Chapter 7 ~ Exhange Surfaces And Breathing Flashcards
Why are specialise exchange surfaces needed?
Because they provide a surface area to volume ratio, which is needed for diffusion
For metabolic activity
Single celled and multicellular organisms
What are the features of an efficient exchange surface?
Increase surface area which is provided by the root hair cells
Thin layer provided by the alveoli
Good blood supply/ventilation to maintain gradient provided by the girls and alveolus
Mammalian gas exchange system:
Explain the features of nasal cavity
Large surface area with good blood supply this warms the air to body temperature. It has a hairy lining which secretes mucus to trap dust and bacteria. It has a moist surface which increases the humidity of incoming air which reduces evaporation from exchange services.
Mamalian gas exchange system:
What is the function and structure of a trachea?
It is a wide tube, supported by incomplete ring of strong fixable cartilage which provides support. The rings are incomplete so that food can move easily. It is lined with ciliated epithelium with goblet cells between and below the epithelial cells. The goblet cells to create mucus and the cilia beat and move the mucus
Mammalian gas exchange system:
Explain the function and structure of bronchus and bronchioles
The trachea splits to form two bronchi, which form bronchioles. the bronchioles contain cartilage for structural support. The smaller bronchioles have no cartilage rings, and the walls of the bronchi contains smooth muscles. When the small smooth muscles contract, the bronchi constrict when it relaxes the bronchi dilate.
** mammalian gas exchange system:**
Describe the structure and function of alveoli
Alveoli are the main gas exchange surfaces of the body.
It has a large surface area, Good blood supply provided by lots of capillaries surrounding the alveolus Its one cell thick which provides a short diffusion distance -
There are moist surfaces which dissolve gases and facilitates diffusion.
Made up of thin flat cells
What are the two ways of ventilate from the lungs?
Inspiration and expiration
Explain the process of inspiration
The external intercostal muscles contract and the internal intercostal muscles relax.
The rib cage moves in and out and the diaphragm muscles contract flatten and move down.
The volume of the thorax increases .
The pressure in the thorax decreases and becomes lower than atmospheric pressure .
Air flows into the lungs and down the pressure.
Explain the process of expiration
The external intercostal muscles relax and the internal intercostal muscles contract.
The rib cage moves down and inwards.
The diaphragm muscles relaxes and moves up.
The volume of the thorax decreases.
pressure in the thorax increases and becomes higher than atmospheric pressure.
Air flows out of the lungs down a pressure gradient
What are ways to measure the capacity of the lungs with explanation?
A peak flow meter measures, the rate at which air can be exhaled from the lungs
A vitalograph is a sophisticated version of the peak flow meter
A spirometer measures the volume of air inhaled and exhaled
Explain the definition of tidal volume
It is the volume of air in each breath
Explain the definition of vital capacity
It is the maximum volume of air a person can expel from lungs after maximum inhalation
What is oxygen uptake / consumption
Volume of oxygen used up by body
What is the breathing rate?
Number of breath taken per minute
Process of ventilation in fish
1.the fish opens its mouth, lowering the floor of the buccal cavity. This increases the volume of buccal cavity which lowers the pressure in the buccal cavity
2. As pressure in the buccal cavity is lower than outside pressure, water flows up.
3. The fish closes its mouth raising the floor of the buccal cavity. Volume inside buccal cavity decreases,pressure increases and water is forced out across gill filaments
4. The pressure now builds up in cavity which forces that are to open and water out.
Explain, expiration in fish
The mouth opens. The floor of the mouth is lowered, this increases volume of buccal cavity. Pressure decreases und water moves into buccal cavity. Opercular value closes and opercular cavity expands. The pressure lowers and floor of buccal cavity moves up increasing pressure so water moves out
Explain, inspiration in fish
The mouth closes, the operculum opens and the sides of the opercular cavity move inwards. All of these actions increase the pressure in the opercular cavity and force water over the gills and out of the operculum. The floor of the buccal cavity is steadily moved up, maintaining a flow of water over the gills.
How does gas exchange take place in insects?
In the thorax and abdomen of insects, there are small openings known as spiracles air enters and leaves the system through the spiracles, but water is also lost. The spiracles sphinicors are kept closed as much as possible to minimise water loss.
Explain gas exchange of insects
Waterproof waxy cuticles which reduce evaporation
Thin hairs
Spiracles where air enters and leaves, this is opened and closed by sphincters
tracheae lined by spirals of hint in which is impermeable to gases
Explain how tracheal fluid buildup in insects
The end of the trachioles are filled with water, the muscle cells which are around the tracheal respire and carry out an aerobic respiration. This produces lactate. This lowers the water potential and water moves from the tracheal into the cell via osmosis. This decreases the volume of liquid in the tragal, causing more air from the atmosphere to move in.
What are ways, insects control water loss?
The closest very close using muscles/sphinicters
They have waterproof, waxy cuticles, which were reduces evaporation
They have thin hairs which also reduce evaporation
Explain the countercurrent system of gas exchange in fish
Blood in the capillaries flow in the opposite direction to the water to maintain the concentration gradient of oxygen in the blood
Oxygen concentration in the water is higher than in blood so lots of water flow in
What is the function of cartilage?
It’s strength and flexibility provides support and prevent the airways from collapsing when pressure drops during inhalation
What do globlet cells do?
They secrete mucus which which traps dust and microorganisms to prevent infection
Explain smooth muscle
They control and relax to expand a narrow airways
Explain elastic fibre
They stretch when we breathe in and recoil when we breathe out
Explain cilia
Beat to move mucus up towards the throat when when it swallowed and destroyed by stomach acid
Explain ciliated epithelium
It is at tissue which contains hair like projections called cilia which help move particles out of the body
