Hormones Of Heart, Kidney And Gastrointestinal Tract Questions in English

(C) When an animal is anaemic,the oxygen-carrying capacity of the blood decreases,leading to tissue hypoxia.
In response to low oxygen levels,the kidneys release a hormone called erythropoietin.
Erythropoietin stimulates the bone marrow to increase the production of red blood cells (erythropoiesis) to restore oxygen levels in the blood.

(C) $Erythropoietin$ is a peptide hormone secreted by the juxtaglomerular cells of the kidney. It plays a crucial role in the regulation of $erythropoiesis$,which is the process of red blood cell production in the bone marrow.

(A) Prostaglandins are a group of lipid compounds that have diverse hormone-like effects in animals.
Specifically,certain prostaglandins and their derivatives,such as prostacyclins,play a crucial role in regulating blood pressure by causing vasodilation or vasoconstriction.
Thromboxanes,which are related to prostaglandins,are synthesized in platelets and,upon release,cause vasoconstriction and platelet aggregation.
Therefore,they are significantly involved in the regulation of blood pressure and cardiovascular function.

(C) The correct answer is $C$. The $X$ cranial nerve,also known as the Vagus nerve,plays a crucial role in regulating visceral functions. It controls visceral sensations and movements,including peristalsis,sound production,respiratory movements,and the regulation of the heartbeat by slowing it down.

(A) Secretin is a peptide hormone produced by the $S$-cells of the duodenum in the small intestine.
It is released into the bloodstream in response to acidic chyme entering the duodenum from the stomach.
Its primary function is to stimulate the pancreas to secrete bicarbonate-rich pancreatic juice,which neutralizes the acidity of the chyme.
Therefore,the correct option is $A$.

(C) Secretin is a hormone produced by the $S$-cells of the duodenum,which are endocrine cells located in the gastrointestinal mucosa.
It is released into the bloodstream and acts on the pancreas (an exocrine gland) to stimulate the secretion of bicarbonate-rich pancreatic juice.
Therefore,it is secreted from an endocrine gland and acts on an exocrine gland.

(A) The gastrointestinal tract secretes several hormones that regulate digestive processes.
$1$. Cholecystokinin $(CCK)$ is secreted by the duodenal mucosa and acts on the gall bladder to stimulate the contraction and release of bile.
$2$. Secretin is also secreted by the duodenal mucosa and acts on the exocrine pancreas to stimulate the secretion of water and bicarbonate ions.
Therefore,these are hormones liberated by the mucosa of the duodenum that stimulate the gall bladder and pancreas respectively.

(B) The question describes the definition of a hormone.
$1$. Hormones are non-nutrient chemicals which act as intercellular messengers and are produced in trace amounts.
$2$. They are secreted by endocrine glands and are released directly into the blood to act on target organs located away from the site of production.
$3$. Among the given options,$Renin$ is an enzyme secreted by the juxtaglomerular cells of the kidney,but it acts as a hormone in the context of the Renin-Angiotensin-Aldosterone System $(RAAS)$ to regulate blood pressure.
$4$. $Rennin$ is a digestive enzyme,$Cholesterol$ is a lipid,and $Cholesterase$ is an enzyme.
$5$. Therefore,$Renin$ is the correct answer as it functions as a hormone.

(C) The kidney acts as an endocrine organ and secretes a peptide hormone called $Erythropoietin$.
$Erythropoietin$ is produced by the juxtaglomerular cells of the kidney in response to hypoxia (low oxygen levels in the blood).
It stimulates the bone marrow to increase the production of red blood cells $(RBCs)$,a process known as erythropoiesis.
Gastrin is secreted by the stomach,Secretin by the small intestine,and Aldosterone by the adrenal cortex.

(A) When there is an increase in blood flow to the atria of the heart,the atrial walls are stretched.
This stretching stimulates the release of Atrial Natriuretic Factor $(ANF)$ from the atrial wall.
$ANF$ acts as a vasodilator (dilates blood vessels) and promotes the excretion of sodium and water,thereby decreasing blood pressure.

