respiratory system

Question 1

what are the features of the upper respiratory tract?

Answer 1

nasal cavity / pharynx / larynx

Question 2

what is the function of the nasal cavity?

Answer 2

nasal cavity = filtration of air / conduction of air / smell / warming of air

Question 3

what is the function of the pharynx?

Answer 3

pharynx = allow air to pass through your windpipe / food and rink through oesophagus / vocal production

Question 4

what is the function of the larynx?

Answer 4

larynx = voice generation / conduction of air / protection of lower airways / separation of digestive tracts

Question 5

what are the main anatomical structures in the upper respiratory tract?

Answer 5

nasal cavity / pharynx (and its three subdivisions) / larynx / thyroid cartilage / cricoid cartilage / hyoid bone

Question 6

describe the nasopharynx

Answer 6

• it goes from the choanae to the soft palate
• the pharyngeal tonsil (adenoid) is located here
• the eustachian tube is located here

Question 7

describe the oropharynx

Answer 7

• b/w the palate and superior border of the epiglottis
• palate tonsil is located here
• has the palatopharyngeal arch

Question 8

describe the laryngopharynx

Answer 8

• connects the oropharynx and oesophagus
• posterior to the larynx until inferior border cricoid

Question 9

describe the nasal cavity

Answer 9

• divided by septum
• septum removed -> 3 conchae (superior and middle which is part of the ethmoid bone / inferior which is a bone in its own right)
• septum removed -> 3 meatus (inferior, middle, superior)
• roof has CN1
• the lateral walls connect to the paranasal sinuses
• nasolacrimal duct ends at the inferior meatus

Question 10

what are the 4 paranasal sinuses?

Answer 10

maxillary, frontal, ethmoidal, sphenoid

Question 11

describe the hyoid bone

Answer 11

connects the pharynx, larynx, and mandible via membranes and muscles

Question 12

describe the pharynx

Answer 12

made of pharyngeal constrictor muscles

Question 13

describe the thyroid cartilage

Answer 13

• largest cartilage
• laryngeal prominence
• posteriorly open
• connected to the cricoid cartilage, epiglottis and vocal ligaments

Question 14

describe the cricoid cartilage

Answer 14

• signet ring structure
• complete ring
• connected to thyroid and arytenoid cartilages (mvmt of arytenoid cartilages change width of rima glottidis)

Question 15

what features are included in the lower respiratory tract?

Answer 15

trachea all the way to the lungs

Question 16

what are the functions of the lower respiratory tract

Answer 16

transport of air / cleaning / gas exchange ONLY at the alveoli

Question 17

what are the main anatomical structures in the lower respiratory tract

Answer 17

trachea, muscles (e.g diaphragm and intercostal), lungs (pleura, bronchi, bronchioles)

Question 18

describe the trachea

Answer 18

has abt 20 cartilaginous semicircular rings that are connected by CT and muscle which assist in moving the neck

Question 19

describe the muscles during breathing

Answer 19

the diaphragm does the majority of the work while muscles like the sternocleidomastoid and pectoralis are accessory muscles

Question 20

describe the lungs

Answer 20

• contains pleura (two layers which connect at the hilum = visceral and parietal / between the two layers there is pleural fluid)
• contains bronchi (left [more oblique / aorta passes] and right [straight / azygos vein passes] main bronchus branching off of the carina
• left lung has 2 lobes
• right lung has 3 lobes
• alveoli = largest surface area in body that is exposed to outer environment

Question 21

voluntary breathing pathway

Answer 21

cortex > corticospinal tract > discharge of motor neurons to diaphragm and intercostal muscles

Question 22

involuntary breathing

Answer 22

medulla > pacemaker cells > discharge of motor neurons to diaphragm and intercostal muscles

Question 23

what are the 3 walls of airway tubes

Answer 23

mucosa, submucosa, adventitia

Question 24

what does the mucosa consist of

Answer 24

epithelium, basement membrane, lamina propia (loose CT)

Question 25

what does the submucosa consist of

Answer 25

fibrous CT, hyaline cartilage, large veins

Question 26

what does adventitia consist of

Answer 26

CT

Question 27

respiratory epithelium in the mucosa of the trachea consist of…

Answer 27

• pseudostratified columnar w ciliated cells, goblet cells, and basal cells
• CT (which has seromucous glands, smooth muscle and hyaline cartilage)

Question 28

describe the lamina propia

Answer 28

• loose CT beneath the epithelium
• has defence cells
• has elastic fibres
• has seromucous glands
• has mucosal venules

Question 29

what are the functions of respiratory mucosa

Answer 29

• trap particles w secretions from goblet cells
• humidify air
• warm air
• removal of pathogens

Question 30

describe the adventitia

Answer 30

outermost CT layer of wall > hold tube in place

Question 31

describe alveolar epithelium

Answer 31

• type 1 alveolar cell > squamous for exchange
• type 2 alveolar cell > cuboidal for surfactant release
• alveolar macrophage

Question 32

What is ventilation

Answer 32

Mechanical process of moving air in and out of airways

Question 33

Anatomy of ventilation

Answer 33

Muscles, bones, joints, membranes, extra cellular structures

Question 34

Control of ventilation

Answer 34

Nerves > sensors and processors and efferent phrenic/intercostal nerves

Question 35

4 components of respiration

Answer 35

Pulmonary ventilation diffusion of O2 and CO2 b/w alveoli and pulmonary circulation, gas transport, gas exchange within body tissue

Question 36

Mechanics of pulmonary ventilation

Answer 36

Two ways lungs expand to alter volume > contraction of diaphragm to lengthen chest cavity / elevation of ribs to increase anteroposterior diameter of chest cavity

Question 37

Normal quiet breathing

Answer 37

Diaphragm lengthen + contract to increase chest cavity

Question 38

Forced breathing

Answer 38

Diaphragm involved BUT ALSO external intercostal for inspiration and abdominal recti and internal intercostals for expiration

Question 39

Air modification

Answer 39

Inspiration
- warming (surfaces of nasal septum and conchae)
- humidification
- filtration (mucous coating of airways)

Expiration
- expired gas passing over cooler upper airway mucosa leads to return of some of its heat
- water reclaimed by process of condensation

Question 40

Components of blood air barrier

Answer 40

Alveolar type 1 epithelial cells, basement membrane, endothelial cell, plasma, erythrocyte membrane

Question 41

Gas transport

Answer 41

• O2 transported in blood dissolved or bound to haemoglobin (cooperative binding)
• CO2 transported in blood dissolved or converted to bicarbonate or bound to proteins
• N2 rapidly dissolves in blood
• unloading of O2 in capillaries facilitates loading of CO2 = haldane effect

Question 42

Gas exchange in tissue

Answer 42

PO2 low in tissues and PCO2 high in> drives diffusion