Solution-Class-11-Science-Biology-Chapter-14-Human Nutrition-Maharashtra Board

(b) pancreas

(d)  Molars

(c)  Talking

(d)  Protease

• Sugarcane juice contains Policosanol. Consuming this compound causes loose motion, spinning of head.
• Policosanol is also a blood thinner compound which disables the blood to make clots on excessive bleeding.
• So, consumption of sugarcane must be avoided during school athletic meet.

• Alcoholism causes different disorders of liver like steatosis (fatty liver), alcoholic hepatitis, fibrosis and cirrhosis.
• Most of the alcohol in the body is broken down in the liver by an enzyme called alcohol dehydrogenase, which transforms ethanol into a toxic compound called acetaldehyde (CH₃CHO).
• Over consumption of alcohol leads to cirrhosis (distorted or scarred liver) and eventually to liver failure.
• Therefore, alcoholic people may suffer from liver disorder.

Pepsin acts in acidic medium thus it is active in stomach. There is alkaline condition in the small intestine. pH of small intestine is very high for pepsin to work. Therefore, pepsin gets denatured in the small intestine.

• Mesentery is a tissue found in the abdomen. It links the small intestine to the abdominal wall and holds it in place, preventing twisting while running and jumping.
• If the small intestine twists, the affected area may obstruct the passage of food and drink. If the twist is particularly severe, it can potentially cut off the blood flow. If this occurs, the surrounding tissue may kill, causing major complications.

• It is essential that the digestive enzymes and juices are produced in sequential manner and at a proper time.
• These secretions are under neurohormonal control. Sight, smell and even thought of food trigger saliva secretion.
• Tenth cranial nerve stimulates secretion of gastric juice in stomach.
• Even the hormone gastrin brings about the same effect.

Structure of tooth:

• A tooth consists of the portion that projects above the gum called crown and the root that is made up of two or three projections which are embedded in gum.
• A short neck connects the crown with the root.
• The crown is covered by the hardest substance of the body called enamel which is made up of calcium phosphate and calcium carbonate.
• Basic shape of tooth is derived from dentin which is a calcified connective tissue.
• The dentin encloses the pulp cavity. It is filled with connective tissue pulp. It contains blood vessels and nerves.

• Pulp cavity has extension in the root of the tooth called root canal.
• The dentin of the root of tooth is covered by cementum which is a bone like substance that attaches the root to the surrounding socket in the gum.

Human dentition :

• Human dentition is described as thecodont, diphyodont and heterodont. .
• It is called thecodont type because each tooth is fixed in a separate socket present in the jaw bones by gomphosis type 0f joint.
• It is called diphyodont type because we get only tow sets of teeth, milk teeth and permanent teeth.
• It is called heterodont type because humans have four different type of teeth like incisors, canines, premolars and molars.

• Pancreas is a leaf shaped heterocrine gland present in the gap formed by bend of duodenum under the stomach.
• Exocrine part of pancreas is made up of acini, the acinar cells secrete alkaline pancreatic juice that contains various digestive enzymes.
• Pancreatic juice is collected and carried to duodenum by pancreatic duct.
• The common bile duct joins pancreatic duct to fonn hepato-pancreatic duct. It opens into duodenum.
• Opening of hepato-pancreatic duct is guarded by sphincter of Oddi.
• Endocrine part of pancreas is made up of islets of Langerhans situated between the acini.
• It contains three types of cells alpha-cells which secrete glucagon, Beta-cells which secretes insulin and delta cells secrete somatostatin hormone.
• Glucagon and insulin together control the blood-sugar level.
• Somatostatin hormone inhibits glucagon and insulin secretion.

• There are three pairs of salivary glands which open in buccal cavity.
• Parotid glands are present in front of the ear.
• The submandibular glands are present below the lower jaw.
• The glands present below the tongue are called sublingual.
• Salivary glands are made up of two types of cells.
• Serous cells secrete a fluid containing digestive enzyme called salivary amylase.
• Mucous cells produce mucus that lubricates food and helps swallowing.

• Jaundice is a disorder characterized by yellowness of conjunctiva of eyes and skin and whitish stool.
• It is a sign of abnormal bilirubin metabolism and excretion.
• Jaundice develops if excessive break down of red blood cells takes place along with increased bilirubin level than the liver can handle or there is obstruction in the flow of bile from liver to duodenum.
• Bilirubin produced from breakdown of haemoglobin is either water soluble or fat soluble.
• Fat soluble bilirubin is toxic to brain cells.
• There is no specific treatment to jaundice.
• Supportive care, proper rest are the treatments given to the patient.

The layer marked in the diagram represents glandular epithelium of mucosa

Significance of the glandular epithelium of mucosa :

Globlet cells of the epithelial layer of a mucous membrane secrete mucus which lubricates the lumen 0f the elementary canal. This helps in movement of food through the gastrointestinal tract.

Salivaxy amylase = 6.8

Trypsin = 8

Nucleotidase = 7.5

Pepsin = 2

• Kwashiorkor is a protein deficiency disorder.
• This protein deficiency disorder is found generally in children between one to three years of age.
• Children suffering from Kwashiorkor are underweight and show stunted growth, poor brain development, loss of appetite, anaemia, protruding belly, slender legs, bulging eye, oedema of lower legs and face, change in skin and hair colour.

A- Bile duct, B- Stomach, C- Common hepatic duct, D- Pancreas, E- Gall Bladder

Functions:

• Bile duct: It carries bile from the gall bladder and empties it into the intestine.
• Common hepatic duct: It drains bile from the liver. It helps in transportation of waste from liver and helps in digestion by releasing bile.