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 zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Cholecystokinin and enterocrinin are secreted by 

  1. Intestine

  2. Pancreas

  3. Adrenal cortex

  4. Thyroid gland
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Cholecystokinin is secreted from the duodenum and causes contraction of gall bladder and secretion of pancreatic juice into duodenum. Enterocrinin is secreted from duodenum and stimulates release of alkaline mucus from the intestinal glands.
  • Pancreas is a heterocrine gland as it acts both as endocrine and exocrine gland. It secretes insulin hormone into blood and act as endocrine gland and when it secretes digestive enzymes and juice through pancreatic duct, it acts as exocrine gland.
  • Adrenal cortex is part of adrenal gland and secretes glucocorticoids (cortisol,) mineralocorticoids (aldosterone) and sexocorticoids (androgens).
  • Thyroid gland is situated between the trachea and larynx in the neck and secretes thyroxine hormone which increases oxygen consumption by metabolically active tissues.
 Hence, cholecystokinin and enterocrinin are secreted from duodenum (part of small intestine).
So, the correct answer is 'Intestine'.
Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Gastric secretion is stopped by hormone

  1. Enterogastrone

  2. Gastrin

  3. Pancreozymin

  4. Cholecystokinin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A. Enterogastrone is secreted from the duodenal mucosa and decreases the secretion of gastric juices.
B. Gastrin is secreted in stomach by the parietal cells and stimulates the secretion of gastric juices from the gastric glands.
C. Pancreozymin is the former name of Cholecystokinin.
D. Cholecystokinin is secreted from the duodenum and causes contraction of gall bladder and secretion of pancreatic juice into duodenum.
Hence, gastric secretion is stopped by Enterogastrone.
So, the correct answer is 'Enterogastrone'.
Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

The hormone which brings about the contraction of gall bladder is

  1. Oxytocin

  2. Gastrin

  3. Cholecystokinin

  4. Secretin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A. Oxytocin is secreted from the posterior pituitary and helps in the contraction of uterus during childbirth and also stimulates release of milk from mammary glands i.e. lactation.
B. Gastrin is secreted in stomach by the parietal cells and stimulates the secretion of gastric juices from the gastric glands.
C. Cholecystokinin is secreted from the duodenum and causes contraction of gall bladder and secretion of pancreatic juice into duodenum.
D. Secretin is secreted in duodenum and stimulates the secretion of pancreatic juice but inhibits the secretion of gastric juices.
So, the correct answer is 'Cholecystokinin'.
Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Secretin stimulates secretion of bicarbonate from

  1. Liver

  2. Kidneys

  3. Pancreas

  4. Stomach
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A. Liver is the digestive organ that secretes bile juice.
B. Kidneys are the paired excretory organs.
C. Pancreas is a heterocrine gland that secretes hormones insulin, glucagon and somatostatin and also secretes alkaline pancreatic juice that contains bicarbonate ions.
D. Stomach is the digestive organ that stores the food.
Secretin is secreted from the duodenum and stimulates secretion of pancreatic juice. 
So, the correct answer is 'Pancreas'.
Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Secretin hormone is secreted by and stimulates 

  1. Duodenum - pancreas

  2. Duodenum - liver

  3. Stomach - gastric glands

  4. Thyroid - thyroid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Secretin is secreted in duodenum and stimulates the secretion of pancreatic juice but inhibits the secretion of gastric juices. It is released in response to acid in the small intestine, and stimulates the pancreas and bile ducts to release a flood of bicarbonate base, which neutralizes the acid.
So, the correct answer is 'Duodenum - pancreas'.

Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Select the correct match.

  1. Pineal gland - Does not influence menstrual cycle

  2. Corpus luteum- Secretes oxytocin

  3. Interstitial cells - Erythropoietin

  4. Cholecystokinin - Stimulates pancreatic enzyme secretion

  5. Thyroxine - Triiodothyronine
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A. Pineal gland is a small, rounded and reddish brown gland present at the dorsal side of forebrain. This gland secretes melatonin and serotonin hormones. Melatonin regulates circadian rhythm of body. 
B. Corpus luteum is formed in ovary after ovulation and degenerates in absence of pregnancy but if pregnancy occurs it persists and secretes progesterone and oestrogen hormones. During pregnancy, corpus luteum also secretes relaxin hormone which dilates the cervix and aids in childbirth.
C. Interstitial cells, also known as Leydig's cells are present in the testis near seminiferous tubules. They secrete testosterone hormone which helps in the development of secondary sexual characteristics in males.
D. Cholecystokinin is secreted from the duodenum and causes contraction of gall bladder and secretion of pancreatic juice into duodenum.
E. Thyroxine (tetra-iodothyronine) is secreted from thyroid gland. It stimulates the consumption of oxygen by metabolically active tissues and also increases the oxidation of glucose in tissues. 
Hence, option D is a correct match.
So, the correct answer is 'Cholecystokinin - Stimulates pancreatic enzyme secretion'.
Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Gastrin hormone is secreted by 

