A & P - Respiratory system Flashcards
name the 3 lobes and 2 fissures of the right lung
lobes - superior -middle -inferior fissures - oblique - horizontal
name the 2 lobes and 1 fissure of the left lung
lobes - superior
- inferior
fissure - oblique
where can the visceral pleura be found?
covering the lungs - passes into fissures
where can the parietal pleura be found?
lining the chest wall - continuous with visceral pleura around hilum
what is the space between the parietal and visceral pleura called?
pleural cavity - filled with serous fluid
the respiratory system has two zones, name them and say what they consist of
conducting zone -
nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles
respiratory zone -
respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli
what does the upper respiratory tract consist of?
nose nasal cavity paranasal sinuses pharynx larynx
what does the lower respiratory tract consist of?
trachea
bronchi
bronchioles
alveoli
name three important areas of the nasal cavity
conchae
meati
paranasal air sinuses
what are the functions of the nasal cavity?
warm, cleanse and humidify air
detect odour
resonating chamber
describe the structure and function of the conchae in the nasal cavity
S- ridges in cavity increase surface area, cause turbulence
F - warming, humidifying, filtering air
describe the structure and function of the sinuses in the nasal cavity
S- tiny bone cavities
F - speech, lighten skull
name the four sinuses in the nasal cavity
maxilla
sphenoid
frontal
ethemoidal
name the three sections of the pharynx
nasopharynx
oropharynx
laryngopharynx
what is the function of the pharynx?
passage for air and food (mucus too)
warm and humidify air
resonating chamber
protection
what does the larynx consist of?
epiglottis
thyroid cartilage
what are the functions of the larynx?
route for food and air
protects airway
triggers cough reflex
vocal folds vibrate with expelled air
what is the wall of the larynx composed of?
9 pieces of cartilage
what is the trachea made of?
cartilaginous c shaped rings
what does the open part of the cartilaginous c shaped rings in the trachea abut?
oesophagus
describe the respiratory mucosa
pseudo stratified ciliated columnar epithelium
what function does the muco-ciliary escalator have?
moves dust particles and debris with mucus out of lungs
in which direction does the muco-ciliary escalator move mucus? in the upper and lower respiratory tract?
upper: down towards pharynx
lower: up towards pharynx
what does the bronchial tree consist of?
trachea primary bronchi secondary bronchi - 3 r/lung, 2 l/lung tertiary bronchi bronchioles terminal bronchioles
which primary bronchi is most likely to have an object lodged in it and why?
right - its shorter
what does a bronchus have that a bronchiole does not?
cartilage rings or plates
do bronchioles have cilia?
no
what are bronchioles made of and which system controls them?
smooth muscle controls by ANS
describe which membranes oxygen diffuses through to get from the alveoli to the capillary
squamous epithelial cell then basement membrane then capillary epithelium
what makes up the alveoli wall?
type I alveolar cell -squamous epithelium
type II alveolar cells - septal cells
what carries deoxygenated blood to the lungs?
pulmonary arteries
what carries oxygenated blood to the heart?
pulmonary veins
what supplies the lung tissue with blood?
bronchial arteries
what is pulmonary ventilation?
exchange of air between atmosphere and alveoli
what is involved in quiet inspiration?
diaphragm - 80%
external intercostal muscles - 20%
what happens during quiet expiration?
diaphragm moves upwards
ribs move down
sternum moves in
what muscles are involved in forced inspiration?
scalenes sternocleidomastoid pectoralis minor and major internal intercostals rectus abmoninis
what muscles are involved in forced expiration?
internal intercostals
oblique and rectus abmoninis muscles
quadratus lumborum
what is atmospheric pressure?
pressure exerted by the air and gases surrounding the body
what is intrapleural pressure?
opposing forces
recoil vs. elasticity of chest wall
what is created between the pleural membranes in health?
a vacuum - negative intrapleural pressure created which stops lungs from collapsing
what should intrapleural pressure be in relation to intra pulmonary pressure?
4mmHg less
during expiration what happens to pressure?
increases - as pulmonary cavity gets smaller
during inspiration what happens to pressure?
decreases - as pulmonary cavity gets bigger
when does air stop entering the lungs?
when intra pulmonary and atmospheric pressure is equal
when does air leave the lungs?
when intra pulmonary pressure is more that atmospheric pressure
what is pulmonary compliance?
ease with which lungs expand
what is high pulmonary compliance?
lungs/ thoracic wall expands easily
lungs are elastic and have adequate surfacent
what is low pulmonary compliance?
lungs resistant to expansion
what is pulmonary compliance reduced by?
scar tissue on lungs difficulty expanding lungs blockage of resp. passage low level of surfacent high surface tension
what regulates the diameter of airways?
smooth muscle
in disease/illness such as asthma or COPD what happens to the bronchioles?
they can’t expand fully due to increased airflow resistance
name some pulmonary function tests
spirometer - measures amount of air entering/ leaving lungs
respiratory volumes
respiratory capacities - combo of different resp. volumes
what do the following abbreviations stand for?
IVR
VT
EVR
IVR - inspiratory reserve volume
VT - resting tidal volume
EVR - expiratory reserve volume
what are the normal IVR values for men and women?
men - 3300
women- 1900
what are the normal VT values for men and women?
both - 500
what are the normal EVR values for men and women?
men - 1000
women - 700
what is forced vital capacity (FVC)?
deep breath followed by rapid maximal exhalation
FVC and FEV (forced expiratory volume in a second) at used to diagnosis what? and what are the healthy and abnormal levels?
obstructive disorders eg. asthma
FEV/FVC x 100
>70% healthy
<70% asthma
what is Dalton’s law of partial pressure?
in mixture of gases each gas exerts its own pressure as if the other gases where not there
what is partial pressure?
pressure exerted by each gas
how can you work out the partial pressure?
