Resp Pre-Practical Lecture

Question 1

1. Describe the thoracic cage.

Answer 1

• LOOK AT NOTES WITH PICTURES BEFORE DOING THIS* The superior thoracic aperture refers to the opening at the top of the thoracic cavity. It is referred to anatomically as the thoracic inlet and clinically as the thoracic outlet.

Question 2

What is the superior thoracic aperture/opening/ thoracic inlet bounded by?

Answer 2

The first thoracic vertebra (T1) posteriorly,
The first pair of ribs laterally,
The costal cartilage of the first rib and the superior border of the manubrium

Question 3

What is the inferior thoracic aperture/ thoracic outlet bounded by?

Answer 3

12th thoracic vertebra posteriorly,
11th and 12th pairs of ribs laterally,
Costal cartilage of ribs 7 through 10 and xiphersternal joint anteriorly.

Question 4

How is the inferior thoracic aperture/thoracic outlet separated from the abdominal (peritoneal) cavity?

Answer 4

By the thoraco-abdominal diaphragm.

Question 5

Diaphragm

Answer 5

fibromuscular membrane, stretched across the midline of the body

Question 6

How do the ribs articulate with the vertebra?

Answer 6

Via costovertebral joints (synovial plane joints)

Question 7

The tubercle of the rib articulates with?

Answer 7

Transverse process of the thoracic vertebra of the same number at the costotransverse joint

Question 8

What type of joint is the costotransverse joint?

Answer 8

= synovial plane joint.

Question 9

2. Describe the First rib.

Answer 9

• Broad and flat, its surface looking upward and downward

- The head possesses only a SINGLE ARTICULAR FACET, for articulation with the body of the first thoracic vertebra.

Question 10

First rib- what is the upper surface of the body marked by?

Answer 10

• The upper surface of the body is marked by two shallow grooves which is separated by the scalene tubercle, for the attachment of the anterior scalene muscle.
• The ANTERIOR GROOVE lodges the subclavian vein, and the POSTERIOR GROOVE lodges the subclavian artery and the lowest trunk of the brachial plexus.

Question 11

3. Outline the attachments of the Diaphragm

Answer 11

It has three peripheral attachments:

• Lumbar vertebrae and arcuate ligaments
• Costal cartilage of ribs 7-12
• Xiphoid process of the sternum

One Central attachment:
- Central tendon

Question 12

Describe the parts of the diaphragm that arise/attach from the vertebrae?

Answer 12

Tendinous in structure; known as the right and left crura.

• Right crus- Arises from L1-L3. Some fibres from the right crus surround the oesophageal opening, and help prevent reflux of gastric contents back into the oesophagus.
• Left crus- Arises from L1-L2 and their intervertebral discs.

Question 13

What are the actions of the diaphragm?

Answer 13

• Primary muscle of respiration
• During inspiration, it contracts and descends (domes flatten), increasing the vertical diameter of the thoracic cavity.

Question 14

What are the hiatuses/openings of the diaphragm?

Answer 14

T8- Caval opening

T10- Oesophageal hiatus

T12- Aortic hiatus

Question 15

Describe the T8 canal opening of the diaphragm?

Answer 15

T8- Caval opening

- Passes through the central tendon of the diaphragm. It transmits the inferior vena cava and the right phrenic nerve.

Question 16

Describe the T10- Oesophageal hiatus of the diaphragm?

Answer 16

T10- Oesophageal hiatus

- Located through the muscular sling of the right crus. It transmits the oesophagus and both vagus nn.

Question 17

Describe the T12- Aortic hiatus of the diaphragm?

Answer 17

• Located between the left and right crus. It transmits the aorta, the azygos vein, the hemiazygos vein and the thoracic duct.

Question 18

Describe the T12- Aortic hiatus of the diaphragm?

Answer 18

• Located between the left and right crus. It transmits the aorta, the azygos vein, the hemiazygos vein and the thoracic duct.

Question 19

What is the Phrenic nerve?

Answer 19

The phrenic nerve is a nerve that originates in the neck (C3–C5) and passes down between the lung and heart to reach the inferior surface of the diaphragm.

Question 20

Describe the nerve roots, motor and sensory functions of the phrenic nerve.

Answer 20

Nerve roots: Anterior rami of C3, C4 (mainly) and C5.

Motor functions: Pierces and innervates the diaphragm from its inferior surface.

Sensory functions:
 Supplies the central part of the diaphragm.
 (The peripheral portions of the diaphragm are also innervated by sensory fibres of intercostal nerves, T7-T12.)

Question 21

4. Describe the lymphatic drainage of chest wall.

Answer 21

• Left side of chest wall drains to the thoracic duct => left brachiocephalic v.
• Right side of chest wall drains to right lymphatic duct -> right brachiocephalic v.

