Question
Sphincter of Oddi is present at [NEET 2021]
(a) ileo-caecal junction
(b) junction of hepato-pancreatic duct and duodenum
(c) gastro-oesophageal junction
(d) junction of jejunum and duodenum
Answer/Explanation
Ans. (b)
Sphincter of Oddi is the smooth muscle or a muscular valve that surrounds the end portion of the common bile duct and pancreatic duct (hepato-pancreatic duct). It controls the flow of digestive juices into the intestine.
Question
Identify the correct statement with reference to human digestive system. [NEET (Sep.) 2020]
(a) Serosa is the innermost layer of the alimentary canal
(b) Ileum is a highly coiled part
(c) Vermiform appendix arises from duodenum
(d) Ileum opens into small intestine
Answer/Explanation
Ans. (b)
The option (b) is correct as ileum is a highly coiled tube with reference to human digestive system. Other option can be corrected as Serosa is the outermost layer of the alimentary canal. A narrow finger-like tubular projection, the vermiform appendix arises from caecum part of large intestine. Ileum opens into the large intestine.
Question
Identify the correct statement with reference to human digestive system. [NEET (Sep.) 2020]
(a) Serosa is the innermost layer of the alimentary canal
(b) Ileum is a highly coiled part
(c) Vermiform appendix arises from duodenum
(d) Ileum opens into small intestine
Answer/Explanation
Ans. (b)
The option (b) is correct as ileum is a highly coiled tube with reference to human digestive system. Other option can be corrected as Serosa is the outermost layer of the alimentary canal. A narrow finger-like tubular projection, the vermiform appendix arises from caecum part of large intestine. Ileum opens into the large intestine.
Question
Match the following structures with their respective location in organs. [NEET (National) 2019]
Select the correct option from the following
A B C D
(a) (ii) (iv) (i) (iii)
(b) (iii) (iv) (i) (ii)
(c) (iii) (ii) (i) (iv)
(d) (iii) (i) (ii) (iv)
Answer/Explanation
Ans. (b)
(A)–(iii), (B)–(iv), (C)–(i), (D)–(ii)
Crypts of Lieberkuhn are simple, tubular intestinal glands which occur throughout the small intestine between the villi. They secrete digestive enzymes and mucus. Glission’s capsule is the inner
thin layer of connective tissue in liver. Islets of Langerhans constitute the endocrine part of pancreas which secrete hormones. Brunner’s glands are located in the submucosa of duodenum and they open into the crypts of Lieberkuhn.
Question
Which one of the following terms describe human dentition? [NEET 2018]
(a) Pleurodont, Monophyodont, Homodont
(b) Thecodont, Diphyodont, Heterodont
(c) Thecodont, Diphyodont, Homodont
(d) Pleurodont, Diphyodont, Heterodont
Answer/Explanation
Ans. (b)
The terms, thecodont, diphyodont and heterodont describe human dentition. In men, two types of teeth are found, milk or deciduous teeth and permanent teeth. Thus, they have diphyodont teeth. The teeth are thecodont, i.e. they remain embedded in the sockets of the jaw bones. Men have four types of teeth; incisors, canine, premolars and molars, i.e., heterodont teeth.
Question
Conversion of milk to curd improves its nutritional value by increasing the amount of [NEET 2018]
(a) vitamin- $B_{12}$
(b) vitamin-A
(c) vitamin-D
(d) vitamin-E
Answer/Explanation
Ans. (a)
Conversion of milk to curd improves its nutritional value by increasing the amount of vitamin- $\mathbf{B}_{12}$. Vitamin-A is found in milk, carrot, tomato, etc. Skin can synthesise vitamin-D in the presence of sunlight. Vitamin-E is found in wheat, green leafy vegetables, etc.
Question
A baby boy aged two years is admitted to play school and passes through a dental check-up. The dentist observed that the boy had twenty teeth. Which teeth were absent? [NEET 2017]
(a) Incisors
(b) Canines
(c) Premolars
(d) Molars
Answer/Explanation
Ans. (c)
In human beings, after birth the first set of teeth that develops are deciduous teeth or temporary teeth. These are 20 in number. The dental formula of child is 2102/2102.
Thus, they have 2 incisors, 1 canine, 0 premolars and 2 molars. Therefore, the baby boy would not have premolars.
Question
Which cells of ‘Crypts of Lieberkuhn’ secrete antibacterial lysozyme? [NEET 2017]
(a) Argentaffin cells
(b) Paneth cells
(c) Zymogen cells
(d) Kupffer cells
Ans. (b)
The mucosa present in between the bases of villi of small intestine (Crypts of Lieberkuhn) contain paneth, which secrete antibacterial lysozyme.
Answer/Explanation
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A section of small intestinal mucosa showing villi and the Crypts of
Concept Enhancer Kupffer cells are phagocytic cells of liver. Zymogen cells produce enzyme. Argentaffin cells produce hormones.
Question
The hepatic portal vein drains blood to liver from [NEET 2017]
(a) heart
(b) stomach
(c) kidneys
(d) intestine
Answer/Explanation
Ans. (d)
In the hepatic portal system, the hepatic veins takes blood from intestine to the liver. This way, it takes all the nutrients absorbed from intestine to the liver first, where screening and storing of nutrition takes place.
Concept Enhancer
The portal system is a system of veins in which vein takes blood to some organ/tissue of the body other than heart. In this, the vein has capillary network at it’s both ends. There is one more portal system in human body named hypophyseal portal system present in the hypothalamus, which brings neuro secretions of hypothalamus to pituitary gland.
The renal portal system is found in fishes and amphibians. It supplies blood from posterior region of the body to the kidneys by renal portal veins to remove waste products before sending it to heart via renal veins and post canal veins.
