Respiratory P1 Flashcards
What is included in the upper respiratory tract?
- Nose and nasal cavity
- Pharynx
- Larynx
What is included in the lower respiratory tract?
- Trachea (windpipe)
- Bronchial tubes
- alveoli.
What are the characteristics of the nose and nasal cavity?
- The external nose is constructed from bone and hyaline cartilage
-It is lined with a mucus membrane - Divided internally by the nasal septum
- Two openings are known as the external nares or nostrils
- Olfactory receptors are located in the olfactory epithelium in the
roof of the nose/nasal cavity
▫ Permit the reception of odourants
Serves the following functions:
▫ Warms air
▫ Prevents dehydration
▫ Covered with mucus membrane
and traps particles
▫ Cilia propel particles towards the
pharynx where they can be
swallowed
What is the characteristics of the pharynx?
- Posterior to the nasal cavity and extends to the larynx
- Three regions
▫ Nasopharynx
▫ Oropharynx
▫ Laryngopharynx - Contains the openings of the auditory tubes
▫ Also known as pharyngotympanic tubes or eustachian tubes
▫ Linked to the middle ear and equalises air pressure
You can feel this as ‘popping’ when rapidly changing altitude
Constructed of skeletal muscle - Circular and longitudinal
▫ Contraction involved in swallowing (deglutition) - Lined with mucus membrane
- Contains the tonsils (palatine and lingual)
▫ Patches of lymphatic tissue similar to lymph nodes
▫ Play a role in immunity
▫ Subject to inflammation (tonsilitis), especially common in children
and young adults
What is the characteristics of the larynx?
- Connects the pharynx with the trachea
- Constructed from 9 sections of cartilage
- Contains the vocal folds for speech
- Also contains the epiglottis
▫ Leaf-shaped elastic cartilage
▫ Closes off the glottis
▫ Prevents food or fluid from entering the trachea during swallowing
What is the characteristics of the trachea?
- Tubular windpipe extending from the larynx to the two primary
bronchial tubes
▫ Around the level of the 5th thoracic vertebra (T5) - Constructed from 4 layers:
- Mucosa
▫ Inner-most layer
▫ Pseudostratified ciliated epithelium
▫ Mucus traps particles and is propelled by the cilia to be swallowed
Submucosa
▫ Mostly areolar (loose) connective tissue
▫ Also contains mucus-secreting glands and their ducts - Hyaline cartilage
▫ 16-20 incomplete cartilage rings
▫ Open portion faces posteriorly towards the oesophagus – ends
connected by trachealis muscle - Adventitia
▫ Connective tissue outer layer
What are the characteristics of the bronchial tubes?
The trachea divides into the two primary bronchi
* Each primary bronchus feeds air into and out of either the left or
right lung
* Lined with pseudostratified ciliated epithelia
* Also has incomplete cartilage rings
* Lower internal ridge where the right and left
bronchi originate is known as the carina
▫ Very sensitive and triggers cough reflex
* Primary bronchi divide into secondary or lobar bronchi
▫ Each secondary bronchus feeds a single lobe of the lung
* These further divide into tertiary or segmental bronchi
* More divisions into smaller bronchioles
* Smallest bronchioles known as terminal bronchi
* Branching of bronchial tubes know as the bronchial tree
What are the characteristics of the lungs?
- Paired organs that sit inside the thoracic cavity
- Surround the heart
- The left and right lung reside in separate double-walled structures
called pleural membranes
▫ Parietal pleura line the inside of the thoracic cavity
▫ Visceral pleura cover the lungs - Small space between these layers known as the pleural cavity
▫ Contains lubricating fluid to allow smooth inflation and deflation of
the lungs
What are the characteristics of the alveoli?
