Systems Lesson 1 - Nutrition and Digestion

Systems Lesson 1 - Nutrition and Digestion

• All living things need essential nutrients to survive
• Six essential nutrients, categorized into Macronutrients and Micronutrients
• Macronutrients include Carbohydrates, Proteins, and Fats, as well as Water.
• Micronutrients include Vitamins and Minerals
• Carbohydrates are composed of carbon, hydrogen, and oxygen atoms
• Carbohydrates are a source of energy that the body accesses quickly
• Simple sugars like glucose, fructose, and galactose are examples of monosaccharides.
• Monosaccharides combine to form disaccharides and polysaccharides.
• Examples of disaccharides include sucrose, lactose, and maltose.
• Polysaccharides are more complex, made of many simple sugars combined.
• Plants make starch; animals make glycogen. Both are made of glucose subunits.
• Cellulose is a polysaccharide made by plants, providing structural support.
• Lipids (fats) are essential for energy and building cell membranes and hormones.
• They are known as roughage and help move food through the digestive system.

Systems Lesson 2 - Proteins, Vitamins and Minerals

• Proteins are made up of amino acids
• Proteins are joined together by peptide bonds.
• Proteins like antibodies, enzymes, and hormones are formed by polypeptides.
• Our bodies cannot produce nine amino acids therefore they are called essential amino acids.
• Essential amino acids come from food sources.
• Vitamins and Minerals are required in small amounts by the body and crucial to certain bodily functions.
• Vitamins and Minerals are essential components of hormones and enzymes.
• Some vitamins are stored in the body: others need to be consumed regularly.

Systems Lesson 2 - Water

• Water is an essential nutrient for making up approximately 60% of the body
• Water plays a vital role in many body function
• Water is needed for proper functioning of cells and organs.

Systems Lesson 3 - Energy and Digestive System

• We obtain energy through cellular respiration.
• Cellular respiration converts glucose and oxygen into carbon dioxide, water, and ATP
• 40% of energy is used for cellular function and 60% for maintaining body temperature.
• Dietary calories represent a measure of energy.
• Fats are a rich source of energy. Carbs have less energy density than fats.
• Nutraceutical - A substance purified from food and ingested for its potential health benefits.
• Probiotics are substances that strengthen the body’s natural defenses.

Systems Lesson 4 - Digestive System Structure and Function

• Ingestion - Taking in food
• Digestion - Breaking food down into nutrients
• Absorption - Taking in nutrients by cells
• Elimination - Removing waste.
• The digestive system begins with the mouth where food is mechanically broken down by teeth and chemically by enzymes in saliva.
• The esophagus transports food to the stomach.
• The stomach mixes food with gastric juices, creating chyme.
• The small intestine absorbs most nutrients.
• The large intestine absorbs water and forms waste.

Systems Lesson 6 - Absorption, Small Intestine and Liver

• Nutrients are absorbed into the cells for energy & building blocks
• The small intestine is the primary site of absorption and contains villi to increase the surface area for nutrient absorption.
• The liver plays a crucial role in processing nutrients, producing bile, and filtering toxins.
• The liver helps process absorbed nutrients before they enter the bloodstream.

Systems Lesson 7 - Large Intestine, Pancreas and Appendix

• The large intestine's primary role is to absorb water, electrolytes, and vitamins from indigestible food.
• The pancreas produces enzymes to help break down fats, carbohydrates, and proteins.
• The Appendix is located in the caecum of the large intestine.

Systems Lesson 8 - Circulatory System

• The circulatory system transports gases, nutrients, and waste.
• It regulates internal body temperature and transports chemicals.
• Blood is made up of plasma (55%), red blood cells (responsible for carrying oxygen), white blood cells (immune response), and platelets (clotting).
• Blood circulates through the body, delivering nutrients and removing waste products.
• The heart is made of cardiac muscle. It continuously contracts and relaxes to pump blood throughout the body.
• Four chambered heart (2 atria & 2 ventricles).
• Electrical signals from the sinoatrial (SA) node initiate and regulate the heart's contractions.
• Blood vessels transport blood throughout the body.
• Arteries carry blood away from the heart.
• Veins carry blood towards the heart.
• Capillaries carry out the exchange of gases and materials with body cells.

Systems Lesson 9 - Immunity & Blood Cells

• Phagocytes are a type of white blood cell that attacks and destroys pathogens. Different types exist for different specific tasks.
• Platelets are crucial for blood clotting.

Systems Lesson 10 - Respiratory System

• Respiration involves taking in oxygen and releasing carbon dioxide.
• The respiratory system includes the nose, trachea, bronchi, bronchioles, and alveoli.
• Exchange of oxygen and carbon dioxide occurs in the alveoli.
• Lungs expand during inhalation by expanding the chest cavity, creating lower pressure than outside air that causes air to rush into the lungs.
• Lungs contract during exhalation, returning the chest cavity to its normal size and causing higher pressure than outside air, causing air to rush out of the lungs.

Systems Lesson 11/12 - Respiratory and Other Related Diseases

• Diseases, such as SARS, can affect the respiratory and other systems of the body, thereby causing inflammation, fever, and difficulty breathing.
• Lung Cancer involves cells growing uncontrollably and forming tumors or masses.