Key Points
Key Points: Digestive Glands
- Digestive glands associated with the alimentary canal are salivary glands, liver, gall bladder (storage) and pancreas.
- Three pairs of salivary glands (parotid, submandibular, sublingual) pour saliva into the buccal cavity; serous cells secrete salivary amylase and mucous cells secrete mucus.
- The liver is the largest gland (about 1.2–1.5 kg), located in the upper right abdomen, divided into right and left lobes made of hepatic lobules covered by Glisson’s capsule.
- Hepatic cells produce bile (stored in gall bladder), store excess glucose as glycogen, synthesize vitamins A, D, K, B₂, and Kupffer cells remove toxins and worn‑out cells.
- The pancreas is a heterocrine gland lying in the C‑shaped curve of the duodenum; its exocrine acini secrete alkaline pancreatic juice with enzymes.
- The endocrine islets of Langerhans contain α‑cells (glucagon), β‑cells (insulin) and δ‑cells (somatostatin).
- The common hepato‑pancreatic duct opens into the duodenum and is guarded by the sphincter of Oddi.
Key Points: Nutritional and Digestive Tract Disorders
- Nutritional disorders are linked to the quality and quantity of food intake (e.g., protein‑energy malnutrition like kwashiorkor and marasmus).
- Disorders of the digestive system arise from malfunctioning of digestive organs or glands (e.g., liver, stomach, intestine).
- Diarrhoea is defined as abnormally frequent bowel movements with increased liquidity of faeces, leading to poor absorption of nutrients.
- Constipation is the prolonged retention of faeces in the rectum, often with irregular or difficult bowel movements.
- Other common digestive disorders include jaundice (abnormal bilirubin metabolism), vomiting (forceful expulsion of stomach contents) and indigestion (improper digestion causing discomfort).
Concepts [13]
- Introduction of Digestion and Absorption
- Alimentary Canal
- Digestive Glands
- Digestion of Food
- Absorption of Digested Products
- Nutritional and Digestive Tract Disorders
- Role of Digestive Enzymes and Gastrointestinal Hormones
- Peristalsis, Digestion, Absorption and Assimilation of Proteins, Carbohydrates and Fats
- Digestion and Absorption Questions
- Calorific Values of Proteins
- Calorific Values of Carbohydrates
- Calorific Values of Fats
- Egestion of Food
