Topic 7: Human Nutrition

What is a balanced diet?

A meal or diet consisting of all food groups; carbohydrates, proteins, fats, lipids, minerals, vitamins, dietary fiber, and water in the correct amount and proportions.

Why are carbohydrates needed for a balanced diet?

Carbohydrates give energy to the body for various activities.

Why are proteins needed for a balanced diet?

Proteins are needed for growth and repair of damaged tissues.

Why are lipids needed for a balanced diet?

Lipids are needed by the body for various reasons:

1. protecting organs like the heart and brain from eternal shock.

2. They create energy in the absence of carbohydrates.

3. Lipids help heavy animals float on water.

Why are mineral salts needed for a balanced diet?

Mineral salts are needed by the body to make certain cells, tissues, or organs to ensure proper functioning of the body.

Why is calcium needed for a balanced diet?

Calcium is needed to develop and build strong bones and teeth. It is also needed for blood clotting.

Why does the body need iron?

Iron is needed because they make haemoglobin, the red pigment which carries oxygen.

What happens when there is a lack of iron?

It leads to Anemia. Meaning that there are not enough red blood cells so the tissues don't get enough oxygen delivered to them.

Why is vitamin C needed for a balanced diet?

Vitamin C keep tissues in good repair as they make the stretchy proteins, collagen. They keep the body healthy as they help fight off diseases, and gives healthy gums.

What does roughages/ dietary skin do?

It helps in the movement of food through the alimentary canal, keeping it in a good working order. Lack of it can cause constipation.

Why is water needed for a balanced diet?

It provides a medium where chemical reactions occur. Its is a solvent that carries nutrients through the body, and regulates body temperature.

What are some examples of carbohydrates?

Maize, Bread, Pasta, Potatoes, Rice

What are some examples of proteins?

Milk, cheese, meat, eggs, fish

What is the deficiency of Vitamin C?

Scurvy, causes pain in joints and bleeding from gums

What is the deficiency of Vitamin D?

Rickets, causes soft and deformed bones

What are some examples of lipids?

Meat, nuts, milk, seeds

What are some examples of calcium?

Milk, fish, vegetables, cheese, yogurt

What are some examples of Vitamin C?

Orange, Limes, Raw Vegetables

What happens when the body has a lack of Vitamins?

Vitamin C leads to bleeding gums (scurvy) & Vitamin D leads to bad skin.

Define ingestion.

Food and drink are taken into the body through the mouth, using the lips, teeth, and tongue.

Define digestion.

The process of breaking down large, insolubale food substances into small soluble food substances that can be absorbed into the bloodstream.

Define mechanical digestion.

The process of breaking down large food substances into small food particles to increase the surface for chemical digestion.There isn't any chemical change to the food molecules. It occurs in the teeth and stomach.

Define chemical digestion.

The process of breaking down bonds in polymers to form small molecules using enzymes. This occurs in the mouth, stomach, and small intestine.

Define absorption.

The movement of digested food molecules from the digestive system into the blood and lymph.

Define assimilation.

The process of nutrients becoming part of the body. They are absorbed by individual cells and used for energy or to make new substances.

List the body parts of the alimentary canal in order.

Mouth, esophagus, stomach, small intestine (duodenum & ileum), large intestine (colon &rectum), anus

What is the function of the mouth?

Ingests food using the lips, teeth, and tongue. Biting and grinding food into small, soluble pieces

What is the function of the stomach?

A wide part of the alimentary canal; To store food and mix it with enzymes & mucus and digest proteins.

What is the small intestine and what does it do?

A long narrow part of the alimentary canal consisting of the duodenum and ileum; Breaks down and digest food, absorb nutrients, and water into the bloodstream, and remove any unnecessary compoments.

What is the large intestine and what does it do?

A wide part of the alimentary canal consisting of the colon and rectum.

They absorb water and electrolytes from undigested food matter, produce & absorbs vitanims, form and store feces before removing them from the body.

What is the gall bladder and what does it do?

It is a small organ that stores bile, before releasing it into the duodenum via the bile duct. They store and concentrate bile produced by the liver.

What is the function of the pancreas?

They produce amylase, protease and lipase enzymes being released into the duodenum. They regulate blood sugar by producing hormones like insulin and glycegon.

What is the function of the liver?

Bile is produced here. Bile aids the digestion of fats, as well as neutralising stomach acid as it exits the stomach.

They filter all of the blood in the body and breaks down poisonous substances such as drugs or alcohol.

