trachea, bronchial tree and lungs Flashcards
structure of trachea?
- fibrous and cartilaginous tube conducting air from larynx to bronchi
- 10-11 cm long
- around 2.5cm diameter
- from C6 to T4/T5
- c shaped rings to maintain latency
posteriorly of the trachea what is the muscle called?
What control is it under?
- trachealis which joins each end of the rings and controls the diameter
- under the control of the ANS and is responsible for altering tracheal diameter
Where does the trachea enter the thoracic cavity?
Where does the left recurrently laryngeal nerve lie in relation to the trachea?
Where does the trachea divide?
The trachea enters the thoracic cavity through thoracic inlet (rib 1, T1, superior manubrium)
The left recurrent laryngeal nerve lies in the groove between the trachea and the oesophagus
At the level of the Sternal angle (T4/5 intervertebral disc) the trachea divides into left and right principal (main) bronchi (at about 2cm below entry into thoracic cavity)
What is the trachea composed of?
Why is this?
What is the muscle in the trachea?
What is the role of this muscle?
What would happen if the trachea didn’t consist of cartilage?
The trachea is composed of C-shaped hyaline cartilages
This is to ensure the trachea stays open at all times
The trachealis muscle along with some fibrous tissue is found in the posterior trachea between the ends of the tracheal cartilages
The trachealis muscle is smooth muscle under the control of the ANS, and is responsible for altering the tracheal diameter
If the trachea didn’t consist of cartilage, it would collapse on inhalation due to the negative intra-thoracic pressure
what is the trachea continues with?
what does cricotrachael membrane connect with?
continuous airway from the larynx
the cricotrachael membrane will connect the first tracheal cartilage with cricoid cartilage
surrounding structures of the trachea:
posteriorly?
anteriorly?
posteriorly = oesophagus
anteriorly
= - thyroid gland
- brachiocephalic trunk, Left brrachiocephalic vein
- cardiac plexus nerves (sympathetic and parasympathetic)
- trachaebronchial nodes
- manubrium (manubriosternal joint)
what does the manubriosternal joint mark?
bifurcation of the trachea
lateral surrounding structures of trachea?
posterolateral surrounding structures of trachea?
lateral = - thyroid gland lobes
- parathyroid glands
- common carotid arteries
- aortic arch, common carotid and left subclavian artery
- azygos arch
- right vagus nerve.
posterolateral =
recurrent laryngeal nerves
arterial supply of the trachea?
inferior thyroid artery and bronchial arteries
venous drainage of trachea?
drains to the inferior thyroid and bronchial veins
lymph drainage of trachea?
lymph drains to pre and para tracheal nodes
neuro supply of the trachea?
- sympathetic and parasympathetic?
supplied by the pulmonary plexus
(Formed by pulmonary branches of the vagus nerve and the sympathetic trunk)
- sympathetic from sympathetic trunk (dilation)
- parasympathetic from vagus nerve (constriction)
If the trachea didn’t consist of cartilage what would happen to it?
It would collapse on inhalation due to the negative intra-thoracic pressure
Where does the trachea enter the thoracic cavity?
Where does the left recurrent laryngeal nerve lie in relation to the trachea?
Where does the trachea divide?
1- the trachea will enter through the thoracic inlet (rib 1, T1, superior manubrium)
2- the left recurrent laryngeal nerve will lie in the grove between trachea and the oesophagus
3- sternal angle
What 4 neurovascular structures will lie on the right of the trachea in the thoracic cavity?
What 2 neurovascular structures will lie on the left of the trachea in the thoracic cavity?
Right =
- right vagus nerve
- azygos vein
- SVC
- right brachiocephalic
Left =
- left vagus nerve
- left brachiocephalic vein
3 borders of the lungs?
1) Anterior border
* The anterior border of the lung corresponds to the pleural reflection, and it creates a cardiac notch in the left lung
2) Posterior border
* The posterior border is thick and extends from the C7 to the T10 vertebra, which is also from the apex of the lung to the inferior border.
3) Inferior border
* The inferior border is thin and separates the base of the lung from the costal surface
What prominent structures of the aortic arch can be seen at T3?
What prominent structures can be seen at T4?
T3=
- Brachiocephalic trunk
- left common carotid artery
- left subclavian artery
T4=
- cross section of aortic arch
- SVC (The right and left brachiocephalic veins have joined to form the SVC)
How does the right and left main bronchi is differ?
Right is short, wider and more vertical
What will the right and left main bronchi divide into?
