Chapter 3: Digestive system Flashcards
Cell
the smallest functional unit of living organisms
Tissue
a collection of cells that have a similar origin
Organs
assembly of different tissue types
Organ systems
groups of organs that work together to carry out one or more functions
Types of tissues
nervous, muscle, epithelial, connective
function The Digestive System
The primary function of the digestive system is to digest, or break down, the nutrients in our foods into compounds that are small enough to be taken up (absorbed and utilized) into the body.
Carbohydrate - single sugar molecules.
Proteins - amino acids.
Fats - fatty acids and glycerol.
Vitamins and minerals are released
Four stages of digestive process
ingestion-digestion-absorption-excretion
The gastrointestinal tract extends from the mouth to the anus. Food is - ingested - into the body Food is - digested - and broken into smaller units in the GI tract. It is then - absorbed -. Nutrients pass into the bloodstream or lymphatic system to transport throughout the body. Anything not absorbed is - excreted - through the anus (the opening at the other end).
what are the gastrointestinal tract organs
mouth, esophagus, stomach, small intestine, large intestine.
t/f: Small intestine is responsible for absorbing of most nutrients nutrients
TRUEEEEEEEEE
what are accessories organs function
They function to secrete fluids containing a variety of agents, such as enzymes and acids, that aid in digestion.process
what are the accessories organs
Accessory organs are not a part of the continuous tube that makes up the GI tract.
Salivary glands: Moisten, secrete enzymes
Liver: Produces bile
Gallbladder: Stores bile
Pancreas: Produces enzymes and bicarbonate (insulin hormone)
Mechanical and Chemical Digestion
Mechanical Digestion - Physical breakdown of food
Begins in the mouth and extends to stomach
Chemical Digestion - Breaks chemical bonds to cleave large molecules into smaller ones
Involves enzymes and other substances
Motility is a term used to describe the contractions of the GI tract’s smooth muscles that mix food with digestive fluids and propel food along the length of the tract. There are two patterns of these contractions:
peristalsis and segmentation
Peristalsis
Propulsive contractions move food forward from esophagus to anus (smooth muscle-supports it) (stomach)
segmentation
Uncoordinated contractions that mix intestinal content with digestive fluids
Brings nutrients in contact with absorptive surface
(side to side)
enzymes
Enzymes are protein molecules that catalyze the rate at which a chemical reaction produces new compounds with altered chemical structures.
mouth (salivary glands)
Saliva
Amylase (carbs)
Lipase
stomach (gastric juices)
Acid (HCL)
Proteases
Lipase
liver
Produces bile
gallbladder
Stores bile until released
small instestine
Cholecystokinin (CCK)
pancreas (juices)
Bicarbonate
Amylase (carbs)
Proteases (protein)
Lipases (lipids)
ulcer
acids eats the stomach wall
function of BICARBONATE
NEUTRAZILIZE HCL, Produced in the pancreas realizes to stomach
Strongest muscles in the GI track
smooth muscle
anatomy of small intestine (3 regions)
Coiled hollow tube ~20 feet long and 1.5 inches wide
Three regions
Duodenum
Jejunum
Ileum
what are the function of structure of small intestines
the brush border (villi, microvilli) increase surface area for absorption
what is the primary site for the digestion of food and the absorption of nutrients.
The small intestine
Transport Mechanisms in Nutrient Absorption
Passive transport-higher to lower (simple and facilitate diffusion)
active transport - lower to high (with energy)
WHERE TO TAKE THE NUTRIENTS
circulatory system
2 SYSTEM THAT NUTRIENTS ARE DELIVERED TO
- Circulatory system
Blood vessels
Carbohydrates, amino acids, minerals, water-soluble vitamins - Lymphatic system
Most fats and some vitamins
What’s the role of large intestines
The primary role of role of the large intestine is to form and store feces.
Any undigested nutrients that remain in the chyme are passed into the large intestine. As a result, little digestion and absorption occur in the large intestine. (There are no villi.)
what is the large intestine consist of
The large intestine consists of the cecum, colon, and rectum.
What nutrients gets absorbed by large intestines? What do bacteria eat?
electrolytes, some fatty acids, water, and vitamins (K, biotin, and folate). There are hundreds of types of bacteria in the colon that eat undigested material, such as fiber and starch.
health benefits of probiotics
Help restore or maintain a healthy balance of “friendly” bacteria in the GI tract
health benefits of prebiotics
Undigested carbohydrates healthy bacteria use to boost their growth
what are prebiotics
They are compounds that promote the growth of beneficial bacteria in our gut. Probiotic bacteria may have many possible health benefits.
Name at least 5 digestive disorders
Acid Reflux, GERD
Gallstones
Vomiting
Diarrhea
Constipation
Hemorrhoids
Diverticular disease
Gastritis, Ulcers
differentiate irritable boewl syndrome from inflammatory bowel disease
Irritable bowel syndrome (IBS)
Group of symptoms including abdominal pain, bloating, diarrhea, and other discomforts
Does not lead to serious disease
Inflammatory bowel disease (IBD)
Chronic conditions caused by an abnormal response by the immune system, causing inflammation of GI tract
Ulcerative colitis
Crohn’s disease
Define Celiac Disease (gluten intolerence)
Autoimmune disease that causes an abnormal reaction to the protein gluten in wheat, which causes damage to the villi in the small intestine. This damage to the villi/microvilli causes them to flatten out and interrupts digestion and absorption, causing malabsorption. Over time, this damage increases the risk of certain cancers and mortality.
What is lumen lined by and what they do
The lumen, or inner space of the GI tract, is lined by mucosal cells that allow our body to absorb nutrients so they can be transported by the blood and lymph to where they are needed.
define hormones
chemical messengers that participate in the control and regulation of body processes.
What is the semiliquid that foods get breakdown into
chyme
exclusive fuel
glucose
3 regions of Small intestine
Ileum,duodenum, jejenum
Vitamin absorption happens in
large intestines
