Unit 1: Anatomy of the Lungs, the Bronchial Tree, Major Vessels, Nerves of the Thorax

-surrounded by pleura
-separated from each other via mediastinum
-superior to diaphragm

How are the lungs positioned in the thorax in relation to the pleurae, mediastinum, and diaphragm?

-bronchi
-pulmonary arteries, veins, and nerves

How are the lungs anchored to the mediastinum?

-Mesothelium: single layer of cells
-Supportive connective tissue

What are pleural cavities lined with?

-pleura

The pleural cavities form the ____.

-serous membrane
-it is double layered

The pleura is a ______. What does this mean?

-parietal pleura
-visceral pleura

What are the two types of pleura?

-superficial layer
-closer to thoracic wall

The parietal layer is the ___.

-Costal part = near ribs and intercostal spaces
-Diaphragmatic part = near diaphragm
-Mediastinal part = near mediastinum

What are the different portions of the parietal pleura?

-Deeper layer
-Closer attached to lung tissue

The visceral layer is the ___.

pleural cavity

The two pleura are separated by the ____.

parietal pleura

2

visceral pleura

1

pleural cavity

Serous fluids

What is between the parietal and visceral layers?

-Allows for sliding movement
-does not allow for pulling movement

Describe the purpose of the serous fluids.

-Surface of lung & visceral layer directly opposes and slides freely over parietal pleura attached to wall

Why do serous movements allow for sliding movement?

visceral pleura gets pulled with it

Since the parietal pleura attaches to the thoracic wall, what happens when the thorcic wall moves or when the parietal pleura is pulled?

-fill with air, fluid, blood

What can happened to the pleural cavity?

-Air fills pleural cavity
-lung collapsing

Describe a pneumothorax.

-Fluid fills pleural cavity

Describe a pleural effusion.

Blood fills pleural cavity

Describe a hemopneumothorax.

-spaces formed by pleura that are not filled with lungs
-Where two layers of the parietal pleura oppose each other

What are pleural recesses?

lungs do not expand into the recesses

When normally breathing, what happens to pleural recesses?

lungs do expand into the recesses

When forced inspiration, what happens to pleural recesses?

-Fluid can collect here
-May need to aspirate the fluid

Why are recesses clinically important?

-anterior
-where copstal pleura are opposed to mediastinal pleura

Describe costomediastinal recess.

-On left and right lungs
-Larger on left side overlying the heart

The costomediatsinal recess is located _____.

-largest recess
-between costal pleura and diaphragmatic pleura
-between inferior margin of lungs and inferior margin of pleural cavities

Describe costodiaphrgamatic recess.

-Smaller during inspiration
-Larger during expiration

The costodiaphrgamatic recess is smaller ___ and larger ___.

Fluid will tend to collect here because of gravity

Why is the costodiaphrgamatic recess clinically important?

Costomediastinal Recess

A

Costodiaphragmatic Recess

B

Inferior margins of lungs rest on top

Where is the respiratory diaphragm?

Pulmonary ventilation

What is the process of respiration?

gas flows into lungs

Describe inspiration.

gas flows out of lungs

Describe expiration.

-changes in volume of thoracic cavity
-changes in volume leads to changes in pressure

What does respiration depend on?

-Inverse relationship
-increase volume → decrease pressure
-decrease volume → increase pressure

Describe the relationship between volume and pressure.

-Respiratory diaphragm (domed to flat)
-Intercostal muscles

What are volume changes dependent on?

Relaxed = expiration

When does the diaphragm become domed?

Contracts = inspiration

When does the diaphragm become flat?

-External intercostal muscles = elevate the ribs
-Internal intercostal muscles = depress the ribs

Describe the intercostal muscles and their movement.

-Sternum = moves anteriorly when taking a deep breath
-Ribs = move laterally when taking a deep breath

Describe the movement of the rib cage.

-attached to the walls of the rib cage and lungs
-serous fluid between the pleura

Pleura are firmly _____. What causes this?

pleura to pull apart

The serous fluids does not allow ___.

