Respiratory System

Question 1

list the primary functions of the respiratory system

Answer 1

deliver oxygen to cardiovascular system and remove carbon dioxide from body (gas exchange between blood and air)

-produce sound-speech/vocalistaion
-provide olfactory senses-sense of smell
-regulate blood pH

protect respiratory surface from
-dehydration
-temperature changes
-invasion of pathogens

Question 2

describe the structural divison of upper respiratory tract

Answer 2

upper respiratory system=nose –> pharynx

lower respiratory system=larynx–>lungs

Question 3

describe the functional divisions of respiratory system

Answer 3

conducting zone=nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles
- series of interconnected cavities and tubes

Respiratory zone = respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli
- main sites of gas exchange between air and bloo

Question 4

discuss the types of respiratory epithelium

Answer 4

mucus glands (mucin) and serous glands (lysosomes) present

GOBLET CELLS-produce mucus to trap dust and inhaled particles

CILIATES CELLS-move mucu towards the pharynx (expectorated/swallowed)

Question 5

list the differences in the epitheliums

Answer 5

stratified epithelium-protects against abrasion (oropharynx and laryngopharynx)

simple squamous-single cell layer to facilitate diffusion for gas exchange (aveoli)

Question 6

describe the nasal cavity

Answer 6

includes the nose=external nose + nasal cavity

nasal cavity=nares choanae (opening to pharynx)

-the shape of the nose is defined by bone
-lined by respiratory epithelium
-mucous membrane on floor of nasal cavity

Question 7

what divides the nasal cavity

Answer 7

divided L-R by nsasal septum
-cartilage anterior
-bone posterior

Question 8

list the functions of nasal cavity

Answer 8

-warms, humidifies and filters air
-smell (olfaction)
-contributes to voice and sound

Question 9

what is the mucous membrane rich in

Answer 9

rich in blood vessels
-epistaxis

Question 10

define Rhinitis

Answer 10

infection of nasal mucousa-virus or bacteria, allery or chemical irritants

Question 11

describe the paranasal sinuses

Answer 11

sinuses=cavities inside bone

-open into nasal cavity
-lined with mucous membrane
-named by bone located in
-reduce skull weight
-enlarge volume of nasal cavity
-modify resonance of voice

Question 12

discuss sinusitis and the 2 types

Answer 12

=inflammation of the paranasal sinuses

-often accompinies rhinitis
-mucous blocks passageway for sinuses to drain into nasal cavity

acute: severe headache localized to forehead/cheek lean forward

chronic: longer than 8 weesk less pronounced symptoms

Question 13

describe the pharynx

Answer 13

=”throat” common opening digestive and respiratory system
-posterior to nasal/oral cavities; inferiorly connects to larynx and oesophagus

Question 14

name the 3 types of pharynx and describe them

Answer 14

Nasopharynx – post. to choanae, sup. to soft palate; air passes through it
-adenoids/pharyngeal tonsils at -posterior, fight infection

Oropharynx – soft palate → epiglottis; air & food & liquids pass through it

Laryngopharynx – epiglottis → oesophagus; passes post. to larynx; air passes through it

Question 15

discuss the structure of pharynx

Answer 15

wall=skeletal muscke
-circular and longtidal muscle layers-relaxed muscle help keep patent…contarction assist swallowing

-lined by mucous membrane

epithelium
-respiratory epithelium in nasopharynx=pseudostratified ciliated columnar epithelium
-stratified squamous epithelium in oro and laryngophartn

Question 16

list the functions of the pharynx

Answer 16

-Part of upper airways (airflow)

-Part of the digestive tract (swallowing)

-Immune system: pharyngeal tonsil

-Contributes to sound/speech

-Auditory tube open into nasopharynx - equalise pressure in middle ear

-Pharyngitis ‘sore throat’: typically viral or bacterial infection.

Question 17

describe the larynx

Answer 17

anterior part of throat=voice box

-passage for air from pharynx to trachea-RESPIRATORY ONLY

Question 18

discuss the structure of larynx

Answer 18

Connected to hyoid bone by membranes & muscles

Outer casing of 9 cartilages connected by muscle/ligaments

Lined by mucous membrane

Above vocal folds lined by stratified squamous epithelium

Below lined by respiratory epithelium (pseudostratified ciliated columnar epithelium)

Question 19

describe the larynx cartilages

Answer 19

-6 paired cartilages, 3 unpaired
-hyaline cartilage –>except epiglottis=elastic cartilage
-unpaired=thyroid (largest), circoid (most inf.) and epiglottis (most sup)
-paired=arytenoid, corniculate and cuneiform
-arytenoids anchor vocal cords

Question 20

what does the larynx prevent

Answer 20

will controll flow of air ensuring to prevent entry of solids and liquids

Question 21

describe acute laryngitis and acute epiglottis in the larynx

Answer 21

AL-inflammation and swelling of larynx, mild respiratory distress only

AE-bacterial infection, typically in children, serious breathing and swallowing difficulties; suffocation risk