(B) Secretin is a peptide hormone produced by the $S$-cells of the duodenum in response to low $pH$ (acidic chyme) entering the small intestine.
Its primary functions include:
$1$. Stimulation of the pancreas to secrete water and bicarbonate ions $(HCO_3^-)$ into the duodenum to neutralize the acidic chyme.
$2$. Inhibition of gastric acid secretion (gastrin release) from the stomach to prevent further acidification.
$3$. Stimulation of the liver to increase bile production.
Therefore,option $B$ is the most accurate description of its physiological roles.

(B) The $Vagus$ nerve (Cranial nerve $X$) is a major component of the parasympathetic nervous system.
It stimulates the secretion of gastric juices,including hydrochloric acid $(HCl)$ and pepsin,in the stomach.
Excessive stimulation of the $Vagus$ nerve leads to hypersecretion of gastric acid.
This persistent high acidity can erode the stomach lining,eventually leading to the formation of gastric ulcers.

(B) The wall of the atria of the heart secretes a very important peptide hormone called Atrial Natriuretic Factor $(ANF)$.
When blood pressure increases,$ANF$ is secreted,which causes dilation of the blood vessels (vasodilation).
This vasodilation results in a reduction of blood pressure.
Therefore,$ANF$ acts as an antagonist to the Renin-Angiotensin mechanism,which increases blood pressure.

(D) The $A$ (Duodenal epithelium) secretes hormones like secretin,cholecystokinin,and gastric inhibitory peptide.
The $B$ (Testis) secretes androgenic hormones like testosterone.
The $C$ (Adrenal medulla) secretes catecholamines like adrenaline and noradrenaline.
The $D$ (Submaxillary gland) is a salivary gland that secretes saliva containing enzymes like salivary amylase,but it does not have an endocrine function to secrete hormones.

(C) The first hormone to be discovered was $Secretin$. It was identified by $William \text{ } Bayliss$ and $Ernest \text{ } Starling$ in $1902$. They observed that the presence of acid in the duodenum triggered the release of a substance into the blood that stimulated the pancreas to secrete digestive juices.

(D) The kidneys function as endocrine organs in addition to their excretory role.
$1$. Renin: Secreted by the juxtaglomerular cells of the kidney,it plays a crucial role in the renin-angiotensin-aldosterone system $(RAAS)$ to regulate blood pressure.
$2$. Renomedullary prostaglandin: These are produced in the renal medulla and help in regulating renal blood flow and sodium excretion.
$3$. Erythropoietin: Secreted by the peritubular interstitial cells of the kidney,it stimulates the production of red blood cells (erythropoiesis) in the bone marrow in response to hypoxia.
Therefore,all the listed hormones are secreted by the kidney.

(D) Renin is a proteolytic enzyme secreted by the juxtaglomerular cells of the kidney. It acts as an enzyme by converting angiotensinogen in the blood into angiotensin $I$. However,it is also classified as a hormone because it is secreted into the bloodstream to regulate blood pressure and fluid balance as part of the Renin-Angiotensin-Aldosterone System $(RAAS)$.

(D) The correct answer is $D$.
$CCK$ (Cholecystokinin) stimulates the secretion of pancreatic enzymes and bile juice,rather than inhibiting them.
$JG$ (Juxtaglomerular) cells in the kidney produce the hormone erythropoietin,which stimulates red blood cell production.
Gastrin acts on the gastric glands and stimulates the secretion of hydrochloric acid and pepsinogen.
Secretin acts on the exocrine pancreas and stimulates the secretion of water and bicarbonate ions.

(A) The wall of the atria of the heart secretes a peptide hormone called Atrial Natriuretic Factor $(ANF)$.
This hormone is released in response to an increase in blood volume or blood pressure.
$ANF$ acts as a vasodilator and helps in decreasing blood pressure by promoting the excretion of sodium and water in the urine.

