Chapter 6 Flashcards
Why is the volume of oxygen that has to be absorbed and the volume of carbon dioxide that has to be removed large?
They are large organisms with a lot of respiring cells
They have high metabolic rates so require a lot of respiration
What do lungs do?
Ensure efficient gas exchange occurs
Why are lungs located in the body?
Because air isnt dense enough to support and protect the delicate structures
The body would loose a great deal of water and dry out
What are the lungs protected by?
Ribcage
What are the lungs made up of?
A series of highly branched tubules - bronchioles - ending in tiny sacs called alveoli
What is the structure and function of the trachea?
A flexible airway supported by rings of cartilage which prevents it from collapsing when the air pressure decreases when breathing in
The walls are made of muscles and lined with ciliated epithelial cells
What is the structure and function of the bronchi?
2 division of the trachea with each division leading to 1 lung
They produce mucus to trap dirt particles and cilia move it towards the throat
What is the structure and function of the bronchioles?
Are a series of branching subdivisions of the bronchi.
The walls ate made up of muscle and lined with epithelial cells which allows then to constrict so that they can control the flow of air in and out of the alveoli
What is the structure and function of the alveoli?
Small air sacs at the end of the bronchioles. Between the alveoli there are some collagen and elastic fibres what allow the alveoli to stretch as they fill with air and string back to expel carbon dioxide rich air
What is the approximate size of the alveoli ?
100 micrometres to 300 micrometres in diameter
What is the gas exchange surface in the lungs?
The alveolar membrane
What is ventilation?
The idea of moving air in and out of the lungs to maintain a steep concentration gradient
Which intercostal muscles contract and which relaxed in inspiration?
External intercostal muscles contract
Internal intercostal muscles relax
Which intercostal muscles contract and which relaxed in expiration?
Internal Intercostal muscles contract
External intercostal muscles relax
Which 3 muscles are needed for pressure changes in the lungs?
Diaphragm
Internal intercostal muscles
External intercostal muscles
Is inspiration active process or a passive process?
Active
Is expiration active process or a passive process?
Passive
Explain the process of inspiration
External intercostal muscles contract and internal intercostal muscles relax
The ribs are pulled upwards and outwards
The diaphragm muscles contract and it flattens
These increase the volume so the pressure of the lungs decreases
The atmospheric pressure is now greater than the lung pressure so air is forced into the lungs
Explain the process of expiration
The internal intercostal muscles contract and the external intercostal muscles relax
The ribs move downwards and inwards
The diaphragm relaxes so it is pushed upwards by the contents of the abdomen that had been compressed earlier
The decreased volume of the thorax increases the pressure in the lungs so the atmospheric pressure is less so air is forced out of the lungs
What is pulmonary ventilation rate?
How much air is taken in and out of the lungs in a given time