1.5 breathing and respiration

• The reason people's breathing rate increases when exercising is because respiration (which gives your muscles energy to contract) needs oxygen to occur, which is found in standard atmospheric air. The more exercise you do, the more muscle cells need to release more energy. This requires more oxygen so your body responds by breathing deeper and faster to deliver oxygen to the cells quickly
• Respiration is the release of energy from food using oxygen
• The 10 parts of the human breathing system are pleural membranes, larynx, trachea, lungs, bronchi, alveoli, intercostal muscles, ribs, and diaphragm
• When air is inhaled through the nose, the air is filtered, moistened and warmed as it passes through. This makes it more beneficial to breathe nasally than through the buccal cavity
• The epiglottis is a small flap which is at the back of the throat, it makes sure that no food particles enter the respiratory system
• Ciliated epithelial cells line the passages of the breathing system, they waft mucus to trap dust and bacteria. The mucus gets swallowed where it reaches the stomach, where it is met with hydrochloric acid to kill all harmful bacteria
• A punctured lung is called a pneumothorax.
• The rings of cartilage in the trachea and bronchi to stop them from collapsing
• Alveoli is where gas exchange takes place in humans
• pleural fluid provides a cushion to prevent friction between the lungs and ribcage
• breathing is the physical process of ventilating the lungs
• when we breathe in, the intercostal muscles contract, which pull the ribs up and out
• when we breathe in, the diaphragm contracts and it moves down and flattens
• the volume of the thorax increases which causes the pressure of the thorax to decrease
• when we breathe in, the air pressure is lower than the atmosphere which causes air to be forced into the lungs to inflate them
• when we breathe out, the intercostal muscles relax, causing the ribs to move down and in
• when we breathe out, the diaphragm relaxes and moves upwards
• when we breathe out, the volume of the thorax decreases, which causes the pressure of the thorax to increase. this causes the air to be rushed out of the lungs
• gas exchange is the act when oxygen diffuses into the blood and waste CO2 diffuses out of the blood
• the alveoli is adapted for efficient gas exchange because of its large surface area, thin walls, good blood supply, moist appearance and ventilation system
• the three gases present in our atmospheric air are oxygen, nitrogen and carbon dioxide
• limewater is a chemical which detects CO2 which causes it to change from clear to cloudy/milky
• Hydrogen carbonate indicator/bicarbonate indicator turns yellow when CO2 is detected and purple when CO2 is taken away.
• hydrogen bicarbonate indicator/bicarbonate indicator is naturally red/orange
• nitrogen is an inert (unreactive) gas. we breathe it in and breathe it straight back out
• the gas exchange surface of a human is composed of millions of alveoli in each lung
• the main gas exchange surface of a plant is its leaves
• for plants, they have a large surface area for gas exchange. the leaves are flat and most plants have lots of leaves
• for animals, they have a large surface area for gas exchange, there are millions of alveoli in each lung
• for plants, they are thin for gas exchange, leaves are very thin and are filled with many stomata. this means there is onlt a short distance for gases to diffuse
• for animals, alveoli are thin for gas exchange, the walls of the alveoli and capillaries are thin (only one cells thick) this means there is a short distance for gases to diffuse
• for plants, they are moist, gases are more easily transported in a moist environment. there is a layer of moisture on the outer surface of cells (especially the spongy mesophyll layer)
• for animals, they are moist. gases are more easily transported in a solution. there is a layer of moisture on the inner surface of an alveolus
• for plants and animals, cell membranes are permeable to gases in solution
• for animals, they have a rich blood supply for gas exchange. each alveolus has an extensive capillary network so the oxygen can reach the blood quickly and carbon dioxide can diffuse from the blood to the alveolus
• for animals, they maintain a steep concentration gradient by breathing in and out and the circulation of the blood
• for plants, they maintain a steep concentration gradient by gases being constantly used or produced by cells
• aerobic respiration is the release of energy from food in the presence of oxygen
• glucose + oxygen -> carbon dioxide + water + energy
• C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy