The respiratory system

• The bronchi are two tubes that branch off from the trachea into the lungs.
• The trachea is the windpipe, which connects to the larynx.
• Bronchial tree refers to the network of airways within the lungs.
• The larynx is also known as the voice box.
• Breathing = movement of air in and out of the lungs.
• Respiration = oxygen taken into body, transported to cells, used to release energy, waste products removed
• Glucose + oxygen -> ATP + carbon dioxide + water
• Air passage & tubes - trachea, bronchus, bronchioles
• Pump that moves air in & out - diaphragm
• Respiratory surface - alveoli
• Nose: filter dust through nose hair, filter bacteria through mucus
• Blood vessels beneath nasal lining release heat
• Trachea = 10 cm long, 1.5 cm wide, has cartilage rings to keep trachea open. The lining of the trachea has 2 types of cells:

  mucus - secreting cells & ciliated epithelial cells
• Singular: bronchus. Plural: bronchi (2). Also has cartilage rings. Divide into many bronchioles. (diameter 1mm) have walls of muscle, no cartilage
• Allergies or asthma affects the muscles in the bronchioles. Making breathing difficult
• Pleural cavity: small space between the lungs and the chest wall, has a lubricating liquid for easy breathing
• Diaphragm = sheet of muscle, attached to lowest ribs. Separates chest cavity from the lower body cavity
• Chest wall consists of ribs & intercostal muscles (internal & external)

  2 layers: internal intercostal muscles & external intercostal muscles
• Inhalation/inspiration: diaphragm contracts, external intercostal muscles contract pulling ribcage up, lungs expand, air moves in
• Exhalation/expiration: muscles relax, diaphragm and ribs return to original shape, lungs deflate, air is pushed out
• Amount of air breathed at rest = tidal volume = 500cm3
• Maximum amount of air breathed = vital capacity = 4000cm3
• At the end of each bronchiole = alveolar ducts, ends in alveolus. Has thin wall and many capillaries (blood vessels)
• Alveoli = respiratory surface - gaseous exchange takes place here
• Oxygen diffuses through the alveolus and capillary walls into the blood
• Oxygen + haemoglobin = oxyhaemoglobin (red colour)
• Blood with oxygen = oxygenated blood
• Carbon dioxide dissolves in the plasma of the blood. Diffused through the capillary and alveolar wall, changes into a gas and gets exhlaed
• 300,000,000 alveoli - very large surface area for fast gaseous exchange
• life processes happens in cells, like building proteins from amino acids for repairing cell membranes or making enzymes
• Energy from food molecules are released by respiration
• Aerobic respiration : body has enough oxygen. chemical process in which oxygen is used to make energy from carbohydrates (sugars)
• Anaerobic respiration: body not have enough oxygen to use glucose to make ATP
• Energy released from sugar taking part in chemical reactions with oxygen
• Carbon dioxide and water is released as waste products
• Glucose + oxygen -> carbon dioxide + water
• Body cannot get enough oxygen for aerobic respiration
• Body releases the energy anyway and other substances are made, to be broken down by aerobic respiration later.
• Smoking damages the respiratory system
• 1000+ chemicals in cigarettes