(B) Secretin is a peptide hormone produced by the $S$-cells of the duodenum,which is the first part of the small intestine.
It is released into the bloodstream in response to the acidity of the chyme entering the duodenum from the stomach.
Its primary function is to stimulate the pancreas to secrete bicarbonate-rich pancreatic juice,which helps neutralize the acidic chyme.

(N/A) Hormones are also secreted by tissues that are not classified as endocrine glands.
$1$. Heart: The atrial wall of the heart secretes a peptide hormone called Atrial Natriuretic Factor $(ANF)$. It functions to decrease blood pressure by causing the dilation of blood vessels when blood pressure is elevated.
$2$. Kidney: The juxtaglomerular cells of the kidney produce a peptide hormone called erythropoietin,which stimulates erythropoiesis (the formation of $RBCs$).
$3$. $GI$ Tract: The gastrointestinal tract contains endocrine cells that secrete four major peptide hormones:
- Gastrin: Stimulates the secretion of hydrochloric acid $(HCl)$ and pepsinogen.
- Secretin: Acts on the exocrine pancreas to stimulate the secretion of water and bicarbonate ions.
- Cholecystokinin $(CCK)$: Acts on the pancreas and gallbladder to stimulate the secretion of pancreatic enzymes and bile juice.
- Gastric Inhibitory Peptide $(GIP)$: Inhibits gastric secretion and motility.
Additionally,several non-endocrine tissues secrete growth factors,which are essential for normal tissue growth,repair,and regeneration.

(B) The function of $ANF$ (Atrial Natriuretic Factor) is to decrease blood pressure.
When blood pressure increases,the atrial wall of the heart secretes $ANF$.
$ANF$ causes vasodilation (dilation of blood vessels),which reduces the resistance to blood flow and consequently lowers the blood pressure.

(D) The Juxtaglomerular cells of the kidney produce a peptide hormone called erythropoietin.
This hormone is responsible for stimulating erythropoiesis,which is the process of $RBC$ formation in the bone marrow.

(B) Enterogastrone is a gastrointestinal hormone produced by the small intestine that inhibits the secretion of gastric juice. Prolactin is a pituitary hormone involved in milk production. $GH$ (Growth Hormone) is secreted by the anterior pituitary. $FSH$ (Follicle Stimulating Hormone) is a gonadotropin secreted by the anterior pituitary.

(D) The atrial wall of our heart secretes a very important peptide hormone called Atrial Natriuretic Factor $(ANF)$,which is peptide in nature.
$ANF$ functions to decrease blood pressure $(BP)$.
When blood pressure is increased,$ANF$ is secreted by the atrial wall.
This hormone causes vasodilation (dilation of the blood vessels),which reduces the blood pressure back to normal levels.
Therefore,all the given statements are correct.

(D) The four major hormones of the $GI$ tract are:
$(i)$ Gastrin: Acts on gastric glands and stimulates the secretion of $HCl$ and pepsinogen.
$(ii)$ Secretin: Acts on the exocrine pancreas and stimulates the secretion of water and bicarbonate ions.
$(iii)$ $CCK$ (Cholecystokinin): Acts on both the pancreas and gall bladder and stimulates the secretion of pancreatic enzymes and bile juice.
$(iv)$ $GIP$ (Gastric Inhibitory Peptide): Inhibits gastric secretion and motility.
Therefore,the correct combination is $I, II, III$ and $VI$.

(D) Cholecystokinin $(CCK)$ is a peptide hormone secreted by the endocrine cells in the gastrointestinal tract.
It acts on both the pancreas and the gall bladder.
$CCK$ stimulates the pancreas to secrete pancreatic enzymes and the gall bladder to release bile juice.
Therefore,the pair 'Cholecystokinin - stimulates pancreatic enzyme secretions' is correctly matched.

(B) Atrial Natriuretic Factor $(ANF)$ is a peptide hormone secreted by the atrial wall of the heart in response to increased blood flow or blood pressure.
It acts as a vasodilator and helps in the regulation of blood pressure by promoting the excretion of sodium and water.

