3.1- Exchange surfaces Flashcards
Do small animals have a large or small surface area to volume ratio?
Large
How do you calculate surface area to volume ratio?
Divide the surface area by the volume
Why do single-celled organisms normally not need specialist transport systems?
The substances can diffuse directly into or out of the cell across the membrane
The diffusion rate is quick because of the small distances
Why do multicellular organisms normally need specialist transport systems?
There’s a large diffusion distance
They have a low surface area to volume ratio
They have a high metabolic rate, so use up oxygen in glucose faster
What three features improve the efficiency of specialised exchange surfaces?
Large surface area
Thin
Good blood supply / ventilation
How are root hair cells adapted for efficient exchange?
The cells and plant roots grow into long have which stick out into the soil and gives the roots and large surface area which increases the rate of absorption of water and mineral ions
How are alveoli specially adapted for efficient exchange?
Each alveolus is made from a single layer of thin flat cells which decrease the diffusion distance
The large capillary network surrounding each alveolus helps maintain concentration gradient
Name 4 substances an organism needs to exchange with its environment.
Oxygen, glucose, carbon dioxide, urea
How are fish gills specially adapted for efficient exchange?
They contain a large network of capillaries and a well ventilated which maintains a high concentration gradient
What are the exchange organs in mammals?
Lungs
Describe the route that air takes to get to your lungs.
Trachea splits into two bronchi
Each bronchus then branches off into bronchioles
The bronchioles go to the alveoli
What is the function of goblet cells?
Goblet cells secrete mucus which traps microorganisms and dust particles, stopping them from reaching the alveoli
What is the function of cilia?
Cilia move mucus upwards away from the alveoli towards the throat where it is swallowed to prevent lung infection
What is the function of elastic fibres?
Elastic fibres help the process of breathing out.
On inhalation, the fibres are stretched and then recoil during exhalation
What is the function of Smooth muscle?
Smooth muscle Lines the walls of the trachea, bronchi and bronchioles
It allows there diameter be to be controlled so that during exercise, the tubes are wider
What is the function of rings of cartilage in the trachea and bronchi?
Rings of cartilage stop the trachea and bronchi collapsing when you breathe in and the pressure drops
Does the trachea contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: Large c shaped pieces Smooth muscle: Yes Elastic fibre: Yes Goblet cells: Yes Epithelium: Ciliated
Does the Bronchi contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: smaller pieces than tranchea Smooth muscle: Yes Elastic fibre: Yes Goblet cells: Yes Epithelium: Ciliated
Does the Larger Bronchiole contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: No Smooth muscle: Yes Elastic fibre: Yes Goblet cells: Yes Epithelium: Ciliated
Does the Smaller Bronchiole contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: No Smooth muscle: Yes Elastic fibre: Yes Goblet cells: Yes Epithelium: Ciliated
Does the Smallest Bronchiole contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: No Smooth muscle: No Elastic fibre: Yes Goblet cells: No Epithelium: No cilia
Does the Alveoli contain cartilage, smooth muscle, elastic fibres, goblet cells and epithelium?
Cartilage: No Smooth muscle: No Elastic fibre: Yes Goblet cells: No Epithelium: No cilia
Where is cartilage found in the mammalian gas exchange system?
Trachea and bronchi
Where is smooth muscle found in the mammalian gas exchange system?
Trachea
Bronchi
Large bronchiole
Smaller bronchiole
Where are elastic fibres found in the mammalian gas exchange system?
Everywhere!
Where are goblet cells found in the mammalian gas exchange system?
Trachea
Bronchi
Larger bronchiole
Where is non ciliated epithelium found in the mammalian gas exchange system?
Alveoli and smallest bronchiole
What is the process of inspiration?
The external intercostal muscles and diaphragm contract
The rib cage moves upwards and outwards
The volume of the thorax increases
The lung pressure decreases below atmospheric pressure
This causes air to flow into the lungs
What is the process of expiration?
The intercostal and diaphragm muscles relax
The rib cage moves downwards and inwards
The thorax volume decreases
The lung pressure increases above atmospheric pressure
Air is forced out of the lungs
Is inspiration a passive or active process?
Active process
Is expiration a passive or active process?
Passive process
What is the definition of tidal volume?
The volume of air in each breath
What is the definition of vital capacity?
The maximum volume of air that can be breathed in or out with each breath
What is the definition of breathing rate?
How many breaths taken in a given amount of time
What is the definition of oxygen consumption?
The rate at which an organism uses up oxygen
What machine can be used to investigate breathing?
Spirometer
Subject X is connected to a spirometer. When subject access is inhaling, what will the spirometery trace be doing?
Going down, as the air in the chamber is decreasing
Subject X is connected to a spirometer. When subject access is exhaling, what will the spirometery trace be doing?
Going up, as the air in the chamber is increasing
What is the purpose of a soda lime in spirometery?
The soda lime absorb carbon dioxide so the subject only breathes oxygen
What is the purpose of a valve in a spirometery setup?
It ensures the inhaled and exhaled air passes through the soda-lime so carbon dioxide is absorbed
What are the three structures that make up fish Gills?
Gill filaments
Gill plates
Gill Arch
How are Gill plates adapted for efficient gas exchange?
They have lots of blood capillaries and a thin surface layer of cells to speed up diffusion
They also have a counter-current system which maintains a large concentration gradient
How are fish Gills ventilated in bony fish?
The fish opens its mouth which lowers the floor of the buccal cavity and water is sucked in
The fish then closes its mouth and the floor of the buccal cavity is raised which forces water out across the Gill filaments
The operculum opens and water leaves the gills
How do you dissect fish Gills?
Push back the operculum and cut each gill arch through the bone at the top and bottom
How does the counter-current system in bony fish maintain a large concentration gradient?
Blood flow through the Gill plates in One Direction and water Flows In the opposite direction
The concentration of oxygen in the water is always higher than that in the blood so diffusion occurs
What do insects use for ventilation?
Tracheae- microscopic air filled pipes
How does air move into the tracheae?
Through pores on the insects surface called spiracles
Describe the route that oxygen takes through insects?
Spiracles Tracheae Tracheoles Fluid Individual cells
