Lecture: The Digestive System Pt 1 Flashcards
The autonomic system is divided into what to sub-systems?
The sympathetic and the parasympathetic
The salivatory nuclei are in what part of the brain?
The medulla oblongata
What does the autonomic system control?
Unconscious body functions (glands, smooth muscle, cardiac muscle, etc.)
Role of the parasympathetic nervous system?
Fight or Flight response
Role of the sympathetic nervous system?
Relaxes the body and slows many high energy functions.
If you’re nervous how might your nervous system affect your salivary glands?
The parasympathetic nervous system might make your mouth dry
If you’re relaxing, how might your nervous system affect your salivary glands?
The sympathetic nervous system might make your mouth dry.
What is Anabolism?
Constructive metabolism; the synthesization of raw materials into energy.
What is Catabolism?
Destructive metabolism; the break down of complex molecules into simpler ones.
What 2 components are necessary for catabolism?
- Organic Materials
2. Oxygen
How long is the esphogus
10 inches long
Between what two organs is the esophagus located?
The inferior portion of the pharynx and ends at the stomach.
What organs make up the digestive tract?
- pharynx
- esophagus
- stomach
- small and large intestines
What are the 4 parts of the stomach?
- Cardia
- Fundus
- Body
- Pylorus
What is Ingestion?
The first step of the D.S.,
when food enters the mouth.
What is mechanical prossesing?
The second step of the D.S.,
food is chewed and mixed with salivary enzymes in the mouth
What is Digestion?
The third step of the D.S.,
food is broken down chemically in the stomach for absorption.
What is Secretion?
The fourth step of the D.S.,
glandular organs and epithelium in the tract secrete water, buffers, enzymes and salts.
Why do babies need to be burped?
Air gets trapped in the fundus of the stomach.
What is Absorption?
The fourth step of the D.S.,
Nutrients, and water pass through digestive epithelium into interstitial fluid of digestive tract
What is Excretion?
The final step of the D.S.,
Removal of waste products from body fluids
What are the layers of the digestive tract from superficial to deep?
- Peritoneum
- Muscular
- Submucosa
- Mucosa
Where us the Nervous Supply Mesenteric Plexus located? (What layer)
The submucosa of the digestive tract.
The lining of the digestive tract protects against what?
- Chemical corrosion
- Mechanical abrasion
- Bacteria
What 2 significant cells are in the stomach?
- Pariental cells
2. Chief cells
What are Parietal Cells?
Cells of the stomach that secrete intrinsic factor and hydrochloric acid
What are Chief Cells?
Secrete pepsinogen which is converted by hydrochloric acid into Pepsin
What is the only enzyme secreted by the stomach?
Pepsin
Where are the gastric glands?
The fundus of the stomach
What is Peritoneal Fluid?
Lubriacting fluid produced by the serous membrane.
Why doesn’t hydrochloric acid break the wall of the stomach?
Protection by the mucosa
What are Mesentaries
Double sheets of peritoneal membrane
What creates gastric ulcers?
A break in the mucosa (wall of the stomach)
What is the function of the Mesentaries?
- Stabilize organs
2. Prevent entanglement of intestines
What is the Rugae?
The ridged lining of the stomach, helps it expand.
What is the Lesser Omentum?
A double layer of peritoneum extending from the liver to the lesser curvature of the stomach and the first part of the duodenum
What is the Falciform Ligament?
a ligament that attaches the liver to the front body wall, and separates the liver into the left and right lobes
What is the entry and exit to the stomach called?
Gastric Sphincters
What causes heartburn?
The reflux of stomach acid through the gastric sphincter into the esophagus.
What are the major functions of the stomach?
- Food storage
- Mechanical Breakdown
- Chemical Breakdown
- Production of intrinsic factor
What is the only macronutrient digested by the stomach?
Protein
What is the pH of the stomach?
2.0 (Very Strong Acid)
What enzyme breaks down protein?
Pepsin
What are the 3 phases of acid production?
Cephalic phase, gastric phase and intestinal phase
How long is the large intestine?
1.5 meters or 5 feet long
How long is the small intestine?
6 meters or 20 feet long
Where does the most digestion occur?
In the duodenum (1st 10 inches) of the small intestine
What is the narrowest part of the intesine?
The junction (ileocecal valve) of the illium and the cecum