(D) The Atrial Natriuretic Factor $(ANF)$ is a peptide hormone secreted by the atrial walls of the heart.
When blood pressure increases,the increased blood flow to the atria triggers the release of $ANF$.
$ANF$ acts as a vasodilator (dilates blood vessels) and promotes the excretion of sodium and water,thereby reducing blood pressure.
Therefore,all the given statements are correct.

(C) In addition to the endocrine glands, several other organs in the human body produce hormones.
$1$. The Heart produces Atrial Natriuretic Factor $(ANF)$, which decreases blood pressure.
$2$. The Kidney produces Erythropoietin, which stimulates red blood cell formation.
$3$. The Gastrointestinal tract produces several hormones like Gastrin, Secretin, Cholecystokinin $(CCK)$, and Gastric Inhibitory Peptide $(GIP)$.
$4$. The Liver produces hormones like Insulin-like Growth Factor $(IGF-1)$ or Somatomedin.
Therefore, all the organs mentioned in options $A$ and $B$ are capable of producing hormones.

(D) An antagonistic effect occurs when two hormones have opposing actions on a physiological process.
Gastrin is a hormone that stimulates the secretion of hydrochloric acid $(HCl)$ and pepsinogen in the stomach.
$GIP$ (Gastric Inhibitory Peptide) is a hormone that inhibits gastric secretion and motility.
Therefore,Gastrin and $GIP$ act antagonistically to regulate gastric function.

(C) The $Atrial Natriuretic Factor (ANF)$ is secreted by the atrial wall of the heart. The heart is not an endocrine gland, but it performs an endocrine function by secreting this hormone in response to increased blood pressure. $GH$ (Growth Hormone) is secreted by the anterior pituitary, Testosterone by the testes, and Estrogen by the ovaries, all of which are endocrine or reproductive structures with endocrine functions.

(B) $Secretin$ is a peptide hormone produced by the $S$-cells of the duodenum in the small intestine.
Its primary function is to stimulate the pancreas to secrete a bicarbonate-rich fluid into the duodenum to neutralize acidic chyme.
Therefore,the target cells for $Secretin$ are the ductal cells of the pancreas,where its specific receptors are located.

(D) The correct matching is as follows:
$1$. Heart: The atrial wall of the heart secretes a peptide hormone called Atrial Natriuretic Factor $(ANF)$,which decreases blood pressure.
$2$. Kidney: The juxtaglomerular cells of the kidney produce a peptide hormone called Erythropoietin,which stimulates erythropoiesis (formation of red blood cells).
$3$. Gastro-intestinal tract: The gastro-intestinal mucosa secretes several peptide hormones such as Gastrin,Secretin,Cholecystokinin $(CCK)$,and Gastric Inhibitory Peptide $(GIP)$.
$4$. Adrenal Cortex: The adrenal cortex secretes steroid hormones,including glucocorticoids and mineralocorticoids like Aldosterone.
Therefore,the correct match is $A-III, B-I, C-IV, D-II$.

(C) Let's analyze each statement:
$A.$ Erythropoietin is indeed produced by the juxtaglomerular cells of the kidney. This is a correct statement.
$B.$ Leydig cells (interstitial cells) in the testes produce androgens,primarily testosterone. This is a correct statement.
$C.$ Atrial Natriuretic Factor $(ANF)$ is secreted by the atrial wall of the heart,not the seminiferous tubules. This is an incorrect statement.
$D.$ Cholecystokinin $(CCK)$ is produced by the gastro-intestinal tract (specifically the duodenum). This is a correct statement.
$E.$ Gastrin acts on the gastric glands to stimulate the secretion of hydrochloric acid and pepsinogen,not the intestinal wall. This is an incorrect statement.
Therefore,the wrong statements are $C$ and $E$.

(C) The wall of the atria of the heart secretes a peptide hormone called Atrial Natriuretic Factor $(ANF)$ in response to an increase in blood pressure.
$ANF$ causes dilation of the blood vessels (vasodilation),which reduces the blood pressure.
Therefore,$ANF$ acts as a counter-regulatory mechanism to the Renin-Angiotensin system.

