Body Systems - 3.1 Digestion [ARCHIVE] Flashcards
What are humans made up of?
Millions of tiny building blocks called cells.
Where is most of the body’s work carried out?
In the cells.
What are the five systems of your body and what do they do?
Respiratory - takes in oxygen
Digestive - makes food available in a form the body can use
Circulatory - carries food and oxygen to where it is needed
Excretory - gets rid of wastes
Skeletal - supports the body and enables it to move
What is digestion?
The process of breaking down food into a useable form and making nutrients available.
What does the digestive system consist of?
- Digestive tract - pathway that food takes through a series of organs.
- Organs off to the side of the digestive tract that produce chemicals that help with digestion.
What are the two types of digestion?
- Mechanical digestion
- Chemical digestion
What is mechanical digestion?
When food is broken down into smaller pieces.
What is chemical digestion?
When large, complex substances in the food are broken down into simpler chemicals, which are absorbed into the bloodstream.
Where does digestion start?
With the teeth.
What are the four types of teeth?
- Incisors
- Molars
- Pre-molars
- Canines
What do the incisors, molars and pre-molars do?
Incisors bite off pieces small enough to chew, which are pushed back to where the molars and pre-molars grind food into smaller pieces as you chew.
What does saliva do?
Changes any starch to glucose, also moistens the food making it easier to swallow.
What is ‘peristalsis’?
When the muscles of the oesophagus push down food by contracting behind the food.
What does the epiglottis do?
Closes the end of your trachea so the food goes into the stomach, not the trachea.
What does the stomach’s sphincter do?
Separates the stomach from the oesophagus, which makes an opening so food/nutrients passes through before it closes so no food flows back up.
What role does the stomach play in digestion?
Changes the food by contracting and relaxing the muscular walls, churning it up, and the chemicals inside also breaks down the food.
How does the stomach digest the food chemically?
Mixing it with gastric juice, which is produced by special cells in the stomach.
What does gastric juice contain?
Hydrochloric acid - strong acid that kills bacteria
Mucus - layer on lining of stomach, prevents stomach from consuming itself LOL what the hay that is so silly?!?!
Digestive juices - contains chemicals that start digestion of protein.
What is the puropse of the small intestine?
It is a long, narrow tube that breaks down food into smaller parts and absorbs nutrients, which then pass into the bloodstream for the body’s use.
What is the first part of the small intestine and how does it help with digestion?
The duodenum, it has two tubes from the pancreas and liver that carry chemicals that are important for digestion.
What does the pancreas do? (cfp)
The pancreas is not part of the digestive tract, it is an organ that produces pancreatic juice which contains chemicals that help digest carbohydrates, fat and protein.
What is the liver’s purpose?
The liver produces ‘bile’ which breaks down large pieces of fat so they can be digested more easily.
What does the duodenum do?
The walls of the duodenum are muscular. They continue to squeeze and churn the food, breaking it down and making sure that the digestive chemicals are mixed through the food. .
What form is the food in when it passes into the lower part of the small intestine (ileum)?
Tiny particles that can be absorbed by the body.
What are ‘villi’?
Microscopic ‘fingers’ that are on the inner lining of the ileum, which increase the surface area of the intestine wall, so the nutrients from the food can pass.
What are capillaries?
Tiny blood vessels within the villi, which insure the nutrients only travel a small distance from the digestive system into the blood system.
What are the nutrients that pass from the small intestine?
- fatty acids and glyrecol produced from digestion of fats
- amino acids from digestion of protein
- glucose (main source of energy for the body) from the digestion of carbohydrates
What is the large intestine and what does it do?
It is the last section of the digestive tract, it re-absorbs water into the body from what food is left, along with any remaining nutrients.
What does the waste produced in the large intestine form?
Lumps of faeces (known as stools), which later come out through the anus (a sphincter muscle). About ⅓ of faeces is made of bacteria.
What does vomiting do?
It’s a quick way of getting rid of unwanted bacteria from the digestive tract, triggered by stress or infection contracting stomach muscles.
What happens inside the body when you vomit?
The sphincters at the top and bottom of the stomach open, and the contents come up the oesophagus and out of the mouth.
What does diarrhoea do?
It is another quick way of getting rid of bad bacteria and viruses.
Why do you become at risk of dehydration when you have diarrhoea?
The lining of the small intestine becomes inflamed and stops water from being absorbed by the now loose faeces.
What is heartburn?
A burning sensation that rises up the oesophagus from the stomach, which causes pressure on the stomach, leading to contents being pushed up, creating a burning feeling.
Why does heartburn happen?
The oesophagus does not have a lining of mucus, so the burning is the acids attacking the lining of the oesophagus.
What is the appendix?
The appendix is a blind-ended tube connected to the large intestine.
How does appendicitis happen?
If the opening of the appendix is blocked, the appendix fills with mucus. It then becomes inflamed and swollen, causing pain.
Where is bile stored?
In the gallbladder and released into the small intestine by the bile duct.
