Digestive System Flashcards
5 Stages of Digestion
Ingestion, Digestion, Absorption, Compaction, Defacation
Stage of Digestion where you simply take IN food by the mouth
INgestion
Stage of digestion where the mechanical & chemical breakdown of food occur
Digestion
Stage of digestion where substance move from intestinal lumen to capillaries/lymphatics
Absorption
Stage of digestion where the absorption of water turns into feces
Compaction
Stage of digestion where elimination of feces
Defecation
Physical breakdown of food into small pieces
Mechanical digestion
Breaks down dietary macromolecules into their monomers
Chemical Digestion
long chains of amino acids
Proteins
long chains of glucose
carbohydrates
The tube from mouth to anus
Digestive Tract
Digestive Tract includes
Mouth, pharynx, esophagus, stomach, small intestine, and large intestin
This tract includes stomach and intestinal organs
GI Tract
Accessory Organs of Digestive Tract Include
Teeth, tongue, salivary glands, liver, gallbladder, and pancreas
These need little digestion for absorption
Vitamins, AA, minerals, cholesterol, and H20
Digestive Tract Wall layers
Mucosa, Submucosa, Muscularis, Serosa
This system has over 100 milli neurons , 2 plexes and can function independently of CNS but is apart of ANS
Enteric Nervous system
2 plexes of Enteric Nervous System
Submucosal and Myenteric (
Mechanisms that control motility and secretion of digestive tract
Neural , Hormone, Paracrine Mechanims
First step in mechanical digestion by act of CHEWING foods into smaller pieces, exposing more surface area
MASTICATION
Where does the digestion of fat and starch begin?
In the saliva
enzyme that begins starch digestion in the mouth
Salivary Amylase
enzyme that is activated by stomach acid and digests fat after food is swallowed
Lingual Lipase
binds and lubricates a mass of food and aids in swallowing
Mucus
enzyme that kills bacteria
Lysozome
Binding of food by saliva , tthat can be easily swallowed
Bolus
Muscular funnel connecting oral cavity to esophagus and nasal cavity to larynx
pharynx
Esophagus contains this kind of tissue
Nonkeratinized stratified squamous epithelium
Food storage organ that holds up to 4L when extremely full
Stomach
What happens to food in stomach?
Mechanically breaks up food, liquefies it, and begins chemical digestion of protein and fat
soupy or pasty mixture of semi-digested food in the stomach
Chyme
Most digestion occurs after the chyme passes ?
From stomach to small intestine
Too much water in colon w/ fecal matter
Diarrhea
Blood drained from stomach and intestines enters?
Hepatic Portal Circulation
Once blood from stomach enters hepatic portal circulation
material is processed by liver, then passed to the heart, then enters the general circulation.
Cells of the stomach include
mucosa, regenerative (stem), parietal, chief, enteroendocrine cells
These cells secrete HCl , intrinsic factor, hunger hormone & ghrelin
Parietal Cells
These cells are the most numerous & Secrete gastric lipase and pepsinogen
Chief Cells
What activates pepsin & Lingual Lipase?
HCl
The only digestive enzyme in the stomach
Pepsin (inactive)
Most digestive enzymes are made in
the pancreas
What is needed to absorb vitamin b12?
Intrinsic factor
What is needed to produce hemoglobin?
b12
Gastric Juice is a mix of
water, hydrochloric acid, and pepsin
How much gastric juice produced by the glands daily?
2-3L
Gastric Juice has a high concentration of this, which makes it highly acidic?
Hydrochloric Acid
digestive enzymes secreted as inactive proteins
zymogens
Pepsinogen (inactive protein) once active becomes
pepsin
This protein digest big proteins (dietary proteins) into (shorter peptides) smaller pieces
pepsin
Most digestion and nearly all absorption occur after the chyme ?
passes into small intestine (mainly the jejunum)
How is stomach protected from the harsh acidic and enzymatic environment it creates??
Mucous coat, tight junctions, epithelial cell replacement
What neutralizes in duodenum
Bicarbonate
Where does small intestine receive chyme?
From stomach and secretions from liver and pancreas; which mix in duodenum, which turns into jejunum where digestion and absorption take place
organ made up of hepatocytes that secrete bile
liver
Organ that STORES bile
GallBladder
