16. The digestive system Flashcards
We eat because our cells need what?
Nutrients, materials
What are the most important parts of food?
Proteins, carbohydrates, lipids
What does dietry fiber come from?
Cell walls of plant cells
What does dietry fiber do? Is it digestible?
It is not digestible, but it helps the process
What is the order of the nutrients that we should take in? (Most to least)
Carbohydrates, fruit&veggies, dairy, meat&fish, fat&sweets
What kinds of foods is carbohydrates found in?
Rice, bread, potatoes
What elements are carbohydrates made from, and what do those elements form?
Made from carbon, hydrogen, and oxygen. Form glucose
What is carbohydrates used for?
As a source of fast energy
In what foods can you find lipid?
Salmon, avocado, olive oil
What elements are carbohydrates made from?
Carbon, hydrogen, and oxygen
What do lipids include? Are they healthy?
Includes things like fats and oils, and too much is bad
What important roles do lipids play?
*structure & functioning
What type of energy source does lipids provide?
Long-term energy source
Lipids help with maintains temperature. What is this called?
Cushioning & insulation
What kind of foods are proteins found in?
Meat, fish, and eggs
What elements are proteins made from?
Carbon, hydrogen, oxygen, nitrogen and others
What do proteins make up in living organisms?
Muscle
Proteins from long, complicated structured from what?
From chains of amino acids
What is digestion?
The process of breaking down food so nutrients can be absorbed
What 2 stages can digestion be divided into?
Mechanical & Chemical
What is mechanical digestion?
Physically reducing the size of food through grinding and movement (chewing)
What is chemical digestion?
Chemically breaking down food into small molecules through digestive juices
State the order in which food is digested (Alimentary canal)
Mouth, Oesophagus, Stomach, small intestine, large intestine, rectrum, anus
What are some herbivore animals?
Zebra, rabbit, iguanodon
What type of front teeth do herbivores have?
Incisors (sharp front teeth)
What are incisors best for?
Cutting plants
What type of back teeth do herbivores have?
Molars
What are molars best for?
Grinding grass
What are some carnivore animals?
Lion, fox, t-Rex
What type of teeth do carnivores have?
Sharp front and back teeth
What are carnivores teeth most suitable for?
*Biting and holding onto prey
*crushing bones to make them easier to swallow
What is the oesophagus also known as?
food pipe
What is the oesophagus?
A muscular tube connecting the mouth & stomach
How does the oesophagus move food?
In a gentle squeezing motion (peristalsis)
What does the stomach do?
It churns food and digestive juices together
What does the churning motion accelerate?
It accelerates digestion
What environment is the stomach?
Highly acidic (ph1-2)
What does the stoma ch’s environment help with?
Killing bacteria and other harmful substances
What does the small intestine connect?
Connects the stomach with the large intestine
The small intestine consists of 3 parts: what are they?
Duodenum, jejunum, ileum
What is the small intestine’s main functions?
・finish digesting food
・absorb the broken-down nutrients into the body
What is the name of the inner wall of the small intestines covered in small projections?
Villi
What does villi do?
they greatly increase the surface area of the intestine
What do villi contain?
Many blood vessels to absorb nutrients into the body
What stage of digestion does the large intestine perform?
The final stage
What does the large intestine do?
absorbs water from broken down food, leaving waste material
The waste (faeces) is stored where before being discharged through the anus?
The rectum
How many hours does it take for the food to eat to leave as faeces?
24-72 hours
How long is the whole human digestive tract?
9 metres
What food is nutritious and easy to digest?
Meat
What food contains fewer nutrients and is harder to digest?
Plant-based food
What do you need to do when intaking plant-based food?
Take large quantities of it
What type of digestive tracts do herbivores have?
Longer digestive tracts and helpful gut bacteria
What type of teeth do carnivores have?
Canine, Pre-molars
What are canines suitable for?
Tearing meat
What are pre-molars suitable for?
Crushing bones
