Anatomy Of The Respiratory System

Question 1

In the upper respiratory tract (URT), what happens at the level of C5 vertebra?

Answer 1

• the larynx becomes the trachea
• the pharynx becomes the oesophagus

Question 2

What is the pharynx consisted of

Answer 2

The nasal pharynx (most superior part)
The oro pharynx
Larygyl pharynx (most inferior) -

Question 3

What is the surface landmark for the bifurcation of the trachea?

Answer 3

The sternal angle

Question 4

How many lobes are in each lung and what are they called?

Answer 4

Right: 3 lobes
Upper, middle and lower lobe

Left: 2 lobes
Upper and middle lobe

Question 5

What is a fissure?

Answer 5

Deep crevices that separate the lobes from each other

Question 6

How many bronchopulmonary segments does each lung have?

Answer 6

10

Question 7

What is a bronchopulmonary segment?

Answer 7

The area of lung lobe that each on of the segmental bronchi supply with air

Question 8

What’s special about the lungs that means a surgeon can remove a segment of lung rather than the whole lung or lobe if for example there is an isolated tumour?

Answer 8

Each lobe and each bronchopulmonary segment has its own air, blood and nerve supply and lymphatic drainage. This means patients can have just the bronchopulmonary segment removed

Question 9

What are the components of the bronchial tree in order

Answer 9

The trachea the main bronchi (left and right), a lobar bronchus, a segmental bronchus, bronchioles (airways <1mm) and aveoli (thin walled air sacs)

Question 10

What structures are lined by respiratory cells?

Answer 10

Everything from trachea to the proximal part of the bronchioles

Question 11

What’s special about respiratory epithelium? Also known as “mucocillary escilator”

Answer 11

Epithelium has mucous glands that secretes mucous onto epithelial surface
The epithelial surface also has cilla to sweep mucous any foreign bodies in mucous superiorly towards pharynx to be swallowed down into stomach

Question 12

What can stop the cilia from the respiratory epithelium from beating properly

Answer 12

Cooling/drying of the mucosa
Toxins in cigarette smoke

Question 13

How does the trachea and all the bronchi remain open (patency)?

Answer 13

Hyaline cartilage
The amount of cartilage gradually reduces as you go down the respiratory tree

(the bronchioles and the aveoli dont have ant hyaline cartilage tho)

Question 14

Why do the aveoli not have any cartilage or smooth muscle in their walls?

Answer 14

As it would impact on diffusion - aveolar walls are extremely thin

Question 15

Where is most of the smooth muscle in the respiratory tree?

Answer 15

Smooth muscles in the walls progressively become more prominent the further away you get from the trachea (more distally)
Smooth muscle is the most prominent feature of the walls of the bronchioles - they can therefore constrict and dilate

Question 16

What causes a wheeze?

Answer 16

The sound ade as air passes through constricted (narrowed) airways

Question 17

Where do you find a neuromuscular bundle and what does it consist of?

Answer 17

In the costal groove of each rib - also is between internal an innermost intercostal muscle layers

It consists of a vein, artery and nerve

Question 18

What is an intercostal nerve?

Answer 18

It is the anterior ramus of the thoracic spinal nerve (supplying the antero-lateral of the body wall)

Question 19

What arteries and veins supply/drain the posterior aspect of the intercostal space

Answer 19

Arterial supply - thoracic aorta ~anastomoses with the thoracic artery about midway of the intercostal space
Venous drainage - azygous vein

Question 20

What arteries and veins supply/drain the anterior aspect of the intercostal space

Answer 20

Arterial supply - internal thoracic artery (runs on so the side of the sternum) ~ anastomoses with the thoracic artery about midway of the intercostal space
Venous drainage - internal thoracic vein

Question 21

What does the diaphragm do?

Answer 21

Separates the thorax from the abdomen (floor of chest cavity and roof of abdominal cavity)
Considered to be the primary muscle or respiration

Question 22

What is the diaphragm?

Answer 22

A skeletal muscle with an unusual central tendon
Arranged as right and left “domes” - right dome more superior due to liver which is inferior

Question 23

What does the muscular part of the diaphragm attach to? What is it supplied by?

Answer 23

1. Sternum
2. Lower 6 ribs and costal cartilages
3. L1-L3 vertebral bodies

Supplied by the phrenic nerve (C3,4 & 5 anterior rami)

Question 24

What makes up the phrenic nerve?

Answer 24

The combined anterior rami of cervical spinal nerves C3,4 &5

Question 25

Where would you find the phrenic nerve?

Answer 25

Found in the neck on the anterior surface of the scalenus anterior muscle
Found in the chest (thorax) descending over the lateral aspects of the heart (on the fibrous pericardium)

Question 26

What type of axons does it supply to the diaphragm and fibrous pericardium?

