Digestive glands Questions in English

(A) The gastric glands in the stomach contain different types of cells.
$1$. Chief cells (also known as peptic or zymogenic cells) secrete the proenzyme pepsinogen.
$2$. Parietal cells (also known as oxyntic cells) secrete $HCl$ and intrinsic factor.
$3$. Goblet cells secrete mucus.
Therefore,the correct answer is Chief cells.

(D) The characteristic brown color of human feces is primarily due to the presence of stercobilin,which is a derivative of bilirubin.
Bilirubin is a bile pigment produced by the breakdown of red blood cells in the liver.
When the liver malfunctions or the bile duct is obstructed,bile pigments (bilirubin) do not reach the intestine.
In the absence of these pigments,the feces lose their normal brown color and appear pale,whitish,or clay-colored (whitish-grey).

(B) Goblet cells are specialized glandular epithelial cells found in the mucosal lining of the digestive and respiratory tracts.
Their primary function is to secrete mucin,which is a glycoprotein.
When mucin is mixed with water,it forms mucus,which acts as a lubricant and protects the epithelial lining of the gastrointestinal tract from mechanical injury and the acidic environment of the stomach.

(A) Mumps is an acute viral infection caused by the mumps virus (a paramyxovirus).
It primarily affects the parotid glands,which are the largest of the three pairs of salivary glands located in the cheeks.
Inflammation of these glands leads to swelling,pain,and difficulty in swallowing.
Therefore,the correct option is $A$.

(A) compound gland is a gland that has a branched duct system.
Among the given options,the $Parotid$ gland,the $Submandibular$ gland,and the $Sublingual$ gland are major salivary glands which are compound tubulo-alveolar glands.
$Brunner's$ glands are simple tubular glands found in the submucosa of the duodenum.
$Sebaceous$ glands are simple branched alveolar glands.
Therefore,the $Parotid$ gland is a compound gland.

(C) Gastric glands are located in the lining of the stomach. Anatomically,these are classified as branched tubular glands. They consist of a duct that branches into several secretory tubules,which open into the gastric pits of the stomach mucosa.

(B) Bilirubin and biliverdin are bile pigments.
They are produced by the breakdown of the $Heme$ component of hemoglobin when old red blood cells are destroyed in the liver,spleen,and bone marrow.
The $Globin$ part of hemoglobin is broken down into amino acids and reused by the body.
Therefore,the correct answer is $Heme$.

(A) Glisson's capsule is a thin connective tissue sheath that covers the liver. It is composed of dense irregular connective tissue and extends into the liver,dividing it into lobules. Therefore,it is specifically associated with the liver.

(B) Chymotrypsinogen is an inactive proteolytic enzyme (zymogen) secreted by the $Pancreas$.
It is released into the duodenum as part of the pancreatic juice.
In the small intestine, it is activated into its active form, chymotrypsin, by the enzyme trypsin.

(D) The pancreas is a compound gland consisting of both exocrine and endocrine parts.
The exocrine part of the pancreas consists of lobules called acini (acinar cells).
These acinar cells secrete pancreatic enzymes,while the ductal cells of the pancreas secrete bicarbonate ions $(HCO_3^-)$ and water.
In the context of standard biology questions,the secretion of pancreatic juice (including bicarbonate) is primarily attributed to the acinar and ductal system of the pancreas.
Therefore,$D$ is the most appropriate answer among the given choices.

(B) The liver performs many vital functions,including deamination of amino acids,synthesis of plasma proteins (like albumin and fibrinogen),and storage of fat-soluble vitamins $(A, D, E, K)$.
However,the liver does not store bile. Bile is produced by the liver,but it is stored and concentrated in the gallbladder.

(C) Bile is produced by the liver cells (hepatocytes) and not by the gallbladder. The gallbladder only stores and concentrates the bile. Bile does not contain any enzymes; instead,it contains bile salts (like sodium glycocholate and sodium taurocholate) which are responsible for the emulsification of fats. Bile pigments (bilirubin and biliverdin) are waste products of hemoglobin breakdown and do not participate in fat digestion. Therefore,the statement that bile contains bile salts and bile pigments is correct.

