Anatomy of Breathing Flashcards
Week 1 Resp
What route does air take when it enters the body?
The upper respiratory tract- Nasal cavaties Oral cavity Pharynx - voice box Larynx The lower respiratory tract- Trachea Right and left main bronchus Lower bronchi Segmental bronchi Bronchioles Alveoli
What happens at the level of the C6 vertebrae?
The larynx becomes the trachea
The pharynx becomes the oespohagus
What is the respiratory tree?
This describes the anatomy of the lower respiratory tract airways from the trachea to the alveoli.
How many lobar bronchi are there?
There are 5 lobar bronchus, one for each of the lung lobes.
How many segmental bronchi are there?
There are 10 segmental bronchi, one for each of the bronchopulmonary segments
What is a bronchopulmonary segment?
This is a portion of the lung supplied by a specific segmental bronchus and its respective vessels
What is a lung lobe?
This is an area of the lung that each of the lobar bronchi supply with air.
What are the names of the lung lobes?
Right - upper lobe, middle lobe and lower lobe.
Left - upper lobe and lower lobe
What is a fissure?
These are the deep crevices that separate the lobes form each other
What is the lingula?
This is an extension of the left upper lobe. It is thought to be the replacement for the middle lobe on the left hand side.
What lines the proximal areas of the respiratory tree?
This is known as respiratory epithelium. Mucous glands secrete mucous onto the epithelial surface. Cilia beat the mucous and foreign bodies superiorly towards the pharynx.
What is the mucociliary escalator?
This is the action of the cilia moving mucous up the respiratory tract.
What supports the walls of the trachea and bronchi?
Hyaline cartilage assists with the patency of the airways meaning that it keeps them open. The amount of hyaline cartilage in the airways gradually reduces as we get more distal.
Describe the cartilage within the walls of the of the distal bronchioles and alveoli.
There is no cartilage within their walls as this would restrict gas exchange
Describe the walls of the alveoli.
Alveoli must have neither cartilage or smooth muscle in their walls. This would reduce diffusion rates as their walls must be extremely thin.
What happens to the amount of smooth muscle as we move down the respiratory tract.
The amount of smooth muscle increases with the exception of the alveoli. The smooth muscle allows the bronchioles to constrict or dilate
What are the 4 principles of respiration?
- We must ensure that enought O2 and CO2 can diffuse between alveolus and blood at the pulmonary capillary beds.
- We must ensure that we can move air freely into and out of our lungs
- We must ensure that we move warm, moist clean air into and out of our lungs.
- We must protect our lungs.
What are the main requirements that allow for gas diffusion in the lungs?
- Sufficient functioning lung tissue.
- Sufficient oxygen in the air that we breathe
- No CO2 in the air we breathe.
- Minimal thickness of the walls of the alveoli to facilitate gaseous diffusion.
- Minimal tissue fluid in the tissue spaces around the alveolar capillaries to facilitate gaseous diffusion.
What is an oedema?
Build up of tissue fluid that would prevent or reduce gas exchange
What are the main dangers that would prevent air moving freely in and out of the lungs?
- The respiratory tract can become narrowed by bronchiole constriction, the mucosa lining can swell and overproduce mucous or a tumour may grow and compress the respiratory tract.
- Foreign bodies may be inhaled.
How do we keep our upper respiratory tract patent?
There are two nasal cavaliers in the skull that are separated by an internal wall called the SEPTUM. The posterior part of the nasal septum is bone and the anterior part is cartilage.
There are also several cartilages in on the larynx
What are the bones that make up the nasal septum?
The superior ethmoid bond and the inferior vomer bone
What are the names of the cartilages that make up the larynx?
The epiglottis, the thyroid cartilage, the cricoid cartilage and the 2 arytenoid cartilages.
What are the functions of the larynx?
Cartilages help to maintain the patency of the URT.
The larynx helps to prevent entry of foreign bodies to the LRT.
The vocal cords produce sounds.