- Terminal bronchioles represent the end of the conducting zone of
the lung
▫ Structures that carry air into and out of the lung - Each terminal bronchus gives rise to multiple respiratory
bronchioles
▫ This is the start of the respiratory zone of the lung - Clusters of inter-connected hollow spheres called alveoli extend
from an alveolar duct that is contiguous with each respiratory
bronchus - Each alveolus is covered in pulmonary
capillaries
▫ For gas exchange - Also covered in elastic fibres
▫ Stretch during inspiration
▫ Recoil to aid exhalation - Macrophages are present on the inner
surface
▫ No cilia or mucus for self-cleaning
What is pulmonary ventilation?
The respiratory system constantly delivering oxygen-rich atmospheric air to the alveoli and expelling carbon-dioxide rich are from the alveoli to the atmosphere.
The movement of air into and out of our lungs is dependant on
different air pressures
▫ Atmospheric air pressure and pressures inside our lungs
* Air movement follows Boyle’s law
* Boyle’s law is concerned with the association of the pressure and
volume of a gas
▫ Pressure is inversely proportional to volume
* A simple bicycle pump uses the same principle
▫ Air enters the tyre once the pressure is high enough in the pump
cylinder
What is Boyle’s Law?
P1V1 = P2V2
* The main premise of Boyle’s law is:
▫ If the volume of a gas is increased, its pressure reduces
▫ If the volume of a gas is reduced, its pressure increases
* Our lungs reside in our thoracic cavity
▫ Encased in the pleural membrane
* Our respiratory muscles make our lungs into a type of pump
▫ If we increase their volume, the air pressure reduces
▫ If we reduce their volume, the air pressure increases
To inflate our lungs with external air, we must reduce the air
pressure within them
▫ Known as intrapulmonary or alveolar pressure
* To achieve this, we increase the lung volume
* Once alveolar air pressure is lower than atmospheric pressure, air
flows into our lungs
* To exhale we must increase alveolar air pressure by reducing the
lung volume
* Air is expelled from our lungs once alveolar air pressure is greater
than atmospheric air pressure
What are the jobs of the diaphragm, external intercostals, internal intercostals, abdominals, obliques, scalenes and sternocleidomastoid?
To increase and decrease the lung volume.
What muscles are used for inhalation?
- Diaphragm
▫ Dome-shaped muscle forms the lower section of the thoracic cavity
▫ Flattens around 1 cm during quiet breathing
▫ Can flatten up to 10 cm during strenuous breathing
▫ Contraction contributes ≈ 75% of inhaled air - External intercostals
▫ Raise and widen the rib cage
▫ Contribute ≈ 25% of inhaled air
What is residual volume?
▫ Not all air expelled from lungs
▫ Volume of air remaining in lungs after forced expiration
What is tidal volume?
▫ Resting volume of air inhaled and exhaled
▫ Represents air moved in one breath
What is inspiratory reserve volume?
▫ Achieved during deep inhalation
▫ Excess volume inhaled beyond the normal tidal volume
What is expiratory reserve volume?
▫ Achieved during deep expiration
▫ Excess volume exhaled beyond the normal tidal volume
What is lung capacity?
Combinations of different lung volumes
▫ Often used to determine lung function
What is Inspiratory Capacity?
- Inspiratory Capacity
▫ Inspiratory reserve volume + tidal volume
▫ Maximum volume of air inhaled from normal expiratory level
What is Functional Residual Capacity?
- Functional Residual Capacity
▫ Expiratory reserve volume + residual volume
▫ Volume of air remaining in lungs after normal expiration
What is vital capacity?
▫ Inspiratory reserve volume + tidal volume + expiratory reserve
volume
▫ Maximum volume of air that can be inhaled/exhaled
What is total lung capacity?
▫ Vital capacity + residual volume
What controls breathing?
skeletal muscles and the respiratory centres.
What is the respiratory centre?
- Two clusters of neurons are responsible for breathing
▫ Medullary respiration centre in the medulla oblongata
▫ Pontine respiratory group in the pons - Collectively known as the respiratory centre
- Breathing rate and depth can be influenced by other regions of
the CNS and PNS
▫ We can voluntarily hold our breath
▫ Stimulation is achieved by the hypothalamus and limbic system in
response to emotions inducing laughing a or crying
▫ Receptors detect the concentrations of CO2, O2 and H+ and initiate
changes to breathing
What is the atmospheric pressure at sea level?