(A) Glisson's capsule is a thin connective tissue sheath that covers the hepatic lobules,which are the structural and functional units of the liver.
Each hepatic lobule is covered by this thin connective tissue sheath known as Glisson's capsule.
Therefore,the correct answer is $A$ (Liver).

(A) The bile duct and the pancreatic duct open together into the duodenum as the common hepato-pancreatic duct. This duct is guarded by a sphincter called the sphincter of Oddi. The dilated portion where these ducts join before entering the duodenum is known as the Ampulla of Vater. Therefore,the common passage for both bile and pancreatic juice is the Ampulla of Vater.

(B) Bilirubin and biliverdin are bile pigments. They are produced by the breakdown of hemoglobin from old red blood cells in the liver. These pigments are excreted into the bile,which is stored in the gallbladder and released into the small intestine to aid in digestion. Therefore,they are present in bile.

(A) Trypsinogen is an inactive enzyme (zymogen) secreted by the exocrine cells of the pancreas.
It is released into the duodenum as part of the pancreatic juice.
Once in the small intestine,it is activated into its active form,trypsin,by the enzyme enterokinase,which is secreted by the intestinal mucosa.

(C) The gastric glands present in the stomach mucosa contain three major types of cells:
$1$. Mucus neck cells which secrete mucus.
$2$. Peptic or chief cells which secrete the proenzyme pepsinogen.
$3$. Parietal or oxyntic cells which secrete $HCl$ (hydrochloric acid) and intrinsic factor (essential for the absorption of vitamin $B_{12}$).
Therefore,the correct answer is $HCl$.

(C) Ptyalin,also known as salivary amylase,is an enzyme that begins the chemical digestion of starch into maltose and dextrin.
It is produced and secreted by the salivary glands (specifically the parotid,submandibular,and sublingual glands) into the oral cavity.
Therefore,the correct option is $C$.

(B) Pepsinogen is a proenzyme (inactive precursor) secreted by the chief cells (also known as peptic or zymogenic cells) located in the gastric glands of the stomach.
Upon coming into contact with hydrochloric acid $(HCl)$ in the stomach,pepsinogen is converted into its active form,pepsin,which is responsible for the digestion of proteins.

(C) Pepsinogen is a proenzyme (zymogen) secreted by the chief cells (also known as peptic or zymogenic cells) located in the gastric glands of the stomach.
Upon contact with hydrochloric acid $(HCl)$,pepsinogen is converted into its active form,pepsin,which is responsible for the digestion of proteins.

(A) : Paneth cells,present in the base of the 'Crypts of Lieberkuhn',are rich in zinc and contain acidophilic granules.
These cells are known to secrete antibacterial lysozyme,which helps in maintaining the intestinal flora.
Zymogen cells (or chief cells) are found in the stomach and secrete pepsinogen.
Kupffer cells are specialized macrophages found in the liver that perform phagocytosis.
Argentaffin cells,found in the 'Crypts of Lieberkuhn',are involved in the synthesis of hormones like secretin and $5$-hydroxytryptamine.

(C) The correct option is $C$.
Pancreatic juice is secreted by the pancreas and contains several inactive enzymes (proenzymes) and active enzymes.
The key components include:
$1$. Proenzymes: $Trypsinogen$,$Chymotrypsinogen$,and $Procarboxypeptidase$.
$2$. Active enzymes: Pancreatic $\alpha$-amylase,Pancreatic lipase,$DNase$,$RNase$,and $Elastase$.
$3$. Sodium bicarbonate: To neutralize stomach acid.
Option $C$ correctly lists Lipase,Amylase,Trypsinogen,and Procarboxypeptidase,which are all essential components of pancreatic juice. Pepsin and Rennin are gastric enzymes,and Maltase is an intestinal enzyme.

