Chapter 18-1 Flashcards
Covers Digestive System
Six (6) major functions of the Digestive System
- Ingestion
- Secretion
- Digestion: Mechanical and Chemical
- Mixing and Propulsion
- Absorption: from the lumen into the bloodstream
- Defecation
Describe the alimentary canal and accessory organs of the digestive system. Identify specific organs that are examples of each category
Alimentary Canal: “digestive tract” from mouth to anus. Digests and absorbs nutrients.
Canal Organs: Mouth, Pharynx, Esophagus, Stomachm, Small Intestine, Rectum & Anus
Accessory Organs: Pancreas, Liver and Gallbladder
Define: Mastication, Bolus & Deglutition
1.Mastication: Chewing Food
2.Bolus: Food that is masticated/ coated with Saliva
3.Deglutition: Act of swallowing a bolus
Describe the two (2) types of digestion that typically occur inside of the alimentary canal.
- Mechanical Digestion: physical process of breaking down food into smaller pieces
- Chemical Digestion: process of breaking down food into smaller molecules using enzymes
Describe the functions of secretion and absorption and how it relates to the digestive system
Secretion and absorption is part of both mechanical and chemical digestion
histology of the alimentary canal:
The tissue layer that is most superficial and helps anchor digestive organs to
surrounding structures in the abdominal cavity:
Serosa
histology of the alimentary canal:
The tissue layer where secretion and absorption occurs
Mucosa
histology of the alimentary canal:
The tissue layer that comes in direct contact with food/fluids in the alimentary canal
Mucosa
Identify the two (2) functions of the peritoneum
- Anchors the abdominal organs
- Protects the abdominal organs
histology of the alimentary canal:
The tissue layer that anchors the mucosa to the muscularis:
Submucosa
histology of the alimentary canal:
The tissue layer that consists of either smooth or skeletal muscle
Muscularis
Components of the peritoneum:
Greater omentum
Largest fold, associated with beer bellies protects anterior abdomen
Components of the peritoneum:
Lesser omentum
Anchors stomach and Duodenum to liver
Components of the peritoneum:
Falciform ligament
Anchors liver to diaphragm and anterior abdominal wall
Components of the peritoneum:
Mesentery
Anchors jejunum and illeum to posterior abdominal wall
Components of the peritoneum:
Mesocolon
Anchors large intestine to the posterior abdominal wall
Explain the function of the uvula in the oral cavity
Prevents substance in the oral cavity from passing top to the nasal cavity
Regarding teeth:
What type of teeth are found most posterior in the mouth?
Molars
Regarding teeth:
The total number of adult teeth?
32
Regarding teeth:
Usually the sharpest teeth in the mouth
Canine
Regarding teeth:
What type of teeth are wisdom teeth?
3rd Molars
Regarding teeth:
what type of teeth are found most anterior in the mouth
Incisors
Regarding teeth:
Part of tooth that is exposed to the surface and contains enamel
Crown
Regarding teeth:
Part of teeth that sits at the gum line
Neck
Regarding teeth:
Part of the tooth that sits inside the tooth socket
Root
What function does the periodontal ligament serve?
Anchors the tooth inside the alveolar process (tooth socket) and absorbs impact
Identify and explain the three (3) functions of saliva
- Lubrication of food (easier to swallow)
- Digestion: via Salivary amylase and Lingual lipase
- Immunity: IgA antibodies
What is the primary function of the esophagus?
Esophagus: Propulsion
Explain how the composition of muscle and how it changes as you progress from superior to
inferior through the esophagus.
- Superior: Muscularis = skeletal muscle
- Middle: Muscialris mixture of skeletal and smooth muscle
- Inferior: Smooth muscle
Describe the purpose of the following:
- Upper esophageal sphincter
- Lower esophageal sphincter
- Upper esophageal sphincter— Separates upper esophagus from the pharynx
- Lower esophageal sphincter— Seperates lower esophagus from the cardia (stomach)
Which sphincter is associated with gastroesophageal reflux (heartburn)?
“heart burn” stems from the inferior sphincter = Lower esophageal sphincter
Identify and briefly describe the four (4) primary functions of the stomach
Stomach Regions
Cardia: connects the stomach to the lower esophagus
Body: main portion of the stomach
Fundus: upper extensionn
Pylorus: connects the stomach to the duodenum
Functions:
1. Reservoir of food
2. Production of chyme (liquefied food)
3. Chemical digestion
4. Controlled release of chyme into the duodenum
What is the significance of rugae in the stomach?
Folds in the mucosal lining of the stomach that allow expansion
Explain the importance of the following types of cells located in the stomach:
a. Mucous neck cells
b. Parietal cells
c. Chief cells
d. G cells
a. Mucous neck cells— gastritis pits, secrete mucous on the lining of the stomach
b. Parietal cells— secrete HCl and Intrinsic factor
c. Chief cells— secrete Pepsinogen which is activated pinto pepsin
d. G cells— only endocrine cell, secretes gastrin inro bloodstream
