Digestive glands Questions in English

(B) . Each liver lobe is formed of hexagonal lobules surrounded by a connective tissue sheath called Glisson's capsule.

(B) The fundic part of the stomach consists of $2$ types of cells: chief or zymogenic cells,which secrete pepsinogen,and oxyntic or parietal cells,which secrete $HCl$ and intrinsic factor. Therefore,$HCl$ is secreted by oxyntic cells.

(C) Chief cells (also known as Zymogen cells or Peptic cells) are primarily located in the basal region of the gastric glands in the stomach. These cells are responsible for the secretion of proenzymes like pepsinogen and prorennin,which are essential components of gastric juice.

(A) The gastric glands in the stomach contain different types of cells.
$1$. Chief cells (also known as peptic or zymogenic cells) are responsible for secreting proenzymes like pepsinogen and prorennin.
$2$. Parietal cells (or oxyntic cells) secrete $HCl$ and intrinsic factor.
$3$. Mucous cells secrete mucus.
Alpha cells,Beta cells,and Islets of Langerhans are components of the pancreas,not the stomach.
Therefore,the correct option is $A$.

(A) Pepsinogen is secreted by the $Chief$ cells,also known as $pepsinogenic$ or $zymogenic$ cells.
These cells are primarily located in the fundic part of the stomach.
They secrete inactive proenzymes like pepsinogen and prorennin,which are later activated in the presence of $HCl$.

(B) The intestinal glands,known as the Crypts of Lieberkuhn,are located between the bases of the villi in the small intestine.
These glands are responsible for secreting the intestinal juice,which is also referred to as $Succus \ entericus$.
$Succus \ entericus$ contains various enzymes such as disaccharidases,dipeptidases,lipases,and nucleosidases that help in the final digestion of food components.

(B) The $Sphincter$ $of$ $Oddi$ (also known as the hepatopancreatic sphincter) guards the opening of the common bile duct and the pancreatic duct into the duodenum.
The $Sphincter$ $of$ $Boyden$ is a sphincter muscle located at the junction of the common bile duct and the pancreatic duct,just before they enter the duodenum.
Both these sphincters are associated with the biliary system and the flow of bile and pancreatic juice into the small intestine,which originates from the liver and pancreas. Among the given options,the liver is the primary organ responsible for bile production,which is regulated by these structures.

(A) The wall of the duodenum contains intestinal glands known as crypts of Lieberkühn and characteristic duodenal glands,also known as Brunner's glands.
These glands are located in the submucosa of the duodenum.
They secrete an alkaline mucus that helps neutralize the acidic chyme coming from the stomach and protects the duodenal mucosa from acid damage.

(B) The correct answer is $B$. Pancreatic juice is a rich source of lipase,which is an enzyme responsible for the digestion of fats.
Lipase acts on emulsified fats and converts them into fatty acids and glycerol.
While gastric juice contains small amounts of gastric lipase,pancreatic lipase is the primary enzyme responsible for the majority of lipid digestion in the small intestine.

(C) Liver sinusoids are specialized blood capillaries found in the liver lobules.
These sinusoids are lined by a discontinuous layer of endothelial cells and contain specialized phagocytic cells known as $Kupffer$ cells.
$Kupffer$ cells are macrophages that play a crucial role in the immune defense of the liver by removing debris and pathogens from the blood.

(B) The parotid glands are the largest pair of salivary glands. They are situated just below and in front of the ear $(pinna)$.

(B) The pancreas contains exocrine acinar cells,which are often described as having a pear-like or pyramidal shape. These cells are responsible for synthesizing and storing digestive enzymes in the form of inactive precursors known as zymogen granules. These granules are released into the pancreatic ducts to aid in digestion.

(C) Pancreatic juice is often referred to as the complete digestive juice because it contains enzymes capable of digesting all major food components.
It contains inactive enzymes like trypsinogen (which is converted to trypsin) and chymotrypsinogen (which is converted to chymotrypsin),along with pancreatic amylase and lipase.
Trypsin and chymotrypsin digest proteins,pancreatic amylase digests carbohydrates,and lipase digests fats.
Therefore,the correct option is $C$.

