Zusammenfassung der Ressource
Module 3.1 Digestion
- The mouth
- The types of teeth
- Incisors
- The four teeth at the front they bite of
pieces small enough to chew on
- Canines
- The canine teeth have no significant
function
- Premolars & Molars
- These teeth grind the food into tinier and
tinier pieces as you chew
- Chewing and bitting is a form of
mechanical digestion the process
starts at the teeth
- Saliva
- Saliva is a watery liquid, it has a chemical that
turns any starch in the food into glucose,
since glucose is easily absorbed
- Oesophagus
- Bolus
- A slimy ball of food
- Peristalsis
- The process of rhythmic contracting and
relaxing of the oesophagus's muscles. This
keeps food moving though the oesophagus
- A long muscular tube starting at the
mouth ending at the stomach
- Types of digestion
- Mechanical
- Food is sliced, crushed and torn
by your teeth, although no new
substance is made
- Chemical
- Large, complex substances are
broken down to simpler chemicals
- Digestive tract
- A pathway of organs that food goes though. It
stars at the mouth end at the anus
- Digestion
- The process in which breaks down food into
usable form to make its nutrients available
- Stomach
- Gastric juice
- Hydrochloric acid
- A very strong acid that kills many bacteria that may
have been swallowed with the food
- Mucus
- A layer of mucus on the lining of the
stomach stopping the stomach from
digesting itself.
- Digestive juices
- Contain chemicals that begin the digestion of protein
- Produced by special cells in
the stomach wall
- The stomach is shaped as a bag,
its found in the left side of the
upper abdomen.
- Small intestine
- Duodenum
- This is the first part of the small intestine. The walls are muscular they continue to churn
and squeeze the food, this breaks the food down even more. Two tubes do enter the
duodenum they carry chemicals crucial for digestion from the pancreas and liver
- Ileum
- Villi
- Villi are microscopic 'fingers' that line the ileum
- Villi very much increase the surface area of the small intestine's wall, and also
greatly increase the amount of nutrients being absorbed.
- Inside villus are tiny blood vessels named capillaries. Since capillaries
and villi are only a cell thick the nutrients move a microscopic distance to
enter the blood
- The ileum is the lower part of the small
intestine. Here digested food are absorbed
by the body
- This is the longest part of the digestive
tract at 6 metres long and 3cm diameter
- Nutrients that pass though the intestine
- Fatty acids and glycerol
- This is from the digestion of fats
- Amino acids
- From digestion of proteins
- Glucose
- The digestion of carbohydrates
- Pancreas
- Pancreatic juice
- Contains chemicals that help with
digest fats, protein, and
carbohydrates
- Pancreas is not part but connected to the
digestive tract
- Large intestine
- Anus
- The anus is a sphincter muscle, stools are let out though
the anus. Its at the end of the digestive tract
- Stool is poo
- This is the final section of the digestive tract. The large intestine is
1.5 meters long and 6 or 7 cm in diameter
- Water is reabsorbed into the body
- Liver
- The liver is the largest internal organ. It performs over 500
chemical processes