(D) : Parietal cells,also known as oxyntic cells,are large cells present on the side walls of the gastric glands.
They lie against the basement membrane.
They secrete hydrochloric acid $(HCl)$ and Castle's intrinsic factor,which is essential for the absorption of vitamin $B_{12}$ in the ileum.

(A) The secretion of the cells of the gastric glands forms gastric juice with a $pH$ of $2$ to $3.7$.
It contains two proenzymes,pepsinogen and prorennin (rennin),along with gastric lipase,mucus,and hydrochloric acid.
Rennin (chymosin) is responsible for clotting milk by acting on the soluble milk protein caseinogen and converting it into insoluble calcium paracaseinate (curd).
This ensures that milk remains in the stomach long enough to be acted upon by protein-digesting enzymes.
The concentration of rennin is highest in young mammals (as their primary diet is milk),which reduces gradually with age.

(C) is the incorrect statement.
Brunner's glands are located in the submucosa of the duodenum,not the stomach.
These glands secrete an alkaline,watery fluid containing mucus and some enzymes,which helps neutralize the acidic chyme entering from the stomach.
Pepsinogen is secreted by the chief cells (or peptic cells) located in the gastric glands of the stomach mucosa,not by Brunner's glands.

(A) The correct answer is $A$.
Pancreatic juice contains inactive proenzymes,including trypsinogen,chymotrypsinogen,and procarboxypeptidase.
These enzymes are secreted into the duodenum via the pancreatic duct.
Trypsinogen is an inactive precursor that is converted into active trypsin by the enzyme enterokinase,which is secreted by the intestinal mucosa.
Chymotrypsin and trypsin are the active forms,not the constituents of the pancreatic juice itself,as they are secreted in their inactive proenzyme forms.
Enterokinase is a component of the intestinal juice (succus entericus),not the pancreatic juice.

(C) The wall of the gut (alimentary canal) contains various types of glands.
Goblet cells are specialized unicellular glands found in the epithelial lining of the gut.
These cells are responsible for the secretion of mucus,which lubricates the gut lining and protects it from mechanical injury and chemical damage.
Peptic cells and oxyntic cells are multicellular components of gastric glands,while microvilli are cellular projections,not glands.

(C) The $Liver$ is the largest gland in the human body.
It is an accessory organ of the digestive system that performs various vital functions, including the production of bile, detoxification of blood, and metabolism of nutrients.
It weighs approximately $1.2$ to $1.5 \, kg$ in an adult human.

(C) The liver is the largest gland of the body,weighing about $1.2$ to $1.5 \ kg$ in an adult. It is situated in the abdominal cavity,just below the diaphragm,and has two lobes. The hepatic lobules are the structural and functional units of the liver containing hepatic cells arranged in the form of cords. Each lobule is covered by a thin connective tissue sheath called the Glisson's capsule. Therefore,the statement that 'Hepatic lobules are not the structural and functional unit of liver' is incorrect.

(C) The stomach lining contains gastric glands which consist of different types of cells:
$1$. $Mucus$ cells secrete mucus that protects the stomach lining.
$2$. $Chief$ cells (or peptic cells) secrete proenzymes like pepsinogen.
$3$. $Parietal$ cells (or oxyntic cells) are responsible for the secretion of $HCl$ (hydrochloric acid) and intrinsic factor,which is essential for the absorption of vitamin $B_{12}$.
$4$. $Goblet$ cells are primarily found in the intestine and secrete mucus.
Therefore,the correct answer is $Parietal$ cells.

(B) Ptyalin,also known as salivary amylase,is an enzyme that initiates the digestion of carbohydrates in the mouth.
It is secreted by the salivary glands,specifically the parotid,submandibular,and sublingual glands,into the oral cavity.
Therefore,the correct option is $B$.

(D) The stomach lining contains gastric glands which consist of different types of cells.
$1$. Oxyntic cells (also known as Parietal cells) are primarily responsible for the secretion of hydrochloric acid $(HCl)$ and intrinsic factor.
$2$. Peptic cells (or Chief cells) secrete proenzymes like pepsinogen.
$3$. Mucus neck cells secrete mucus which protects the stomach lining from the acidic environment.
Therefore,the correct answer is Oxyntic cells.

