Tag: digestive system - organs

Questions Related to digestive system - organs

Ingestion of food  in human beings is facilited by

  1. Oesophagus

  2. Buccal activity

  3. Muscular tongue

  4. Trachea


Correct Option: C
Explanation:

The food is ingested through the mouth. The mouth contains tongue, teeth and salivary glands. Teeth break the food into smaller particles. This process is called as mastication. The chewed food is mixed with saliva. Saliva is a watery fluid secreted by the salivary glands. Saliva contains a type of enzyme called the salivary amylase, which converts starch into sugar. The tongue is a muscular organ. Tongue helps to mix saliva in the food. It also helps to push the food down the food-pipe or oesophagus. Taste receptors are present in tongue and give us the sense of taste. 

Therefore, the correct answer is option C.

Digestion begins in the mouth. Which of the following statement is incorrect?

  1. The tongue aids in the digestion of the food.

  2. The saliva changes some of the starches in the food to sugar.

  3. The tongue keeps the food in place in the mouth while the food is being chewed.

  4. The digestive juices can react more easily with food when chewed.


Correct Option: A
Explanation:
The tongue consists of eight interwoven, striated muscles that can move in any direction, making it quite flexible. Throughout the muscles are glands and fat, while the outside is covered by a mucus membrane. The top of the tongue, also called as the dorsum, is covered with papillae, tiny nodes that contain the taste buds and the serous glands.
Produced in salivary glands, saliva is 98% water, but it contains many important substances, including electrolytes, mucus, antibacterial compounds and various enzymes. The digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily.
Therefore, the correct answer is option A.

The first stage of digestion in human beings takes place in

  1. Oesophagus

  2. Small intenstine

  3. Buccal cavity

  4. Stomach


Correct Option: C
Explanation:

The fist stage of digestion in human being takes place in the buccal cavity where the chewing and churning of food and mixing of saliva occurs. Saliva consists salivary amylase which acts on the starch molecule of food and converts it into the simple form. The semisolid food with saliva in buccal cavity is called as a bolus. Bolus is then transferred to the stomach with the help of peristaltic movement of the oesophagus. Thus, the correct answer is option C.

Common passage for swallowing food and breathing is

  1. Gullet

  2. Pharynx

  3. Glottis

  4. Larynx


Correct Option: B

Length of human alimentary canal is

  1. 100 cm

  2. 3-4 m

  3. 4-6 m

  4. 6-9 m


Correct Option: D
Explanation:

The alimentary canal is a long tube through which food is taken into the body and digested. In human beings, this passage is about 30 ft (9 m) long." The alimentary canal, or the digestive tract as it is most commonly known, is 9 meters from the oesophagus to the anus.


So, the correct option is '6-9 m'.

In man even though both air and food go through the pharynx, food does not normally enter the wind pipe because during swallowing of food

  1. The epiglottis covers the glottis

  2. Sphincter of Oddi closes the hepato-pancreatic duct

  3. Pyloric sphincter covers the opening of stomach into the duodenum

  4. None of these


Correct Option: A

A complete digestive tract consists of an oral and an anal opening.

  1. True

  2. False


Correct Option: A
Explanation:

In humans, the alimentary canal begins with an anterior opening, called mouth and it opens out posteriorly through another opening, anus. Such an alimentary canal is called complete. In some animals like coelenterates only single opening is present, such an alimentary canal is called incomplete. 

In humans, protein digestion is completed in the mouth.

  1. True

  2. False


Correct Option: B
Explanation:

The digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily. Saliva contains the enzyme amylase that breaks some starches down into maltose and dextrin. The pancreas produces a juice containing several enzymes that break down carbohydrates, fats, and proteins in food. Hence, partial digestion occurs in the mouth.

Soidum potassium pumps in the axonal membrane ionic gradients across the resting membrane by 

  1. Passive transport of $Na^+$ outwards and $K^+$ inwards

  2. Active transport of $Na^+$ inwards amd $K^+$ outwards

  3. Transport of $Na^+$ and $K^+$ ions along their concentration gradients.

  4. Active transport of $Na^+$ outwards and $K^+$ inwards


Correct Option: D
Explanation:

Sodium-potassium pumps in the axonal membrane ionic gradients across the membrane by active transport of Na${+}$ outwards and K${+}$ inwards.

So, the correct option is 'Active transport of Na+ outwards and K+ inwards'.

Match the items in Column I with Column II.

Column I Column II
A. Mouth a. Protein
B. Stomach b. Water
C. Small Intestine c. Starch
D. Large Intestine d. Fat

Select the alternative which shows the correct matching.

  1. A - d, B - c, C - a, D - b

  2. A - c, B - d, C - b, D - a

  3. A - c, B - a, C - d, D - b

  4. A - b, B - a, C - d, D - c


Correct Option: C
Explanation:

Amylase is an enzyme that catalyses the hydrolysis of starch into sugars. Amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion in mouth. Protein digestion begins in the stomach with the action of an enzyme called pepsin. Lipids are digested mainly in the small intestine by bile salts through the process of emulsification, which allows lipases to divide lipids into fatty acids and glycerol. The large intestine is the final section of the gastrointestinal tract that performs the vital task of absorbing water and vitamins while converting digested food into faeces.