gastro system Flashcards
what are the organs of digestion
- mouth
- oesophagus
- stomach
- small intestine
- large intestine
what are the accessory organs
- liver
- gall bladder
- pancreas
why is digestion important
it is important for breaking down food into nutrients to be used for energy, growth and repair
what must happen to food to be absorbed into the body
it must be broken for into smaller molecules of nutrients before it can be absorbed into the blood and carried throughout the body
how does digestion work
- starts in the mouth - chewing breaks down food
- food mixes with digestive juices breaking down molecules
- small molecules absorbed through walls of the small intestine into the bloodstream
- bloodstream delivers molecules to the body
- water passes through large intestine
What is the ‘mouths’…
- Movement
- Digestive juices
- Food broken down into
- chewing
- saliva
- starches
What is the oesophagus’
- Movement
- Digestive juices
- Food broken down into
- Swallowing
- None
- None
What is the stomachs’
- Movement
- Digestive juices
- Food broken down into
- upper muscles relax to let food enter and lower muscles mix food with digestive juices
- Stomach acid
- Protein
What is the Small Intestines
- Movement
- Digestive juices
- Food broken down into
- Peristalsis
- Small intestine digestive juices
- Starches, Protein and carbohydrates
What is the Pancreas
- Movement
- Digestive juices
- Food broken down into
- None
- Pancreatic juice
- Starches, fats and protein
What is the Livers’
- Movement
- Dugestive juices
- Food broken down into
- None
- Bile Acid
- Fats
how does movement of food occur non the GI tract
peristalsis
what is peristalsis
movement of the organ walls propelling food and liquid mixing it together
where does peristalsis usually occur
- oesophagus
- stomach
- intestine
what is the oesophagus’ role in the movement of food through the GI tract
- it is a muscular tube from the mouth to the stomach
- food by involuntary movements (peristalsis) is pushed into the stomach
- as food approaches sphincter it relaxes which allows food into the stomach
what is the stomachs role in the movement of food through the GI tract
- upper muscles of stomach relax to accept the food
- swallowed food is stored
- ## digestive enzymes in the lower part of the stomach turns food into digested food called chyme- this is emptied into the small intestine
what is the small intestine role in the movement of food through the GI tract
- mixes chyme with digestive juices from the pancreas and liver
- Walls absorbs digested nutrients into bloodstream
- blood will deliver nutrients to the body
- Peristalsis further pushes food forward to the large intestine
What is the Large Intestine role in movement of food through the GI tract
- it absorbs any remains nutrients
- changing any remaining undigested food into stools
- pushing waste products further down
- the rectum then stores the stool until it is pushed out
what is the important in nerve regulation in the stomach
- it produces and releases hormones which stimulate the production of digestive juices which regulates appetite
what is an enzyme
a biological catalyst which speeds up or create a chemical change
when enzymes undergo a chemical change do do they alter
no enzymes dent undergo any alteration in itself when they speed up or bring about a chemical change
what are the 3 enzymes used in the GI tract
- pepsin
- rennin
- gastric lipase
what is Pepsins role
- starts the breakdown of protein release as pepsinogen which is inactive
What is the role of Gastric Lipase
- it starts the breakdown of fat
What is the role of Rennin
- acts on milk products in children
What happens to food when it enters the mout
- it is broken down by teeth (mechanical digestion) and mixed with saliva which contains enzymes amylase (chemical digestion) before being swallowed
what are the 2 types of digestion used in the mouth
- mechanical digestion
- chemical digestion
what are the 3 stages of swallowing
- oral = voluntary
- pharyngeal = involuntary
- oesophageal = involuntary
what is the role of saliva in the mouth
- it aids digestion by breaking food down
- keeps the mouth clean by washing away bacteria and food
- controls amount of good and bad bacteria
what happens if saliva is reduced
- causes a reduced ability to taste
- could lead to infection if the saliva isn’t able to move freely around the mouth
Where is the Patroid gland situated
- in front of and beneath the ear
Where is the sublingual gland situated
under the tongue on the floor of the mouth
Where is the submandibular gland situated
both superiorly and inferiority to the posterior aspect of the mandible
What flavours can people taste
bitter
sweet
salty
sour
What is olfaction and what does it help with
the sense of olfaction(smell) which helps us detect the subtle differences in the flavour of food