(D) Bile is a digestive juice produced by the $Liver$.
It is then stored and concentrated in the $Gall$ $bladder$ before being released into the small intestine to aid in the digestion of fats.
Therefore, the correct option is $D$.

(D) The liver plays a crucial role in the storage of various fat-soluble and water-soluble vitamins.
Specifically,the liver cells (hepatocytes) are capable of synthesizing Vitamin $A$ from its precursor,carotene.
Furthermore,the liver acts as a primary storage site for Vitamin $A$,Vitamin $D$,and Vitamin $B_{12}$ in the human body.
Therefore,all the given options are correct.

(C) Argentaffin cells,also known as enterochromaffin cells,are specialized endocrine cells found in the epithelium of the gastrointestinal tract. They are primarily located at the base of the gastric glands in the stomach. These cells are responsible for secreting serotonin ($5$-hydroxytryptamine),which plays a crucial role in regulating gastrointestinal motility and secretion.

(A) The pancreas secretes various digestive enzymes,including trypsin,carboxypeptidase,and ribonuclease,which are released into the small intestine to aid in digestion.
Pepsin is a proteolytic enzyme secreted by the chief cells of the stomach lining in the form of an inactive precursor called pepsinogen. Therefore,it is not secreted by the pancreas.

(B) The salivary amylase,also known as ptyalin,functions optimally at a slightly acidic $pH$ of approximately $6.8$.
This enzyme is secreted by the salivary glands and initiates the chemical digestion of starch into maltose within the oral cavity.

(A) 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,which include the parotid,submandibular,and sublingual glands.
Therefore,the correct option is $A$.

(B) The presence of $Glisson's$ capsule is a characteristic feature of the mammalian liver.
It is a thin layer of dense connective tissue that covers the liver.
Each liver lobe is composed of a number of smaller hepatic lobules,which are separated from one another by the $Glisson's$ capsule.

(A) Saliva is produced by the salivary glands located in the oral cavity.
These include the parotid,submaxillary (submandibular),and sublingual glands.
Therefore,the submaxillary and sublingual glands are responsible for secreting saliva.

(B) The correct answer is $B$. Humans possess $3$ pairs of salivary glands,which are the parotid,submandibular,and sublingual glands.
These glands secrete saliva,which contains the enzyme salivary amylase (ptyalin) that participates in the digestion of starch.

(A) $Ptyalin$ (also known as salivary amylase) is an enzyme found in the saliva.
It is secreted by the salivary glands and is a key component of salivary juice.
It initiates the process of carbohydrate digestion in the mouth by breaking down starch into maltose.

(B) The enzymes responsible for starch digestion are salivary amylase (ptyalin) and pancreatic amylase.
Salivary amylase is secreted by the salivary glands into the oral cavity.
Pancreatic amylase is secreted by the pancreas into the small intestine (duodenum).
Therefore,these enzymes are present in the salivary and pancreatic secretions.

(C) The trypsin enzyme is a proteolytic enzyme present in the pancreatic juice,which is secreted by the pancreas. It is secreted in an inactive form called trypsinogen,which is later activated in the small intestine.

(D) The human body has three pairs of salivary glands:
$1$. Parotid glands: These are the largest salivary glands located near the ears. They drain their secretions into the oral cavity via the duct of Stensen (or Stensen's duct).
$2$. Submaxillary (or submandibular) glands: These are located below the jaw. They drain their secretions via Wharton's duct.
$3$. Sublingual glands: These are the smallest salivary glands located under the tongue. They drain their secretions via the ducts of Rivinus (or Bartholin's ducts).
Therefore,the correct pairing is: Parotid $\to$ duct of Stensen; submaxillary $\to$ Wharton's duct; sublingual $\to$ duct of Rivinus.

