KNES260 - Pulmonary cavities

How is the thoracic cavity divided ?

2 pulmonary cavities — contain the lungs

1 mediastinum — contains the heart

What’s the difference between the pulmonary artery/vein and bronchial artery/vein?

Pulmonary = involved in gas exchange (from heart to lungs then lungs to heart)

Bronchial = brings blood supply to lung muscles, not involved in gas exchange

Each pulmonary cavity is completely lined by the _____________ (a mesothelial membrane)

Pleural membrane

How many layers make up the pleural membrane (or pleural sac)? What are they?

2 → parietal and visceral pleurae

Where/What is the parietal pleura?

Pleural lining the walls of the pulmonary cavity, adhering to the endothoracic membrane on the inner surface of the thoracic wall, mediastinum, and diaphragm

Where can we find the visceral pleura?

In contact with the lungs → closely covers the lung and adheres to its external surface

We can find the pleural cavity between ____________ and ____________

The parietal pleura and the visceral pleura

What is the pleural cavity?

A potential space (normally exists) between the two layers of pleura

• it contains serous pleural fluid which lubricates surfaces for smooth movement during respiration

T/F: the visceral pleura is associated with the walls of the pulmonary cavities

False, it’s the parietal pleura

Name and briefly describe the different parts of the parietal pleura (4)

1. Cervical pleura → dome-shaped layer of parietal pleura lining the cervical extension of the pleural cavity

2. Costal pleura → related to the ribs and intercostal spaces, and is separated from the internal surface of the thoracic wall by the endothoracic fascia

3. Diaphragmatic pleura → covers the diaphragm

4. Mediastinal pleura → covers the mediastinum

Identify the colored parts (pleura layers or parts)

• Orange : visceral pleura

• Pink-ish: mediastinal pleura (parietal)

• Green: diaphragmatic pleura (parietal)

• Blue: costal pleura (parietal)

• Yellow: cervical pleura (parietal)

What nerve(s) innervate the costal, diaphragmatic and mediastinal pleurae? Do they bring in/out sensory or motor information?

Sensory information for all

• Costal pleura : intercostal nerves

• Diaphragmatic and mediastinal : phrenic nerves

The visceral pleura is _______ than the parietal pleura, its attached firmly to the ______________, including those within the horizontal and oblique fissures; it is continuous with the ________ pleura at the hilium of the lungs

Thinner, surface of the lung, parietal

What are the functions of the pleural cavity/space?

1. Contains a small amount of serous/pleural fluid that helps lubricate the pleurae and allows the lungs to move smoothly when breathing

2. Generates surface tension that provides the cohesion that keeps the lungs surface in contact with the thoracic wall → allows pulmonary cavity to expand during inspiration

3. Creates a suction between the parietal pleura and visceral pleura

4. Keeps the two layers stuck to one another but allows the two layers to slide on one another

T/F: lungs do not completely fill the anterior or posterior inferior regions of the pulmonary cavities

True

Name the the two pleural recesses

Costodiaphragmatic recess and costomediastinal recess

Where is the costodiaphragmatic recess? When are they at their biggest and smallest

Inferior to the lungs, between the lungs and the diaphragm

• Deepest after forced expiration

• Shallowest after forced inspiration

Where are the costomediastinal recesses?

Behind the sternum and rib cartilages

Define thoracocentesis. Where does it take place (anatomical structure)?

A procedure that is performed to remove fluid from the pleural cavity, done for diagnostic or therapeutic purposes

• Inserting the needle into the 9th intercostal space → costodiaphragmatic recess (during expiration) to avoid puncturing the lung

Give general characteristics of the lungs and give their primary function

Function = oxygenate blood by bringing inspired air into close contact with the venous blood in the pulmonary capillaries

• Also important in removing CO2 and waste products, and regulating blood pH

• Lungs are the organs of respiration

• They are elastic and spongy

• Each lung is contained within the pulmonary cavities, and they lie on either side of the mediastinum

Each lung has 10 functionally independent regions supplied by one segmental/tertiary bronchus; what are those called?

