S9) The Respiratory System Flashcards Preview

(LUSUMA) Body Logistics > S9) The Respiratory System > Flashcards

Flashcards in S9) The Respiratory System Deck (48)
Loading flashcards...
1
Q

How can you locate the 2nd rib?

A
  • Finding the sternal angle (between manubrium and the sternum)
  • Move laterally
  • Palpate the attachment of the 2nd rib
2
Q

Why is the inferior aspect of each lung curved upwards?

A

The inferior aspect lies on top of the domed diaphragm

3
Q

What sort of membranes are found in the respiratory system and what do they do?

A
  • A mucous membrane; which lines the conducting portion of the respiratory tract, bearing mucus-secreting cells
  • Serous membranes; which line the pleural sacs, enveloping each lung
4
Q

The pleural cavity can fill with four different substances.

What are they and what is the resulting condition named?

A
  • Air – pneumothorax
  • Blood – haemothorax
  • Pus – empyema
  • Transudate/exudate – pleural effusion
5
Q

How can fluid be drained from the pleural cavity?

A

Fluid is drained by the insertion of a wide-bore needle through an intercostal space (usually 7th posteriorly), performed under ultrasound guidance

6
Q

Identify the different lobes and respiratory airways observed in the image below:

A
7
Q

Identify the 7 components of the conducting portion of the respiratory tract

A
  • Nasal cavity
  • Pharynx
  • Larynx
  • Trachea
  • Primary bronchi
  • Secondary bronchi
  • Bronchioles
  • Terminal bronchioles
8
Q

Identify the 3 components of the respiratory portion of the respiratory tract

A
  • Respiratory bronchioles
  • Alveolar ducts
  • Alveoli
9
Q

What does one observe as you progress down the respiratory tract?

A

The walls of the passageways become thinner as their lumens decrease in diameter

10
Q

Which components of the respiratory tract are extrapulmonary?

A
11
Q

What are the intrapulmonary components of the respiratory system?

A
12
Q

There are epithelial changes in the respiratory system.

What sort of epithelium can be found in the nasal cavity, pharynx, larynx, trachea, primary bronchi and secondary bronchi?

A

Pseudostratified epithelium, with cilia and goblet cells

13
Q

There are epithelial changes in the respiratory system.

What sort of epithelium can be found in the bronchioles and terminal bronchioles?

A

Simple columnar epithelium with cilia, Clara cells and no goblet cells

14
Q

There are epithelial changes in the respiratory system.

What sort of epithelium can be found in the respiratory bronchioles and alveolar ducts?

A

Simple cuboidal epithelium with Clara cells and a few sparsely scattered cilia

15
Q

There are epithelial changes in the respiratory system.

What sort of epithelium can be found in the alveoli?

A
  • Simple squamous cells (type 1)
  • Septal cells (type 2)
16
Q

Identify 3 characteristics of olfactory regions

A
  • Particularly thick pseudostratified columnar epithelium
  • No goblet cells
  • Located in posterior, superior region of each nasal fossa
17
Q

Identify 4 characteristics of non-olfactory regions

A
  • Pseudostratified ciliated epithelium
  • Venous plexuses swell often to prevent overdrying
  • Arterial blood flow warms inspired air
  • Patency maintained by surrounding cartilage/ bone
18
Q

Identify some key anatomical features on the larynx diagram below:

A
19
Q

Describe the features of the ventricular folds of the larynx

A
  • Lined by pseudostratified epithelium
  • Contain mucous glands
  • Contain numerous lymph nodules
20
Q

Which 2 structures contribute to the resonance of the voice?

A
  • Ventricles
  • Ventricular folds
21
Q

What are the components of each vocal cord of the larynx?

A
  • A vocal ligament (large bundle of elastic fibres)
  • A vocalis muscle (bundle of skeletal muscle)
22
Q

Identify 2 functions of the vocal cords

A
  • Stop foreign objects from reaching the lungs
  • Close to build up pressure when coughing is required
23
Q

The trachea divides into two primary bronchi in the mid-thorax.

How does the cartilage in these structures differ?

A
  • Trachea has cartilage crescents which partially enclose the lumen
  • Primary bronchi have cartilage rings which completely encircle the lumen
24
Q

What are the features of Chronic Obstructive Pulmonary Disease?

A
  • There is goblet cell hyperplasia
  • A smaller proportion of ciliated cells
  • Hypertrophy of the submucous glands
25
Q

As bronchioles get smaller, goblet cells give way to Clara cells, interspersed between ciliated cuboidal cells.

What is the role of Clara cells?

A

Clara cells secrete a surfactant lipoprotein, which prevents the walls sticking together during expiration

26
Q

Clara cells also secrete abundant Clara cell protein (CC16).

What is the importance of this protein?

A
  • A measurable marker in bronchoalveolar lavage fluid (lowered in lung damage)
  • A measurable marker in serum; if raised then leakage across air-blood barrier
27
Q

Which different structures can alveoli open up to?