How many lobar bronchi are in each lung?
Where does the bronchi receive blood from?
The main bronchi will divide into lobar (secondary) bronchi… which then subdivide into segmental (tertiary) bronchi
Left = 2 lobar bronchi
Right = 3 lobar bronchi
Bronchi receive blood from bronchial arteries (1right and 2 left )
How do segmental bronchi become respiratory bronchi?
Where is the greatest resistance to air flow?
What is the diameter of the bronchioles dependant on?
Segmental bronchi… terminal bronchi… respiratory bronchi
Bronchioles cause the greatest resistance to airflow in the conducting passages
The diameter of bronchioles is dependant on smooth muscle tone
What happens to the diameter of the bronchioles in asthma?
How can you treat it?
In asthma the smooth muscles contract strongly enough to almost completely shut
Salbutamol are B2 agonists and cause bronchodilation.
What happens as the size of the bronchial decreases?
How do you get from respiratory bronchi to alveolar sac?
As the size decreases, the number increases which will also increase the surface area
Respiratory bronchi… alveolar ducts… alveolar sacs
Describe the vascular urge around the alveoli?
- Pulmonary vasculature branches in a similar pattern around each bronchi
- forms capillary beds around alveoli
- alveoli are single cell thick
- this provides a large surface area for effect gas exchange
What are respiratory epithelium?
Describe the histology of bronchioles?
Ciliated pseudo-stratified columnar epithelium
- smooth muscle
- no cartilage, no glands
- has adjacent blood vessels
- surrounding alveoli
Describe the histology of terminal bronchiole?
- lumen on the right
- alternating thickness
- sparse smooth muscle
- club cells (non ciliated cuboidal epithelium)
Club cells produce a protective secretion
Describe the histology of acini?
- capillaries
- type 1 pneumocytes
- type 2 pneumocytes (septal cells, produce surfactant)
- alveoli
Main functions of the lungs?
- primarily gas exchange
- pH balance
- other metabolic functions (angiotensin 1->angiotensin 2)
- prostaglandin synthesis
What is lung parenchyma?
What does it consist of?
How does main bronchi branching differ between each lung?
Where is the pulmonary artery usually located in the root of the lung?
Where are pulmonary veins usually located in the root of the lung?
What is the pulmonary ligament made from?
What does it allow?
Lung parenchyma is the portion of the lungs involved in gas exchange
The lung parenchyma consists of gas exchanging units, the alveoli.
On the right lung, the main bronchi gives off a superior lobar bronchi branch in the root, then when in the lung, splits into middle and inferior lobar bronchi
On the left lung, the main bronchi branch into the superior and inferior lobar bronchi in the lung
In the root of the lung, the pulmonary artery is usually anterior and superior to the bronchi and pulmonary veins
In the root of the lung, the pulmonary veins are usually located anterior and inferior to the bronchi
The pulmonary ligament is made from a fold of the mediastinal pleura
The pulmonary ligament allows for the movement of the root of the lung during respiration
What are the 3 different surfaces of the lungs?
What are the lungs connected by?
What will you find at the root of the lung?
What is the lung covered in?
1- costal, mediastinal, diaphragmatic surfaces
2- hilum
3- root of lung = vasculature and airways entering the lung
4- covered in visceral pleura
What are the right and left lungs split into?
What are these 2 lobes split into?
1- superior and inferior lobe
Superior =
- apical
- posterior
- anterior
Inferior =
- superior (apical)
- anterior basal
- posterior basal
- medial basal
- Lateral basal
Where are each of the 10 bronchopulmonary segments found in the right lung?
What lobe are they each found in?
10 bronchopulmonary segments found in the right lung:
1) Superior lobe:
* Apical
* Anterior
* Posterior
1) Middle lobe:
* Medial
* Lateral
2) Inferior lobe:
* Superior/Apical
* Anterior
* Posterior
* Medial
* Lateral
Card 22 of 40
Q
Where are each of the 10 bronchopulmonary segments found in the left lung?
What lobe are they each found in?
10 bronchopulmonary segments found in the left lung:
1) Superior lobe:
* Apical
* Superior
* Inferior
* Anterior
* Posterior
2) Inferior lobe:
* Superior/apical
* Anterior
* Posterior
* Medial
* Lateral
What will you find on the right lung only?
What will you find on the left lung only?
Right lung only = lateral and medial segments of middle lobe
Left lung only = superior lingual and inferior lingual of superior lobe
What are the lung segments supplied by (oxygen)?
How many of these are there per side?
