The Respiratory system Flashcards
Name some functions of the respiratory system
-humidifying and filtering air
-special sense smell- olfaction
-protection and defence
-speech/phonation
-pulmonary ventilation
-maintains blood PH by regulating acid-base balance of blood
-endocrine functions
-gas exchange between lungs and blood supporting gas exchange between blood and tissues
Name the key parts of the upper and lower respiratory tracts
upper
-nose
-pharynx
-larynx
lower
-trachea
-airways
-lungs
What are some examples of upper and lower tract infections?
u-common cold l-bronchitis
u-sinusitis l-bronchiolitis
u-tonsilitis l-chest infection
u-laryngitis l-pneumonia
structure of the nose
-nasal cavity is connected to several paranasal sinus cavities in cranial bone
-like other orifices the cavities are lined with highly vascular mucosal membrane made of ciliated columnar epithelial cells
-mucus contains lysozyme-antimicrobial enzyme thats part of the innate immune system
function of the nose
-air enters nostrils into nasal cavity of the septum
-network of veins warms the air
-glands in and under the mucosa produce mucus which moistens air and traps debris and bacteria
-cilia move mucus towards the pharynx
-olfactory receptos are stimulated by chemicals in the air-brain interprets these as smells
Give some examples of how the structure and function of the nose expains conditions such as
-runny nose
-sinus headache
-nose bleeds
-poor sleep
-runny nose- when cilia get cold they dont work as well
-sinus headache-when exit is blocked by pressure changes in sinus
-nose bleeds-highly vascualar mucosa
-poor sleep-deviated septum can cause breathing problems
Describe the location of the pharynx
-back of nasal cavity
-down back of mouth
-past larynx entrance
-then becomes the osophagus
Describe the location of the nasopharynx
-auditory eustachian tubes connects middle ear
-purpose to balance air pressure either side of the tympanic membrane/ear drum
Name some functions of the pharynx
-passage for food,air,fluids
-warms and humidifies air
-hearing-protects middle ear from pressure changes
-protection-dense with lymphoid tissue including adenoids (tonsils)
-speech-resonance created in pharyns
What is Broca’s area?
-speech centre in the left hemisphere of the brain that controls the vibrations in the vocal chords
Describe the structure and function of the LRT airways-trachea
-windpipe
-extends larynx to lungs
-kept open by c-shaped cartilage to support airway
-lined by columnar ciliated epithelium
-goblet cells and mucous glands produce mucus
-cilia stroke mucus up and out of the tracheas to be coughed out or swallowed mucocillary escalator
-warms and humidifies air
-tracheas splits into right and left bronchus
Describe tracheostomy
-hole created into trachea through an incision in the neck
-used to treat airway obstruction person can breathe by nose and mouth -speech through speaking valve
-changes usually temporary
Describe a laryngectomy
-complete removal of the larynx with redirection of trachea
-used to treat cancer of the larynx-person breathes through stoma
-speech is never normal again
-changes are permanent and irreversible
Describe the structure of the lungs
-cone shaped
-right-3 lobes left-2 lobes
-mass of airways and alveoli and connective tissue and nerves and cappilaries all sitting in an elastic matrix of connective tissue
-thoracic cavity
-apex rises above clavicle
-base lies on diaphragm
-costal surface lies against costal cartilage,ribs and intercostals
-hilum is exit
function of pleural fluid
-creates surface tension so lungs can expand when ribcage and diaphragm expand
-lubricates expansion and contraction of lungs without lungs getting wet
Where is the visceral pleura and parietal pleura?
v-inside edge against lungs
p-outside edge against ribs
What is the main function of each division in the RS?
URT-conductiong zone/air passage, dead space, 150ml
Division at bottom of larynx-division at bronchioles
-LRT-gaseous exchange
Describe the airways in the lungs
-traches divides into L+R primary bronchus
-each bronchi divides 5/6 times into lobar and segmental bronchi before becoming bronchioles
-terminal bronchioled final division with alveolar ducts and sacs at the end of them
-walls are thinner, muscle and connective tissue disappear until single layer of squamous epithelium in ducts and sacs
Describe bronchiole structure
narrower air tubes in which cartilage is replaced with spirals of smooth muscle
-site of bronchoconstriction
Describe the structure of alveoli
-single layer of squamous epithelium
-supported by loose,elactic,connectibe tissue fibroblasts containing:
macrophages,fibroblasts,nerves,blood vessels,lymph vessels
Define respiratory membrane
fused wall of alveoli and cappilary wall
Describe the role of alveoli in regards to its surfactant function
-decreases surface tension of fluid-lungs inflate easier
-prevents alveoli from collapsing
-pre term babies have not developed siffiecent surfactant-resp support
What’s boyles law?
pressure is inversley proportional to volume
-air flows down pressure gradient
What does Boyle’s law help us to understand?