Pressure decreases

When the volume of the lungs increases during inhalation?

Pressure increases

When the volume of the lungs decreases during exhalation?

-Diaphragm contracts → flat
-External intercostal muscles = elevate the ribs

During inhalation, describe the muscles.

-Increase volume
-Decrease pressure

-Air moves in

During inhalation, describe the volume and pressure.

-Diaphragm relaxes → domed shape
-Internal intercostal muscles = depress the ribs

During exhalation, describe the muscles.

-Decrease volume
-Increase pressure

air moves out

During exhalation, describe the volume and pressure.

passive = muscles relaxed

Quiet respiration is _____.

-active

-Requires contraction of other muscles

Forced respiration is _____.

-Internal and innermost intercostals
-Abdominal muscles

What muscles are used in forced respiration?

Apex
Diaphragmatic surface
Superior Lobe
Inferior Lobe
Oblique Fissure

Both right and left lungs have _____.

-left lung = 2 (superior, inferior)
-right lung = 3 (superior, middle, inferior)

How many lobes does each lung have?

-left lung = oblique fissure
-right lung = horizontal fissure & oblique fissure

How many fissures does each lung have?

separates superior and inferior lobes

What does the oblique fissure separate?

separates superior and middle lobes

What does the horizontal fissure separate in the right lung?

-cardiac notch
-lingula

The left lung has _____.

-Heart bulges more to left than right

Describe the cardiac notch.

Tongue-like extension over bulge of heart

Describe the lingula.

Heart
aortic arch
thoracic aorta
esophagus

The medial surface of the left lung lies adjacent to _____.

Heart
inferior vena cava V
superior vena cava V
azygos V
esophagus

The medial surface of the right lung lies adjacent to _____.

apex of lung

diaphragmatic surface of lung

superior lobe of left lung

inferior lobe of left lung

superior lobe of right lung

middle lobe of right lung

inferior lobe of right lung

Oblique Fissure of right lung

Oblique Fissure of left lung

horizontal Fissure of right lung

cardiac notch

lingula

collection of structures that attach the lung to the mediastinum

Define the root.

bronchus, pulmonary artery, pulmonary vein

What does the root consist of?

posterior to root of lung

Where is the vagus nerve located?

anterior to root of lung

Where is the phrenic nerve located?

area of entrance and exit of main vessels of lung

Define the hilum.

bronchus, pulmonary artery, pulmonary vein

What does the hilum contain?

hilum

root

pulmonary trunk artery

Where emerges off the right ventricle?

L and R Pulmonary Arteries

What arises from the pulmonary trunk artery?

deoxygenated blood from heart to lungs

The left and right pulmonary arteries carry ____.

superiorly placed in the hilum

Left and right pulmonary arteries are located ____.

-right pulmonary artery = longer
-left pulmonary artery = shorter

Describe the difference between right and left pulmonary artery.

-passes horizontally across mediastinum
-passes anteroinferior to bifurcation of trachea
-anterior to right main bronchus
-posterior to ascending aorta, superior vena cava, most superior right pulmonary vein

Describe the location of the right pulmonary artery.

-into 2 at the root
-Divides again within lung so branch goes to each lobe

The right pulmonary artery branches ____.

-Anterior to ascending aorta
-Posterior to superior to upper most pulmonary vein

Describe the location of the left pulmonary artery.

within the lung

The left pulmonary artery branches ____.

oxygenated blood from lungs back to left atrium of heart

The left and right pulmonary veins carry ____.

-2 veins per lung
--Superior pulmonary vein
--Inferior pulmonary vein

How many pulmonary veins are there?

-trachea
-main bronchi
-lobar bronchi
-segmental bronchi
-bronchioles
-alveoli

What are parts of the bronchial tree?

Vertebral level C6-T4/5

Where is the trachea located?

-Flexible tube
-C-shaped cartilaginous rings to strengthen

Describe the trachea.

esophagus its behind the trachea

Why is the trachea C-shaped?

Enters lungs via hilum

Where are the two main bronchi located?