Anatomy of Breathing

Question 1

List the four anatomical components that make up the upper respiratory tract (URT).

Answer 1

1. The right and left nasal cavities.
2. The oral cavity.
3. The naso-, oro-, and laryngo- pharynx.
4. The larynx.

Note that either 1. or 2. can be the start of the upper respiratory tract as can breath through either.

Question 2

List the six anatomical components that make up the lower respiratory tract (LRT).

Answer 2

1. The trachea.
2. The right and left main bronchi.
3. The lobar bronchi.
4. The segmental bronchi.
5. Bronchioles.
6. Alveoli.

Question 3

What two things occur at the level of C6 vertebra in terms of the respiratory and GI tracts?

Answer 3

1. The larynx becomes the trachea.

2. The pharynx becomes the oesophagus.

Question 4

Where can the trachea be palpated?

Answer 4

At the jugular notch of the manubrium.

Question 5

Anterior to which tracheal cartilages is the isthmus of the thyroid located?

Answer 5

Tracheal cartilages 2-4.

Question 6

What makes up the chest cavity?

Answer 6

The mediastinum, the right pleural cavity, and the left pleural cavity.

Question 7

What is the purpose of pleural fluid?

Answer 7

Acts as a lubricant and provides surface tension.

Question 8

Where does the pleura reflect?

Answer 8

At the lung roots.

Question 9

Name the lobes of the right lung.

Answer 9

Upper, middle, and lower lobes.

Question 10

Name the lobes of the left lung.

Answer 10

Upper and lower lobes.

Question 11

What are lobes separated by in the lungs?

Answer 11

Fissures.

Question 12

What is a bronchopulmonary segment?

Answer 12

An area of a lung lobe that one of the segmental bronchi supplies with area.

Question 13

How many bronchopulmonary segments does each lung have?

Answer 13

Ten.

Question 14

What ribs are described as the “true” ribs and what does this mean?

Answer 14

Ribs 1-7.

They are “true” as they attach via their own costal cartilage to the sternum.

Question 15

What ribs are described as “false” ribs and what does this mean?

Answer 15

Ribs 8-10.

They are “false” as they attach via the costal cartilage above to the sternum.

Question 16

What ribs are described as “floating” ribs and what does this mean?

Answer 16

Ribs 11 & 12.

They are “floating” as they have no attachment to the sternum.

Question 17

What are the four areas of the sternum?

Answer 17

1. Manubrium.
2. Body.
3. Xiphoid.
4. Sternal angle.

Question 18

What is the purpose of the costal groove and where is it located?

Answer 18

It provides the pathway for the intercostal neurovascular bundle (NVB).

Located inferiorly on the deep surface of ribs.

Question 19

What is the rib angle?

Answer 19

Where the shaft subtly changes direction.

Question 20

What does the head of the rib articulate with?

Answer 20

It articulates with the body of the vertebra of the same number and the body of the vertebra superiorly.

Question 21

What does the rib tubercle articulate with?

Answer 21

The transverse process of the vertebra of the same number.

Question 22

What is the name given to the joints attaching the costal cartilage to the sternum and what type of joints are these?

Answer 22

Sternocostal joints.

These are synovial joints.

Question 23

What is the name given to the joints which attach the ribs to costal cartilage?

Answer 23

Costochondral joints.

Question 24

What is the name given to the joints which attach the ribs to vertebrae?

Answer 24

Costovertebral joints.

Question 25

What are the three layers of skeletal muscle located between the ribs and within the intercostal spaces?

Answer 25

1. External intercostals. 2. Internal intercostals. 3. Innermost intercostals.

Question 26

What is the purpose of intercostal muscles during breathing?

Answer 26

They make the chest wall expand by pulling adjacent ribs upwards and outwards.

Question 27

How many pairs of intercostal spaces are there?

Answer 27

11.

Question 28

What does an intercostal NVB consist of and between which intercostal muscle layers can it be found?

Answer 28

They contain a vein, an artery, and a nerve. They are located between the internal and innermost intercostal muscle layers.

Question 29

What is the nerve supply to the intercostal spaces?

Answer 29

Anterior ramus of spinal nerve (intercostal nerve).

Question 30

Describe the blood supply to the posterior intercostal spaces in terms of a) the arterial supply and b) the venous drainage.

Answer 30

a) Thoracic aorta. | b) Azygous vein.

Question 31

Describe the blood supply to the antercostal intercostal spaces in terms of a) the arterial supply and b) the venous drainage.

Answer 31

a) Internal thoracic artery. | b) Internal thoracic vein.

Question 32

What are the bilateral posterior branches from the thoracic aorta that supply the chest wall called?

Answer 32

Intercostal arteries.

Question 33

What are the anterior branches from the thoracic aorta that supply arterial blood for the lung tissue called?

Answer 33

Bronchial arteries.