% of gas in mixture x total pressure of mixture =partial pressure
describe the solubility in plasma of CO2, O2 and N2
CO2 has a greater solubilty than O2 in plasma
O2 has a much greater soulilty than N2 (nitrogen) in plasma
what is Henry’s law?
amount of gas that dissolves in water is determined by its solubility in water and its partial pressure in air
describe the relative partial pressures and solubility of CO2 and O2
partial pressure of O2 is greater than CO2
solubility of CO2 is greater than O2
the exchange of Co2 and O2 must be what in the respiratory system?
equal
what does CO2 rely on to make its exchange with O2 equal?
its greater solubility than O2 in plasma
what does O2 reply on to make its exchange with CO2 equal?
its greater partial pressure than CO2
down which gradient do gases diffuse?
pressure gradient
what % of oxygen binds to haemoglobin?
98.5%
how many molecules of oxygen can each haeme carry?
4
what % of oxygen is carried in plasma?
1.5%
if the partial pressure of oxygen is greater what happens?
more oxygen will combine with haemoglobin until saturated
if the partial pressure of oxygen is lower what happens?
haemoglobin doesn’t hold as much oxygen
how does the partial pressure in the alveoli and systemic tissues affect the amount of O2 bound to haemoglobin?
partial pressure in alveoli is greater so more oxygen bound
partial pressure in tissues is lower so less oxygen is bound
what influences the amount of oxygen that the blood will give up?
partial pressure in that area
name 5 factors that influence haemoglobin saturation
- carbon dioxide
- temp
- acidity of blood
- 2, 3- diphosphoglycerate
- structure of Hb
how does carbon dioxide influence Hb saturation?
increased CO2 cause blood to release oxygen allowing CO2 to bind
how does acidity of blood affect Hb saturation?
increased acidity lowers O2 affinity with Hb.
how does temperature affect Hb saturation?
increased temperature means more O2 are released from Hb
how does 2,3- diphosphoglycerate (DPG)
affect Hb saturation?
reduces affinity of oxygen to Hb - it is produced during glycosis
why does foetal Hb have a greater affinity to O2?
it binds 2,3- diphosphoglycerate (DPG) less strongly
what % of CO2 is dissolved in plasma?
~ 7%
what % of CO2 is bound to Hb in RBCs?
~ 23% - binds to globin peptide chains
where is the highest % of CO2 found in the blood?
as bicarbonate (HCO3-) ion in plasma (~ 70%)
what happens if Co2 level in blood increase?
more CO2 moves out of RBCs
what happens if Co2 level in blood decrease?
more CO2 moves into of RBCs
how much oxygen and carbon dioxide are exchanged from the alveolar air to RBCs and vice versa? and in which direction?
carbon dioxide - 100% from RBC to alveolar
oxygen - 100% from alveolar to RBC
how much oxygen and carbon dioxide are exchanged from respiring tissue to capillary blood and vice versa? and in which direction?
carbon dioxide - 100% from tissue to RBC in capillary
oxygen - 100% from RBC in capillary to tissue
name the two pontine respiratory centre
apneustic centre
pneumotaxic centre
what is the function of the apneustic pontine centre
activates and prolongs inspiration
what is the function of the pneumotaxic pontine centre
increase breathing rate
turns off inspiratory area before lungs overfill
name the two areas of the medulla involved with respiration
ventral respiratory group (VRG)
dorsal respiratory group (DRG)
what are the functions of the VRG and DRG?
VRG - accessory muscles of inspiration and expiration
DRG - active during inspiration, modifies rhythm of VRG
what factors affect the rate and depth of breathing?
change in body demands
altitude
disease
changing levels in atrial blood : eg CO2, H+, O2
which is the most important factor within the atrial blood which is monitored by the body to alter respiration?
CO2
how does the body detect increases CO2 in blood?
increased CO2 leads to increased H+, raising blood acidity. This acidity id detected by chemoreceptors
what is likely to happen to blood acidity in respiratory disease such as emphysema?
CO2 levels will increase, then H+ level increase. Partial pressure of CO2 increases thus blood becomes acidic leading to respiratory acidosis
what happens if a patient is O2 when the partial pressure of CO2 is increased?
partial pressure of CO2 increases further, then chemoreceptors respond to increased H+, returning the PaCO2 to normal by increased ventilation and exhaling more CO2
what is hypoxic drive? often seen in COPD patients?
CO2 in retained so chemoreceptors adapt to increased paCO2
where are the peripheral chemoreceptors located?
aortic bodies
carotid bodies - main O2 receptors
where are the central chemoreceptors located?
surface of medulla - primarily monitor pH of CSF
what % of change is mediated by the peripheral and central chemoreceptors in response to changes in CO2?
peripheral - 30%
central - 70%
what happens if paCO2 decreases?
blood acidity levels decrease and blood pH rises, leading to respiratory alkalosis
what might cause respiratory alkalosis?
hyperventilation or panic attack
what happens if the paO2 increases?
free radials are generated leading to coma and death
what happens if paO2 decreases?
atrial paO2 must be below 60mmHg,
then increased ventilation, central chemoreceptors switch off and peripheral chemoreceptors increasing breathing rate