(B) The correct statement is that bile is stored and concentrated in the gall bladder.
$1$. The weight of the liver in an adult human is approximately $1.2$ to $1.5 \text{ kg}$,not $1.5$ to $1.8 \text{ kg}$.
$2$. The structural and functional units of the liver are hepatic lobules,not Langerhans cells (which are found in the pancreas).
$3$. Bile from the liver passes through the hepatic ducts,not the cystic duct (the cystic duct comes from the gall bladder).
$4$. Therefore,option $B$ is the only correct statement.

(A) The gastric glands in the stomach contain three major types of cells:
$1$. $Parietal$ or $Oxyntic$ cells: These cells are primarily responsible for the secretion of $HCl$ (hydrochloric acid) and $Intrinsic$ factor.
$2$. $Chief$ or $Peptic$ cells: These cells secrete proenzymes like $Pepsinogen$ and $Prorennin$.
$3$. $Mucous$ cells: These cells secrete mucus,which protects the stomach lining from the acidic environment.
Therefore,the correct answer is $Parietal$ cells.

(B) The $Liver$ is the largest gland of the human body.
It is an accessory digestive organ that performs many essential functions, including the production of bile, detoxification of blood, and metabolism of nutrients.
It weighs approximately $1.2$ to $1.5$ $kg$ in an adult human.

(B) The parotid glands are the largest salivary glands located in the cheeks.
The duct that carries saliva from the parotid gland into the oral cavity (specifically the vestibule near the second upper molar) is called Stensen's duct (or the parotid duct).
Therefore,the correct option is $B$.

(C) The human body has three pairs of salivary glands: the parotid,submandibular,and sublingual glands.
$1$. The parotid glands are the largest and their secretion is drained by Stensen's duct.
$2$. The submandibular (or submaxillary) glands are located below the jaw,and their secretion is drained by Wharton's duct.
$3$. The sublingual glands are the smallest and their secretion is drained by the ducts of Rivinus.
Therefore,Wharton's duct is associated with the submandibular salivary gland.

(D) Zymogen cells,also known as chief cells or peptic cells,are primarily located in the gastric glands of the fundic region of the stomach.
These cells are responsible for the secretion of proenzymes such as pepsinogen and prorennin,which are essential for protein digestion.
Therefore,the correct location is the fundic part of the stomach.

(D) The brown color of human feces is primarily due to the presence of stercobilin,a pigment derived from the breakdown of bilirubin. Bilirubin is a waste product produced by the liver and excreted into the bile. When the liver is dysfunctional or the bile duct is obstructed,bile cannot reach the intestine. Without bile,stercobilin is not formed,resulting in pale or grey-colored stools (acholic stools). Therefore,the dysfunction of the liver is the primary cause of this condition.

(C) The intestinal juice,also known as $succus$ $entericus$,contains a variety of enzymes including disaccharidases (e.g.,maltase,lactase,sucrase),dipeptidases,lipases,and nucleosidases.
Nucleases are enzymes that break down nucleic acids into nucleotides. These are primarily secreted by the pancreas into the small intestine,not by the intestinal mucosa itself.
Therefore,nucleases are not a component of the intestinal juice.

(A) The stomach lining contains gastric glands.
$1$. Parietal cells (also known as oxyntic cells) are responsible for the secretion of hydrochloric acid $(HCl)$ and intrinsic factor.
$2$. Peptic cells (also known as chief cells or zymogenic cells) secrete proenzymes like pepsinogen.
$3$. Therefore,the acidic nature of gastric juice is primarily due to the $HCl$ secreted by the parietal cells.

(B) The Crypts of Lieberkühn are tubular glands found at the base of the villi in the small intestine.
These crypts contain specialized cells known as $Paneth$ cells.
$Paneth$ cells are located at the base of the crypts and are responsible for secreting antimicrobial peptides,including lysozyme,which helps in protecting the intestinal lining from bacterial infection.