-action of muscles
-changes in intrapleural pressure
-changes in intrapulmonary pressure
-flow of air down pressure gradient
Describe the events that occur during relaxed inspiration
1- diaphragm and external intercostasl contract
2-rib cage rises and sternum flares,diaphragm moves inferiorly during contraction
3-lungs volume increases
4-intrapulmonary pressure drops
5-air flow into lungs down pressure gradient
Describe the events that occur during relaxed exhalation
1-inspiratory muscles relax,diaphragm moves superiorly, rib cage descends due to recoil of costal cartilages
2-thoracic cavity volume decreases
3-elastic recoil of lungs,intrapulmonary volume decreases
4-intrapulmonary pressure rises
5-air flows out of lungs down pressure gradient
State wether relaxed inspiration and exhalation is passive or active
I-active
E-passive
Describe elasticity shrink
-lungs ability to return to normal shape after inspiration due to connective tissue
-loss of connective tissue results in disease
-loss of connective tissue results in forced expiration which requires energy
Describe compliance stretch
-effort required to inflate alveoli
-healthy lungs are very compliant
-compliance reduces when surfactant is insufficent
Describe airway resistance
-more resistance=more effort to inhale and exhale
-airway obstruction-physical or physiological
-conditions that require forced breathing use accessory muscles
describe quiet breathing
-not thoracic breathing
-using the diaphragm
-as diaphragm moves up and down the abdomen moves in and out
-as intercostals conctract rib cages move up and out
Whats the average adult RR?
12-20 resps per min
What’s the avergae infant RR?
30-55 resps per min
Describe the different cavities of the lungs
-functional residual capacity
-inspiratory capacity
-vital capacity
-total lung capacity
What parts make up the functional residual capacity?
-2400ml
residual volume-1200
expiratory reserve volume-1200
What parts make up the inspiratory capacity?
-3600ml
-inspiratory reserve volume-3100ml
-tidal volume-500ml
What parts make up the vital capacity?
-4800ml
-inspiratory reserve volume-3100ml
-tidal volume-500ml
-expiratory volume-1200ml
define tidal volume (TV)
volume of air inhaled or exhaled with each breath under resting condtions
Define inspiratory reserve volume (IRV)
Volume of air that can be forcefully inhaled after a normal tidal volume inspiration
Describe Expiratory reseve volume (ERV)
volume of air that can be forcefully exhaled after a normal tidal volume expiration
Define Residual vilume (RV)
-volume of air emaining in the lungs after a forced expiration
What’s Dalton’s law?
in a mix of non reacting gases, the total pressure is the sum of the partial pressures of each gas in the mix
What’s the equation for daltons law?
p total+PN2+PO2+PCO2
What detects the PO2 +PCO2 change in arterial blood?
receptors in the aorta, cartoid artery and chemoreceptors in medulla oblongata
Describe the events of gas exchange in alveoli
1-arterial blood arrives (low O2, high CO2
2-alveoli after inspiration
(high O2,Low CO2)
3-gases diffuse down gradient
(O2 moves into cappilaries and CO2 moves out of cappilaries
4-venous blood leaves
(high O2, Low CO2)
Describe gas exchange in tissues
1-conc gradient is the other way around to that in alveoli
2-O2 moves from high conc in blood to low conc in tissue
3-CO2 moves from high conc in tissues to low conc in blood
What 2 things is respiration dependent on?
-ventilation
-perfusion
Whats perfusion?
blood surrounding alveoli in cappilaries
describe local autoregulation of blood vessels
-poor ventilation,low alveolar PO2- blood vessels constrict to redirect blood
-good ventilation,high alveolar PO2- blood vessels dilate to accept more blood
Describe local autoregulation of bronchioles
-good ventialation,low alveolar PCO2-bronchioles constrict redirecting airflow
-poor ventilation, high alveolar PCO2- bronchioles dilate to accept more air
Describe the Bohr effect with regards tot hte property of HB
-rise in PCO2
-Increase in H+ ions and lower PH
-results in release of O2 from HB
-helps use venous reserve of O2
-HB carries 4 O2 molecules
-2 Leave easily , other two need a stronger drive
Describe the haldane effect
-oxygenation of blood in lungs displaces CO2 bound to HB
-HB carries more CO2 in deoxygenated blood than in oxygenated blood
give an overview of oxygen transport in the blood
1.5% dissolved in plasma
98.5% attaches to HB molecules inside RBC
HB+O2 =oxyhaemoglobin
Give an overview of CO2 transport in blood
7% dissolves in plasma
70% transported as bicarbonate ion
HCO3 has a negative charge and a role in buffering blood PH
23% attached to HB in RBC-carbaminohaemoglobin
List the solubility of the gases in blood
most soluble-least
CO2
O2
N2
describe pulmonary ventilation
-automatic mechanical process
-Purpose is to refresh air in alveoli
-At rest: Inhalation 2 seconds, exhalation 3 seconds, pause
-Movement of air is due to changes in volume which causes changes pressure
Describe systemic respiration
ventilation of the lungs
Describe tissue respiration
gas exchange between air/blood and blood/tissue fluid
Describe cellular respiration
use oxygen in cellular metabolism
List the order of air flow from the nose to pulmonary alveoli
nostril
nasal cavity
choanae
pharynx
larynx
trachea
primary bronchus
secondary bronchus
tertiary bronchus
bronchiole
terminal bronchiole
respiratory bronchiole
alveolar duct
alveoli
Whats the function of the hard and soft pallate?
seperate nasal and oral cavities and allow breathing whilst there is food in the mouth
