3.1 Exchange surfaces and breathing Flashcards
What are the 2 main reasons why diffusion alone is enough to supply the needs of single celled organisms?
- the metabolic activity of a single celled organism is usually low so the O demand and CO2 production are relatively low
- the SA:V of the organism is large
What are the characteristic features of effective exchange surfaces?
- increased surface area
- thin layers
- good blood supply
- ventilation to maintain diffusion gradient
Where does gas exchange occur in the human body?
The lungs
What are the important features of the nasal cavity?
- large surface area
- hairy lining
- moist surfaces
What are the important features of the trachea?
- strong flexible cartilage to prevent collapse
- lined with ciliated epithelium
- presence of goblet cells
What type of muscle do the bronchioles contain?
smooth muscle
What are the alveoli?
Tiny air sacs which are the main gas exchange surfaces of the body
What are the main adaptations of the alveoli for effective gas exchange?
- large surface area
- thin layers
- good blood supply
- good ventilation
What parts of the body are involved with ventilation?
- rib cage
- diaphragm
- internal and external intercostal muscles
- thorax lined with pleural membranes
Is inspiration an energy using or passive process?
energy using
Is expiration an energy using or passive process?
passive
Do the ribs go up or down during inspiration?
up
Does the diaphragm go up or down during expiration?
up
Name 3 ways of measuring the capacity of the lungs?
- Peak flow meter
- Vitalographs
- Spirometer
What are the 6 different components of lung volume that can be measured?
- Tidal volume
- Vital capacity
- Inspiratory reserve volume
- Expiratory reserve volume
- Residual volume
- Total lung capacity
What is the tidal volume?
The volume of air that moves into and out of the lungs with each resting breath
What is the vital capacity?
The volume of air that can be breathed in and out when the strongest possible exhalation is followed by the deepest possible intake of breath
What is the inspiratory reserve volume?
the maximum volume of air that you can breath in over and above a normal inhalation
What is the expiratory reserve volume?
the extra amount of air you can force out of your lungs over and above the normal tidal volume of air you breathe out
What is the residual volume?
the volume of air that is left in the lungs when you have exhaled as hard as possible. this cannot be measured directly
What is the total lung capacity?
the sum of the vital capacity and the residual volume
How is ventilation rate calculated?
ventilation rate = tidal volume x breathing rate
How does gaseous exchange take place in insects?
air enters and leaves the system through spiracles which are opened/closed by sphincters it travels through the tracheae lined with chitin, leading to tracheoles which are not lined with chitin so gas can exchange freely
How are the gills adapted for efficient gas exchange in bony fish?
- large surface area
- good blood supply
- thin layers
- maintain a continuous flow of water in one direction
What is the name of the part of the gill that helps fish to maintain a constant flow of water over the gills even when they stop moving?
Operculum
What 2 additional adaptations do gills have?
- the tips of adjacent filaments overlap
- the water flowing over the gills and the blood in the fill filaments move in opposite directions
