17 Flashcards
functions of the respiratory system
IMPT:
Gaseous Exchange
Acid-Base Balance
Phonation
Warming, humidification, filtration of gas
Defense against airborne pathogens
what are the two main divisions of respiratory system
upper respiratory tract
lower respiratory tract
what’s the upper respiratory tract made up of
Nasal cavity
Pharynx
Larynx
what’s the lower respiratory tract made up of
Trachea
Main Bronchi
Lungs
what’s the subdivision of lower respiratory tract and what is each made up of
Non respiratory part of the system (made up of conducting airways) Respiratory part (made up of alveoli and terminal bronchioles
where does lower respiratory tract begin
at top of trachea below the larynx
what’s the carina
bifurcation
where are C shaped cartilage found
trachea bronchi bronchioles
how many lobes in R and left lung
R: 3
L: 2 (missing middle lobe)
what’s the name of the division entre superior and inferior lobe
oblique fissure
what’s the name of the division entre superior and middle lobe
horizontal fissure
both lungs have which fissure
oblique
what the lingula
bottom part of upper lobe of left lung.
what’s the place for the heart in the lungs called
cardiac notch
what tidal volume and normal value
difference between full inspiration and full expiration in quiet breathing (500mL but only 300mL make it to respirator alveoli because it gets diluted)
what’s the inspiratory reserve volume and what’s the normal value
extra amount you can inspire if you force yourself (3100mL)
what’s the expiratory reserve volume and what’s the normal value
extra amount you can expire if you force yourself (1200mL)
ALWAYS SMALLER THAN INSPIRATORY RESERVE VOLUME
what’s the vital capacity and normal values
maximum amount of air a person can expel from the lungs after a maximum inhalation
4800 mL
what’s residual volume and normal values
air in airways after full expiration (always there)
1200mL
what functional residual capacity
RC is the volume in the lungs at the end of a natural exhalation
and is equal to expiratory reserve volume+ residual volume
2400mL
what’s the total lung capacity
6000mL
what inspiratory capacity
volume of air that can be inspired following a normal, quiet expiration and is equal to tidal volume + inspiratory reserve volume
3600mL
what’s the volume of conducting airways
150-200mL
why is oxygen concentration lower in primary bronchi than trachea
because you always have residual volume in carina area that dilutes incoming air.
what volume of tidal volume actually reaches respiratory exchange tissue
300mL
how many times does the airway tree divide
23 times
what’s the name of the last structure of the airway tree
alveolar sac (just apres alveolar DUCTS)
how many alveolar sacs in each lungs
2^23 so about 8 million
how many of the 23 divisions make up the conducting airway (non respiratory)
first 16 divisions
bronchi,
bronchioles,
terminal bronchioles
how many of the 23 divisions make up the respiratory zone
last 7
including respiratory bronchioles, alveolar ducts, alveolar sacs
gas exchange in the alveolar sacs occur thanks to what mechanism. why?
diffusion bc as cross section area of the lung increases inward velocity of the gas decreases
what percentage increase does alveolar sac increase during inspiration
20%
what happens to alveoli in expiration
passive ‘elastic recoil’ which shrinks alveolar volume back to their resting size NOT COLLAPSE
what epithelium lines upper airway
pseudo stratified columnar epithelium
what are some key aspects of pseudo stratified columnar epithelium that make it good in the upper respiratory tract
its resistant to wear (bits of dirt fragments of pollen whatever)
so tough lining
what epithelium lines bronchioles
simple epithelium
what epithelium lines alveoli and alveoli sac
thin single layer of epithelium
what cells secrete mucous
globblet cells
what does mucous contain
antibiotic peptides
what moves mucous
cilia on bronchus and bronchioles on top of epithelial cells
is there mucous in alveoli
no bc would inhibit gas exchange
where is mucous found
everywhere Sauf alveoli
how is mucous of CF patients diff from healthy person
abnormally thick (due to a defective gene), and difficult for the cilia to move. People with CF have to have regular physiotherapy to ‘cough up’ and remove the thick mucus to stop it becoming infected with viruses or bacteria.
