Digestive System: From Eating to Excretion 🍽️

How does the digestive system work? In this video, we explain the entire digestive process from ingestion to egestion — how food travels from your mouth through the esophagus, stomach, small intestine, and large intestine, and how your body breaks it down into nutrients your cells can use. Learn about mechanical and chemical digestion, peristalsis, stomach acid, enzymes, bile, villi, and how gut bacteria help your immune system.

Whether you're a biology student preparing for an exam, or just curious about what happens to the food you eat, this beginner-friendly animated explainer covers the complete journey.

CHAPTERS:
0:00 – How much food do you eat per year? (550 kg!)
0:33 – What is the digestive system?
1:00 – The 7 organs of the digestive system
1:37 – The alimentary canal (GI tract) explained
1:51 – Accessory glands: liver, pancreas, gallbladder
2:03 – The mouth: teeth, saliva, and making a bolus
2:40 – Enzymes: amylase (carbs) and lingual lipase (fats)
3:00 – The esophagus and peristalsis
3:37 – Why food stays down even when you're upside down
3:49 – The stomach: gastric juice and hydrochloric acid
4:33 – Stomach acid so strong it dissolves metal
4:47 – Pepsin: breaking proteins into peptides
5:03 – Intrinsic factor and vitamin B12 absorption
5:25 – From bolus to chyme: 1-4 hours of digestion
5:42 – The small intestine: duodenum, jejunum, ileum
6:27 – Pancreatic enzymes and bile from the gallbladder
7:00 – Villi: the hairy carpet that absorbs nutrients
7:38 – The large intestine: gut bacteria and water absorption
8:12 – 36 hours from large intestine to egestion
8:27 – The gut-brain connection and immune system

WATCH NEXT:
▶ Immune System: Innate and Adaptive Immunity Explained – https://youtu.be/PzunOgYHeyg
▶ Lymphatic System Explained in Simple Words – https://youtu.be/eWUAB194qhU
▶ What Are Neurons and How Do They Work? – https://youtu.be/HUuUUJktL6E

KEY TOPICS COVERED:
• The 7 organs of the digestive system and 3 accessory glands
• Mechanical vs chemical digestion: how teeth and enzymes work together
• Peristalsis: the muscle contractions that move food through your gut
• Stomach acid (HCl): strong enough to dissolve metal
• The small intestine: 20 feet of nutrient absorption via villi
• Gut bacteria, the gut-brain connection, and immune system links

#DigestiveSystem #HumanDigestion #BiologyExplained #StomachAcid #HumanBody #GutHealth

REFERENCES:
https://www.mayoclinic.org/digestive-system/expert-answers/faq-20058340
https://onlinelibrary.wiley.com/doi/abs/10.1002/jsfa.7601
https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001424

Original Article: https://www.scienceabc.com/pure-sciences/ingestion-excretion-journey-food-time-enters-body-time-leaves.html

Voice Over: John Staughton (https://www.fiverr.com/jswildwood)

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