Question 22

describe the trachea

Answer 22

trachea=windpipe

-10/12cm long pipe attatched to larynx
-dense CT and smooth muscle
-reinforced with 15-20 C shaped cartilages
-protects trachea
-maintain open airway
-begins below circoid cartilage
-end by bifurcating at carnia (T4/5)

Question 23

what lines the trachea

Answer 23

lines by mucous membrane=pseudostratified ciliated columnar epith and goblet cells

Question 24

describe what occurs in the trachea during a “cough”

Answer 24

air moves rapidly through trachea by contracting smooth muscle and expelling mucus

Question 25

discuss the primary bronchi

Answer 25

Trachea divides into                                       -2 main/primary bronchi  Primary bronchi are asymmetric: right bronchus steeper, wider & shorter than left main bronchus Foreign body more likely to  go into and obstruct the right primary bronchus Foreign bodies in air passageway inf. to trachea don’t stimulate cough Cartilage around tracheobronchial tree to keep it open, smooth muscle changes diameter

Question 26

describe the tracheobronchial tree

Answer 26

Primary (Main) Bronchi -  divide on entering lungs, cartilage rings                   Secondary Bronchi (lobar) – 2 left and 3 right, cartilage plates                                                       Tertiary bronchi (segmental) – one to each bronchopulmonary segment of the lung, cartilage plates Bronchioles – no cartilage, smooth muscle in walls Terminal Bronchioles (end of conducting zone) – simple cuboidal epithelium Respiratory Bronchioles (start of respiratory zone)

Question 27

discuss the folowing conditions that originate from tracheobronchial tree i)bronchial asthma ii)COPD

Answer 27

i) allergy associated with spasm of small bronchiols due to muscles contracting ii)chronic bronchitis and/or emphysema (smokers, miners)

Question 28

discuss -cystic fibrosis -smoking in the repiratory system

Answer 28

Cystic fibrosis: mucus very thick - breathing problems, infections Smokers: cilia movement reduced, epithelial cells lose cilia over time

Question 29

describe alveoli and the 2 types of cells they are composed of

Answer 29

Air-filled chambers for gas exchange air → blood ~ 250um diameter Thin walls composed of 2 cell types type  I : ~ 90%, squamous epithelial cells - gas exchange type II : cuboidal secretory epithelial cells – produce surfactant to keep the alveoli open 300million in 2 lungs

Question 30

define neonatology:

Answer 30

surfactant is not secreted untill about 35 weeks of gestation

Question 31

discuss gas exchange

Answer 31

Gas exchange occurs between alveolar walls & pulmonary capillaries Less so in alveolar ducts Efficient gas (O2 / CO2) exchange facilitated by -Thin alveolar epithelium -Thin basement membrane -Thin capillary endothelium -Thin layer surfactant lining alveolus

Question 32

what is gas exchange permitted by

Answer 32

-Dense network of pulmonary capillaries cover 90% of alveoli surface -Large surface area of alveoli (~75 m2;  ~ tennis pitch!)  -Moist surface (surfactant) to allow oxygen to dissolve - O2 from air to blood

Question 33

describe the lungs

Answer 33

Paired - Right > Left lungs Among largest organs by volume Conical shaped Located in thorax, in upper ribcage  Separated by mediastinum  heart, great blood vessels, esophagus Base of lungs rest on diaphragm  Apex extends 2.5cm above clavicle

Question 34

discuss the following -visceral pleura -parietal pleura

Answer 34

visceral pleura-lines surface of lung parietal pleura-covers inner surfaces

Question 35

overall what does pleura do

Answer 35

-fills fluid cavities lubricant-reduced friction -holds parietal and visceral membranes together-holds lungs to thoracic wall

Question 36

describe pneumothorax

Answer 36

-air in pleural cavity result sin collapse of lung and serious breathing dificulties -chest drains

Question 37

discuss the roots of lung s

Answer 37

structures passing through hilum=root of lung -main bronchi, pulmonary arteries, veins, lymph nodes and vessles -gateway to lungs for air and blood -anchors lungs to mediastinum

Question 38

discuss the lobes of the lungs

Answer 38

large fissures divide the lungs into-lobes -natural groove -right lung (3 lobes) -left lung (2 lobes) -cardiac notch lobes supplied by lobar (2ary) bronchi

Question 39

define segments

Answer 39

=anatomical and funcional unit of lung, seperated by CT -major BVS dont cross CT -important for surgery

Question 40

discuss the process of inspiration

Answer 40

2 phases -  1. Movement of ribs (costal breathing) external intercostal muscles contract & lift ribs  total volume of ribcage increases 2. Movement of diaphragm (diaphragmatic breathing) central part downward movement chest volume increases  Lungs extend to fill available space

Question 41

list the muscles involved in respiration

Answer 41

Muscles of inspiration  elevate ribs so ↑ thoracic volume Diaphragm (flattens & descends) Pressure in lungs falls so air drawn in Muscles of expiration  depress ribs