5 Breathing and Respiratory System Flashcards
Define respiration
A chemical reaction which occurs in all living cells, requiring oxygen and glucose. It takes place in the mitochondria, continuously releasing energy in all cells that organisms can use for heat, movement, growth, reproduction and active transport
Name three ways that energy released from respiration is used
- Reproduction
- To provide heat to keep organisms warm
- Movement e,g to allow muscles to contract
Word equation for respiration
Oxygen + glucose —> carbon dioxide + water + energy (atp)
Balanced Chemical equation for respiration.
6O2 + C6H12O6 —> 6CO2 + 6H2O + energy (atp)
Why does anaerobic respiration occur?
To allow muscle cells to continue to function when they are in conditions in which the cells demand more oxygen than can be supplied in the bloom stream
Equation for anaerobic respiration
Glucose —> Lactic Acid + energy
What is an oxygen debt?
When more oxygen is used to break down the lactic acid that has built up
Equation for anaerobic respiration in yeast
Glucose —> ethanol + carbon dioxide + energy
Change in diaphragm when inhaling
Diaphragm contracts and flattens
Change in diaphragm when exhaling
Diaphragm relaxes and comes upwards
One structure in the respiratory system that isn’t represented by the Bell jar lung model
Intercostal muscles
Changes in the bell jar which cause the balloon to inflate
When the rubber sheet is pulled down the volume increases, the pressure decreases and the balloons inflate
Three ways that aerobic respiration differs from anaerobic respiration in muscles
- During aerobic respiration lactic acid is not built up as a product
- Aerobic respiration produces more energy
- Aerobic respiration takes place at all times whenever there is a good supply of oxygen
Describe how two features of the respiratory system adapt for efficient gas exchange
- The alveoli are air sacs with walls only 1 cell thick to decrease diffusion distance
- The good blood supply maintains a concentration gradient enabling efficient diffusion
What are alveoli? (5)
- They are air sacs with walls only 1 cell thick which are the sites of gas exchange
- they provide a large surface area around 80m2
- the inner surfaces of alveoli keep air moist and allow the diffusing gases to dissolve
- their walls are highly permeable
- there is a steep concentration gradient between blood containing low oxygen and high carbon dioxide and air containing high oxygen and low carbon dioxide
When the rubber sheet is pulled down how does this affect the volume inside the bell jar?
The volume increases
As the volume increases, how does this affect the pressure inside the bell jar ?
The pressure decreases
Inhaling :
Diaphragm contracts and flattens. Intercostal muscles contract Rib cage moves up and out Volume of chest cavity is increase Pressure is decreased Air is drawn into the lungs
Why is the left lung smaller than the right?
The left lung has to share chest cavity space with the heart
What does the pleural cavity surrounding the lungs contain and what is it’s function
It contains a pleural fluid which helps to reduce the friction between the rib cage and lungs
Why are the lungs, bronchi and trachea prone to a variety of infections ?
They are kept moist and warm which are good growth conditions for bacteria
Why are the reinforcing rings of cartilage on the trachea C shaped with the gap at the back ?
The rings are to protect the trachea and are easily collapsible in order to allow food to travel down the oesophagus
What causes the difficulty in breathing with an asthma attack ?
The spasms in the lungs and bronchi cause the airways to narrow.
Why does the thorax need to be airtight?
Allows a change in pressure
Explain how two named features of the respiratory system adapt it for efficient gas exchange
- The alveoli are air sacs with walls only 1 cell thick to decrease diffusion distance and allow efficient gas exchange
- Good blood supply maintains a concentration gradient
Describe and explain the differences in the composition of inhaled and exhaled air
- Oxygen is essential to the body, therefore the amount exhaled is smaller than the amount inhaled.
- CO2 is a waste product or respiration and therefore the amount inhaled is going to be smaller than the amount exhaled
- Exhaled air is warmer, inhaled air has more moisture
- Gases are transported into the blood
- Oxygen gas diffuses from the lungs into the blood and less is released outside the body
- Respiration taking place in the body cells means energy, excess oxygen and CO2 are released
Anaerobic respiration in yeast
Glucose —> energy + alcohol + carbon dioxide
Trachea
A long tube leading from the larynx to the lungs
Bronchus
Branch of the trachea which delivers air into the lungs
Bronchioles
Small branching tubes of the bronchi which end in a group of alveoli
Alveoli
Tiny air sacs with walls only one cell thick. Sites of gas exchange
Pleural membranes
Membranes that create a cavity surrounding the lungs and hold the pleural fluid
Pleural fluid
Fluid held in the membranes which help to reduce friction by lubricating the movement of the lungs
Adaptions of respiratory surfaces:
- large surface area
- thin
- moist
- permeable
- good blood supply
- diffusion gradient
Similarities between anaerobic respiration in yeast and human muscle cells (2)
- Amount of energy released is much less than the amount released by aerobic respiration
- CO2 is a product and glucose is a reactant
Differences between the anaerobic respiration of human muscle cells and yeast
- Ethanol produced in yeast
- Lactic Acid produced in human cells
