L5 Flashcards
is a long tube surrounded by muscles
GIT
It includes; pharynx, esophagus, stomach, small intestine (duodenum, jejunum and ileum), large intestine (colon, rectum, and anal canal).
GIT
Its entire length from mouth to anus is 9 meters long.
GIT
Accessory digestive organs include;
gall bladder, liver, and pancreas.
What is to be digested?
• Micronutrients: Vitamins and Minerals
• Macronutrients: Proteins, Carbohydrates, Lipids, and Water
Ingestion
ايش يعني
تناول
Mouth (Buccal or Oral Cavity):
lips, cheeks, upper & lower jaws, gums, teeth (32 teeth, 4 different types) and tongue.
Buccal or Oral Cavity
Mouth
In mouth the digestion is Chemical digestion or mechanical digestion ? Or both ?
both
Teeth (Mechanical digestion)
Saliva (Chemical digestion)
bolus
ايش يعني
بلعة وحدة
is formed with saliva and the tongue.
bolus
Saliva
ايش فوائد اللعاب
1-» secretes amylase enzyme to digest starch,
2-» secretes lipase enzyme to digest fat,
3-» lubricates food for easier swallowing,
4-» protects soft lining of digestive system,
5-» neutralizes acid to prevent tooth decay (buffers),
6-» kills bacteria that enter mouth with food.
During swallowing, no choking occur because…………………… closes trachea → food travels down esophagus.
epiglottis
Process of breaking down food by the body into absorbable nutrients.
• Carbohydrates → glucose.
• Proteins → amino acids.
• Fats → fatty acids, glycerol.
Digestion
The GIT muscles alternate contraction and relaxation pushing food along GIT
Peristalsis
involuntary muscle contractions and relaxations to move food along.
Peristalsis
Functions of stomach
1- storage of food : can stretch to fit ~2L food.
2- disinfect food: HCl (PH 2) kills bacteria.
3- chemical digestion: (pepsin and lipase enzymes).
(PH 2) kills bacteria.
HCl
Hydrochloric acid
حمض موجود في المعدة
Why stomach don’t digest itself since it is protein?
Mucus secreted by stomach cells protects stomach lining.
Accessory Digestive Organs
Pancreas, Gall Bladder, Liver
Digestive enzymes in the pancreas
– digest proteins (trypsin, chymotrypsin)
– digest starch (amylase)
– digest fat (lipase)
Pancreas and Buffers ???
Buffers: neutralizes acid from stomach
وظيفة من وظائف البنكرياس انه يعادل الحمضية القادمة من المعدة
Concentrates and stores bile.
Gall bladder (GB)
emulsify lipid Discharged into duodenum
Bile