What is the function of the duodenum?

Food enters the small intestine from the stomach here. The acidic stomach contents are neutralised by bile and become slightly alkaline. Enzymes complete chemical digestion here

What is the function of the ileum?

Food and water are absorbed into the blood via the villi in the lining of the ileum. They absorb nutrients and mineral ions.

What is the function of the colon?

Remaining water is absorbed from food into the blood, and the solid waste left behind, they turn it into feces.

What is the function of the rectum?

To store feces, prior to egestion.

What is the function of the anus?

For feces to leave the body; this is egestion.

State the types of the teeth.

Incisors, canines, premolars and molars

How many incisors are in the mouth?

They are 8 into total.

What is the structure & location of the incisors?

Chisel Shaped; Front part of the jaw

What is the function of incisors?

Biting and cutting into the food.

How many canines are in the mouth?

4 in total

What is the structure & location of the canines?

Sharp and pointed; Front sides of the jaw

What is the function of the canines?

Tearing, holding, and biting into the food.

How many pre-molars in the mouth?

8-12 in the mouth.

What is the structure & location of the pre-molars?

Large, flat surfaces with ridges/2-3 cups; The middle section of the jaw

What is the function of the pre-molars?

Chewing & Grinding up Food

How many molars are in the mouth?

12 molars.

What is the structure & location of molars?

Large, flat surfaces with ridges/ 3 roots & 4 cusps; Back of the jaw

Define Bile.

An alkaline fluid produced by the liver, which helps with fat disgestion.

What is the function of amylase and where is it found?

They break down starch to simple reducing sugars in the mouth and duodenum, found in salivary glands and pancreas

What is the function of protease and where is it found?

They break down proteins to amino acids in the stomach and duodenum, found in stomach and pancreas.

What is the function of lipase and where is it found?

Breaks down fats and oils to fatty acids and glycerol in the duodenum, found in pancreas.

What is the function of hydrochloric acid?

Killing harmful microorganisms in food and providing an acidic pH for optimum enzyme activity

Digestion of starch in digestive system

- Amylase breaks down starch molecules to maltose molecules
- Maltase breaks down maltose to glucose molecules on the membranes of the epithelium lining the small intestine

Digestion of proteins in digestive system.

- Pepsin breaks down protein in the acidic conditions of the stomach
- Trypsin breaks down protein in the alkaline conditions of the duodenum

Define Villi.

A very small finger-like projection that lines the inner surface of the small intestine, increasing its surface area.

What is the function of lacteals in the villi?

Absorb fatty acids and glycerol in the small intestine, where it is emptied into the blood.

What is the function of the blood capillary?

Absorbs glucose and amino acids and carries it away from the small intestine in the blood.

What are the functions of bile?

1. Its alkaline salts helps neutralize the hydraulic acid which comes from the stomach.

2. It breaks down large drops of fat into tiny droplets, increasing the surface area for chemical digestion. Also, so they can fully mix with the watery fluids inside the digestive system.

Define gastric juices.

Fluids produced by the stomach.

What are the functions of hydraulic acid in gastric juice?

• They kill harmful microorganisms in food.

• Providing an acidic pH for an optimum enzyme activity

What are the function of bile?

They neutralize the acidic mixture of food and gastric juices entering the duodenum from the stomach, to provide a suitable pH for enzyme action.

Define microvilli.

Tiny folds on the surface of the cells of the epithelium of the villi in the small intestine.

What is A?

Pre-Molar

What is B?

Incisors

What is C?

Canine

What is D?

Molars

Why is Vitamin D needed for a balanced diet?

Vitamin D helps calcium to be absorbed, for making bones and teeth. They develop the epitheral layer, tissues, and organs. Additionally, it supports immune function and may protect against certain diseases.

What are some examples of Vitamin D?

Butter, Salmon, Tuna, Egg Yolk

What is the deficiency disease for calcium?

Brittle bones and teeth; poor blood clotting

What is chyme?

The semi-solid mixture of food and digestive enzymes. It happens when the cardiac sphincter muscle (above the stomach) and phyloric sphincter muscle (below the stomach) closes.

What is churning?

The process of stomach walls contracting and relaxing rhythmically to break down the boluses and mix the food with digestive juices

What is 1?

Nerves

What is 2?

Cement

What is 3?

Jawbone

What is 4?

Blood Capillaries

What is 5?

Enamel

What is 6?

Dentine

What is 7?

Gum

What is 8?

Pulp Cavity