Biology · Science General

Human Digestive System

2,002 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 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 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 evs transportation in living organisms circulatory system and organs blood and blood vessels circulatory system blood pressure

Adventitia is outermost coat of.

  1. Stomach

  2. Intestine

  3. Rectum

  4. Artery
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The tunica adventitia (or tunica externa) is the outermost connective tissue layer of blood vessels, particularly arteries and veins. While other organs have outer layers, the term is most characteristically associated with the histology of blood vessels.

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'.

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

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 the 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. The ingestion of food stimulates the hormonal responses to food which includes endocrine system to ensure releases of various digestive hormones at appropriate time. Thus, tye correct answer is option B.

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

Which nerve fibres supply the stomach and intestine?

  1. Sympathetic nerve fibres

  2. Parasympathetic nerve fibres

  3. Parasympathetic and sympathetic nerve fibres

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

The stomach and intestines receive dual innervation from both the sympathetic and parasympathetic nervous systems to regulate motility and secretion.

Multiple choice biology plant kingdom and the environment around us some important plants uses of plants as medicine medicinal plants

Soluble fibre is useful medically for

  1. Optimum functioning of alimentary canal

  2. Reduction in blood cholesterol

  3. Binding of faecal matter

  4. Non-corrosion of intestinal lining
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Soluble fiber attaches to cholesterol and takes them out of the body from our system that helps in reducing blood cholesterol and also reducing the risk of heart disease. These are found in the food like oats, apples, nuts etc.

So, the correct option is 'Reduction in blood cholesterol'.

Multiple choice evs - i more about organ system human lymphatic system lymph and its function lymph and tissue fluid introduction to excretory system structures and functions related to the excretory system introduction to excretion

Mucus is secreted by the

  1. Stomach

  2. Duodenum

  3. Large intestine

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

Stomach - Foveolar cells are mucus-producing cells, which cover the inside of the stomach, protecting it from the corrosive nature of gastric acid. The mucus produced by these cells is extremely important, as it prevents the stomach from digesting itself.
Duodenum - Brunner's glands (or duodenal glands) are compound tubular submucosal glands present in the duodenum. The main function of these glands is to produce a mucus-rich alkaline secretion (containing bicarbonate) in order to: protect the duodenum from the acidic content of chyme (which is introduced into the duodenum from the stomach); provide an alkaline condition for the intestinal enzymes to be active, thus enabling absorption to take place and lubricate the intestinal walls.
Large intestine - Goblet cells reside throughout the length of the small and large intestine and are responsible for the production and maintenance of the protective mucus blanket by synthesizing and secreting high-molecular-weight glycoproteins, known as mucins. 

Multiple choice evs - i busy at work - our internal organs human lymphatic system lymph and its function lymph and tissue fluid

Complete digestion takes place in which part of cockroach?

  1. In crop

  2. In Gizzard

  3. In stomach

  4. In oesophagous
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cockroaches belong to phylum Arthropoda which has well developed the digestive system. The digestion of starch in the buccal cavity is followed by complete grinding of food in crop and gizzard which finally enters the stomach. The digestive enzymes secreted by the gastric caeca act upon the food in the stomach. These enzymes include amylase, maltase, invertase, tryptase and lipase. The remaining carbohydrates, proteins and fats are digested here.The digested food is absorbed through the stomach walls into the surrounding space which is called the haemocoel. The haemocoel consists of a large number of fat bodies which are fat cells having fat globules, protein granules and glycogen. They form storage structures which transport to different parts of the body. So, the correct answer is option C.