvallate Papillae
Large papillae.
What do papillae do?
They increase the frictional surface of the tongue.
Taste Buds
Taste receptors on the tongue.
Where are taste buds located?
Located on the tongue along the sides of some of the papillae.
What is the Oral Cavity important for?
Physical Breakdown of Food.
The physical breakdown of food is driven by powerful muscles called ______________.
Muscles of Mastication
Masseter
Involved in the closing of the jaws.
Temporalis Muscles
Involved in the closing of the jaws.
Pterygoid Muscles
Important in the sideways grinding action of the molar and premolar teeth.
Digastric Muscles
Muscles open the mandible.
Platysma Muscles
Muscles open the mandible.
A tooth consists of _________, _________, and _______,
Crown, Neck and Root.
Crown
Exposed part of the tooth.
Neck
A constricted portion of the tooth normally located at the surface of the gingivae.
Root
Embedded in the jaw.
Enamel
An extremely hard material.
Dentin
Made up of like a bonelike material.
Pulp Cavity.
Innermost portion of the tooth. Leads to root canal.
Root Canal
A passageway for nerves and blood vessels into the tooth.
Apical Foreman
Nerves and blood vessels enter the tooth through here.
Alveolar Sockets
The teeth depressions in the mandible or maxilla.
Anchored to the bone by the periodontal ligaments.
Four Types of Teeth in the Adult Mouth
Incisors, Canines (Cuspids), Premolars (Bicuspids), and Molars
Incisors
Flat, bladelike front teeth that nip food.
8 Incisors in the Adult Mouth.
Canines, or Cuspids
The pointed teeth just lateral to the incisors that shear food.
4 Cuspids in the Adult, and they are identified as the teeth that just have one cusp, or point.
Premolars, or Bicuspids
Posterior to the Cuspids and grind food.
Typically 8 Premolars in adults, and they are identified by their Two Cusps.
Molars
Most posterior. Like premolars, these grind food.
12 Molar Teeth in the Adult Mouth (Including the Third Molars, or WISDOM TEETH).
Typically have Three to Five Cusps.
What are the two sets of teeth humans have?
Primary or Deciduous Teeth (Milk Teeth) and Secondary or Permanent Teeth
Primary or Deciduous Teeth
Appear first, and these are replaced by the Secondary or Permanent Teeth.
“Milk Teeth”
20 Deciduous Teeth
No Deciduous Premolar Teeth, and there are Only 8 Deciduous Teeth.
Secondary or Permanent Teeth
Replaces the Deciduous Teeth.
8 Premolar Teeth and 12 Molar Teeth.
Oropharynx
The space behind oral cavity.
Begins at the soft palate and continues to the larynx.
Composed of nonkeratinized stratified squamous epithelium.
A common passageway for food, liquids and air.
Nasopharynx
Superior to the oropharynx. Leads to the nasal cavity, and inferior to the oropharynx.
Begins at the external nares and ends at the soft palate.
Laryngopharynx
Leads to the larynx and the esophagus.
Posterior to the larynx.
Pharyngeal Constrictor Muscles
Muscles around the wall of the oropharynx.
Involved in swallowing.
Esophagus
Food is moved by the tongue to the region of the pharynx, where it is propelled here.
Conducts Food and Liquid from the Oropharynx, through the Diaphragm, and the into the Stomach.
Normally, the Esophagus is a Closed Tube at about the level of the Sixth Cervical Vertebra.
Pharynx consist of:
Nasopharynx, Oropharynx, Laryngopharynx, Pharyngeal Constrictor Muscles and Esophagus.
VOLUNTARY
VOLUNTARY
VOLUNTARY
Pharynx
Swallowing Food
Bolus
Lump of food, enters the Esophagus.
Skeletal Muscle
Begins to move it toward the stomach.
Smooth Muscle
The Inferior Portion of the Esophagus is made of this.
Peristalsis
Muscle contracts, moving the bolus by this process.
Esophagus
Middle Portion of the Esophagus is composed of both Skeletal and Smooth Muscle.
Adventitia
The esophagus had an inner epithelial lining of stratified squamous epithelium and an outer connective tissue layer called this.
Lumen
Space in the esophagus that the food passes through.
Esophageal Sphincter
The Inferior Portion of the Esophagus, which prevents the backflow of stomach acids.
Heartburn or Gastroesophageal Reflux Disease (GERD)
Occurs if the stomach contents pass through the esophageal sphincter and irritate the esophageal lining.
Esophagus
Bolus, Skeletal Muscle, Smooth Muscle, Peristalsis, Adventitia, Lumen, Esophageal Sphincter.
Esophagus
Involuntary Muscle Movement
The inner surface of the body has been referred to as a ____________.
“tube within a tube”.
What forms the outer tube? What forms the inner tube?
Outer Tube: Body Wall
Inner Tube: Digestive Tract, Stomach, Small Intestine and Large Intestine.
Coelom (Body Cavity) of the Digestive Tract
Specialized serous membranes cover the various organs and line the inner wall of this.
Visceral Peritoneum (Serosa)
Membrane lining the outer surface of the digestive tract
Mesentery
Digestive tract continues as a double-folded membrane, which attaches the tract to the back of the body wall.
Parietal Peritoneum
Mesentery is continuous with the membrane on the inner side of the body wall, where it is called this.
Mucosa
The innermost layer of the Abdominal Portion of the Digestive Tract.
Epithelium
A tissue in the Mucosa.
Lamina Propria
Closest to the Lumen, a Connective Tissue Layer.
Muscularis Muscosae
An outer, muscular layer.
Mucous Membrane
Three layers called the mucous membrane. In the Mucosa:
- Epithelium
- Lamina Propria
- Muscularis Muscosae
Submucosa
The next layer (2nd) of the Abdominal Portion of the Digestive Tract.