Introduction and anatomy of lungs, airways and blood supply Flashcards
What is ventilation?
the movement of air into and out of the lungs, it does not include the exchange of gas with the blood.
what are the main functions of the respiratory system?
- gas exchange
- acid-base balance- regulation of the extracellular fluid pH
- protection from infection
- communication via speech
what is the function of gas exchange?
for transporting oxygen to cells so they can respire aerobically and removal of toxic carbon dioxide
what is external respiration?
how we move oxygen from the environment to our cells and carbon dioxide away from our cells
what sort of blood does the pulmonary artery carry?
oxygen poor, carbon dioxide rich
what sort of blood does the pulmonary vein carry?
oxygen rich, carbon dioxide poor
why does respiratory rate and depth of breathing increase when muscles are working during exercise?
to cater for the increased energy deman
it allows substrate (oxygen) acquisition and waste disposal (carbon dioxide) to speed up.
why does heart rate and force of contraction increase when muscles are working during exercise?
to speed up substrate delivery to muscle via blood
and to speed up waste removal via blood
where is the only point of gas exchange in the lungs?
the alveoli (gas is exchanged with capillaries)
what is the steady state, in terms of gases?
there is a balance between net volume of oxygen/carbon dioxide exchanged at the lungs per minute and the net volume exchanged in the tissues.
what is the role of the nose in the respiratory system?
air enters the body through the nose, cilia and mucus trap particles and air is warmed and moistened.
what is the pharynx?
(aka throat) it is the section of the respiratory tract which is shared with the digestive system
what is the epiglottis and what is its role in the respiratory system?
a small flap of tissue that folds over the trachea and prevents food from entering it when you swallow. it is horizontal when you swallow but vertical when breathing
what is the larynx?
(aka voice box) contains vocal cords which vibrate to produce sound
what is the trachea?
the section of the respiratory tract just below the larynx, it is made up of rings of cartilage that support and protect it
what is a bronchus?
the bifurcates into two of these tubes which are the structures through which air enters and exits the lungs
what is the upper respiratory tract?
it consists of everything in the respiratory tract from the larynx up
what is the lower respiratory tract?
everything in the respiratory tract below the larynx
why do we breath through our nose at rest?
- the nasal tract contains more crevices so hasd a larger surface are and so it is better at moistening air
- also better and warming air, this helps easily maintain body temp and requires less energy than breathing through the mouth
how many lobes does the right lung have?
3
how many lobes does the left lung have?
2
how many secondary bronchi does the left lung have?
2
how many secondary bronchi does the right lug have?
3
where do tertiary bronchi take air to?
segments of the lung
what is patency?
the condition of being open
why are the cartilage rings in the trachea and bronchi important?
they maintain patency
how does resistance change moving further into the lungs?
it decreases, this is because the total area of the airways increases
what the conducting zone?
the trachea, bronchi and bromchioles
what is the respiratory zone?
respiratory bronchioles, alveoli and alveolar ducts
what is the function of the elastic fibres of the alveoli?
allows increase in volume of alveoli during inspiration and store energy which is released on expiration
what is the function of type I alveolar cells?
gas exchange
what is the function of the type II alveolar cells?
produce surfactant
reduces surface tension at alveolar surface
reduces work of breathing
what is anatomical dead space?
the air inside the conduction zone of the respiratory tract
what tissue is the lining of the upper respiratory tract?
ciliated pseudostratified columnar epithelium with gland (goblet cells), blood vessels and lymph nodes
what happens to the lining of the respiratory tract moving from the nose to the alveoli?
epithelium becomes more squamous
cilia lost
mucous cells lost
purpose of mucous?
traps particles
moistens air
provides large surface area for cilia to act on
