Case 6- lung anatomy part 2

Question 1

Limits of the lungs

Answer 1

The lungs extend to rib 8. Its limits are T6 in the mid-clavicular line, T8 in the mid axillary and T10 is the posterior and inferior limits of the lungs

Question 2

Palpating the suprasternal notch and associated structures

Answer 2

You can find the jugular (suprasternal) notch of the manubrium of the sternum. If you move down, you will feel a slight bump - this is the sternal (manubriosternal) angle which is the joint between the manubrium of the sternum and the sternal body. The costal cartilage of rib 2 articulates at this joint, therefore, if you move laterally you will feel the 2nd rib which will allow you to continue counting the ribs inferiorly and laterally.

Question 3

How air moves through the upper respiratory system

Answer 3

When you breathe in air goes through your nasal cavities or oral cavity into the pharynx, then the Larynx and the trachea. The trachea extends down the neck and into the thoracic cavity within the superior mediastinum.

Question 4

Where does the trachea split into the bronchi

Answer 4

At the sternal angle (T4/T5), at this division you have the Carina cartilage

Question 5

Cartilige in the trachea

Answer 5

Arranged in C-shaped rings, between the cartilage you have smooth muscle and fibroelastic tissue to allow for flexibility and to keep the airways open. There is mucosa which is adapted to warm and moisten the air, as well as trap any particles.

Question 6

Lobes of the lungs

Answer 6

In the right lung there are three lobes and in the left lung there are two lobes.

Question 7

Divisions of the lung

Answer 7

Trachea -> bronchus -> Lobar bronchi -> segmental bronchi -> bronchioles -> terminal bronchiole -> respiratory bronchiole -> pulmonary alveolus (alveolar duct/ alveolar sac)

Question 8

Structure of right lung

Answer 8

The right lung has three lobes; the superior lobe, the middle lobe and the inferior lobe. The superior lobe is split from the middle lobe using the horizontal fissure. The inferior lobe is split from the middle lobe by the Oblique fissure. The apex is the top of the lungs and the inferior border is on top of the diaphragm.

Question 9

Structures surrounding the right lungs

Answer 9

The inferior and superior vena cava, the oesophagus and the subclavian vessels

Question 10

Structure of left lung

Answer 10

The left lung only has two lobes, the superior lobe and the inferior lobe. It contains the lingula left lung which is like a very small lobe. There is a cardiac notch where the heart sits.

Question 11

Structures surrounding the left lung

Answer 11

The descending aorta and aortic arch, the oesophagus and subclavian vessels.

Question 12

The hilum of the right lung

Answer 12

The main bronchus is on the side, it contains cartilage so is easy to identify. The pulmonary artery is in the middle, it comes from the right ventricle. On the other side and down is the pulmonary vein, the pulmonary artery has a thicker wall then the pulmonary vein. The pulmonary artery is superior to the pulmonary vein and the bronchus is superior to the pulmonary artery. Lymph nodes and nerves also go through the hilum

Question 13

Hilum of the left lung

Answer 13

Has two pulmonary veins going to the heart. The pulmonary vein is anterior and the pulmonary artery is more superior and inferior

Question 14

The difference between the right and left bronchus

Answer 14

The right bronchus is wider and goes straight down, on the left side it is longer. If you inhale a particle it is more likely to go down the right side

Question 15

Upper respiratory tract

Answer 15

Contains the oral/nasal cavity, pharynx and larynx

Question 16

Lower respiratory tract

Answer 16

Trachea, bronchi and lungs

Question 17

Pleural membrane

Answer 17

A thin double mesothelial layer which is adherent to/surrounds the lungs. Has a visceral and parietal layer, the visceral layer is against the lung whilst the parietal layer is against the surrounding tissue. Between the two layer is the pleural cavity which is a potential space containing the pleural fluid. The visceral and parietal layer are continuous with each other

Question 18

Role of pleural fluid

Answer 18

It allows the lungs to expand during inspiration as it causes surface tension between the two layers. When the thoracic cage expands the parietal layer will go with the thoracic wall and the surface tension between the visceral and parietal layers will cause the lung to go with it and expand

Question 19

The regions of the parietal pleura

Answer 19

The parietal pleura has 4 regions: the Diaphragmatic, the Mediastinal (on the mediastin), the Costal (lateral and posterior ribs) and the Cervical (cupola) which is near the apex of the lungs

