The Respiratory System Workbook Flashcards
The respiratory system
The respiratory system provides oxygen to all living tissue in your body, as well as removing waste products such as carbon dioxide, heat and water Vapour. Oxygen is required for every cell in your body to function.
Central to the respiratory system are your lungs which enable oxygen to enter the body and carbon dioxide waste to be removed through the mechanism of breathing.
Your bodies ability to inhale and transport oxygen while removing waste products is critical to sports performance: the better your body is at this process, the better you will be able to train or perform in sport.
Nasal cavity
filter and warms the air, and make it moist before it goes into the lungs.
Pharynx
Pathway for food as well as air.
Larynx
Allows you to speak
Trachea
Know as the windpipe.
Made of rings of cartilage.
Epiglottis
Closes at the top of the trachea when you swallow to ensure food and drink passes into the stomach and not the lungs
Lungs
The organ that allows oxygen to be drawn into the body.
Bronchi
Branches off the trachea and transports oxygen to lungs.
Bronchioles
Branch off the main bronchi and are small airways that connect to alveoli.
Alveoli
Tiny air sacks found at the end of every bronchioles.
Thin walls for gas exchange to take place.
Transfers oxygen into the blood as well as carbon dioxide out of it.
Diaphragm
It is a large, dome-shaped muscle that contracts rhythmically and continually, and most of the time, involuntarily. Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges.
Thoracic cavity
Provides protection and support to the body’s vital organs. The thoracic cavity is surrounded by the rib cage and several layers of membranes, which help keep the organs protected from any dangers in the environment.
Internal intercostal muscles
Responsible for expiration by lowering the rib cage and pulling it inwards.
External intercostal muscles
Responsible for inspiration by pulling the rib cage upwards and outwards - increasing the size of the thoracic cavity.
Inspiration
Diaphragm contracts (flattens)
Intercostal muscles contract
Ribs move outwards and upwards
Volume of the thoracic cavity increases
Lung air pressure decreases under atmospheric pressure
Air rushes into the lungs
Expiration
Diaphragm relaxes (dome shaped)
Intercostal muscles relax
Ribs move downwards and inwards
Volume of the thoracic cavity decreases
Lung air pressure increases increases above atmospheric pressure
Air rushes out of the lungs
Gaseous exchange
Blood entering the heart from the pulmonary arteries has a lower partial pressure of oxygen and therefore oxygen diffuses into the blood and binds onto the haemoglobin.
Similarly carbon dioxide diffuses in the opposite direction, from the blood to the alveoli due to the lower CO2 in the alveoli.
Tidal volume
The amount of air that can be breathed in or out in one breath.
Usually around 500mL.
Minute ventilation (VE)
The volume of air passing through the lungs each minute.
EV = Tidal Volume x Breathing Rate
Residual volume
This is the amount of air that remains in the lungs after maximal expiration.
The lungs never fully empty otherwise they would collapse.
Vital capacity
It is the total amount of air exhaled after maximal inhalation.
It is normally around 4800ml
Inspiratory reserve volume
The extra volume of air that can be inspired with maximal effort after reaching the end of a normal inspiration.
Expiration reserve volume
The amount of additional air that can be breathed out after normal expiration.
Total lung volume
The total lung capacity after you have inhaled as deeply as you can and after maximal inspiration.
Neural control
Breathing is controlled by neurones (cells that conduct nerve impulses) in the the brain stem.
Neurones in two areas of the medulla oblongata are critical in respiration.
There are the dorsal respiratory group (DRG) and the ventral respiratory group (VRG).
VRG responsible for the rhythm generation that allows rhythmic and continuous breathing.
Chemical control
Change in the level of O2 and CO2 in the blood are other factors that control breathing.
Chemoreceptors detect changes in blood CO2 levels and blood acidity.
Chemoreceptors will then send signals to the medulla oblongata.
The medulla oblongata will then either increase/decrease the frequency of signals to the respiratory muscles in order to change the breathing rate.
