Week 1 - Digestive System Flashcards
Name the four layers of the digestive tract in the correct sequence from innermost to outer layer.
- Mucosa
- Submucosa
- Muscularis
- Serosa
Describe the function of the Mucosa
Absorption and secretion`
Describe the function of the submucosa
Loose connective tissue to allow the mucosa to move flexibly during peristalsis. Also contains blood vessels, lymphatic vessels, and nerves
Describe the function of the Muscularis
To aid in propelling nutrients in a uniform direction from the lumen to the submucosa.
Describe the function of the serosa
Provides a partition between the internal organs and the abdominal cavity. Cells of the serous layer secrete a serous fluid that provides lubrication to reduce friction
State the tissue type of the mucosa
Epithelium and supporting loose connective tissue
State the tissue type of the submucosa
Connective Tissue
State the tissue type of the muscularis
Smooth muscle
State the tissue type of the serosa
Epithelial layer and a thin connective tissue layer which reduces the friction from muscle movements
Name the 6 digestive processes
- Ingestion
- Motility (Propulsion)
- Mechanical digestion
- Chemical digestion
- Absorption
- Defecation
Describe what happens during ingestion
Creating a bulk flow of nutrients from the outside world into your tissues (eating/drinking)
Describe what happens during Motility (Propulsion)
Mechanism of swallowing (voluntary action), then it’s quickly turned over to the involuntary process of Peristalsis
- The smooth muscles of the walls of the digestive organs take turns contracting and relaxing to squeeze food through the lumen of the alimentary tract. Waves of Peristalsis continue through the esophagus, stomach and intestines, and they’re strong
Describe what happens during mechanical digestion
- More smooth muscle segments push the food back and forth to keep crumbling it up
- The goal is to increase the surface area of that bite of food by breaking it down into increasingly tiny pieces, to prepare it to encounter more enzymes
Describe what happens during chemical digestion
- Process of digestion only occurs when the main action becomes more chemical then mechanical
- Liver, Pancreas and Gallbladder secrete enzymes into the alimentary canal, where they ambush the food and break it down into its most basic chemical building blocks
Describe what happens during absorption
- Digestion allows for absorption for those nutrients (fatty acids, sugars, amino acids) as they pass from the small intestine into the blood, by both active and passive transport
- Once those nutrients are absorbed by our cells, we can use the energy inside of them, or use them to build new tissues :: ABSORPTION OF THE NUTRIENTS IS THE GOAL OF THE ENTIRE PROCESS
Describe what happens during defecation
Indigestible substances like fiber are escorted out of the body (pooping/defecation)
Name all 9 regions of the abdomen
- Right hypochondriac
- Right Lumbar
- Right Iliac (Inguinal)
- Epigastric
- Hypogastric
- Umbilical
- Left hypochondriac
- Left lumbar
- Left Iliac
Name the 4 quadrants of the abdomen
- Right upper (RUQ)
- Right lower (RLQ)
- Left Upper (LUQ)
- Left Lower (LLQ)
Name the three layers of the peritoneum from deep to superficial
- Visceral layer
- Peritoneal cavity
- Parietal layer
What does the visceral layer cover?
Organs