Question 20

Recesses in the lungs

Answer 20

Regions which are not completely filled by the lungs, the two recesses are the costodiaphragmatic and costomediastinal

Question 21

Costodiaphragmatic

Answer 21

Located between the costal and diaphragmatic pleura (inferiorly)

Question 22

Costomediastinal

Answer 22

Located between the costal and mediastinal layers of the paritetal pleura (anteriorly)

Question 23

Nerves of the parietal pleura

Answer 23

It is innervated by the phrenic and intercostal nerves, it can sense pressure, pain and temperature

Question 24

Nerves of the visceral pleura

Answer 24

It is innervated by the pulmonary plexus (autonomic – sympathetic trunk and vagus nerve), it can sense stretch. The bronchial and intercostal arteries supply the visceral and parietal pleura respectively.

Question 25

Larynx

Answer 25

Produces phonation (production of speech sounds). It is located at the C4-C6 level, extending from the base of the tongue to the trachea. It opens into the laryngopharynx at the inlet.

Question 26

What is the larynx made of

Answer 26

• Cartilage (and joints).
• Membrane (and ligaments).
• Mucosa (coats cartilage and membranes).
• Muscles

Question 27

The Hyoid bone

Answer 27

The larynx is suspended from the Hyoid bone, the Hyoid bone does not articulate with any other bone

Question 28

The thyroid cartilage

Answer 28

The adams apple. It is a C-shaped cartilage with two lamina joined anteriorly forming the laryngeal prominence. The oblique line is the site of attachment of the inferior constrictor and infrahyoid muscles. Has a superior and inferior horn, the inferior horn articulates with the cicoid cartilage.

Question 29

The Epiglottis cartilage

Answer 29

Goes over the inlet of the larynx when we swallow to stop food going down the airway. It is an elastic cartilage which is behind the root of the tongue. It attaches to Hyoid cartilage above and thyroid cartilage below.

Question 30

The Cricoid cartilage

Answer 30

Articulates with the Thyroid cartilage and is just above the trachea. Unlike the thyroid cartilage, the cricoid cartilage is a full ring which articulates with the arytenoids at the cricoarteynoid joint.

Question 31

The Artenoids

Answer 31

Articulates with the posterior portion of the cricoid cartilage to form a synovial joint called the cricoarytenoid joint. The vocal processes are where vocal ligaments attach to. The muscular processes attach to some intrinsic muscles of the larynx that move the vocal folds, which change tone.

Question 32

Two types of membrane in the larynx

Answer 32

The extrinsic membrane start from outside the larynx and then goes into it, the intrinsic membrane starts and finish’s in the larynx

Question 33

The external membrane

Answer 33

Thyrohyoid membrane, Cricotracheal membrane and Hyoepiglottic membrane

Question 34

Thyrohyoid membrane

Answer 34

Comes from the hyoid bone and goes into the thyrohyoid cartilage. There is a thickening in the middle called the median thyrohoid ligament

Question 35

Hyoepiglottic and Thyroepiglottic membrane

Answer 35

Keeps the epiglottis in place, the Thyroeppiglottic is internal

Question 36

Cricotracheal membrane

Answer 36

Connects the larynx to the trachea, it is seen inferiorly

Question 37

The internal membranes

Answer 37

The Quadrangular, Cricothyroid and Thyroepilottic membrane

Question 38

The Cricothyroid membrane

Answer 38

Can be seen externally but extends internally along the thyroid cartilage and is considered an internal membrane. Has a thickening which is called the median Cricothyroid ligament which is used for emergency openings of the airway if the patient is unable to breath. It is made of elastic tissue, also known as conus elasticus, has a free upper border which forms the vocal ligament

Question 39

The Quadrangular membrane

Answer 39

Forms the epiglottis and arytenoids and hangs down from the aryepiglottic fold. Has a free lower border which forms the vestibular ligament.

Question 40

Aryepiglottic fold

Answer 40

A mucus membrane covering the aryepiglottic muscle and the lateral borders of the laryngeal. Extends down over the Quadrangular membrane

Question 41

Vestibular fold (false vocal fold)

Answer 41

Mucosa covering the vestibular ligament, the vestibular fold lies superior to the vocal fold.

