Introduction:
The human digestive system is a group of organs responsible for:
1.Ingestion of food
2. Digestion of food
3. Absorption of nutrients
4. Elimination of waste
It converts complex food substances into simple absorbable forms.
Main Functions of the Digestive System:
1.Ingestion — taking food into the mouth
2.Digestion — breaking food into smaller molecules
3.Absorption — nutrients enter blood and lymph
4.Assimilation — cells use absorbed nutrients
5.Egestion — removal of undigested waste.
Organs of the Digestive System:
1. Mouth:
•Entry point of food
•Teeth perform mechanical digestion
•Saliva contains salivary amylase
•Tongue helps in swallowing.
Types of Teeth:
1.Incisors → cutting
2.Canines → tearing
3.Premolars → crushing
4.Molars → grinding
2. Pharynx:
•Passage connecting mouth to esophagus
•Helps in swallowing.
3. Esophagus:
•Muscular tube carrying food to stomach
•Food moves by peristalsis
Peristalsis:
Wave-like muscular contractions pushing food forward.
4. Stomach:
•J-shaped muscular organ
•Stores and churns food
•Secretes gastric juice
Gastric Juice Contains:
•Hydrochloric acid (HCl)
•Pepsin enzyme
The human digestive system is a group of organs responsible for:
1.Ingestion of food
2. Digestion of food
3. Absorption of nutrients
4. Elimination of waste
It converts complex food substances into simple absorbable forms.
Main Functions of the Digestive System:
1.Ingestion — taking food into the mouth
2.Digestion — breaking food into smaller molecules
3.Absorption — nutrients enter blood and lymph
4.Assimilation — cells use absorbed nutrients
5.Egestion — removal of undigested waste.
Organs of the Digestive System:
1. Mouth:
•Entry point of food
•Teeth perform mechanical digestion
•Saliva contains salivary amylase
•Tongue helps in swallowing.
Types of Teeth:
1.Incisors → cutting
2.Canines → tearing
3.Premolars → crushing
4.Molars → grinding
2. Pharynx:
•Passage connecting mouth to esophagus
•Helps in swallowing.
3. Esophagus:
•Muscular tube carrying food to stomach
•Food moves by peristalsis
Peristalsis:
Wave-like muscular contractions pushing food forward.
4. Stomach:
•J-shaped muscular organ
•Stores and churns food
•Secretes gastric juice
Gastric Juice Contains:
•Hydrochloric acid (HCl)
•Pepsin enzyme
