3.3.2.3 Gas exchange in humans Flashcards
(29 cards)
What are the lungs supported and protected by?
The ribcage
What are lungs?
Lungs are a pair of lobed structure made up of a series of highly branched tubles called bronchioles
Each bronchiole ends with an alveoli
What is the trachea?
Flexible airway which is made of muscle which is supported by cartalige
What are some adaptations of the trachea?
Supported by rings of cartalige to prevent the collapsing of it
Lined with ciliated epiithelium cells to move mucus which may contain bacteria out
Goblet cells which produce mucus to trap any bacteria
What are bronchi?
Bronchi are two division of the trachea which lead to one lung
What are bronchioles?
Series of branching subdivisions of the bronchi
What are alveoli?
Alveoli are small air-sacs and are the site of gas exchange
What is intercostal muscle?
Intercostal muscle is the muscle that is present between each rib
What are the two types of intercostal muscle?
External and intercostal muscles
What is the process of inspiration (inhalation)?
- Internal IM relax while the external IM contract
- The ribs therefore get pulled upwatds and outwards, increasing the volume of the thoratic cavity
- The diaphragm mucles contract, causing it to flatten, which further increses the volume of the thoratic cavity
- This increase in volume decreases the pressure below atmospheric pressure. Which leads the movement of air into the lungs
What is the process of Expiration (exhalation)?
- Internal IM contract while the external IM relax
- The ribs therefore get pulled downwards and inwards, decreasing the volume of the thoratic cavity
- The diaphragm mucles relax, causing it to push up, which further decreases the volume of the thoratic cavity
- This decrease in volume increase the pressure above atmospheric pressure. Which leads the movement of air out of Ethe lungs
How to remember the movement of the intercostal muscles and diaphragm?
During Inspiration, the Internal EM relax
During Expiration, the External EM relax
The diaphragm does the same as the External EM
What type of process is inspiration/inhalation?
Active - Requires ATP
What type of process is expiration/exhalation?
Passive - Does not require ATP
What must be maintained in the alveoli for gas excahnge?
A continious concentration gradient
What are the adaptation of alveoli?
Thin - for a short diffusion pathway
Large Surface area - faster rate of diffusion
How does gas exchange happen in alveoli?
- Lage number of alveoli therefore there is a large surface area
- Alveoli are surrounded bt a network of capillaries
- Oxygen diffuses out of the alveoli, across the alveolar epithelium and the capilary endothelium and into haemoglobin in the blood
- Carbon Dioxide diffuses into the alveoli from the blood, and is breathed out
What is tidal volume (TV)?
The volume of air from each breath
What is Ventilation Rate?
THe number of breaths per minute
What is Forced expiratory volume 1 (FEV-1)?
The maximum volume of air that can be breathed out in 1 second
What is Forced Vital Capacity?
Maximum volumne of air it is posible to breathe forcefully out
What is pulmonary tuberculosis?
The immune system cells build a wall around the bacteria in the lungs which form small,hard lumps known as tubercles
The infecxted tissues then die
What does TB lead to?
