Week 4 Science and Scholarships: Respiratory Flashcards
identify structures of upper respiratory tract
nose, oral cavity, pharynx and larynx
location + what makes up nasopharynx
-upper part of throat behind nasal cavity, passageway for air and food and contains opening of auditory tube
location + what makes up oropharynx
-middle part of throat behind mouth, serving as a passage for both air and food and contains tonsils
location + what makes up Laryngopharynx
-lower part of throat where respiratory and digestive tracts diverge, allowing for pasha of air and food in their respective channels
functions of nasal cavity
-conduction of air
-warm air
-clean air
-sense of smell
what divides nose
septum
how many conchae in nasal cavity
3 (superior and middle and inferior)
how many meatus in nasal cavity
3 (superior and middle and inferior)
identify the paranasal sinuses
- Frontal sinus
- Maxillary sinus
- Ethmoidal cells
- Sphenoid sinus
FEMS
where does the nasolacrimal duct end
inferior meatus
what connents larynx, pharynx and mandible
hyoid bone
what is the pharynx made of
pharyngeal constrictor muscles
identify the functions of larynx
-separates digetsive tract and airway
-voice generation
-protection of lower airways
describe structure of thyroid cartilage
- Largest cartilage
- Laryngeal prominence/Adam’s
apple - Posteriorly open
- Connected to cricoid cartilage, Epiglottis and Vocal ligaments
describe structure of cricoid cartilage
- complete signet ring structure
- Arch and lamina
- Connected to Thyroid cartilage and Arytenoid cartilages
how does the arytenoid cartilage move
change the width of the rima glottidis
identify the three main layers of the trachea
mucosa
submucosa
adventitia
what makes up the mucosa in the trachea
-epithelium
-basal lamina (loose connective tissue)
-basement membrane
-glands
-smooth muscle
what makes up the submucosa in the trachea
-dense (fibrous) connective tissue
-hyaline cartilage and large veins
what makes up adventitia in trachea
connective tissue
where is respiratory epithelium found
in the mucosa
what is respiratory epithelium
pseudo stratified columnar epithelium with
-ciliated cells
-goblet cells
-basal cells
where are seromucous glands found
mucosa (lamina propria/basal lamina)
function of trachealis (smooth) muscle
joins posterior ends of C shaped hyaline cartilage
what is found in lamina propria of trachea
-defence cells
-elastic fibres
-seromucous glands
-mucosal venules
how would you describe the transition from looser to more dense connective tissue in trachea
gradual
inner CT of trachea (relative to lumen) is ___ than outer CT
looser
until it reaches adventitia
walls shared by alveoli are named
interalveolar septae
what makes up inter alveolar septum
little smooth muscle, lots of elastic fibre and extensive capillary network
what cells make up the alveolar epithelium
-type 1 alveolar cell/ septal cell/ pneumocyte (squamous+no visible nuclei))
-type 2 alveolar cell/ septal cell/ pneumocyte (cuboidal)
-alveolar macrophage (dust cell)
function of type 2 alveolar cells
release surfactant to decrease alveolar surface tension
function of alveolar macrophages
remove particulate matter on alveolar surfaces to maintain a thin gas exchange surface
what makes up respiratory membrane
+what’s the other name for this membrane
aka air blood barrier
-type 1 alveolar cell
-basement membrane
-capillary endothelium
structures of lower respirator tract run where to where
trachea to lungs
describe Boyles law in relation to lungs
When lung volume increases (inspiration) but the amount of gas inside remains the same, pressure decreases. Air follows the pressure from high (outside lungs) to low (inside lungs) until its equal.
what muscles of lower airways aid breathing
diaphragm, intercostal muscles, scalene muscles
where is the parietal pleura
attaches to the inner part of ribcage and diaphragm (bordering mediastinum)
where is the visceral pleura
closely connected to lungs and adheres to parietal pleura (on lung)
what is found in between visceral and parietal pleurae
pleural fluid which lubricates and has adhesive role.
what structures of lower airways are found outside lung
trachea and main bronchi
what structures of lower airways are found inside lung
bronchi
functions of conducting airway
NO gas exchange
transport air
cleaning
humidifiction
warming
features of trachea
-windpipe, flexible tube with cartilaginous rings
-conducts air from larynx to bronchi and facilitating airflow to and from the lungs
features of bronchi
-two main branches
-leads air into lungs
-further branches into smaller bronchioles
describe angles of L and R bronchus
-R is more straight
-L is more oblique
how many lobes on left lung and right lung
left=2
right=3
how many segments in lungs
9-10 (L)
10 (R)
how many generations in lung
23
what is the Hering-Breur inflation reflex
-when lungs become overstretched stretch receptors in the bronchi and bronchioles trasnmit signals through the vagus nerve to DRG
-switching off inspiratory signals and preventing further inspiration/prelonging expiration
-also increases RR
-serves as a protective reflex against over inflation of lungs
what structures are involved in voluntary breathing
cortex, corticospinal chord
what structures involves in involuntary breathing
medulla, pace maker cells
two main factors that make up respiration
ventilation and gas exchange
define ventilation
movement of air in and out of airways
identify the two main physical properties of lungs
compliance and recoil
what is meant by compliance of lung
-stretchiness of lungs
-determined by elastic forces of lungs and elastic forces caused by surface tension
the higher the compliance of a lung
the greater the volume of air in lungs
identify the main factor effecting recoil of lungs
surface tensions of alveoli
describe the function of pleura
pleural pressure is negative, creating a vacuum between lung surface and thoracic cavity
outline law of lapace
Pressure in alveoli is proportional to the surface tension and inversely proportional to the radius of alveoli
how does the body prevent collapsed lung
pulmonary surfactant
how to calculate Work on breathing (WOB)
pressure x volume
what does quiet breathing involve
65% = elastic work
35% = frictional/resistive work
airway resistance formula
pressure difference/ volumetric airflow
describe air flow in upper vs lower respiratory system
upper turbulent and lower laminal
describe inspiration (normal breathing)
Diaphragm contracts to increase thoracic volume , lungs lengthen.