Question 42

Vocal fold (true vocal cord)

Answer 42

Mucosa covering the vocal ligament (upper border of the Cricothyroid membrane), adduction of vocal folds close the airways.

Question 43

Trachea structure

Answer 43

Contains C-shaped Hyaline cartilage, easily recognised by the chondrocytes in the Lacunae

Question 44

Bronchus structure

Answer 44

1) Ciliated pseudostratified columnar epithelium
2) Goblet cells and mucus glands
3) Lamina propria
4) Serous gland
5) Cartilage

Question 45

Segmental bronchi structure

Answer 45

1) Ciliated columnar epithelium
2) Reduced goblet cells and Mucus glands
3) Thin Lamina propria
4) Smooth muscle is more prominent
5) Reduced cartilage

Question 46

Bronchioles structure

Answer 46

1) Ciliated columnar epithelium
2) No goblet cells
3) Smooth muscle
4) No cartilage

Question 47

Terminal bronchiole structure

Answer 47

1) Ciliated cuboidal epithelium
2) No goblet cell
3) No smooth muscle
4) No cartilage
5) Ciliated Clara cells

Question 48

Respiratory bronchiole structure

Answer 48

1) Ciliated cuboidal epithelium
2) No-goblet cells
3) Non-ciliated Clara cells

Question 49

Alveolar duct structure

Answer 49

1) Squamous epithelia (no cilia)
2) Type 1 pneumocyte
3) Type 2 pneumocyte

Question 50

Alveolar sac structure

Answer 50

1) Squamous epithelia (no cilia)
2) Type 1 pneumocyte
3) Type 2 pneumocyte

Question 51

Alveolus structure

Answer 51

1) Squamous epithelia (no cilia)
2) Type 1 pneumocyte
3) Type 2 pneumocyte
4) Shares basal lamina with endothelial cells for gas exchange as thin barrier
5) No connective tissue just elastic fibre which allow elastic recoil and prevent alveolar collapse

Question 52

Pneumocyte

Answer 52

An alveolar cell involved in gas exchange. The organelles group centrally to save space. Type 1 pneumocytes are found in the alveolar ducts and alveoli, they are extremely thin and slender. There are more type 1 pneumocytes the type 2. They function to secrete surfactant which reduces alveolar surface tension. Act as progenitor cells for type 1 pneumocytes. They are short and fat.

Question 53

Alveolar Macrophage

Answer 53

Monocytes that have escaped from the pulmonary vasculature and function to phagocytose foreign matter in the alveoli. Large and very dark.

Question 54

Function of capillaries, cilia and goblet cells

Answer 54

Warm (capillaries in the Lamina propria), filter (cilia), moisten (goblet cells)

Question 55

Capillaries- air-blood barrier

Answer 55

Thin due to the shared basal lamina

Question 56

Basal cells

Answer 56

Progenitor and stem cells that reside at the bottom of the epithelium and replenish cells above. They are short, triangular and darker

Question 57

Divisions of the bronchioles

Answer 57

Has 14 divisions with less cartilage on each division but more smooth muscle

Question 58

Conducting area of bronchial tree

Answer 58

Trachea, bronchi, bronchioles and terminal bronchioles

Question 59

Respiratory area of Bronchial tree

Answer 59

Alveolar ducts and alveolar sacs

Question 60

Goblet cells

Answer 60

They secrete mucous which is formed from mucin granules in the cytoplasm. The mucus traps particulates and microbes. Located in conducting airways, found in the epithelium with pale, cup like structure.

Question 61

The submucosa layer

Answer 61

Contains seromucous glands and allows for the mucocilary escalator

Question 62

Structure of the nasal cavity

Answer 62

The nasal cavity is lined by respiratory mucosa. Along the nasal surface is pseudostratified ciliated columnar epithelium, between these cells are goblet cells. At the bottom of these cells is the basement membrane, beneath the basement membrane is a thicker layer of loose connective tissue called the lamina propria. There are many blood vessels and seromucosal glands within the lamina propria.

Question 63

Mucus production and clearance in the nasal cavity

Answer 63

The blood vessels in the lamina propria warm the air near to body temperature. Simultaneously the watery mucus secreted from the goblet cells and seromucosal glands humidifies the air. It also traps the foreign particles and keeps them from entering other parts of the respiratory tract. The wave like beating of the epithelial cilia move the debris to the throat where it is swallowed.