Biology · Science General

Human Digestive System

1,953 Questions

The human digestive system explores the breakdown of biomacromolecules, covering organs from the stomach to the small intestine. It involves physiological processes like chyme movement, pH levels, and nutrient absorption in the gut. These fundamental biology concepts are regularly featured in medical and general science competitive exams.

Small intestine functionsBiomacromolecule breakdownStomach and digestionIntestinal bacteria

Human Digestive System Questions

Multiple choice biology digestive system of human digestive glands liver pancreas

Choose the correct statement.
A) The anterior surface of the pancreas faces the front of the abdomen.
B) Pancreas drain enzymes through the ampulla of Vater into the duodenum.
C) Lighter-staining cells of pancreas form clusters called acini

  1. Only A

  2. Only C

  3. Both A and B

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The pancreas is a compound (both exocrine and endocrine) elongated organ situated between the limbs of the ‘U’ shaped duodenum in the abdomen behind the stomach.
  • The anterior surface of the pancreas faces the front of the abdomen.
  •  Pancreas drain pancreatic enzymes through the ampulla of Vater into the duodenum. The ampulla of Vater is located where the bile duct and pancreatic duct join and empty into the duodenum.
  • Lighter-staining cells of the pancreas which form clusters are called Islets of Langerhans. These cells secrete hormones such as insulin and glucagon.
  • So, the correct answer is 'Both A and B'.
Multiple choice biology digestive system of human digestive glands liver pancreas

Secretion of which of the following digestive gland is considered as the complete digestive juice?

  1. Liver

  2. Gall bladder

  3. Salivary gland

  4. Pancreatic acini
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Pancreatic juice is considered the complete digestive juice because of the fact that it contains enzymes for the digestion of carbohydrates, fats, and proteins in addition to bicarbonate ions that provide an alkaline medium. Its alkaline nature helps to neutralize the acidic chyme that comes from the stomach. It also has pancreatic amylase that converts complex polysaccharides into disaccharides and the presence of lipase enzymes helps to digest fats. Lastly, it also contains protein-digesting enzymes like trypsin, chymotrypsin, and carboxypeptidase.
So the correct answer is 'Pancreatic acini'.
Multiple choice bio-chemistry digestion digestion in small intestine digestive glands and their secretions alimentary canal

Which of the following are secreted by duodenum or small intestine?

  1. Enterokinin

  2. Secretin

  3. Villikinin

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

(A) Enterokinin is the hormone secreted by Brunner's gland activates the inactive enzyme of the pancreas and convert procarboxypeptidase into carboxypeptidase.

(B) Secretin secreted bu duodenum into blood stimulates the secretion of the pancreas and liver.
(C) VIlikinin is released by duodenal mucosa and increases the motility of villi.
So the correct option is 'All of the above.

Multiple choice bio-chemistry digestion digestion in small intestine digestive glands and their secretions alimentary canal

Partially digested acidic food released from the stomach into the duodenum is called as ________.

  1. Food bolus

  2. Chyme

  3. Chyle

  4. Faeces
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In the stomach, food is mixed with gastric juices and hydrochloric acid, churning it into a semi-fluid state known as chyme. This acidic mixture is subsequently released in small portions into the duodenum through the pyloric sphincter. Bolus refers to chewed food mixed with saliva before swallowing, while chyle refers to milky lymphatic fluid containing emulsified fats found in the intestine.

Multiple choice bio-chemistry digestion digestion in small intestine digestive glands and their secretions alimentary canal

If the pH of duodenum decreases below $5$, then secretion of ________ stop.

  1. Secretin

  2. Enterokinase

  3. CCK

  4. Gastrin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Secretin is a hormone released by the duodenum in response to low pH (acidic chyme). Its primary function is to stimulate the pancreas to release bicarbonate-rich fluid to neutralize the acid. If the pH is not low, the stimulus for secretin release is absent.

Multiple choice bio-chemistry digestion digestion in small intestine digestive glands and their secretions alimentary canal

Sphincter that helps in opening of stomach into duodenum ____________.

  1. Cardiac

  2. Pyloric

  3. Anal

  4. Gastric
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pyloric sphincter is a band of smooth muscle at the junction between the pylorus of the stomach and the duodenum of the small intestine. It acts as a valve to control the flow of partially digested food (chyme) into the small intestine. The cardiac sphincter guards the opening from the esophagus into the stomach.

Multiple choice bio-chemistry digestion digestion in small intestine digestive glands and their secretions alimentary canal

Ileum is characterised by

  1. Brunners glands and leaf like villi

  2. Brunners glands and club-shaped villi

  3. Club-shaped villi and Peyers patches

  4. Peyers patches and Brunners glands
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The ileum is characterized by the presence of Peyer's patches and club-shaped villi. Brunner's glands are a characteristic feature of the duodenum, not the ileum.

Multiple choice bio-chemistry digestion digestion in small intestine digestive glands and their secretions alimentary canal

Which of the following is absorbed in ileum?

  1. Fat

  2. Bile salts

  3. Vitamin K

  4. Glucose
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bile salts are synthesized in the liver, stored in the gall bladder, and aid in fat digestion in the small intestine before being actively reabsorbed specifically in the terminal ileum. This process is known as the enterohepatic circulation of bile salts. Other nutrients like glucose and fats are mostly absorbed in the duodenum and jejunum.