what happens when an animal starts to exercise
- muscle cells need more energy for contraction to produce movement -> more respiration
- breathing and heart rate increases, allowing more oxygen and glucose to reach the muscle cells -> more aerobic respiration
- the body may also break down glycogen stores (in the liver and muscles) to release more glucose
- anaerobic respiration may also occur due to lack of oxygen, producing lactic acid
- after exercise the breathing rate may remain high to allow extra oxygen intake which replenishes the oxygen debt, oxidising toxic lactic acid and removing it from the body
respiration function and formula
-Respiration is a chemical reaction that occurs in cells to release energy
C6H12O6 + 6O2 -> 6CO2 + 6H2O
where is the respiratory system found
thorax (chest)
rings of cartilage in trachea function
to ensure the airway remains open
which respiratory structures contain cartilage
bronchioles, bronchi and trachea
difference between air entering vs leaving the body
entering: -contains more oxygen
- contains less carbon dioxide
- contains less water vapour
- contains pollen, dust and other particles, like viruses
leaving: -contains less oxygen
- contains more carbon dioxide
- contains more water vapour
- is cleaner with fewer particles
how is air that enters the bodies cleaned
- cells lining the bronchi produce mucus to trap any particles in the inhaled air
- small hairs, cilia, on the cells then move the mucus up to the top of the trachea where it can be swallowed into the acid contents of the stomach in the digestive system
- this destroys and removes them from the body
ventilation definition
- ventilation is the process of breathing in (inhaling) and breathing out (exhaling)
- it allows the air within the respiratory system to be exchanged with the air outside the body
inhaling
- intercostal muscles contract and pull ribs up and outwards
- the diaphragm contracts and flattens downwards (away from the lungs).
- volume within the thoracic cavity increases
- air pressure inside the thoracic cavity decreases compared to outside the body
- air from outside the body enters the lungs via the trachea and bronchi to equalise the pressure
exhaling
- intercostal muscles relax and pull ribs down and inwards
- the diaphragm relaxes and becomes domed
- volume within the thoracic cavity decreases
- air pressure inside the thoracic cavity increases compared to outside the body
- air from inside the lungs is forced out of the body through the bronchi and trachea to equalise the pressure.
How is the body adapted to allow efficient gas exchange?
- thousands of alveoli to increase surface area across which diffusion can occur
- alveoli and capillary walls are only one cell thick and the capillaries are wrapped around the alveoli, reducing the distance that the gases must diffuse
- blood constantly flows through the capillaries to maintain the conc. gradients of each gas (rapid diffusion in the right direction)
pleural cavity
- fluid filled cavity in which the lungs sit
- pleural cavity is contained by 2 pleural membranes which are slippery to stop them from sticking to each other during breathing
Emphysema
a lung condition which causes alveoli to fuse together, reducing the surface area for gas exchange
carbon monoxide
binds to haemoglobin in the blood to form carboxyhaemoglobin -> less haemoglobin for oxygen to bind to -> less oxygen transported around the body
an increase of aerobic respiration can cause…
- increase in expired CO2
- larger % of water vapour in expired air
- increase in inspired O2
- increased heat production (which could lead to thermoregulatory processes e.g. vasodilation, perspiration)
anaerobic respiration in animals
glucose -> pyruvate -> lactic acid +2ATP
-2 molecules of lactic acid are produced per glucose molecule
anaerobic respiration in plants and yeast
glucose -> CO2 + ethanol
-2 molecules of CO2 and 2 molecules of ethanol are produced per glucose molecule