(D) $ANF$ stands for Atrial Natriuretic Factor.
It is a peptide hormone secreted by the atrial wall of the heart.
Its primary function is to decrease blood pressure by causing vasodilation and promoting the excretion of sodium and water by the kidneys.

(D) The kidney produces a hormone called $1,25$-dihydroxycholecalciferol,also known as $Calcitriol$ (the active form of Vitamin $D$).
Calcitriol plays a crucial role in the absorption of calcium from the gastrointestinal tract and its deposition in bones.
$A$ deficiency of Calcitriol leads to reduced calcium absorption,resulting in weak or brittle bones.
Therefore,the correct option is $D$.

(B) $ANF$ (Atrial Natriuretic Factor) is a peptide hormone secreted by the atrial wall of the heart in response to increased blood flow or blood pressure.
Its primary functions include:
$1$. Vasodilation: It causes the dilation of blood vessels,which helps in reducing blood pressure.
$2$. Promotion of sodium excretion: It increases the excretion of sodium ions in the urine,which leads to a decrease in blood volume.
$3$. Inhibition of the renin-angiotensin mechanism: It inhibits the release of renin from the juxtaglomerular apparatus,thereby counteracting the effects of the renin-angiotensin-aldosterone system.
Vasoconstriction is the opposite of the effect produced by $ANF$. Therefore,$ANF$ does not cause vasoconstriction.

(B) The kidneys produce two primary hormones:
$1$. $Erythropoietin$: This hormone is produced by the interstitial fibroblasts in the kidneys in response to hypoxia (low oxygen levels). It stimulates the production of red blood cells in the bone marrow.
$2$. $Calcitriol$: This is the active form of Vitamin $D_3$ $(1,25-dihydroxyvitamin D_3)$. It is produced in the kidneys by the enzyme $1\alpha-hydroxylase$ and helps in the absorption of calcium from the gastrointestinal tract.
Therefore, the correct pair is $Erythropoietin$ and $Calcitriol$.

(A) When blood volume and blood pressure increase,the walls of the atria of the heart are stretched.
This stretching stimulates the cardiac atrial cells to secrete a peptide hormone known as Atrial Natriuretic Peptide $(ANP)$.
$ANP$ acts as a vasodilator and promotes the excretion of sodium and water in the urine,thereby reducing blood volume and blood pressure.
Therefore,the correct option is $A$.

(A) The gastrointestinal tract produces several peptide hormones that regulate digestion.
$1$. $Gastrin$: Stimulates the secretion of $HCl$ and pepsinogen in the stomach.
$2$. $Secretin$: Stimulates the pancreas to secrete water and bicarbonate ions.
$3$. $Cholecystokinin$ $(CCK)$: Stimulates the gallbladder to release bile and the pancreas to secrete digestive enzymes.
$Amylase$, $Trypsin$, $Enterokinase$, and $Nuclease$ are digestive enzymes, not hormones.
Therefore, the correct set of hormones is $Gastrin$, $Secretin$, and $Cholecystokinin$.

(B) The kidneys produce two primary hormones:
$1$. $Erythropoietin$: This hormone is produced by the juxtaglomerular cells of the kidney in response to hypoxia (low oxygen levels) and stimulates the production of red blood cells in the bone marrow.
$2$. $Calcitriol$ $(1,25-dihydroxyvitamin \ D_3)$: This is the active form of vitamin $D$,which is produced by the kidneys and helps in the absorption of calcium and phosphate from the gastrointestinal tract.
Therefore,the correct pair is $Erythropoietin$ and $Calcitriol$.

(D) When there is an increase in blood flow to the atria of the heart,the atrial walls are stretched.
This stretching stimulates the cardiac cells to secrete a peptide hormone known as Atrial Natriuretic Factor $(ANF)$.
$ANF$ acts as a vasodilator and promotes the excretion of sodium and water in the urine,which helps in reducing blood pressure.