Chapter 4: Exchange surfaces Flashcards
What are the properties of a good exchange surface?
Large surface area, thin for maximized diffusion, must have a diffusion gradient, not dry
How does oxygen and CO2 diffuse into lungs?
A blood capillary is very close to an alveoli and these both have 1 cell thick walls
What group of muscles move the lungs?
The diaphragm
How are epithelial tissue in the airways adapted?
Tubes leading down to the lungs are lined with this tissue and it is adapted to remove particles from the air before it reaches the lungs
Name the two type of cells that make up epithelial tissue?
Ciliated cells and goblet cells
Cilium contains what to allow it to slide?
Microtubules, makes it able to bend
What do goblet cells secrete?
Mucus
Mucus contains what?
Glycoproteins, makes it slimy and sticky
How does mucus help the epithelium?
Prevents it from drying out and traps particles before reaching alveoli
Where do you find smooth muscle in the lungs?
Trachea, bronchi and bronchioles, it is an involuntary muscle so it contracts steadily on its own
What tissue is not found in the bronchioles?
Cartilage
How do elastic fibers help the alveoli?
During breathing in, the alveoli expand stretching the elastic fibers. during breathing out the fibers recoil helping decrease the volume
When breathing what happens to the lungs?
Pressure decreases as volume increases. External intercostal muscles contract to move rib cage up and out. Diaphragm contracts to bring it lower, to increase volume =
What happens to your lungs when breathing out?
Elastic fibers are stretched, diaphragm and intercostal muscles relax. Pressure increases
What does vital capacity mean?
Greatest volume of air you can breath in and out of your lungs in one breath
Tidal volume?
Normal volume of air breathed in and out at once
Inspiratory reserve volume definition?
The extra air you breath in after taking a deep breath
Expiratory reserve volume definition?
Extra air breathed out
Equation for surface area of a sphere?
4πr squared
Equation for the volume of a sphere?
4/3πr cubed
Process of breathing out?
External intercostal muscles relax and the rib cage moves down, diaphragm relaxes making pressure increase and volume decrease, air moves out down the pressure gradient
Process of forced breathing out?
Contraction of internal intercostal muscles moving rib cage further down, volume decrease and pressure increase in the thorax. Abdominal muscles contract and raise the diaphragm further upwards
Alveoli adaptations?
Very close to capillaries to maximise gas exchange into the blood, 1 cell thick walls for shorter diffusion distance, lots of air spaces for more oxygen to fit, contain elastic fibres
Where is the cartilage in the lungs?
Supports the walls of the trachea and bronchi
What measures an individuals lung capacity?
Spirometer
Describe how a spirometer works?
Person breathes in and out of a chamber. Inside the chamber there is water making it float up and down when breathing. Breath in volume decreases and vice versa. The chamber has a pen attached to a kymograph to record the volumes
what absorbs the CO2 in a spirometer?
Soda Lime
Precautions to take when using a spirometer?
Ensure you have a healthy patient, sterilise the mouthpiece and use a nose clip to prevent unwanted air leaving