Question 34

What two anatomical features of the diaphragm allow for it to be categorised as an internal part of the body wall?

Answer 34

1. It forms the floor of the chest cavity. | 2. It forms the roof of the abdominal cavity.

Question 35

What is unusual about the diaphragm as a skeletal muscle?

Answer 35

It has an unusual central tendon.

Question 36

The right dome of the diaphragm is more inferior than the left dome. True or false?

Answer 36

False - the right dome is more superior than the left dome normally. This is due to the presence of the liver inferiorly.

Question 37

What three parts of the skeleton does the diaphragm attach to?

Answer 37

1. The sternum. 2. The lower six ribs (ribs 7-12) and costal cartilages 3. L1-L3 vertebral bodies.

Question 38

What nerve supplies the diaphragm and where does this come from?

Answer 38

The phrenic nerve from C3, 4 and 5 anterior rami.

Question 39

Where are the phrenic nerves found in the neck?

Answer 39

On the anterior surface of the scalenus anterior muscle.

Question 40

Where are the phrenic nerves found in the chest (thorax)?

Answer 40

Descending over the lateral aspects of the heart.

Question 41

What do the phrenic nerves supply to both the fibrous pericardium and the diaphragm?

Answer 41

Somatic sensory and sympathetic axons.

Question 42

What do the phrenic nerves supply to the diaphragm only, which they do not supply to the fibrous pericardium?

Answer 42

Somatic motor axons. | Note, also supplies somatic sensory and sympathetic axons.

Question 43

Describe the three steps involved in the mechanics of inspiration.

Answer 43

1. The diaphragm contracts and descends - increases the vertical thoracic dimension. 2. Intercostal muscles contract, elevating the ribs - this increases AP and lateral chest dimensions. 3. The chest walls pull the lungs outwards with them (pleura) - air flows into the lungs due to the negative pressure created.

Question 44

Describe the three steps involved in the mechanics of expiration.

Answer 44

1. Diaphragm relaxes and rises - decreases the vertical thoracic dimension. 2. Intercostal muscles relax, lowering ribs - decreases AP and lateral chest dimensions. 3. Elastic tissue of lung recoils - air flows out of the lungs.

Question 45

Where does lymph from the medial quadrants of the breast drain to?

Answer 45

Parasternal nodes - chains run parallel and deep to the sternal edges.

Question 46

Where does lymph from the lateral quadrants of the breast drain to?

Answer 46

Unilateral drainage to axillary nodes.

Question 47

What blood vessels supply the breast?

Answer 47

Subclavian & internal thoracic artery and vein.

Question 48

What muscles lie posteriorly to the breast?

Answer 48

Pectoralis major and minor.

Question 49

What is the purpose of superficial fascia?

Answer 49

Insulation.

Question 50

What is the purpose of deep fascia?

Answer 50

Fibrous and tough - provides protection.

Question 51

Where can the cephalic vein be found?

Answer 51

In the delta-pectoral groove.

Question 52

Name the two lateral muscles of the chest wall.

Answer 52

1. Latissimus dorsi. | 2. Serratus anterior (anchors scapula to ribs).

Question 53

What does paralysis of the serratus anterior cause and what is the usual reason why this happens?

Answer 53

It causes a "winged" scapula. Usually through injury to the long thoracic nerve.

Question 54

What are the most dependent parts of the pleural cavity?

Answer 54

The costodiaphragmatic (costophrenic) recesses at the costophrenic angles.

Question 55

What are the four borders of the parietal pleura?

Answer 55

1. Cervical parietal pleura. 2. Costal parietal pleura. 3. Diaphragmatic parietal pleura. 4. Mediastinal parietal pleura.

Question 56

Where is the costodiaphragmatic recess located?

Answer 56

Between the diaphragmatic parietal pleura and the costal parietal pleura.

Question 57

Where does abnormal fluid the pleural cavity drain to and what does this appear as on a CXR?

Answer 57

Into the costodiaphragmatic recess (e.g. from pleural effusion or haemothorax). This appears as "blunting of the angles" and a fluid level on CXR.

Question 58

What are all the structures found at the root of the lung?

Answer 58

1. One main bronchus. 2. One pulmonary artery. 3. Two pulmonary veins. 4. Lymphatics. 5. Visceral afferents. 6. Sympathetic nerves. 7. Parasympathetic nerves.

Question 59

What is auscultation?

Answer 59

Listening to the sound of air moving through the larynx.

Question 60

What are the nature of normal breath sounds heard via a stethoscope?

Answer 60

Rustling in nature.

Question 61

Along what pathway does the horizontal fissure of the right lung follow?

Answer 61

Following rib four.

Question 62

Along what pathway do the oblique fissures of both lungs follow?

Answer 62

At the level of ribs six anteriorly rising to T3 vertebral level posteriorly.