Question 22

5. Describe the respiratory organs.

Answer 22

The upper respiratory tract lies above the sternal angle (outside of the thorax)

• Nasal cavity
• Pharynx
• Larynx

The lower resp tract (inside the thorax):

• Trachea
• Bronchi (1y, 2y, 3y)
• Bronchioles (terminal, respiratory)
• Lungs (including alveoli)

Question 23

6. What is the respiratory/tracheobronchial tree?

Answer 23

The BRANCHING structure of airways supplying air to the lungs, including the trachea, bronchi and bronchioles.

Question 24

What makes up the conducting portion and respiratory portion?

Answer 24

Conducting portion: Respiratory portion

• Trachea - Respiratory bronchiole
• Main bronchus - Alveolar duct
• Lobar bronchus - Alveolar sac
• Segmental bronchus - Alveolus
• Conducting bronchiole
• Terminal bronchiole

Question 25

Describe where the Larynx is found, extends from and innervates.

Answer 25

- Found in anterior neck between C3-6 - Extends from the tip of the epiglottis to the inferior order of the cricoid cartilage - Innervates branches of vagus n.

Question 26

What are the vertebral levels in the larynx?

Answer 26

- Hyoid- C2/C3 - Thyrohyoid membrane (between the hyoid bone and thyroid cartilage)- C4 - Laryngeal prominence (Adam’s apple)- C5 - Cricoid cartilage and the start of the trachea- C6

Question 27

7. Describe the borders, lobes and surfaces of the lungs.

Answer 27

Borders- Anterior, posterior, inferior Lobes- Superior, inferior, Middle (for right lung only, - Transverse fissure in the right lung. Rib 4.), Lingula (for left lung only, cardiac notch and below it is a “tongue-like” structure= lingula.) Surfaces- Costal (internal surface of chest wall), Mediastinal (medial), diaphragmatic (inferior)

Question 28

What is the lung hilum?

Answer 28

Area located on medial/mediastinal surface of lung. - bronchi - pulmonary artery (in front of the bronchus) - superior pulmonary vein (most anterior) - inferior pulmonary vein (most inferior)

Question 29

What is the lung root?

Answer 29

The group of structures (bronchus, artery, veins, lymphatics, nerves) that enter/leave the lung hilum.

Question 30

What does the right lung have additionally?

Answer 30

Additional bronchus in the lung hilum called eparterial bronchus above the artery). The right main bronchus=hyparterial bronchus.

Question 31

8. What is the pleura?

Answer 31

Membrane lining the thoracic cavity/ribs (parietal pleura) and covering the lungs (visceral pleura).

Question 32

Name the parts of the Parietal Pleura and its nerve supply.

Answer 32

Somatic nerves: - Intercostal nerves - Phrenic nerve Pain sensitive.

Question 33

Conversely, Describe the nerve supply of visceral pleura.

Answer 33

``` Autonomic nerves (T2-T5) Pain insensitive. ```

Question 34

Define pleural reflection and pleural recess.

Answer 34

Pleural reflection is the place at which parietal pleura changes its direction of travel. Pleural recess is the increased space between the layers of pleura occurring at the pleural reflections.

Question 35

Describe the two different pleural reflections and recesses.

Answer 35

- Costomediastinal reflection and recess | - Costodiaphragmatic reflection and recess

Question 36

9. Describe the surface anatomy of lungs and pleurae.

Answer 36

The inferior margin of lung (6,8,10): Midclavicular line- Rib 6 Midaxillary line- Rib 8 Midscapicular line-Rib 10 The inferior margin of parietal pleura (8,10,12): 2 ic spaces difference- Rib 8 2 ic spaces difference- Rib 10 2 ic spaces difference- Rib 12 ``` // Where the lung is at 8, the pleura is at ten. ```

Question 37

Describe where the fissures of the lungs begin.

Answer 37

- Horizontal fissure of the right lung follows line of 4th rib anteriorly. - Oblique fissure of both lungs follows the line of the 6th rib anteriorly and begins at the spine of T3.

Question 38

10. Histology of the Trachea, Bronchi and Lungs.

Answer 38

Bronchioles: - have a diameter of 1mm or less - no cartilage, no glands, no goblet cells in the walls compared to the trachea and the larger bronchi. - Epithelium is either columnar or cuboidal Looking at the picture, we can see that as the tubes becomes smaller within the lung: - Epithelium becomes flatter from trachea to alveoli, going from Columnar -> Cuboidal -> Squamous - Cartilage reduces going from rings -> small plates -> completely absent in the bronchioles - Mucous- secreting glands and goblet cells decrease -> completely absent in the bronchioles