Exchange Surfaces And Breathing Flashcards
(36 cards)
What effects the exchange of substances?
The organisms surface area to volume ratio.
Why do cells need to take in oxygen?
For aerobic respiration and nutrients.
Which animals have a higher surface : volume ratios?
Smaller animals
What does an organism need it supply it’s cells with?
Glucose and oxygen, it also needs to remove waste products to avoid damaging itself.
What’s happens in single felled organisms?
The substances can diffuse directly into or out of the cell across the sell surface membrane.
Why is the diffusion rate quick In single called organisms?
They only have to travel small distances, it is one cell thick.
Why is diffusion rates slow In multicellular organisms?
The cells can be deep within the body, there is abut distance between them and the outside environment. Larger animals have a low surface area to volume ratio, it’s difficult to exchange enough substances to supply a large volume of animal through a relatively small outer surface.
Multicellular animals need specialised exchange substances like lungs, how do the lungs work?
As you breath in air enters the trachea which splits into two bronchi. There is one bronchus leading to each lung. Each bronchus then branches off into smaller tubes called bronchioles. The bronchioles end In small air sacs called alveoli. This is where gases are exchanged.
What body parts work together to move air in and and out?
Ribcage, intercostal muscles and diaphragm.
Where does gas exchange actually occur?
Alveoli, the lungs contain millions. They are the gas exchange surface.
What are the alveoli made from?
A single layer of thin, flat cells called alveolar epithelium.
Where are the alveoli?
They are arranged in bunches at the end of bronchioles. They are surrounded by a network of capillaries.
What happens in the alveoli?
O2 diffuses out of them, passes the capillaries and enter the haemoglobin in the blood. CO2 diffuses into the alveoli from the blood.
What characteristics do gas exchange substances have?
Large surface area, in the lungs the alveoli provide a large surface area.
They are thin to give it a short diffusion pathway.
What do goblet cells do?
They secrete mucus, the mucus traps micro organisms and dust particles In the inhaled air, stopping them from reaching the alveoli.
What do cilia do?
They are on the surface of cells and they beat the mucus moving it upwards away from the alveoli towards the throat. Here it is swallowed.
Where are elastic fibres found?
On the walls of the trachea, bronchi, bronchioles and alveoli.
What do elastic fibres do?
Help the process of breathing out. When breathing in the lungs inflate and the elastic fibres are stretched, they then recoil to help push the air out.
Where is smooth muscle found?
Walls of the trachea, bronchi and bronchioles.
What’s does the smooth muscle do?
It allows the diameter to be controlled, during exercise they relax so the tubes get wider.
Where are rings of cartilage found?
On the walls of the trachea and bronchi.
What’s the role of the rings of cartilage?
They provide support, they are strong and flexible.
Which parts of the lung have ciliated epithelium?
Trachea, bronchi, large and small bronchioles. The smallest bronchioles and alveoli have no cilia.
What is ventilation?
Breathing in and out. It consists of inspiration and expiration. ( breathing in and breathing out).
