Respiratory Structures

Question 1

4 functions of the respiratory system

Answer 1

1. Gas exchange - o2 & co2
2. Warming or cooling & moistening of air
3. Removal of inhaled particles (immunity)
4. Voice production & olfaction (smell)

Question 2

3 types of respiration

Answer 2

1. external
2. Internal
3. Cellular

Question 3

Process of external respiration

Answer 3

Exchange of gases between the blood & lungs
‘Pulmonary capillaries’ carry blood around alveoli
Air is inhaled & exhaled - “ventilation”

Question 4

Process of internal respiration

Answer 4

Exchange of gases between blood & cells

Question 5

Process of cellular respiration

Answer 5

Metabolic process whereby energy ATP is obtained by metabolising carbohydrates, fats & proteins

Question 6

What membrane lines the respiratory tract & what is the mucociliary escalator process

Answer 6

Mucous membrane which is a ciliated (hairy) epithelial membrane that contains mucous-secreting goblet cells
Mucus traps inhaled particles, acts as a surfactant (lowers surface tension) & has antimicrobial properties.
Cilia then move the particles down to the oesophagus where they can be swallowed (mucociliary escalator)

Question 7

Nasal cavity functions

Answer 7

Filters air - hair/cilia/mucous
Warms air
Humidification
Sneezing reflex
Olfactory receptors

Question 8

What are the 4 paranasal sinuses

Answer 8

Air filled cavities within certain facial & cranial bones
Lined with mucous membranes that are continuous with the nasal mucosa lining. Secetions drain into nasal cavity
1. Frontal
2. Ethmoid
3. Sphenoid
4. Maxillary

Question 9

Functions of the sinuses

Answer 9

Resonance in speech
Lighten cranial mass
Nasolacrimal ducts drain tears from the eyes
Moisten/humidify the air

Question 10

3 sections of the pharynx

Answer 10

1. Nasopharynx
2. Oropharynx
3. Laryngopharynx

Question 11

What is the function of the eustachian tubes

Answer 11

They connect the nasopharynx to the middle ear & allows equalisation of pressure in the middle ear - can be a risk of spreading infections between each cavity especially in younger children

Question 12

What are adenoids

Answer 12

Nasopharyngeal tonsils

Question 13

Functions of the pharynx

Answer 13

Passageway for air & food
Warming & humidifying
Taste
Hearing
Equalisation of pressure in middle ear (eustachian tubes)
Immune protection- tonsils
Speech- resonating chamber

Question 14

What are the role of the laryngeal muscles

Answer 14

Attached to the vocal cords & when contracted stretch them
Relaxed = loose cords & low tone
Contracted = tight cords & high tone
Testosterone thickens & lengthens the vocal cords

Question 15

Functions of the larynx

Answer 15

Production of sound & speech
Protection - the ‘epiglottis’ cartilage closes the trachea during swallowing & prevents foods entering the lungs
Air passageway
Warming & humidifying

Question 16

What cartilage is found in the trachea

Answer 16

Hyaline c-shaped rings which are connected to smooth muscle called ‘trachealis’

Question 17

Cartilage found in the larynx

Answer 17

Epiglottis & thyroid

Question 18

How does the sympathetic responsone (fight or flight) affect the trachea

Answer 18

Tracheal dilation

Question 19

How does the parasympathetic response (rest & digest) affect the trachea

Answer 19

Tracheal constriction

Question 20

Trachea functions

Answer 20

Air flow- rings keep trachea open & unobstructed
Mucociliary escalator- removing particles from respiratory tract
Cough reflex
Warming, humidifying, filtering

Question 21

Process of the coughing reflex

Answer 21

Epithelial receptors in the respiratory tract are highly sensitive.
When irritation of the mucous membrane occurs, sensitive nerve endings are stimulated which send an impulse via the Vagus nerve to the respiratory centre in the brain stem. This causes deep inhalation & closure of the glottis & contraction of the abdominal & respiratory muscles to increase pressure & force removal of irritation

Question 22

What is the carina

Answer 22

Where the trachea divide into the two bronchi, literally means an internal ridge & is the most sensitive structure in the system (usually triggers cough reflex)

Question 23

How do the sympathetic & parasympathetic responses affect the bronchioles

Answer 23

Sympathetic - bronchodilation

Parasympathetic- bronchoconstriction

Question 24

What feautures do alveoli have that maximise gas exchange

Answer 24

A large surface area (250 million in each lung!)
Alveolar walls are very thin- single layered
Surrounded by many blood capillaries
Alveolar surfaces are moist with alveolar fluid (gases exchange more easily through thin layers & when in water)

Question 25

3 types of alveolar

Answer 25

Type 1 alveolar- very thin & support overall gas exchange (simple epitheleal cells)
Type 2 alveolar- secrete alveolar fluid which conatins pulmonary surfactant
Alveolar macrophages- leukocytes designed for engulfing foreign cells

Question 26

What is pulmonary surfactant & what processes does it help

Answer 26

It is a mix of lipids (hydrophobic faces air) & proteins (hydrophilic resides in alveolar fluid) that form a surface film in alveoli
Through this structure, surfactant reduces the surface tension within the alveoli, preventing them from collapsing & reducing pressure required to re-inflate

Question 27

2 phases of ventilation

Answer 27

Inspiration

Expiration

Question 28

Primary muscles for ventilation

Answer 28

Intercostal muscles & diaphragm

Question 29

Secondary muscles of ventilation

Answer 29

“Accessory muscles” that assist in breathing
Includes trapezius, sternocleidomastoid & the scalenes (back of the neck muscles)
Only so much lung capacity involvement should only be used as back-up muscles as diaphragmatic breathing is the most efficient

Question 30

Process of inspiration ventilation

Answer 30

An active process requiring muscles, negative pressure in the thoracic cavity causes air to enter lungs down a pressure gradient

Question 31

Process of expiration ventilation

Answer 31

Typically a passive process, muscles relax
Occurs through the elastic recoil of the lungs, only active during forceful breathing or if elasticity is lost through a disease

Question 32

What is the ‘tidal volume’ in lungs

Answer 32

The tidal volume represents the normal volume of air that enters the lungs during inspiration when no extra effort is applied- normal volume is 500ml
Whereas Average pair of lungs can hold around 6 litres of air!