Answer 26

Supplies:
Somatic sensory and sympathetic axons to diaphragm and fibrous pericardium
Somatic motor axons to the diaphragm

Also relays sensory nerves from diaphragm

(C3,4,5 keeps the diaphragm alive)

Question 27

What is the mechanics of inspiration?

Answer 27

1. Diaphragm contracts and descends - increases vertical chest dimension
2. Intercostal uncles contract elevating ribs - increases antero-Posterior and Lateral chest dimensions
3. Chest wall pulls lungs outwards (as the visceral and parietal pleura are stuck together) - causes a negative pressure un the lungs so air flows in

Question 28

What are the mechanics for expiration?

Answer 28

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

Question 29

What are the 4 quadrants of the female breast?

Answer 29

Superolateral quadrant (upper and outer)
Superomedial quadrant (upper and inner)
Inferolateral quadrant (lower outer)
Inferomedial quadrant (lower inner)

Question 30

What are the parts of the breast you examine during a breast examination?

Answer 30

All 4 quadrants, nipple, areola, axillary tail (assoc. with upper outer) and the regional lymphatics

Question 31

What is the arterial supply and venous drainage of the female breast?

Answer 31

Dominant Supply: branches of subclavian artery - main supply is internal thoracic artery which is a branch of the subclavian artery

Drainage: tributaries to the subclavian vein - main vein draining breast internal thoracic vein which drains into subclavian vein

Question 32

How does the lateral quadrants drain into the axillary nodes?

Answer 32

Lateral quadrants of breast drain unilaterally to axillary lymph nodes
Left lateral quadrants drain to the left axillary lymph nodes
The medial quadrants (upper/lower inner) of the breast drains bilaterally to the parasternal nodes (chains run parallel and deep to the sterna’s edges - each breast drains into both right and left parasternal nodes)

Question 33

What are the layer of the anterolateral chest wall from superficial to deep?

Answer 33

Skin
Superficial fascia -adipose tissue (insulation)
Deep fascia - fibrous, tough but thin (protection)
Sensory nerves - intercostal nerves
Skeletal muscles e.g. deltoid, pectoralis major, serratus anterior (anchors scapula to ribs)

Question 34

Where is the serratus anterior muscle groups?
What nerve supplies the serratus anterior?
What happens if damage happens to this nerve?

Answer 34

Sandwiched between the pectoralis major and latissimus dorsi
Supplied by the long thoracic nerve - if injured causes paralysis = winged scapula
Nerve found on the serratus anterior superficial surface - making it more vulnerable to injury

Question 35

When do subclavian vessels become axillary vessels?

Answer 35

When it passes rib 1 (now into armpit/axilla)

Question 36

What does internal thoracic veins & arteries supply in the chest wall

Answer 36

The anterior part of the Intercostal neurovascular bundles
Supply of the breasts

Question 37

What are the different types of parietal pleura?

Answer 37

Mediastinal parietal pleura - contact with mediastinum
Diaphragmatic parietal pleura - contacts with diaphragm
Costal parietal pleura - contact with ribs
Cervical parietal pleura - just at the apex, extending into neck (above rib 1)

Question 38

What is the costodiaphragmatic recess

Answer 38

The inferior most extend of the pleural cavity

The most dependent part of the pleural cavity when someone is standing upright - it is the deepest part of the pleural cavity so any abnormal fluid tend to drain into recess (will be at the costophrenic angle as it is the MOST inferior region)

Question 39

Wat structures are found at the hilum/root of the lung?

Answer 39

1 main/primary bronchus - most posterior and middle structure
1 main pulmonary artery - most superior structure
2 pulmonary veins - most anterior and inferior structure
Lymphyatics - lymph nodes usually dispersed between other structures
Visceral afferents - sensory nerves to lungs
Sympathetic nerves
Parasympathetic nerves

All of these structures must be cut through if you want to remove the lungs

Question 40

What are the fissures on the lungs? And what is the lingula?

Answer 40

Right lung has an oblique and horizontal fissure
Left lung has an oblique fissure and lingula (feature that is unique to the uperizar lobe of the left lung)

Question 41

What is the corresponding surface anatomy to the horizontal fissure on the right lung?

Answer 41

Follows right rib 4 - separates Superior and middle lobe
Help for auscultating: above ~ superior lobe, below ~ middle lobe

Question 42

What is the corresponding surface anatomy of the oblique fissures?

Answer 42

Located anteriorly at rib 6 and rises posteriorly to T3 vertebral level
Between rib 4 and 6 of the right lung is the middle lobe
This just separated the upper and lower lobe of the left lung

Question 43

Where do you put your stethoscope if you want to hear the apex of the lung?

Answer 43

In the root of the neck - superior to the medial 1/3rd of the clavicle

Question 44

Where do you put your stethoscope to listen ti the base of the lung?

Answer 44

Scapular line at T11 vertebral level
(Scapular line - passes vertically through the inferior angle of the scapula)