Bronchopulmonary segments

Size-wise, the right lung is ________ and _______ than the left; length and width-wise, it is _______ (why?) and ________ (why?) than the left lung

Larger and heavier, shorter (right dome of diaphragm is higher) and wider (heart bulge more to the left)

How many lobes and fissures do the right and left lung have?

Right: 3 lobes, 2 fissures

Left: 2 lobes, 1 fissure

Name the lobes and fissures of the right lung

Lobes:

• Superior (mostly anterior)

• Middle

• Inferior (mostly posterior)

Fissures:

• Horizontal (btwn superior and middle lobes)

• Oblique (btwn inferior and middle/sup lobes)

How is the anterior surface of the right lung?

Slightly curved

What are the three surfaces on the right lung?

Costal, mediastinal, diaphragmatic

Name the lobes, the surfaces and the fissures on the left lung

2 lobes : Superior (mostly anterior) and inferior (mostly posterior) lobes

3 surfaces: costal, mediastinal, diaphragmatic

1 fissure: Oblique fissure btwn the two lobes

There are 2 distinctive structures on the superior lobe of the left lung that are not present on the right lung. What are they?

1. Lingula → tongue-like extension found om the inferior portion of the superior lobe, which projects over the heart bulge

2. Cardiac notch → indentation on the surface of the left lung, allowing space for the heart

Is this the right or left lung?

Right

Right or left lung?

Right

Right or left lung ?

Left

Right or left lung ?

left

Identify the structures ; is this the right or the left lung? What’s our view?

Right lung, medial view

1. Superior lobe

2. Horizontal fissure

3. Middle lobe

4. Oblique fissure

5. Inferior lobe

Identify structures 1-3 (hint: lobes) ; which lung is that, what’s the view?

1. Superior lobe

2. Middle lobe

3. Inferior lobe

Right lung, medial view

Identify structures A-G

A- Superior vena cava

B- Inferior vena cava

C- Esophagus

D- Azygos vein

E- Pulmonary ligament

F- subclavian vein

G- subclavian artery

Identify surfaces S1 and S2

S1- Diaphragmatic

S2- Mediastinal

Identify what lung this is and the structures numbered

This is the left lung from a medial view

1. Apex

2. Oblique fissure

3. Inferior lobe

4. Lingula

5. Superior lobe

Identify

1. Esophagus

2. Thoracic aorta

3. Pulmonary ligament

4. Cardiac notch

What is the pulmonary ligament?

A double fold of pleural membrane

What important structures can be found on or touching the medial surface of the right lung?

• Heart → on the lung, there’s the cardiac impression

• Inferior vena cava → groove for IVC

• Superior vena cava → groove for SVC

• Azygos vein

• Esophagus → groove for esophagus

What important structures can be found on or touching the medial surface of the left lung?

• heart (cardiac impression)

• aortic arch (groove for aortic arch)

• thoracic aorta (groove for thoracic aorta)

• esophagus (groove for esophagus)

What is the difference between the root of the lung and the hilum of the lung ?

The root of the lung is the collection of structures that connect the lung to the mediastinum; The hilum is the actual “hole” where those structures enter and leave the lung

The (3 most) important structures that make up the root of the lung are…

1. Bronchi (left and right)

2. Pulmonary arteries

3. Pulmonary veins (2 on each side, one inferior, one superior)

The left bronchus divide ______ entering the root; the right bronchus divide ______ entering the root

After, before

Pulmonary arteries are _______ and _______ to the pulmonary veins

Anterior and superior

The vagus nerve passes _______ to the root of the lung. As it passes distal to the becomes vagal trunks: left vagus nerve becomes the ________ vagal trunk (smaller); right vagus nerve becomes the _________ vagal trunk (larger)

Posterior, anterior, posterior

The phrenic nerve passes _______ to the root of the lung

Anterior

Identify. Make sure to mention right or left when relevant

1. Roots of lungs

2. Bronchi

3. Pulmonary ligament

4. Hilum of lung

5. R pulmonary artery

6. R pulmonary veins

7. L pulmonary artery

8. L pulmonary veins

T/F: the hilum stabilizes the position of the inferior lobe (of the lungs)

True

What’s the difference between the pulmonary and bronchial circulations?

