The digestive system Flashcards
As heterotrophs what CANT we create that we need to ingest in our food
Carbon
What are the 3 reasons why our cells need nutrition
For 1. Growth
2. Repair
3. Maintenance
What are the 3 functions of the digestive system
- Break down food into nutrients
- Body absorbs nutrients
- Body transports nutrients through the circulatory system
What are the four stages of digestion
- Ingestion
- Digestion
- Absorption
- Egestion
Explain what happens in each stage of digestion
- Ingestion- Eat/Drink
- Digestion- Break down molecules
- Absorption- Absorb digested molecules
- Egestion- Remove waste through gastrointestinal tract
What is the gastrointestinal tract
Tube from the mouth to the anus where the process of digestion takes place
What are the two processes of digestion
Mechanical and chemical digestion
What is mechanical digestion
Physical digestion
What happens during mechanical digestion and where
-Large foods become smaller peaces
-Chewing of food into mouth
-Churning and mixing of food into stomach
What happens during chemical digestion
-Digestive tract makes digestive enzymes
-Different enzymes break down macromolecules to small molecules that can be absorbed
Where does digestion start
In the mouth
How does digestion start in the mouth
-Food is broken down physically by teeth and tongue
-Food that has been chewed mixes with saliva, becoming a bolus
-Bolus is pushed into the pharynx
-Epiglottis covers trachea so food does not go into lungs
What is saliva made up of and where is it released from
Water, mucus and enzymes released from saliva glands
What is amylase
Enzyme in saliva that breaks down starch into simple sugars
What is a bolous
Chewed up food mixed with saliva
What is the esophagus
A muscular tube that passes food from the pharynx to the stomach
What makes the food move towards the stomach in the esophagus
Muscle contractions called peristalsis
What shape is the stomach
J shaped
T or F: Does the stomach store food
Yes
What is the stomach’s capacity
2L
What does food enter and leave the stomach through
sphinctors
What are sphinctors
Muscles that open and close
When does the bolus enter the stomach
When the esophageal sphinctor relaxes
What prevents food from moving back into the esophagus
The esophageal sphinctors contracting
When the stomach releases gastrin, it stimulates the release of what?
The release of gastric juice
What is gastric juice produced by
The cells in the stomach lining
What is gastric juice a mixture of
-Hydrochloric acid
-Pepsin
-Mucus
What does the hydrochloric acid do during digestion
Break down fibres and bacteria
What does the mucus do during digestion
Protect the stomach lining from hydrochloric acid
Why is it important that our stomach has mucus
Because the stomach lining can be destroyed by hydrochloric acid, causing ulcers
What are the 2 main cells of the stomach
- Pariental cells
- Chief cells
Where are pariental cells found
in the stomach glands
What are pariental cells responsible for doing
Producing hydrochloric acid
What are chief cells responsible for doing
Producing pepsin
What does pepsin do
Breaks down large proteins into small proteins
What is chyme a mixture of
Water, digested food and gastric juices
Where does chyme travel to
From the stomach to the small intestine
What does the stomach absorb
- Water
- Alcohol
- Medications
What causes acid reflux
When the gastroesophageal sphinctor does not close completely, stomach acid goes to the esophagus causinf burning in the throat
Stomach acid can kill all bacteria except which bacteria
Helicobacter pylori
What does the bacteria helicobacter pylori mean
This bacteria prevents mucus producing cells from making enough mucus to protect the stomach lining, causing stomach ulcers
What are the 3 different parts of the small intestine
The deudenem, jejunum, and ileum
What is the main function of the small intestine
To chemically complete digestion and begin absorption
Where is the deudenum location on the small intestine
The first 25cm of the small intestine
In the small intestine, where does the majority of digestion happen
The deudenum
Secretions from ______ and _______ enter the deudenum via a duct
Pancreas and gallbladder
What are the secretions the pancreas and gallbladder make that enters the deudenum
Maltase and peptidase
What does maltase do in the deudenum
Breakdown carbohydrates
What does peptidase do in the deudenum
Breakdown protein
Most the absorption takes place in what locations in the small intestine
The jejenum and ileum
What increases the surface area of the jejenum and ileum
The villi
What are vili
Tiny hairs that line the inside of the small intestine
What does the villi in the small intestine help with absorption of
simple carbs, fats and proteins
What are the four functions of the liver
- Synthesis
- Breakdown
- Detoxification
- Storage
What happens in the synthesis stage of the liver
-Makes bile that breaks down fats
What happens in the detofixation stage of the liver
-Removes toxins from the body
What are two toxins that are removed from the body during detoxification
Alcohol and chemicals
What happens in the storage stage of the liver
Vitamins and carbs are stored in the liver
What does the pancrease do to the pH of chyme
Increase it from 2.5-9
Why does the pH of chyme increase due to the pancreas
Because of the sodium bicarbonate the pancreas makes
In the large intestine, what is absorbed
Water, sodium and chlorine
What vitamins are released in the large intestine
Vitamin k and B
What is egestion
The removal of the indigestable parts of food
What organ stores and releases waste
The rectum
What component helps in the ejection of materials
Cellulose
What happens if we do not have alot of cellulose in the body
Can lead to colon cancer
What digestive disorder causes sores in the lining of the stomach
Peptic ulcers
What digestive disorder causes causes stunted growth and thinner bones
Crohns disease
What digestive disorder causes loosr and bloody stools
Ulcerative colitis
What digestive disorder causes dry small and dificult go eliminate stools
Constipation
What digestive disorder causes infection in the liver
Hepatitis
How can you get all the diff types of hepatitis’s
Hep A: Contaminated water
Hep B: Sexual contact
Hep C: Contact with infected blood
What digestive disorder causes a chronic disease where scar tissue replaces healthy liver tissue
Cirrhosis
What digestive disorder causes a chronic disease where scar tissue replaces healthy liver tissue
Cirrhosis
What digestive disorder causes small hard masses in the gall bladder
gallstones
What is diabetes and how is it related to the digestive system
Diabetes is when the body cant absorb glucose from food to use as energy, so the pancreas releases insulin after we eat so the glucose can go into the somatic cells.
What are the 3 types of diabetes
type 1, type 2, gastational
What is type 1 diabetes
Cells that make insulin are destroyed by the immune system so our body cant get the insulin made by the pancreas
What is type 2 diabetes
When the body does not make enough insulin or the body cant use the insulin we make
What is gestational diabetes
Happens to pregnant women