A
  • A respiratory bronchiole
  • An alveolar duct
  • An alveolar sac
  • Another alveolus (via an alveolar pore)
28
Q

Describe the features of alveolar walls

A
  • Abundant capillaries
  • Basketwork of elastic and reticular fibres
  • Covering of type I pneumocytes
  • Scattering of intervening type II pneumocytes
29
Q

What is emphysema?

A
  • Emphysema is a condition resulting in the destruction of alveolar walls and permanent enlargement of air spaces due from smoking or alpha 1-antitrypsin deficiency
  • Alveolar walls are damaged, bronchioles collapse during exhalation, so lungs cannot empty and air becomes trapped in the alveoli.
30
Q

What is a hallmark sign of emphysema?

A

Pursed-lip breathing

31
Q

What is pneumonia?

A
  • Pneumonia is a condition involving the Inflammation of the lung by bacteria (commonly Streptococcus pneumoniae)
  • The lung consolidates as the alveoli fill with inflammatory cells
32
Q

Lung cancer often results in a pancoast tumour on the apex of the lung.

Describe the effects of this form of cancer

A
  • Tumour impinges on either phrenic nerve = part of diaphragm paralysed
  • Tumour impinges on the brachial plexus = muscle wasting in lower arm
  • Tumour impinges on the sympathethic trunk = Horner’s syndrome
  • Tumour impinges on left recurrent laryngeal nerve = hoarse voice
33
Q

Identify the 3 hallmark signs of Horner’s syndrome

A
  • Miosis
  • Partial ptosis
  • Anhidrosis
34
Q

What is cohesion?

A

Cohesion refers to the attraction of identical molecules towards each other e.g. H2O molecules have strong cohesive forces due to H2 bonding

35
Q

Cohesive forces are responsible for surface tension. What is it?

A

Surface tension is the tendency of a liquid’s surface to resist rupture when placed under tension or stress e.g. H2O molecules at the surface will form hydrogen bonds with their neighbours

36
Q

Lungs are surrounded by thin tissue called the pleura, a continuous membrane that folds over itself.

Distinguish between the visceral and parietal pleura.

A

- Parietal pleura lines the chest wall

- Visceral pleura covers the lung

37
Q

Normally, the two membranes of the lung are separated only by lubricating pleural fluid.

What is the purpose of this fluid?

A
  • Reduces friction, allowing the pleura to slide easily during breathing
  • Provides the surface tension needed to prevent the lung from recoiling and collapsing
38
Q

Normally, a vacuum (negative pressure) in the pleural space keeps the two pleurae together and allows the lung to expand and contract.

Discuss this in terms of inspiration and expiration

A
  • During inhalation, the intrapleural pressure is approximately -8cmH20 (below atmospheric)
  • During exhalation, intrapleural pressure is approximately -4cmH20 (below atmospheric)
39
Q

Demonstrates Boyle’s Law in terms of volume and pressure in a container

A
  • When the volume of a container increases, the pressure decreases
  • When the volume of a container decreases, the pressure increases
40
Q

In 4 steps, describe inhalation

A

⇒ Diaphragm contracts

⇒ Intrathoracic volume increases

⇒ Intrathoracic pressure decreases

⇒ Air moves from atmosphere into the lungs

41
Q

In 4 steps, describe exhalation

A

⇒ Diaphragm relaxes

⇒ Intrathoracic volume decreases

⇒ Intrathoracic pressure increases

⇒ Air flows out from lungs to atmosphere

42
Q

What is pressure inside the lungs called?

A

Intrapulmonary pressure

43
Q

Describe the intrapulmonary and intrapleural pressure changes

A
  • Intrapulmonary pressure fluctuates during breathing and equalises to atmospheric pressure at end-exhalation (0 cmH2O)
  • Intrapleural pressure also fluctuates during breathing and is ~ 4 cmH2O less than the intrapulmonary pressure
44
Q

What is significant about the differences between intrapleural and intrapulmonary pressure?

A

The pressure difference of 4 cmH2O across the alveolar wall is the force that keeps the stretched lungs adherent to the chest wall

45
Q

What happens during pneumothorax?

A

If air enters the pleural space between the parietal and visceral pleura (in pneumothorax), the -4cmH20 pressure gradient disappears and the lung recoils and collapses

46
Q

What is open pneumothorax?

A

Open pneumothorax is a condition cause by an opening in the chest wall allowing atmospheric air to enter the pleural space due to a penetrating trauma (stab, gunshot, impalement, surgery)

47
Q

What is closed pneumothorax?

A

Closed pneumothorax is a condition wherein atmospheric air enters the pleural space due to the rupture of the lung and visceral pleura with the chest wall still intact

48
Q

What is the role of surfactant during inhalation and exhalation?

A
  • During inhalation – when alveoli expand, surfactant molecules move apart
  • During exhalation – when lungs shorten, surfactant molecules move together and become concentration i.e. surface tension is reduced