What is the rima glottidis?
The narrowest part of the larynx. The vocal cords are on either side. Large foreign bodies tend to block the URT at the rima glottidis.
What is the cough reflex used for?
To expel foreign bodies that have been inhaled into the trachea. It is stimulates to remove these via the pharynx and oral cavity.
What is phonation?
The is the mechanism of producing sound. Air is expired across the vocal cords and the cords will vibrate to produce sound. The cords will also change shape.
What is articulation?
This is when the sound that is produced from the vocal cord is modified in the nose or the mouth to produce vowels and consonants.
What is the heimlich manoeuvre?
This is a manoeuvre that involves using abdominal pressure to force foreign bodies out of the respiratort tract.
What are the dangers of cooling or drying the respiratory tract?
This can lead to damage in the mucociliary escalator and will predispose to infection.
What are nasal conchae?
Nasal concha are several thin, scroll-shaped bony elements forming the upper chambers of the nasal cavities. They produce turbulent flow bringing air into contact with the walls.
How do we warm, humidify and clean the air that we breathe in?
- The nasal cavity has very good arterial blood supply that provides warmth.
- The respiratory mucosa produces mucous providing moisture.
- The sticky mucosa traps potentially infected particles.
- The cillia of the mucosa waft the mucous to the pharynx to be swallowed.
- The tonsils produce white blood cells in defence against infection.
What is the chest wall composed of?
Skin, fascia, bones, skeletal muscle, the diaphragm and the parietal pleura
What is the main danger to the chest wall?
Penetrating injuries.
Describe the bones of the chest wall.
- The STERNOCLAVICULAR JOINT at the top of the sternum where is meets the CLAVICLE.
- MANUBRIUM is the top of the sternum.
- THE STERNAL ANGLE is where the sternum meets the second rib.
- THE BODY is the central portion of the sternum.
- XIPHOID PROCESS is the bottom tip of the sternum.
- COSTAL MARGIN joins up the false ribs to attach them to the sternum.
Describe the joints of the thoracic skeleton.
- The COSTOVETEBRAL JOINTS are where the head of the rib and articulates with the body of the vertebrae above and the tubercle of the rib articulates with the same numbered vertebrae.
- The STERNOCOSTAL (SYNOVIAL) JOINTS are where the costal cartilage articulates with the sternum
- The COSTROCHONDRAL JOINTS are where the ribs articulate with the costal cartilage.
(These joints permit very little movement)
What is the costal groove?
This is a groove inferior on the deep surface of the ribs. This houses the neurovascular bundle.
Name the intercostal muscles of breathing.
- External intercostal muscles.
- Internal intercostal muscles
- Innermost intercostal muscles
What are the main muscles of respiration?
The diaphragm and the intercostal muscles.
What is pleural fluid?
This is fluid secreted by the parietal pleura into the pleural cavity. It is a lubrican the provides surface tension.
What is visceral pleura in the chest cavity?
This is pleura that covers the lungs.
What is parietal pleura?
This is pleura that covers the chest wall.
What is the potential space in the lung cavity?
This is an area of vacuum between the lung and the chest wall that allows the lungs to expand.
What direction do the intercostal muscles pull the chest wall?
They make the chest wall expand and pull the adjacent ribs upwards and outwards
Describe the intercostal spaces.
There are 11 pairs of intercostal spaces. Each contain a neurovascular bundle.
What is contained within the neurovascular bundle?
A nerve, vein and an artery.
Which nerve supplies the intercostal spaces?
Anterior ramus of spinal nerve - intercostal nerve
Name the posterior blood vessels to the intercostal spaces.
Arterial supply = Thoracic aorta
Venous drainage = Azygous vein
Name the anterior blood vessels to the intercostal spaces.
Arterial supply = Right and left internal thoracic artery
Venous drainage = Internal thoracic vein
Whereabouts do the arteries anastomose in the intercostal spaces?
At the midpoint of the intercostal spaces