What shape are they and what are they separated by?
1- supplied by the tertiary segmental bronchi
2- 10 per side
3- lung segments are pyramidal shape with apices converging towards the hilum and separated by septa
How can each segment be respected as one unit?
Infection can be defined to a segment, they each have their own arterial supply from the pulmonary artery, but veins and lymphatics will cross septa
What is the root of the lung?
What 6 things does the root of the lung contain?
The root of the lung is the connection of the lung to the mediastinum, it is covered in pleura that extends Inferiorly as the pulmonary ligament.
- main bronchus
- pulmonary artery
- pulmonary veins
- bronchial arteries
- bronchial veins
- lymph nodes and vessels
what are the 2 arterial supply in the lungs?
bronchial arteries
pulmonary arteries
bronchial arteries?
how many are there right and left?
- supplies tissue of respiratory system
- 2 left from aorta
- one right, from the 3rd intercostal space
pulmonary arteries?
how does the diameter compare to the pressure?
- carries deoxygenated blood from the heart
- larger diameter, low pressure
- left is shorter than right
2 main venous drainage system in the lungs?
- bronchial veins
- pulmonary veins
bronchial veins will drain where?
drain to the azygos on the right or hemiazygos vein on the left
pulmonary veins?
- carry oxygenated blood towards the heart
- two per side (superior and inferior)
PULMONARY plexus:
where are the branches from?
where do the branches distribute?
what does it supply?
1- the pulmonary branches are from the vagus (parasympathetic) and sympathetic trunk (sympathetic)
2- branches from the plexus are distributed along the vessels and airway branches
3- also supplies visceral pleura
action of parasympathetic tone?
action of sympathetic tone?
parasympathetic = bronchoconstriction, vasodilation, secretomotor
sympathetic = bronchodilator, vasoconstriction
what are the 6 lymph nodes of the lung?
1- sub pleural plexus
2- intrapulmonary nodes
3- hilar nodes
4- trachea bronchial nodes (superior and inferior)
5- paratrachael nodes
6- bronchomediastinal trunks
what will drain the lower lobes of both lungs?
what side will they drain into?
inferior/carinal nodes will drain lower lobes of both lungs
primarily draining into the right side.
asthma?
management?
inflammation of airways = reduced diameter
- allergic, non alergic, occupational
management = B2 adrenoreceptor agonist = relaxes brachial smooth muscle
COPD?
risk factors?
what will it cause?
chronic obstructive pulmonary disease
risk factors = smoking
it will cause = mucus hyper secretion and alveolar destruction
what are the 2 ways smoking can lead to COPD?
1- release of oxidants … oxidative stress… COPD
2- Activates inflammatory cells… macrophages and epithelial cells … neutrophils… proteases… COPD
WHAT KEY PROTEIN ENABLES THE RECOIL OF THE LUNGS?
elastin
bronchoscopy?
tracheostomy?
Bronchoscopy=
- scope to visually examine the lungs
- done under sedation
- may also have device to remove foreign body or take a biopsy
Tracheostomy=
- not an emergency procedure
- more likely to be longer term
- inferior thyroid veins at risk
cancer?
risk factor?
what will mesothelioma effect?
Pancoast tumour?
what are different locations of compression?
what will each compression cause?
bronchial carcinoma (95% of tumours)
smoking is biggest risk factor
common site for metastatic tumour via lymphatic
mesothelioma= affective pleura caused by asbestos fibres
Pancoast tumour= apical lobe that can cause nerve compression
- sympathetic trunk, above T4= Horners syndrome
- brachial plexus = pain in shoulder/scapula/arm/ paralysis of hand
pneumothorax?
pneumonia?
risk factor?
- air in pleural cavity
- collapsed lung
pneumonia=
- infective = bacterial, viral , fungal
- affects love/segment “lobar pneumonia”
- lying supine is a risk factor
- often effects those with underlying health conditions.
cystic fibrosis?
Pulmonary embolism?
risk factors?
- autosomal recessive
- mucus is too thick due to abnormal ionic composition (malfunctioning chloride transporter)
PE:
- blockage occurs in the pulmonary artery (clot from lower limb)
risk factors= immobilisation, recent surgery, malignancy, paralysis, smoking, obesity
What is the venous (pirogoffs) angle?
Where does lymph from the bronchomediastinal trunks drain into on each side?
Pirogoffs angle also known as the venous angle, is the junction where the internal jugular and subclavian veins merge to form the brachiocephalic vein
This happens on both sides