(D) Pancreatic juice contains inactive enzymes (proenzymes) and active enzymes that are essential for digestion in the small intestine.
$1$. $Trypsinogen$ is an inactive precursor activated to $trypsin$.
$2$. $Procarboxypeptidase$ is an inactive precursor activated to $carboxypeptidase$.
$3$. $Amylase$ (pancreatic amylase) acts on carbohydrates.
$4$. $Lipase$ (steapsin) acts on fats.
Options $A$,$B$,and $C$ contain enzymes like $pepsin$ (gastric juice),$rennin$ (gastric juice),or $maltase$ (intestinal juice),which are not components of pancreatic juice. Therefore,option $D$ is the correct composition.

(B) The $Parietal$ cells (also known as $Oxyntic$ cells) present in the gastric glands secrete $Intrinsic$ $Factor$ ($Castle's$ $Intrinsic$ $Factor$).
This factor is essential for the absorption of $Vitamin$ $B_{12}$ in the ileum of the small intestine.
$Vitamin$ $B_{12}$ is a crucial co-factor required for the maturation of red blood cells $(RBCs)$ in the bone marrow.
Therefore,by facilitating the absorption of $Vitamin$ $B_{12}$,$Parietal$ cells indirectly support the process of erythropoiesis.

(B) The gastro-intestinal tract lining is protected from the corrosive action of digestive enzymes and acidic gastric juice by a thick layer of mucus.
This mucus is secreted by the $Goblet$ $Cells$,which are specialized glandular epithelial cells found in the mucosal epithelium of the gastro-intestinal tract.
$Chief$ $Cells$ (or $Peptic$ $Cells$) secrete proenzymes like $pepsinogen$.
$Oxyntic$ $Cells$ (or $Parietal$ $Cells$) secrete $HCl$ and $Intrinsic$ $Factor$.
Therefore,the correct option is $B$.

(A) Oxyntic cells,also known as Parietal cells,are found in the stomach epithelium and secrete hydrochloric acid $(HCl)$ and intrinsic factor. The secretion of $HCl$ makes the gastric juice acidic,typically maintaining a $pH$ between $2.0$ and $3.0$.
Alpha cells of the Islets of Langerhans secrete glucagon,which increases blood glucose levels,not decreases them (insulin decreases blood sugar).
Kupffer cells are specialized macrophages in the liver that perform phagocytosis to destroy bacteria and worn-out blood cells,not digestive enzymes.
Sebaceous glands are skin glands that secrete sebum (an oily substance) to lubricate the skin and hair,not digestive enzymes.

(A) Oxyntic cells,also known as parietal cells,are located in the gastric glands of the stomach.
These cells are responsible for the secretion of hydrochloric acid $(HCl)$ and intrinsic factor.
The secretion of $HCl$ results in a highly acidic environment in the stomach,typically maintaining a $pH$ between $2.0$ and $3.0$.
Therefore,the pair of oxyntic cells and their secretion is correctly matched.

(B) There are three pairs of salivary glands in humans.
$1$. Parotid glands: These are the largest salivary glands and are located below the cheeks,near the ears.
$2$. Submaxillary or submandibular glands: These are located in the angle between the two jaws.
$3$. Sublingual glands: These are located below the tongue.

(B) The liver is the largest internal organ of the human body.
It performs several vital functions,including the secretion of bile,which is essential for the emulsification of fats.
Bile helps in breaking down large fat globules into smaller droplets,increasing the surface area for the action of lipase enzymes.
Additionally,the liver is involved in metabolic processes,detoxification,and the storage of glycogen.

(N/A) The main salivary glands are of three types: $(i)$ Parotid gland,$(ii)$ Submandibular gland,and $(iii)$ Sublingual gland.
$(i)$ Parotid gland: This is the largest salivary gland. It is located just below and in front of the ear.
$(ii)$ Submandibular gland: These are located at the angle of the lower jaw (submaxillary).
$(iii)$ Sublingual gland: These are the smallest glands,located beneath the tongue.
These glands are situated just outside the buccal cavity and secrete salivary juice into the buccal cavity.