describe expiration (normal breathing)
Diaphragm relaxes to decrease thoracic volume , Elastic recoil of lungs and chest wall, compresses the lungs and expels air.
describe inspiration (forced breathing)
Scalenes which elevate the upper ribs;
Sternocleidomastoid which elevates the sternum;
Pectoralis major which elevate the ribs and sternum;
External intercostal muscles which elevate the ribs
describe expiration (forced breathing)
Abdominal recti, internal intercostals, , external and internal obliques, act to lower ribs and compress abdomen against the diaphragm.
what do the “PA” values mean
blood in alveoli
what do the “Pa” values mean
blood entering alveoli before gas exchange
summarise ficks law
The higher the concentration gradient and the shorter the distance the more conductive the diffusion
describe gas transport
- O2 transported in blood is either dissolved (low amount) or bound to hemoglobin (high amount)
- O2 shows cooperative binding to hemoglobin
- CO2 transported in blood is either dissolved or converted to bicarbonate or bound to proteins (in erythrocytes)
- N2 rapidly dissolves in blood (high amount)
- Unloading O2 in capillaries of the body outside the lung
facilitates the loading of CO2 = Haldane effect
describe gas exchange at alveoli/tissues
Pressure gradients drive gas exchange:
Partial pressure of oxygen (PO2) is higher in the alveoli (about 100 mmHg) than in the blood (about 40 mmHg), so oxygen moves into the bloodstream.
Partial pressure of carbon dioxide (PCO2) is higher in the blood (about 45 mmHg) than in the alveoli (about 40 mmHg), so carbon dioxide moves into the alveoli to be exhaled.
*same partial pressure values at tissues and same movement ; however, occurs between blood and tissues instead
identify where peripheral chemoreceptors are found
carotid body and aortic body
identify the main driver of alveolar ventilation
CO2
what causes hypercapnia
high CO2
what causes hypoxia
low O2
what causes acidosis
high H+
what receptor is the main driver of increased ventilation
central chemoreceptors
what is measured in the brain for hypercapnia
H+ (initially CO2 that undergoes reactions to become H+ as H+ itself can’t easily pass blood brain barrier)
what’s the main centre for ventilation processing
pons and medulla
where does central processing occur to regulate respiratory rate
-pneumotaxic centre
-apneustic centre
-dorsal group
-ventral group
-pre-botzinger complex
how does exercise effect ventilation
- Increase demand for oxygen in muscle
- Increased production of CO2 in muscle
- Stimulation of chemoreceptors surrounding muscle (metaboreceptors)
- Increased PaCO2 and reduced PaO2
- Stimulation of peripheral and central chemoreceptors
- Increased activity of phrenic and intercostal nerves
- Increase in RR/elevated tidal volume/enhanced O2 diffusion/activation of respiratory muscle/accelerated ventilatory response
how does air flow in the lungs in terms of pressure
I: Increases in lung volume results in a negative alveolar pressure (relative to atmospheric pressure), resulting in air inflow. Expansion of chest wall pulls outwards on lungs, creating a ‘more negative’ pleural pressure.
E: Relaxation of diaphragm and elastic recoil of lungs results in positive alveolar pressure, resulting in air outflow. Pleural pressure decreases back to baseline.
what drives gas exchange at tissues
PO2 in tissues low and PCO2 in tissues high (CO2 moves out of tissues H to L)
central vs peripheral chemoreceptors
-central is located in medulla vs peripheral in carotid and aortic body
-central regulates H+ and CO2 vs peripheral regulates partial pressures of O2/CO2
-central responsible for 70% of ventilation response vs peripheral 30%
Describe the action of central and peripheral chemoreceptors in regulating respiration
Central chemoreceptors : increase in H+ and CO2 (low pH)–> (H+ is not permeable to BBB therefore CO2 passes BBB and then is converted into H+) –> H+ is detected by central chemoreceptors in the medulla..