what epithelial cells make up alveoli
a) Type I pneumocytes (squamous, 90% of area)
b) Type II pneumocytes (cuboidal, 10% of area)
is there mucous in respiratory zone
no
function of mucous
trap pathogens
defence mechanism in alveoli
macrophages (dust cells) that come out of capillaries
What substances do type II pneumocytes release
Surfactant (phospholipoprotein dissolved in a watery secretion that lines the alveolar sac.
Reduces surface tension in alveoli and stops the alveoli collapsing during expiration.
what are septal cells
type II pneumocystes
what are the secretions from type II pneumocytes
surfactant
antibiotic fluid
which are more common upper or lower respiratory tract infection
lower bc no mucous
Partial pressure of gas (A) equation
Partial pressure of gas (A) = total pressure of gas mixture x fractional concentration of (A)
oxygen partial pressure calculation
PO2 = 760 mm Hg (101 kPa) x 0.21 = 160 mm Hg (21 kPa)
partial pressure of water vapour in respiratory tract
47 mmHg
so calculation of PO2 in trachea
P total = 760 mmHg - 47 mmHg = 713 mm Hg
PO2 (trachea) = 713 mm Hg x 0.21 = 150 mm Hg
what’s dead space
volume of air that is inhaled that does not take part in the gas exchange, because it either remains in the conducting airways or reaches alveoli that are not perfused or poorly perfused
Partial pressure of CO2
42 mm Hg. (5.6 kPa)
partial pressure of O2 and CO2 in blood leaving lung
90 mmHg (12 kPa) for oxygen
40 mm Hg (5.3 kPa) for CO2
what has higher partial pressure of oxygen, systemic veins or pulmonary veins
pulmonary veins
the single main cause of emergency admissions during a four year study period ( 1997-2001) in London
Respiratory conditions (acute and chronic)
what percent of all deaths in London were from respiratory disease, mainly pneumonia, bronchitis and emphysema
8.3%
% of GP consultations for respiratory illness
over 30%
most common respiratory disease
Asthma
COPD (chronic bronchitis and emphysema, etc.).
Tumours (Carcinoma of the lung, mesothelioma, etc.).
Pulmonary fibrosis (including fibrosing alveolitis).
Occupational lung disease (silicosis, pneumoconiousis, asbestosis).
Disorders of chest wall, pleura and diaphragm (eg pneumothorax)
most common respiratory infection
Common cold (acute coryza) Influenza Pneumonia (viral, bacterial and fungal) Pulmonary tuberculosis (Poliomyelitis)
what’s pneumonia
alveoli fill w fluid
the main cause of respiratory death in men aged 65 +
Chronic obstructive pulmonary disease (COPD) closely followed by pneumonia;
In women aged 65 + pneumonia was the most common cause, followed by COPD
common virus infection agents
Rhinovirus Coronavirus Respiratory syncytial virus (RSV) Parainfluenza virus Adenovirus
Social, environmental and occupational factors affecting respiratory disease
Social factors:
Poor housing, nutrition and income (eg TB)
Smoking (COPD and CA-lung)
Travel (TB, etc.)
STDs and iv drug abuse (HIV, TB/pneumonia, etc.)
Environmental factors:
Air pollution, especially particulates and SO2 (COPD/asthma)
House dust mites (asthma)
Occupational factors:
Dust and chemical exposure, and allergies (asbestosis, mesothelioma, silicosis, pneumonconiosis, pulmonary fibrosis, fibrosing alveolitis, etc.)
how many alveolar ducts are there
2^23 because airway tree divides 23 times
what epithelium lines upper vs lower airway
upper: psudostr
lower: simple epi
where is mucus found in respiratory tract
partout sauf alveoli
partial pressure of oxygen in alveolus
100 mmHG