Pulmonary: blood circulation between heart and lungs, involved in gas exchange — low pressure

Bronchial: blood supply to the airways and lung tissue and else, NOT involved in gas exchange— high pressure

The pulmonary arteries move __________ blood, while the pulmonary veins move ___________ blood

Deoxygenated, oxygenated

T/F: the bronchial veins drain most of the blood supplied to the lungs

False, they drain only parts of it; majority drained by the pulmonary veins

Define and give characteristics of a pulmonary embolism

It is the obstruction of a pulmonary artery by a blood clot (embolus)

• Forms when a blood clot, fat globule, or air bubble travels in the blood from a leg VEIN → passes through the right side of the heart to a lung (though a pulmonary artery)

• Result: partial or complete obstruction of blood flow to the lung → acute respiratory distress → right side of the heart may become acutely dilated (can’t drain though one of the pulmonary arteries)

Identify

1. Right pulmonary artery

2. Inferior vena cava IVC

3. Right ventricle

4. Pulmonary trunk

5. Hilum of the lung

6. Left pulmonary artery

7. Left pulmonary veins

Identify

1. Thyroid cartilage

2. Circoid cartilage

3. Tracheal cartilage

4. Left primary (or mainstem) bronchus

5. Secondary (or lobar) bronchi

6. Tertiary (or segmental) bronchi

7. Right primary (mainstem) bronchus

8. Carina

From superior to inferior, name the 3 cartilages from the mouth to the bronchi

Thyroid → circoid → tracheal

Are the following cartilages complete or incomplete rings? What does it mean?

• Thyroid

• Circoid

• Tracheal

• Thyroid is incomplete (makes a U-shape, not connected posteriorly)

• Circoid is complete (O-shaped)

• Tracheal is incomplete

“Adam’s apple” is a piece of _________ cartilage that we see on the neck

Thyroid

The trachea divides into two ____________; each of them further divides into ____________ (how many on left vs right?), which further subdivides into ___________. Those become even smaller __________ and ___________

Primary/Mainstem bronchi (a left and a right), secondary/lobar bronchi (2 left, 3 right), tertiary/segmental bronchi, bronchioles (respiratory and terminal), alveoli

What is Carina?

The ridge of cartilage in the trachea that occurs between the division of the two main bronchi (can see from the inside of the trachea)

T/F: the right primary bronchus is wider, shorter, and courses more vertically than the left main bronchus

True!

Referring to the last question, what’s the functional consequence?

Mistakenly swallowed or inspired objects/things are more likely to go down the right side and so, more likely to get a clogged right lung

The trachea is a …

Conducting airway

The tracheal cartilage is a(n) __________ ring lined with _______ membrane, and with a smooth muscle (__________) forming the _________ border of the trachea

Incomplete, mucous, trachealis, posterior

What are the main functions of the mucosa present in the respiratory tract (remember the trachea is lined by a mucous membrane)?

1. Provides humidity, warming, or cooling to the inhaled gases

2. Serves as a mucociliary escalator

What is a mucociliary escalator?

It describes one of the role of the mucosal layer in the trachea: ciliated epithelial cells transport mucus, with any captured foreign particles (such as viruses or bacteria), in an upstream direction toward the upper airway (to be expelled out of the airways) → keeps those foreign particles away from the alveoli and blood

How different is the trachea in kids compared to adults ?

Their trachea is funnel-shaped, and relatively smaller in diameter and shorter in length

• more prone to significant airflow obstruction (can enter more easily since its funnel shaped, then gets clogged in smaller airways)

The alveoli, or alveolar sacs, serve as the location for what?

Gas exchange → blood-air barrier

• where CO2 and O2 exchange between our blood and our lungs

• Happens across the surface of the alveoli and pulmonary capillaries

T/F: Terminal bronchioles facilitate the exchange of air at the alveoli

False, it’s the respiratory bronchioles