Question
Which of the following guards the opening of hepatopancreatic duct into the duodenum? [NEET 2016, Phase I]
(a) Ileocaecal valve
(b) Pyloric sphincter
(c) Sphincter of Oddi
(d) Semilunar valve
Answer/Explanation
Ans. (c)
Sphincter of Oddi guards the opening of hepatopancreatic duct into the duodenum. Hepatopancreatic duct brings secretion of liver as well as pancreas to the duodenum.
Question
The primary dentition in human differs from permanent dentition in not having one of the following type of teeth [CBSE AIPMT 2015]
(a) Canine
(b) Premolars
(c) Molars
(d) Incisors
Answer/Explanation
Ans. (b)
There are four classes of teeth, i.e. incisors, canines, premolars and molars. There are no premolars in primary dentition (deciduous or boby teeth). These are found only in permanent. dentition (adult teeth).
Question
Two friends are eating together on a dining table. One of them suddenly starts coughing while swallowing some food. This coughing would have been due to improper movement of [CBSE AIPMT 2011]
(a) diaphragm
(b) neck
(c) tongue
(d) epiglottis
Answer/Explanation
Ans. (d)
The epiglottis is a flap that is made of elastic cartilage tissue covered with a mucous membrane, attached to the entrance of the larynx. It prevents the entry of food into the larynx and directs it to the oesophagus. Due to the improper movement of epiglottis, one may suddenly start coughing while swallowing some food.
Question
Epithelial cells of the intestine involved in food absorption have on their surface [CBSE AIPMT 2005]
(a) pinocytic vesicles
(b) phagocytic vesicles
(c) zymogen granules
(d) microvilli
Answer/Explanation
Ans. (d)
The mucosa and sub-mucosa of small intestine are thrown into folds. Surfaces of these folds are covered by fine, finger-like projections of the epithelium. These projections are called villi. In addition, the epithelial cells of the villi are covered on their exposed surface by cytoplasmic projections called microvilli.
Question
The richest sources of vitamin- $\mathrm{B}_{12}$ are [CBSE AIPMT 2004]
(a) goat’s liver and Spirulina
(b) chocolate and green gram
(c) rice and hen’s egg
(d) carrot and chicken’s breast
Answer/Explanation
Ans. (a)
Vitamin $-B_{12}$ (cyanocobalamin) is the only vitamin which is not found in vegetables. It is present in animal protein such as meat, liver, fish and Spirulina (single cell protein). It promotes DNA synthesis, maturation of RBCs and myelin formation.
Question
Which one is correctly matched? [CBSE AIPMT 2001]
(a) Vit-E-Tocopherol
(b) Vit-D-Riboflavin
(c) Vit-B-Calciferol
(d) Vit-A-Thiamine
Answer/Explanation
Ans. (a)
Option (a) is correctly matched. Thiamine, riboflavin, calciferol, tocopherol are also known as vitamin $B_1$, vitamin- $B_2$, vitamin- $D_2$ and vitamin- $E$ respectively.
Question
The layer of cells that secrete enamel of tooth is [CBSE AIPMT 1998]
(a) dentoblast
(b) amiloblast
(c) osteoblast
(d) odontoblast
Answer/Explanation
Ans. (d)
The pulp cavity contains a mass of dense but soft connective tissue which is called pulp. A single layer of odontoblast cells is lined by the pulp cavity.These cells secrete enamel which is a bluish white, shiny translucent and the hardest substance of the body.
Question
A dental disease characterised by moltting of teeth is due to the presence of a certain chemical element in drinking water. Which of the following is that element? [CBSE AIPMT 1995]
(a) Mercury
(b) Chlorine
(c) Fluorine
(d) Boron
Answer/Explanation
Ans. (c)
Increased amount of fluorine in drinking water causes fluorosis, responsible for moltting of teeth.
Question
$ Brunner’s glands occur in [CBSE AIPMT 1992]
(a) sub-mucosa of duodenum
(b) sub-mucosa of stomach
(c) mucosa of oesophagus
(d) mucosa of ileum
Answer/Explanation
Ans. (a)
Brunner’s glands are convoluted and branched glands found only in duodenum and located in sub-mucosa.
Question
In man the zymogen or chief cells are mainly found in [CBSE AIPMT 1990]
(a) cardiac part of stomach
(b) pyloric part of stomach
(c) duodenum
(d) fundic part of stomach
Answer/Explanation
Ans. (d)
Chief cells or zymogen are mainly found in fundic part of stomach which secretes two proenzymes, pepsinogen and prorennin and an enzyme gastric lipase.
Question
Whartson’s duct is associated with [CBSE AIPMT 1988]
(a) sub-lingual salivary duct
(b) parotid salivary gland
(c) sub-maxillary salivary gland
(d) Brunner’s glands
Answer/Explanation
Ans. (c)
Whartson’s duct is associated with sub-maxillary salivary gland. These lie beneath the jaw angles, their secretion is carried by Whartson’s duct which open below the tongue. These are compound acinar gland.
Question
Duct leading from parotid gland and opening into vestibule is [CBSE AIPMT 1988]
(a) Haversian duct
(b) Stenson’s duct
(c) Wolffian duct
(d) Infra-orbital duct
Answer/Explanation
Ans. (b)
Parotid glands are largest salivary glands, present just below the external ear. These are compound tubulo-acinar glands. Saliva is secreted by Stenson’s duct which open opposite to the second upper molar tooth.
Question
Lamina propria is connected with [CBSE AIPMT 1988]
(a) acini
(b) liver
(c) Graafian follicle
(d) intestine
Answer/Explanation
Ans. (d)
Lamina propria of ileum shows yellow coloured oval, granular masses of lymph nodules called ‘Peyer’s patches.’