(A) The liver is the largest gland in the human body and it secretes bile juice.
In a healthy adult,the liver produces approximately $700 \, ml$ to $1000 \, ml$ of bile juice daily.
Among the given options,$700 \, ml$ is the most accurate value representing the daily secretion of bile juice.

(B) The bile produced by the liver cells is transported to the gall bladder for storage and concentration via the $Cystic \ duct$.
$1$. The $Hepatic \ duct$ carries bile from the liver.
$2$. The $Cystic \ duct$ connects the gall bladder to the common hepatic duct.
$3$. Therefore,bile enters the gall bladder through the $Cystic \ duct$.

(D) The human salivary glands consist of three pairs: the Parotid,Submaxillary (also known as Submandibular),and Sublingual glands.
$Infra-orbital$ glands are not present in humans; they are found in other mammals such as rabbits.
Therefore,the correct option is $D$.

(B) The correct match is $B$.
$1$. Pituitary gland secretes hormones like growth hormone,$TSH$,$ACTH$,etc.,not thyroxin (which is secreted by the thyroid gland).
$2$. Salivary glands secrete salivary amylase (ptyalin),which helps in the digestion of starch.
$3$. Adrenal cortex secretes glucocorticoids and mineralocorticoids,not vasopressin (which is secreted by the posterior pituitary).
$4$. Islets of Langerhans secrete insulin and glucagon,not secretin (which is secreted by the duodenum).

(A) Gastric juice is secreted by the gastric glands located in the stomach lining.
It primarily contains proenzymes like pepsinogen (which is converted to pepsin) and prorennin (which is converted to rennin),along with small amounts of gastric lipase.
Amylase is primarily found in saliva and pancreatic juice,while trypsin is a component of pancreatic juice.
Therefore,the correct composition of gastric juice among the given options is pepsin,rennin,and lipase.

(D) Amylolytic enzymes,such as salivary amylase and pancreatic amylase,are responsible for the breakdown of starch into simpler sugars.
Salivary amylase is secreted by the salivary glands into the oral cavity.
Pancreatic amylase is secreted by the pancreas into the small intestine.
Therefore,the correct answer is $D$.

(B) The liver is an accessory digestive gland that develops from the embryonic endoderm layer. During embryonic development,the liver bud emerges from the foregut endoderm. Therefore,from the point of ontogeny,the liver is endodermal in origin.

(D) Succus entericus,also known as intestinal juice,is the collective term for the secretions of the intestinal mucosal epithelial cells.
It is primarily secreted by the Crypts of Lieberkuhn and Brunner's glands located in the small intestine.
These secretions contain various enzymes such as disaccharidases,dipeptidases,lipases,and nucleosidases that complete the final stages of digestion.

(B) The pancreatic juice is an alkaline secretion produced by the pancreas. It contains various digestive enzymes and bicarbonate ions. The bicarbonate ions help in neutralizing the acidic chyme coming from the stomach into the small intestine. The $pH$ of the pancreatic juice is typically around $8.4$.

(B) The liver plays a crucial role in carbohydrate metabolism. It performs both glycogenesis (conversion of glucose to glycogen) and glycogenolysis (breakdown of glycogen into glucose) to maintain blood glucose levels. While other organs are involved in excretion,digestion,or histolysis,these specific metabolic processes are primary functions of the liver.

(D) The $Liver$ does not produce any digestive enzymes.
It produces bile juice, which contains bile salts and bile pigments.
Bile juice is essential for the emulsification of fats, which increases the surface area for the action of lipase, but it does not contain any enzymes itself.
In contrast, the intestinal mucosa, gastric mucosa, and pancreas all secrete various digestive enzymes (such as peptidases, pepsin, and pancreatic amylase/lipase/proteases, respectively).

(A) The gall bladder is a small,pear-shaped organ located under the liver.
Its primary function is to store and concentrate the bile produced by the liver.
Bile is not produced in the gall bladder; it is synthesized in the liver and then transported to the gall bladder for storage until it is needed for the digestion of fats in the small intestine.