Peripheral: Increase in PaCO2 (hypoxia b/c proportional) –> detected by peripheral chemoreceptors in carotid and aortic body –
These work simultaneously, respective sensory involuntary afferent messages are sent to the CPG and then efferent messages are sent to the respiratory muscles t/f altering rate and depth of ventilation t/f increase pH to WNL
muscle wasting (testing abduction and adduction) is indicative of
-peripheral lung tumour, compressing T1 nerve root
peripheral cyanosis is indicative of
low peripheral perfusion
clubbing is indicative of
HPO:lung carcinoma
tar staining is indicative of
smoking
wrist tenderness is indicative of
hypertrophic pulmonary osteoarthropathy
asterixis are indicative of
severe CO2 retention eg COPD
what is anhidrosis, partial ptosis and miosis indicative of
horners syndrome: apical lung tumour
anhidrosis is what
decreased/absent sweating response
what is partial ptosis
asymmetric eyelid droop
what is miosis
asymmetric pupil dilation
nasal polyps are indicative of
chronic inflammation eg asthma
septal deviation is indicative of
nasal obstruction
what is inflamed pharynx indicative of
URTI
what is central cyanosis indicative of
severe hypoxemia, COPD, PE, pneumonia
tenderness of frontal, ethmoidal or maxillary sinuses indicates
URTI
which lymph nodes do u palpate in respiratory exam
submental
submandibular
pre and post auricular
occipital
anterior and posterior cervical chain
supraclavicular
what is tracheal tug indicative of
forced inspiration
how to check tracheal tug
three fingers vertically on trachea and check for depression
how to check tracheal deviation
three fingers horizontally on trachea and check for movement away from midline
contralateral tracheal deviation indicates
tension pneumothorax
what do you look for in general inspection of posterior and lateral chest
shape, symmetry, scars and skeletal deformities
how to check checks expansion
1.wrap hands around back of check at T12 with thumbs meeting over spine
2.ask patient to take deep breath, expansion between thumbs should be >5cm
what orientation should you percuss/auscultate posterior chest
zig zag
-left right from top to bottom
-6 locations (mid clavicular)
what orientation should you percuss/auscultate lateral chest
-under axilla (MAL) both sides/lobes
-4th rib, anterior axillary line on right side (right middle lobe)
-8th rib MAL on both sides (left+right lower)
dullness when auscultating lungs indicates
consolidation, effusion, lobar collapse
hyperresonance when auscultating lungs indicates
pneumothorax
what do you get patient to do when auscultating
-breathe through their mouth
-say 99 (vocal resonance)
*seperately
what do normal breath sounds like
vesicular breathing
-no adventitious sounds eg crackles, wheeze and stridor
what does normal vocal resonance sound like
muffled
-abnormal would have decreased breath and hyperresonance
decreased breath when checking vocal resonance indicates
pneumothorax, effusion, lobar collapse
what do u look for in general inspection of anterior chest
scars, symmetry, shape, skeletal deformities (excavatum and carinatum)
barrel chest indicates
COPD
what orientation do you percuss and ausculate anterior chest
-6 spots
-alternating sides
-supraclavicular area (percuss only)
when is dulness normal when percussing anterior chest
over the liver and heart
when do you use bell in respiratory exam
auscultating above clavicle
function of lower respiratory tract
-gas exchange
-mucocilliary clearance: goblet cells, mucous and cilia (escalator)
-airflow regulation:changing width of bronchial tube and bronchioles
what is the interalveolar septum
-CT core of septa that contains extensive capillary network supplied by pulmonary arteries
-consists of basement membrane, CT
features of bronchioles
-narrower air passages within lungs
-branching from bronchi and responsible for directing air to specific regions of lung
features of alveoli
-tiny air sacs at end of bronchioles where gas exchange occurs
-allowing oxygen to enter blood and CO2 to exit
features of lung
-paired, spongy
-plays key role in facilitating the exchange of gases between air and blood
name the four components of ventilation
pulmonary ventilation
diffusion
gas transport
gas exchange
describe pulmonary ventilation as part of ventilation mechanism
inflow and outflow of air between the atmosphere and alveoli
describe diffusion as part of ventilation mechanism
movement of oxygen and carbon dioxide between alveoli and pulmonary circulation
describe gas transport as part of ventilation mechanism
transport of oxygen and carbon dioxide in blood stream
describe gas exchange as part of ventilation mechanism
exhnage of gases within body tissue
quiet vs forced breathing
Q=normal, rhythmic, exhalation and inhalation during rest or light activities (mainly driven by external intercostals and diaphragm)
F=active, intense inhalation and exhalation involves addition respiratory muscles to met increased oxygen demand or when additional ventilation is needed
list the 5 functions during inspiration and expiration
I=warming , humidification and filtration
E=return of heat and condensation
function of pneumotactic centre
regulates seeped of inhalation and exhalation
function apneustic centre
regulates seeped of inhalation and exhalation
function of dorsal group
regulates inhalation and airway defence
function of ventral group
regulates exhalation only
function of Pro-botzinger complex
regulates respiratory rhythm
Outline an overview of homeostatic control of respiration
1.Stimulus: changes to CO2, pH, O2 levels
2.detected by CCR or PCR
3.Sent to the CPG (pneumotactic centre, DRG, VRG, pre-botzinger complex)
4.these centres send messages to the muscles of respiratory system
5.changes to ventilation to maintain homeostasis