  1. Pancreas

  2. Intestine

  3. Liver

  4. Stomach
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Gastrin is a peptide hormone which is produced by G cells present in the lining of stomach. It is secreted in the stomach and stimulates gastric secretions. It stimulate the parietal cells of stomach to release HCl or hydrochloric acid which is main constituent of gastric juice. The release of gastrin is stimulated by the presence of peptides in the stomach lumen.
So, the correct answer is 'Stomach'.
Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Secretion of gastric juice is controlled by 

  1. Enterogasterone

  2. Cholecystokinin

  3. Gastrin

  4. Motilin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A. Enterogastrone is secreted from duodenum and inhibits the secretion of gastric juices.
B. Cholecystokinin is secreted from the duodenum and causes contraction of gall bladder and secretion of pancreatic juice into duodenum.
C. Gastrin is secreted in stomach by the parietal cells and stimulates the secretion of gastric juices from the gastric glands.
D. Motilin is secreted from duodenum and regulates gastrointestinal contractions.
So, the correct answer is 'Gastrin'.
Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Cholecystokinin is a

  1. Bile pigment

  2. Enzyme

  3. Lipid

  4. Gastrointestinal hormone
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Cholecystokinin is a peptide hormone secreted from the cells of duodenum which is an organ of gastrointestinal tract. It was formerly called as pancreozymin. It stimulates the gall bladder to contract and release bile juice (because gall bladder stores bile juice secreted by liver). It also stimulates the secretion of pancreatic juice into duodenum. The secretion of cholecystokinin controlled by the amount of amino acids and fatty acids in duodenum.
So, the correct answer is 'Gastrointestinal hormone'.
Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Enterogastrone is secreted by

  1. Gastric mucosa

  2. Oesophageal mucosa

  3. Saliva

  4. Duodenal mucosa
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Enterogastrone is a peptide hormone secreted by duodenal mucosa. It is secreted in duodenum when there are sugars and proteins and fatty food in the intestine. Duodenum is a part of small intestine present just after the stomach. Enterogastrone decreases gastric secretions. It also affects movement of chyme in the stomach.
So, the correct answer is 'Duodenal mucosa'.
Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

A child took sugarcane and sucked its juice. Regarding this which of the following match is correct? 
Substrate      Enzyme       Site of secretion of enzyme         Products formed

  1. Protein's- Pepsin, Duodenum,Polypeptides

  2. Starch- Amylase, Salivary glands, Glucose

  3. Lipids- Lipase, Pancreas Fat globules

  4. Sucrose -Invertase, Duodenum, Glucose + fructose
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The correct answer is (d).

Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Duodenum has characterized glands which secrete two hormones called as

  1. Kinase, estrogen

  2. Secretin, cholecystokinin

  3. Prolactin, parathormone

  4. Estradiol, progestrone
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cholecystokinin, previously called pancreozymin, is synthesized by I-cells in the mucosal epithelium of the small intestine and secreted in the duodenum. It is responsible for stimulating the digestion of fat and protein. Secretin is a peptide hormone that regulates water homeostasis throughout the body, and influences the environment of the duodenum by regulating secretions in the stomach and pancreas. Secretin is produced in the S cells of the duodenum, which are located in the crypts of Lieberkuhn.

Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Cholecystokinin is secretion of 

  1. Duodenum, that causes contraction of gall bladder.

  2. Goblet cells of ileum stimulates secretion of succus entricus.

  3. Liver and controls secondary sex characters.

  4. Stomach that stimulates pancreas to release juice.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cholecystokinin (CCK), formerly called pancreozymin, is a digestive hormone released with secretin, when food from the stomach reaches the duodenum. Cholecystokinin causes contraction of the gallbladder, which forces bile into the duodenum.

Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Secretin

  1. Stimulates enzymes secretion by pancreas, inhibits acid secretion in stomach, stimulates gall bladder

  2. Stimulates bicarbonate secretion by pancreas, inhibits acid secretion in stomach, stimulates bicarbonate secretion by liver

  3. Stimulates acid secretion in stomach, potentiates action of CCK, inhibits intestinal movement

  4. Stimulates gall bladder, stimulates bicarbonate secretion by pancreas
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Secretin stimulates the release of a watery bicarbonate solution from the pancreatic and bile duct epithelium. Secretin increases water and bicarbonate secretion from duodenal Brunner's glands to buffer the incoming protons of the acidic chyme. It also enhances the effects of cholecystokinin to induce the secretion of digestive enzymes and bile from pancreas and gallbladder, respectively.

Multiple choice zoology endocrine system and chemical co-ordination gastrointestinal tract and liver hormones of heart, kidney, liver and gastrointestinal tract coordination in human beings- chemical control

Which of the following belongs to the class of pepsin and trypsin?

  1. Secretin

  2. Gastrin

  3. Rennin

  4. Steapsin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Chymosin, known also as rennin, is a proteolytic enzyme related to pepsin that synthesized by chief cells in the stomach of some animals. Its role in digestion is to curdle or coagulate milk in the stomach, a process of considerable importance in the very young animal.
So, the correct option is 'Rennin'.