Digestive System Flashcards
What is the point of digestion?
to break down food molecules, so they can get through the cells of the gut wall, and into the blood vessels, where they can then get to all cells of the body to provide energy (by breaking the bonds) , and raw materials (the broken molecule ’bits’, for the cells go grow and repair, and do their ‘jobs’)
What’s the difference between digestion and absorption?
Digestion- breaking down
Absorption- getting across the gut wall into blood vessels
How many layers does the gastro-intestinal tract have, from mouth to anus?
4
What are the tonsils?
Collections of white blood cells involved in defence/immune system tasks
What are the names of the 3 salivary glands ?
Parotid
Sub mandibular
Sub lingual
What is the enteric nervous system?
The brain of the gut
What is the epiglottis?
A flap of skin that covers the trachea when swallowing, which stops food from going down the airways
Why is the oesophagus lined with mucus cells and stratified squamous epithelium?
Mucus lubricates food going down
Stratified squamous because surface cells continually worn off by friction from passage of food
What causes heartburn?
If oesophageal sphincter into stomach can’t close properly, stomach acids can leak up into oesophagus and burns the oesophagus
What is a hiatus hernia?
When the stomach pushes up through the diaphragm
What are the two sphincters that control entry to and exit from the stomach called?
Oesophageal and pyloric sphincters
What sort of molecules does the stomach mainly digest?
Proteins
What protects the stomach from the acid it secretes?
Mucus secretions
What is the most common cause of an ulcer?
Helicobacter pylori bacteria dissolving the mucus and exposing the stomach wall to acid
Why are there a lot of white blood cells in the stomach?
Bacteria and other pathogens can get in via food etc
State 4 important functions of the small intestine
Finish protein and carbohydrate digestion
Water absorption
Start & finish fat digestion
Absorb products of digestion
How are the digestive system and the blood system linked by Intrinsic Factor?
Intrinsic Factor is a molecule produced by stomach cells that is needed for Vitamin B12 absorption from the stomach and vitamin B12 is essential for red blood cell formation
Where are bile salts made and what do they do?
Bile salts are made in the liver. They emulsify fats.
Which 4 vitamins are absorbed with fats through the lymph system?
Vitamins A, D, E, and K
State 4 functions of the liver
Makes bile
Forms non-toxic urea from waste products
Modifies products of digestion
Detoxifies proteins
Makes plasma protein
Makes blood clotting enzyme fibrinogen
What is the hepatic portal system?
a system of veins that delivers blood with products of digestion to the liver
How many enzymes does the pancreas secrete to digest proteins, carbohydrates and lipids, and which two hormones does the pancreas also secrete?
The pancreas secretes 15 enzymes for digestions.
It also secretes the hormones insulin and glucagon.
What does the gall bladder do?
The gallbladder stores and secretes bile
What is cirrhosis of the liver?
Scarring caused by inflammation
