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 nervous system of man divisions of nervous system autonomic nervous system the human brain

Sight of delicious food usually makes mouth watery, it is a

  1. Hormonal response

  2. Neural response

  3. Optic response

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

The sense of smell and sight of food are governed by olfactory and optic responses which work together to initiate the neural response during cephalic phase of digestion. Sight, smell and sense of food initiate the neural response in which central nervous system prepares the stomach to receive food. The responses include salivation and secretion of gastric juices. This makes options C and D incorrect and option B correct. The ingestion of food stimulates the hormonal responses to food which includes endocrine system to ensure releases of various digestive hormones at appropriate time. Correct answer is B.

Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

Production of gastro-intestinal secretions and movement soon after ingestion of food are brought about by

  1. Central nervous system

  2. Sympathetic nervous system

  3. Parasympathetic nervous system

  4. Peripheral nervous system
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The parasympathetic nervous system promotes digestive activities, including gastrointestinal secretions and peristalsis, following the ingestion of food.

Multiple choice biology windows of knowledge human tongue organ of taste tongue : the organ of taste

Chemicals that stimulates taste receptor cells are called as

  1. Dorsum

  2. Tastant

  3. Saliva

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The chemicals or the substances which can stimulate the taste receptor cells are known as tastants. The upper surface contains papillae. There are several taste receptors on the papillae. When the tastants gets dissolved in the saliva, the taste can be detected by the taste receptors.

Thus, the correct answer is option B. 

Multiple choice biology windows of knowledge human tongue organ of taste tongue : the organ of taste

Bitter taste of food can be transduced by

  1. The blockage of efflux of K+

  2. The blockage of influx of K+

  3. The blockage of efflux of Na+

  4. The blockage of efflux of Cl-
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bitterness is the most sensitive of the tastes and perceived as unpleasant, sharp, or disagreeable. The transduction of bitter tastes involves several mechanisms: 

1) Blockage of the efflux of K+ by a number of hydrophilic bitter substances generates a depolarizing potential.
2) Interaction with a receptor membrane receptor coupled to the G protein, gustducin, and activation of a cAMP-dependent protein kinase with blockage of K+ channels and

3) Involves a receptor protein linked to G-protein and activation of phospholipase C, which results in substrate hydrolysis to IP3, releasing Ca2+ from intracellular stores.
So, the correct answer is option A.

Multiple choice biology windows of knowledge human tongue organ of taste tongue : the organ of taste

The taste sensitivity is dependent upon

  1. Concentration of taste

  2. Concentration of food

  3. Solubility of taste in saliva

  4. Both A and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Taste sensitivity refers to the intensity with which one perceives different tastes and flavours. It is dependent upon the concentration of the taste molecules as well as their solubility in saliva. It does not depend upon the concentration of food.
So, the correct answer is option D.
Multiple choice biology windows of knowledge human tongue organ of taste tongue : the organ of taste

Taste receptors detect the taste by

  1. G protein-coupled mechanism

  2. Contractile mechanism

  3. Feedback inhibition

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • The taste receptors are located around the small structures known as papillae found on the upper surface of the tongue, soft palate, upper esophagus, the cheek, and epiglottis.
  • Taste receptors detect the taste by G protein-coupled mechanism.
  • G protein-coupled receptors constitute a large protein family of receptors that detect molecules outside the cell and activate internal signal transduction pathways and, ultimately, cellular responses. Coupling with G proteins.
  • So, the correct answer is 'G protein-coupled receptor.
Multiple choice biology soldiers of defense human lymphatic system lymph and its function lymph and tissue fluid

Which of the following molecule enters into the lymph from intestine?

  1. Fat molecules

  2. Glycerols

  3. Plasma protein

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Chyle is the liquid form of chyme that enters lymph vessels from the small intestine. It is rich in fats, these fats along with lymph often appear as milk. The fat molecules from the intestine will make their way into the lymph.
  • Glycerols also called as glycerine is a colorless, odorless substance. It is found as an intermediate in metabolic pathways.
  • Plasma protein is the proteins that make-up blood plasma. They help in maintaining osmotic pressure, clotting, and transport of certain lipids, enzymes and hormones.
So the correct option is "Fat molecules".
Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

Glucose and amino acids are absorbed in the intestine by

  1. Active transport

  2. Passive transport

  3. Selective absorption

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

Glucose and amino acids are absorbed against their concentration gradients in the small intestine. This process requires energy in the form of ATP, which characterizes active transport.

Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

Glucose and amino acids are absorbed in intestine by

  1. Osmosis

  2. Passive transport

  3. Active transport

  4. Selective absorption
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The monosaccharides glucose and galactose are transported into the epithelial cells by common protein carriers via secondary active transport I.e  by co-transport with sodium ions. The monosaccharides leave these cells via facilitated diffusion and enter the capillaries through intercellular clefts.

Thus C is the correct option. 

Multiple choice biology blood circulatory system of human cardiac disorders cardiac regulation and disorders the blood system

Which condition is associated with the failure of the cardiac sphincter, fails to close and leads to regurgitation of food into the oesophagus:

  1. Heart burn

  2. Indigestion

  3. Achalasia cardia

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

The cardiac sphincter separates the esophagus from the stomach. When cardiac sphincter fails to close and leads to regurgitation of food and gastric acid into the esophagus from stomach it leads to heat burn. The symptoms of heat burn include a chronic cough, burning feeling in the chest, chest pain and burning at the back of the throat.

So, the correct answer is 'Heat burn'.

Multiple choice zoology nervous system nervous systems involved in emotions types of nervous system components of nervous system

A nerve leading to the small intestine causes the rate of digestion to increase, this nerve belongs to 
I. Autonomic
II. Sympathetic
III. Peripheral
IV. Enteric

  1. I and II only

  2. II and III only

  3. I, II, and III

  4. I, III, and IV

  5. II, III, and IV
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • The nervous system is divided into two types CNS and peripheral nervous system.
  • The peripheral nervous system is in turn divided into the somatic nervous system and autonomic nervous system.
  • The autonomic nervous system regulates the internal and involuntary movement.For example,respiration,cardiovascular,digestive etc.
  • The autonomic(visceral) nervous system is again divided into the sympathetic and parasympathetic nervous system.
  • The enteric nervous system receives inputs from the parasympathetic and sympathetic parts of the nervous system,
  • Sympathetic decreases the rate of digestion whereas parasympathetic increases the rate of digestion via the enteric nervous system.
  • A nerve leading to the small intestine causes the rate of digestion to increase, this nerve belongs to Peripheral, Peripheral and Enteric.

So, the correct answer is 'I, III, and IV'.