Chapter 14 Digestive System Flashcards
1
Q
Organs of the Digestive System
A
- Two main groups
- Alimentary canal (gastrointestinal or GI tract [gastrointestinal tract)– continuous coiled hollow tube
- Accessory (things that help digestion) digestive organs
2
Q
Organs of the Alimentary Canal (GI Tract)
A
- Pathway from mouth to anus (food passes through)
- Mouth
- Pharynx
- Esophagus
- Stomach
- Small intestine (97% of chemical digestion)
- Large intestine
- Anus
3
Q
Mouth (Oral Cavity) Anatomy
A
- Lips (Labia)– Protect the anterior opening
- Cheeks– Form the lateral walls– Buccal cavity
- Hard palate- forms the anterior roof
- Soft palate- forms the posterior roof
- Uvula- Fleshy projection of the soft palate (Lymph tissue)
4
Q
Mouth Physiology
A
- Mastication: Chewing of food
- Mixing masticated food with saliva (Bolus)
- Initiation of swallowing by the tongue
- Tonge rolls back
- Larynx rises
- Constriction
- Deglutition (swallowing)
- Allows for the sense of taste
5
Q
Pharnyx Anatomy
A
- Nasopharynx: Not part of the digestive system
- Oropharynx: Posterior to oral cavity
- Laryngopharynx: Below the oropharynx and connected to the esophagus
6
Q
Teeth (Function)
A
- Function is the masticate (chew) food
- Humans have two sets of teeth
- Deciduous (baby or “milk” teeth)
- 20 teeth are fully formed by age two
7
Q
Permanent Teeth
A
- Replace deciduous teeth between the ages of 6 & 12
- A full set of 32 teeth, but some people do not have wisdom teeth (third molars)
- If they do emerge, the wisdom teeth appear between ages 17- 25
8
Q
Classifications of Teeth
A
- Incisors: cutting
- Canines- tearing or piercing
- Premolars- grinding
- Molars – grinding
9
Q
Regions of the Tooth
A
- Crown: Exposed part
- Neck: region in contact with gum
- Root: attaches tooth to periodontal membrane
10
Q
Crown
A
- Enamel- hardest substance in the body
- Dentin- found deep to the enamel and forms the bulk of the tooth
- Pulp cavity: contains connective tissue, blood vessels, and nerve fibers
- Root canal: where the pulp cavity extends into the root
11
Q
Neck
A
- Region in contact with the gum
- Connects crown to root
12
Q
Root
A
- Cementum- Covers outer surface
- attaches the tooth to the periodontal membrane
13
Q
Salivary Glands
A
- Three pairs of salivary glands empty secretions into the mouth
- Parotid glands: In front of the ear
- Submandibular Below the mandible (anterior)
- Sublingual glands: below the tongue (Posterior)
- Sublingual is in back of the submandibular
14
Q
Saliva
A
- Mixture of mucus and serous fluids
- Helps to form a food bolus
- Contains salivary amylase to begin starch digestion
- Dissolves chemicals so they can be tasted
15
Q
Pharynx Physiology
A
- Serves as a passageway for air and food
- Food is propelled to the esophagus by two muscle layers
- Longitudinal inner layer
- Circular outer layer
- Food movement is by alternating contractions of the muscle layers (peristalsis: wave like contractions)
16
Q
Esophagus Anatomy and Physiology
A
- Anatomy
- About 10 inches long
- Runs from pharynx to stomach through the diaphragm
- Physiology
- Conducts food by peristalsis (slow rhythmic squeezing)
- Passageway for food only (respiratory system branches off after the pharynx)
17
Q
Layers of the Alimentary Canal Organs
A
- Mucosa
- Submucosa
- Muscularis Externa
- Serosa
18
Q
Mucosa
A
- Innermost, moist membrane consisting of -Surface epithelium
- Small amount of connective tissue (lamina propria)
- Small smooth muscle layer
19
Q
Submucosa
A
- Just beneath the mucosa
- Soft connective tissue with blood vessels, nerve endings. and lymphatics
20
Q
Muscularis Externa
A
- Smooth muscle
- Inner circular layer
- Outer longitudinal layer