Respiratory System Flashcards
list the primary functions of the respiratory system
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
describe the structural divison of upper respiratory tract
upper respiratory system=nose –> pharynx
lower respiratory system=larynx–>lungs
describe the functional divisions of respiratory system
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
discuss the types of respiratory epithelium
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)
list the differences in the epitheliums
stratified epithelium-protects against abrasion (oropharynx and laryngopharynx)
simple squamous-single cell layer to facilitate diffusion for gas exchange (aveoli)
describe the nasal cavity
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
what divides the nasal cavity
divided L-R by nsasal septum
-cartilage anterior
-bone posterior
list the functions of nasal cavity
-warms, humidifies and filters air
-smell (olfaction)
-contributes to voice and sound
what is the mucous membrane rich in
rich in blood vessels
-epistaxis
define Rhinitis
infection of nasal mucousa-virus or bacteria, allery or chemical irritants
describe the paranasal sinuses
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
discuss sinusitis and the 2 types
=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
describe the pharynx
=”throat” common opening digestive and respiratory system
-posterior to nasal/oral cavities; inferiorly connects to larynx and oesophagus
name the 3 types of pharynx and describe them
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
discuss the structure of pharynx
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
list the functions of the pharynx
-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.
describe the larynx
anterior part of throat=voice box
-passage for air from pharynx to trachea-RESPIRATORY ONLY
discuss the structure of larynx
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)
describe the larynx cartilages
-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
what does the larynx prevent
will controll flow of air ensuring to prevent entry of solids and liquids
describe acute laryngitis and acute epiglottis in the larynx
AL-inflammation and swelling of larynx, mild respiratory distress only
AE-bacterial infection, typically in children, serious breathing and swallowing difficulties; suffocation risk
describe the trachea
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)
what lines the trachea
lines by mucous membrane=pseudostratified ciliated columnar epith and goblet cells
describe what occurs in the trachea during a “cough”
air moves rapidly through trachea by contracting smooth muscle and expelling mucus
discuss the primary bronchi
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
describe the tracheobronchial tree
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)
discuss the folowing conditions that originate from tracheobronchial tree
i)bronchial asthma
ii)COPD
i) allergy associated with spasm of small bronchiols due to muscles contracting
ii)chronic bronchitis and/or emphysema (smokers, miners)
discuss
-cystic fibrosis
-smoking
in the repiratory system
Cystic fibrosis: mucus very thick - breathing problems, infections
Smokers: cilia movement reduced, epithelial cells lose cilia over time
describe alveoli and the 2 types of cells they are composed of
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
define neonatology:
surfactant is not secreted untill about 35 weeks of gestation
discuss gas exchange
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
what is gas exchange permitted by
-Dense network of pulmonary capillaries cover 90% of alveoli surface
-Large surface area of alveoli
(~75 m2; ~ tennis pitch!)
O2 from air to blood
describe the lungs
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
discuss the following
-visceral pleura
-parietal pleura
visceral pleura-lines surface of lung
parietal pleura-covers inner surfaces
overall what does pleura do
-fills fluid cavities
lubricant-reduced friction
-holds parietal and visceral membranes together-holds lungs to thoracic wall
describe pneumothorax
-air in pleural cavity result sin collapse of lung and serious breathing dificulties
-chest drains
discuss the roots of lung s
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
discuss the lobes of the lungs
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
define segments
=anatomical and funcional unit of lung, seperated by CT
-major BVS dont cross CT
-important for surgery
discuss the process of inspiration
2 phases -
- Movement of ribs (costal breathing)
external intercostal muscles contract & lift ribs
total volume of ribcage increases
- Movement of diaphragm
(diaphragmatic breathing)
central part downward movement
chest volume increases
Lungs extend to fill available space
list the muscles involved in respiration
Muscles of inspiration
elevate ribs so ↑ thoracic volume
Diaphragm (flattens & descends)
Pressure in lungs falls so air drawn in
Muscles of expiration
depress ribs
