Page 31 - E-Biology Sec.2 2024-2025 U1_Handy
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The cells line the stomach are protected from gastric juice as:
1- It secretes pepsinogen (inactive) & is activated after secretion
in the cavity.
2- Presence of heavy mucus of the inner wall of stomach.
Flowing back of gastric juice to esophagus due to a
disturbance in the muscle controls cardiac sphincter.
Symptoms: Hyper acidity &
Heart burn.
C) Intestinal digestion
5- Small intestine The largest part of the digestive system as its length is 8 m.
Its diameter at the beginning is 3.5 cm to reach 1.25 cm at its end.
It folds & coils over itself and its loops are connected by the mesentery membrane.
It consists of 2 parts; duodenum and ileum. Digestive juices in it:
a) Bile juice: is secreted from the liver in duodenum, it passes through the bile duct
to be stored in the gallbladder, it has no enzymes.
Bile juice Fatty emulsion (small fat globules).
Fats
To facilitates they enzymatic action on fats.
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First Term
