Bio 6 Flashcards
Name the diet nutrients that human cells and tissues use (balanced diet).
Proteins, Carbohydrates, Fats, Vitamins and Minerals.
What is the role of the mouth?
Teeth and Tongue breaks food down into smaller pieces.
What is the role of the salivary glands?
Produce saliva which contains Amylase to breakdown starch.
What is a bolus?
A lump of swallowed and chewed food.
What is the role of the oesophagus?
Bolus is moved from the mouth to stomach via the Oesophagus by peristalsis.
What is peristalsis?
Peristalsis refers to the waves muscle contractions in the walls of the alimentary canal.
What is the role of the stomach?
Acid and protease are secreted to start protein digestion.
Muscular wall churns food into liquid.
What is the role of the liver?
Produces bile, Amino acids are broken down to urea, Glucose is removed from blood and stored as glycogen.
What is the role of the gallbladder?
Stores bile from the liver
What is the role of the pancreas?
Secretes Pancreatic juices(alkaline) which neutralize the acidic food content.
+ Amylase
What is the role of the small intestine?
Digested food molecules and water are absorbed.
What is the role of the large intestine?
Water is absorbed from the remaining material.
What is the role of the anus?
Faeces are egested through the sphincter.
Name the four types of teeth.
Incisor, Canine, Pre-molar, Molar.
Describe mechanical digestion.
Physically breaks food down into smaller pieces.
> No chemical change/digestion!!!
Done by churning muscles/ Teeth.
Describe chemical digestion.
Chemically breaks large insoluble molecules into small soluble molecules
> Enzymes
Name some molecules which are small enough to not be digested.
Glucose, Minerals, Water, Vitamins.
What does digestion mean?
Process of breaking down food(mechanical + chemical) in the alimentary canal so that substances an be used by body.
Describe the shape + function of Incisors.
Front of mouth
Chisel shaped
Bite off/Cut food
Describe the shape + function of Canines.
After Incisors
Sharp + pointy
Rip/Tear food
Describe the shape + function of Pre-molars.
After Canines
Between canine and molar (roughish?)
Tear + grind food
Describe the shape + function of Molars.
Back of mouth
Flat surface
Grind food
What happens during tooth decay?
- Food particles get stuck between teeth, forms plaque
- Bacteria start to grow and produce acids
- Acids corrode the enamel and expose the dentine.
- When acid reaches the pulp cavity, it can cause pain.
How can you prevent tooth decay?
Avoid sugary foods (bacteria respire)
Brush teeth regularly
Floss frequently
How does toothpaste prevent tooth decay?
> Alkaline
Antibacterial substances such as mint
Mild abrasive that removes plaque
Contains fluoride - strengthens enamel + reduces acidic damage.
What is the function of Bile?
Emulsifies fats into smaller pieces
> larger surface area - rate of digestion increases.
What does emulsify mean?
Split into manageable sizes, particles.
Where are Amylase produced?
Salivary glands, Pancreas.
Where are Protease produced?
Stomach wall, Pancreas.
Where are Lipase produced?
Pancreas.
Describe the structure of the small intestine.
Lined with villi (lined with microvilli)
> increased surface area.
Describe the adaptations of villi.
> Covered in thin layer of cells - so molecules don’t have to travel far.
Well supplied with blood capillaries - high conc. gradient
Lacteals
Define absorption.
After digestion, small food molecules can diffuse across the intestinal wall and get absorbed/pulled into(…?)the body
Describe the function of Lacteals.
Carry fat separately from rest of blood
- Fat doesn’t dissolve well in blood.
