Question

The partially digested food coming from the stomach of a person enters a long and narrow organ A in his body. The organ A receives the secretion of two glands : liver and pancreas. Liver secretes a greenish-yellow liquid B which is normally stored in the organ C. Pancreas secretes pancreatic juice which contains three digestive enzymes D, E and F. The intestinal juice completes the process of digestion of food. The inner wall of organ A has millions of tiny finger-like projections G which help in the rapid absorption of digested food into blood stream. The undigested part of food then passes into wider tube H which absorbs most of the water from undigested food. The last part of tube H called I stores this undigested food (or waste) for some time. The undigested food is then passed out though opening J as faeces in the process known as K.

1. Name the organ A.
2. Name (i) liquid B, and (ii) organ C.
3. What are the digestive enzymes D, E and F?
4. Name the projections G present on the inner wall of organ A.
5. Name (i) tube H (ii) part I (iii) opening J, and (iv) process K.

Answer 1

(a) Organ A is the small intestine (the long, narrow site of complete digestion and absorption).

(b) 

1. Liquid B: Bile (or Bile juice).
2. Organ C: Gallbladder (the small sac where bile is temporarily stored and concentrated).

(c) 

• Digestive enzyme D: Pancreatic amylase (breaks down remaining starches/carbohydrates).
• Digestive enzyme E: Trypsin (breaks down proteins into peptides).
• Digestive enzyme F: Lipase (breaks down emulsified fats into fatty acids and glycerol).

(d) The projections G are villi. These microscopic, finger-like structures vastly increase the surface area of the small intestine to maximize nutrient absorption into the bloodstream.

(e) 

• Tube H: Large intestine (the wider tube responsible for absorbing excess water).
• Part I: Rectum (the final muscular chamber where faeces are stored).
• Opening J: Anus (the muscular opening at the end of the tract).
• Process K: Egestion (or Defecation; the elimination of undigested waste from the body).