(B) The $Duct$ of $Wirsung$ (also known as the main pancreatic duct) is the primary duct of the pancreas.
It joins with the common bile duct to form the hepatopancreatic ampulla,which opens into the duodenum.
Additionally,the accessory pancreatic duct is known as the $Duct$ of $Santorini$.

(A) The liver is anatomically divided into two main lobes: the right lobe and the left lobe. The right lobe is significantly larger,comprising about $\frac{5}{6}$ of the total liver mass,while the left lobe is smaller and occupies approximately $\frac{1}{6}$ of the liver mass. Therefore,the left lobe accounts for about $\frac{1}{6}$ of the liver.

(C) portal triad is a characteristic arrangement found in the liver lobules.
It consists of three primary structures located at the corners of the hexagonal hepatic lobules:
$1.$ $A$ branch of the hepatic portal vein.
$2.$ $A$ branch of the hepatic artery.
$3.$ $A$ branch of the bile duct (interlobular bile ductule).
Therefore,the correct combination is $1, 2,$ and $3$.

(A) The structural and functional unit of the liver is the hepatic lobule. Within these lobules, hepatocytes are arranged in the form of cords, which are often referred to as hepatic cords or cords of hepatocytes. Therefore, the hepatic lobule is the correct answer.

(C) The hepatic sinusoids are specialized blood vessels located within the liver lobules.
They receive blood from both the hepatic portal vein (carrying nutrient-rich blood from the digestive tract) and the hepatic artery (carrying oxygenated blood).
These two vessels merge to form the sinusoids,which then drain into the central vein of the liver lobule.
Therefore,the hepatic sinusoids are branches or continuations of both the portal vein and the hepatic artery.

(D) The liver does not manufacture digestive enzymes like $Diastase$,$Amylase$,or $Lipase$. These enzymes are produced by the salivary glands,pancreas,and small intestine. The liver primarily produces bile,which contains bile salts that emulsify fats,but it does not secrete digestive enzymes into the alimentary canal.

(A) The correct matches are as follows:
$A.$ Stensen's duct is the duct of the parotid gland $(3)$.
$B.$ Ducts of Rivinus are the ducts of the sublingual gland $(4)$.
$C.$ Duct of Wirsung is the main pancreatic duct $(5)$.
$D.$ Ductus choledochus is the common bile duct $(6)$.
$E.$ Wharton's duct is the duct of the submaxillary (submandibular) gland $(7)$.
$F.$ Cystic duct is the duct from the gall bladder $(1)$.
$G.$ Hepatic duct is the duct from the liver $(2)$.
Therefore,the correct sequence is $3, 4, 5, 6, 7, 1, 2$.

(B) Kupffer cells,also known as stellate macrophages,are specialized phagocytic cells located in the liver.
They are attached to the luminal surface of the hepatic sinusoids.
These cells play a critical role in maintaining liver homeostasis by clearing pathogens,debris,and aged red blood cells from the blood circulation.

(A) The liver is the largest gland in the human body.
It is an accessory digestive organ that produces bile,which is essential for the digestion of fats.
It weighs approximately $1.2$ to $1.5 \ kg$ in an adult human.

(B) Goblet cells are specialized glandular epithelial cells found in the mucosal lining of the digestive and respiratory tracts.
Their primary function is the secretion of mucin,which is a glycoprotein.
When mucin is released,it hydrates to form mucus,a viscous substance that protects the lining of the organs from mechanical injury,chemical damage,and pathogens.
Therefore,the correct function of goblet cells is the production of mucin.

(C) . Bile does not contain any digestive enzymes. Since enzymes are proteins,bile lacks proteins that act on food for digestion. It primarily consists of bile salts,bile pigments,cholesterol,and phospholipids,which aid in the emulsification of fats.

(B) Bilirubin and biliverdin are bile pigments.
They are synthesized in the liver from the breakdown of hemoglobin and are secreted into the bile juice.
Therefore,they are found in the bile.