Respiratory System Flashcards
Is the larynx part of the upper or lower respiratory system
Upper
Functions of the nose (4 pts)
sense of smell, warm air, moisten air and trap pathogens
State the order in which air travels through the respiratory system
Mouth
Pharynx
Larynx
Trachea
Carina
Left & Right Main Bronchus
Bronchi
Bronchioles
Alveoli
What are the 3 parts of the pharynx
Nasopharynx
Oropharynx
Laryngopharynx
How many lobes does each lung have
right = 3
Left = 2
Which layer of the pleura is closest to the chest wall?
Parietal
Functions of type 2 alveolar cells
produces surfactant, prevents collapse, repairs alveolar wall
Conducting Zone
interconnecting cavities and tubes inside and outside of the lungs. Responsible for filtering, warming and moistening air
Respiratory Zone
Tissues where gaseous exchange occurs
What is the nasal cavity lined with?
a mucous membrane, stratified ciliated columnar epithelium cells and goblet cells
Why is the nose being high vascular something we should consider?
Epistaxis and potential use of anticoagulant medication - makes it harder to control bleeding
Explain the external structure of the nose
supporting bone and hyaline cartilage which is covered by muscle and skin and then lined by a mucous membrane.
There are always 2 openings called external nares which are separated by the septum
Which structures in the nasal cavity are responsible for warming, moistening and filtering
Nasal conchae and nasal meatuses
Nasopharynx
extends from soft palate and is lined with stratified ciliated columnar epithelium and is responsible for cleaning and filtering air
Where are the pharyngeal tonsils (adenoids) found?
Nasopharynx
How long is the pharynx?
Approx 13cm in adults
Oropharynx…
1.Extends from
2. Contains
3. Lined with
extends from soft palate inferiorly and contains the palatine and lingual tonsils. It is lined with non-keratinised stratified squamous epithelium
Laryngopharynx
begins at the level of the hyoid bone and opens into the oesophagus at the back and the larynx at the front
How many pieces of cartilage does the larynx have?
9
Thyroid cartilage
connected to the hyoid bone by ligaments.
It is 2 fused plates of hyaline cartilage forming the anterior wall of the larynx
Epiglottis
Attached to the thyroid, decompresses over the respiratory tract when swallowing.
made of elastic fibrocartilage
Cricoid
Ring of hyaline cartilage and is attached to the first ring of the trachea and the thyroid cartilage
The glottis
Folds of mucous membrane which form the vocal cords
Narrowest point of the respiratory tract
What is the rima glottis?
opening between the true vocal cords and the arytenoid cartilage
Trachea
Extends from the larynx to around T5
16-20 rings of C shaped cartilage
Carina: site of bifurcation
stratified ciliated columnar epithelial cells
4 main layers of cells: mucosa, submucosa, hyaline cartilage and adventitia
Differences between the right and left lung
The right lung is thicker but shorter as it accomodates the liver, it also has 3 lobes and has a higher volume and total capacity.
The left lung has the cardiac notch and has 2 lobes and lingula
2 layers of the pleural membrane
Visceral: sits on surface of the lungs
Parietal: attached to the thoracic wall
Purpose of the serious fluid in the pleural cavity
reduced friction between the pleura
Conditions that can arise with the pleural membrane
Inflammation: pleurisy or pleuritic pain
Excess Fluid: pleural effusion
Cavity filled with air: pnuemothorax
Cavity filled with blood: Haemothorax
Which bronchus is shorter and why is this important to know/consider?
The right bronchus is shorter and more vertical - this means intubation attempts may end up in this bronchus and inhaled objects are also more likely to enter the right lung
Alveoli overview
Kept in shape by elastin and surfactant
cup shaped to increase surface area
Short diffusion pathway - 1 cell thick
Type 1 alveolar cells
squamous alveolar cells - epithelial
Provide structure
cover 95% of the surface area of the alveolar sacs
Type 2 alveolar cells
AKA pneumocytes
cuboidal or round shaped
production of surfactant
repair alveoli wall
What happens during inhalation?
the diaphragm and intercostal muscles contract (diaphragm flattens)
increased volume = decreased pressure
ribcage moves outwards and upwards
air moves from a high partial pressure (atmosphere - 760mmHg) to a low partial pressure (lungs - 758mmHg)
What happens during exhalation?
The diaphragm and intercostal muscles relax (diaphragm returns to dome shape)
decreased volume = increased pressure
ribcage moves inwards and downwards
Air moves from a high partial pressure (lungs - 762mmHg) to a lower partial pressure (atmosphere - 760mmHg)
Tidal Volume
Inspiratory Reserve Volume
Expiratory Reserve Volume
Residual Volume
TV: amount of air breathed in and out in a normal breath
IRV: extra volume of air that can be inhaled after normal tidal inspiration
ERV: extra volume of air that can be exhaled after normal tidal expiration
RV: the volume of air remaining in the lungs after forced exhalation
Inspiratory Capacity
Functional Residual Capacity
Vital Capacity
Total Lung Capacity
IC: the amount of air that can be inhaled with maximum effort (TV+IRV)
FRC: the amount of air left in air passaged after quiet exhalation - prevents the lungs from collapsing (ERV+RV)
VC: maximum volume of air that can be moved in and out of the lungs (TV+ERV+IRV)
TLC: total volume of air the lungs can hold
External and Internal Respiration
External: between alveoli and capillaries
Internal: capillaries and tissues
Boyle’s Law
How air is brought into the lungs
Increased volume = decreased pressure
Decreased volume = increased pressure
The pressure of gas in a closed container is inversely proportionate to the volume of the container so the volume of the thoracic cavity dictates the intrathoracic pressure
Charle’s Law
Expansion of warm air in the lungs
The mouth and nose warm particles
increased temp = increased volume
the volume of gas is directly proportional to its absolute temperature assuming pressure stays stable
Dalton’s Law
Each gas in a mixture of gases exerts its own pressure as if there are no other gases present
Atmospheric pressure is 760mmHg. Nitrogen (78%), Oxygen (21%), Carbon dioxide (0.04%) and other gases (around 1%)
Partial Pressure of oxygen (inspired): 159mmHg
Partial pressure of carbon dioxide (inspired): 0.3mmHg
Partial Pressure of oxygen (expired): 130mmHg
Partial Pressure of carbon dioxide (expired): 30mmHg
Henry’s Law
How gases dissolve in alveolar fluid
The amount of dissolved gas in a liquid is proportional to its partial pressure above liquid
higher partial pressure of gas in liquid = more gas dissolved
Overview of the Bohr Effect
As acidity increases (carbonic acid) in the bloodstream, the affinity for oxygen in haemoglobin decreases
pH of blood should be 7.35 - 7.45
Chemoreceptors detect acidity of the blood
Carbonic anhydrase coverts carbon dioxide into bicarbonate ions and hydrogen ions = blood becomes more acidic
The Haldane Effect
How carbon dioxide is released at the lungs
The Control of Breathing:
Medullary Rhythmicity Centre
Pneumotaxic Area
Apneustic Area
MRC: Controls rhythm
PA: Increases breathing rate, reduces duration of breaths
AA: prolongs duration of breaths, increased depth of breathing
