Science (ch.8 breathing/digestion)

• What is the primary function of the diaphragm in respiration?

  It helps in the process of breathing by changing the pressure in the chest cavity.
• How does oxygen enter the body from the air?

  Oxygen travels down the bronchi and bronchioles into the alveoli.
• What happens to oxygen after it enters the alveoli?

  It passes through the thin lining into the bloodstream.
• What role does the heart play in oxygen transport?

  The heart pumps oxygenated blood around the body to reach the cells.
• What byproduct is produced when cells use oxygen?

  Carbon dioxide is produced as a byproduct of energy production in cells.
• What is the effect of smoking on the respiratory system?

  Smoking introduces harmful chemicals that can damage the lungs and airways.
• How does the structure of alveoli facilitate gas exchange?

  The alveoli have a thin lining and a large surface area for efficient gas exchange.
• What is the function of cilia in the respiratory system?

  Cilia help to keep mucus and debris out of the lungs.
• What happens to carbon dioxide in the blood?

  Carbon dioxide diffuses from the blood into the alveoli to be exhaled.
• What are the main components of the human digestive system?

  • Mouth
  • Oesophagus
  • Stomach
  • Small intestine
  • Pancreas
  • Liver
  • Gall bladder
  • Large intestine
  • Appendix
  • Rectum
• What is the role of bile in digestion?

  Bile helps to break up large pieces of fat in the small intestine.
• What is the function of the large intestine?

  The large intestine absorbs water from undigested food and forms waste material.
• What happens to the appendix in humans?

  The appendix has no function in humans but can become infected.
• What is the process of physical digestion?

  Physical digestion involves breaking food into smaller pieces using teeth or muscles.
• What is the role of enzymes in digestion?

  Enzymes act as catalysts that speed up the breakdown of food molecules.
• What type of enzyme breaks down carbohydrates?

  Amylase enzymes catalyse the breakdown of carbohydrates.
• What is the journey of food through the digestive system?

  Food travels from the mouth to the oesophagus, stomach, small intestine, large intestine, and finally out through the anus.
• How do carbohydrates and proteins differ in digestion?

  Carbohydrates are broken down into glucose, while proteins are broken down into amino acids.
• What is the significance of the small intestine in digestion?

  The small intestine is where nearly all food is digested and absorbed into the bloodstream.
• What is the function of the pancreas in digestion?

  The pancreas produces pancreatic juice that neutralises stomach acid and contains enzymes.
• What is the role of the rectum in the digestive system?

  The rectum stores dried waste material until it is ready to be expelled from the body.
• What are deficiency diseases caused by a lack of vitamins?

  Examples include anaemia, scurvy, and rickets.
• What is the importance of minerals in the body?

  Minerals are needed in small amounts for various bodily functions.
• What is the role of fibre in the digestive system?

  Fibre helps keep the digestive system healthy and aids in regular bowel movements.
• How does the body maintain hydration?

  The body stays hydrated by consuming water-rich foods like fruits and vegetables.
• What is the relationship between diet and health?

  A balanced diet with fruits, vegetables, and whole grains helps maintain overall health.
• What is the significance of body mass index (BMI)?

  BMI is a measure of body weight relative to height.
• What are the effects of a lack of vitamins on the body?

  A lack of vitamins can lead to deficiency diseases such as fatigue and bleeding gums.
• How does smoking affect the respiratory system?

  Smoking causes inflammation and reduces airflow in the bronchial tubes.