Introduction

Question 0

Define the terms ‘upper’ and ‘lower respiratory tract’ and their component parts

Answer 0

Upper respiratory tract - lies above the lower border of the cricoid cartilage - nose, paranasal sinuses, pharynx, larynx
Lower respiratory tract - trachea, bronchi, bronchioles, lungs

Question 1

Explain the broad functions of the respiratory system in health

Answer 1

Ensures all tissues dispose of CO2 produced
Ensures all tissues receive the O2 needed
Conducting air from atmosphere to lower respiratory tract
Conditioning (warming, humidification, trapping particles) inspired air
Protection of airway during swallowing
Gaseous exchange
Speech
Smell
Swallowing

Question 2

Outline the broad functions of the different parts of the respiratory tract

Answer 2

Nose - respiration (filters, humidifies, warms air), smell, receives local secretions (sinuses, nasolacrimal duct)
Paranasal sinuses - humidification, warming air, secretion of mucus, lightens skull
Pharynx - naso (opening for Eustachian tubue –> middle ear), laryngo (connects oesophagus with larynx)

Question 3

Describe the surface making of the pleural cavity (the lines of pleural reflection), and the surface marking of the lungs and lobes of the lung

Answer 3

!

Question 4

Describe the histology of the respiratory tract and relate it to the functions and defence of the lungs

Answer 4

Paranasal sinuses - pseudostratified columnar, ciliated, goblet cells, glands
Nose - pseudostratified columnar, ciliated, hairs
Nasopharynx - cilia
Oropharynx - non keratinised stratified squamous
Laryngopharynx - non keratinised stratified squamous
Larynx - stratified squamous

Question 5

Describe the structure of the airways in the lung, distinguish bronchi from bronchioles, alveolar ducts and alveolus, and describe the structure of the alveoli

Answer 5

Trachea –> primary bronchi –> secondary bronchi (lobar) –> tertiary bronchi (segmental) –> bronchioles –> terminal bronchioles –> respiratory bronchioles –> alveolar ducts –> alveoli
Bronchi - C-shaped rings
Bronchioles - smooth muscle
Alveolar duct - simple cuboidal
Alveoli - simple squamous
Alveoli - abundant capillaries, basketwork of elastic and reticular fibres, covering of type I pneumocytes (squamous), scattering of type II pneumocytes (surfactant)

Question 6

State Boyles’ law, Charles’ law and the Universal Gas Law

Answer 6

Boyles’ law - pressure is inversely proportional to volume
Charles’ law - pressure is inversely proportional to temperature
Universal gas law - PV = RT (absolute pressure x volume = gas constant x absolute temp.)

Question 7

Define the terms ‘partial pressure’, ‘vapour pressure’, ‘standard vapour pressure’, ‘tension’, and ‘content’ of gas in a liquid

Answer 7

Partial pressure - hypothetical pressure of that gas if it alone occupied the volume of the mixture at the same temp.
Vapour pressure - when molecules leave and enter water at the same rate (tendency of particles to escape), saturated
Tension - pressure of a gas within a liquid (ready to leave)
Content - amount of gas in a liquid (solubility x tension)

Question 8

Define the terms ‘tidal volume’, ‘respiratory rate’ and ‘pulmonary ventilation rate’

Answer 8

Tidal volume - volume of air moved into and out of lungs during quiet breathing
Respiratory rate - rate of ventilation, number of breaths taken in a set amount of time
Pulmonary ventilation rate - tidal volume x respiratory rate