Sigestive System Flashcards
What is the mouth responsible for
-chemical digestion
-mechanical digestion
Points on chemical digestion
- salivary glands release saliva
- saliva contains the enzyme amylase which breaks down starch into maltose
- saliva also softens the food particles to make swallowing easier
What does mechanical digestion do
It makes large food particles into smaller food particles. This is done by the teeth and the tongue helps as well.
what are the 4 types of teeth
A) Incisors - cut
B) Canines - grip
C) Premolars - griping/ chewing
D) Molars - griping/chewing
How many teeth are there
incisors= 4 teeth
canines= 2 teeth
premolars= 4 teeth
molars= 6 teeth
total= 32 teeth
draw a diagram of a tooth
should include:
enamel
dentine
pulp cavity
gingiva
root canal
what are the three sections of a tooth
Crown
Neck
Root
what is bolus
food particles that are swallowed
what does the oesophagus do
carries food (bolus) from the mouth pharynx to the stomach
smooth muscles contract by
involuntary control
what is peristalsis
a rhythmic contraction in one direction (mouth to anus)
what are the functions of the stomach
1) storage of food
2) chemical digestion
-for proteins aka polypeptides protein + pepsin = peptides
-therefore it has an acidic environment -hydrochloric acid (HCl) pH2
draw a diagram of the stomach
should include:
oesophagus
sphincter muscles
gastric juice
HCl + pepsin
ulcer
pyloric sphincter
what can muscular lining in the stomach be damaged or lost by
A) Bacterium H. pylori
B) Stomach ulcers (=wounds)
what is the duodenum
- a part of the small intestine after the stomach that is connected to the pancreas and the bile duct
- the absorption of vitamins, minerals, and other nutrients begins here
what does the liver do
1) produces bile= made of bile salts and bilirubin, contained from haemoglobin
2) has specialised cells (hepatocytes) that are able to remove toxins from the blood. chemically modifies the toxins to be less toxic and more soluble so that they get filtered out by the kidneys faster
3) removes old red blood cells from the blood
4) stores ion
5) stores lipid soluble vitamins
6) deamination
what is bile
- is an emulsifier = makes large lipid particles (droplets) into smaller ones. this increases their surface area
- greenish colour
what is deamination
- the process of removing the amine group from the amino acids
- turned into ammonia which is converted into urea and removed from the kidneys
what is the role of the gall bladder
stores and secretes bile
what reactions take place in the pancreas
A) triglycerides + lipase = fatty acids + glycerol
B) starch + amylase = maltose
C) maltose + maltase = glucose
D) peptide + trypsin = amino acids
E) sodium hydroxide carbonate neutralises stomach acid
what is the role of the small intestine
- finishes chemical digestion
- responsible for nutrient absorption
what are some adaptations of the small intestine for nutrient absorption
A) length- it is long, more time to digest and absorb nutrients
B) folds and structures called VILLI to increase overall area
draw a diagram of a villi
should include:
microvilli
arterial
venule
lacteal
what are some adaptations of the villi
A) microvilli- increases surface area even more, so more nutrient absorption by diffusion
B) short distance from nutrients in the ileum to the blood, faster diffusion
C) constant blood flow, so blood flow prevents equilibrium from being reached resulting in a constant diffusion gradient in favour of absorption
D) fixed enzymes on the surface, so nutrient can be immediately absorbed once produced/hydrolysed by the enzymes
what are the functions of the large intestine
- water absorption - solidifies waste
- production of Vit. K from symbiotic gut bacteria (microflora)
what is the anus
a series of sphincter muscles that regulate waste release
what causes Diabetes II
- bad diet
-blood sugar levels are high after a meal
what causes constipation
low fibber diet
what causes obesity
excess nutrients
can lead to other conditions like diabetes II
what causes jaundice
the liver is failing and bilirubin is building up in tissues
what causes liver cirrhosis
scarring of the liver