760 mmHg (101.325 kPa or 1 atm).
Air pressure reduces as we increase altitude (less air being pulled down)
at 5,500 m, air pressure is ~ half that at sea level (380 mmHg)
Why is breathing important?
- As aerobic organisms, we consume large quantities of oxygen
- During ATP production, we produce carbon dioxide that must be eliminated
▫ Higher CO2 concentration increases H2CO3 formation and reduces blood pH - Therefore, the quantity of oxygen and carbon dioxide in the air we breathe is of importance
▫ We need oxygen
▫ We need to remove carbon dioxide
What is Dalton’s Law?
Total air pressure is the sum of the partial pressures of all gases in a mixture
* N2 - 78.6% PN2 = 597.4 mmHg
* O2 - 20.9% PO2 = 158.8 mmHg
* Ar - 0.093% PAr = 0.7 mmHg
* CO2 - 0.04% PCO2 = 0.3 mmHg
* H2O - 0.367% PH2O = 2.8 mmHg
* Total - 760 mmHg
What is Henry’s Law?
When a gas is in contact with a liquid, the dissolved gas is proportional to its partial pressure and solubility.
* A high partial pressure and solubility will increase the amount of gas dissolved in solution
* A low partial pressure and solubility will cause a decrease in gas dissolved in solution
What are the Partial Pressures of atmospheric air in the Respiratory system?
▫ PO2 = 159 mmHg
▫ PCO2 = 0.3 mmHg
What is the partial pressures of alveolar air in the respiratory system?
▫ PO2 = 104 mmHg
▫ PCO2 = 40 mmHg
How much oxygen is in plasma?
1.5% as it has poor solubility in water.
How much oxygen binds to haemoglobin in RBCs?
98.5%, each haemoglobin molecule has 4 haem units and each one binds to one O2 molecule, when an O2 molecule has bound to a haemoglobin it is known as oxyhaemoglobin.
What factors affect the oxyhaemoglobin saturation?
O2 binding to haemoglobin is easily reversable
* Haemoglobin that is fully converted to oxyhaemoglobin is said to be fully saturated
* Oxyhaemoglobin saturation is dependant on the PO2
* We can plot the relationship between PO2 and oxyhaemoglobin saturation
▫ Oxygen-haemoglobin dissociation curve
- Higher Hb-O2 affinity (left shift), lower CO2, higher pH, lower temp.
- Reduced Hb-O2 affinity(right shift), higher CO2, lower pH and higher temp.
* Acidity
▫ Binding of oxygen to haemoglobin decreases with acidity – Bohr effect
▫ H+ increase causes oxygen to dissociate from haemoglobin
This effect is advantageous in tissues with a high H+ concentration as it increases oxygen unloading
* Carbon dioxide partial pressure
▫ Increased PCO2 decreases O2 binding
▫ CO2 binds to haemoglobin forming carbaminohaemoglobin
* Temperature
▫ Increased heat reduces oxygen binding to haemoglobin
How is Carbon Dioxide transported through the blood?
- Bicarbonate ions – HCO3-
▫ Accounts for around 70% of CO2 transport
▫ Present in plasma and produced by carbonic anhydrase (CA)
CO2 + H2O CA H+ + HCO3-
▫ Reaction reverse in pulmonary capillaries
CO2 exhaled - Carbamino compounds
▫ CO2 binds to amino groups of amino acids
▫ Accounts for 23% of CO2 transport
▫ Haemoglobin is the predominant protein in blood
▫ CO2 binds to form carbaminohaemoglobin
Hb + CO2 Hb-CO2
▫ Promoted by high PCO2 - Dissolved CO2
▫ Simply dissolved in plasma (7%)
What does ventilated mean?
the flow of air into the alveolus
What does Perfused mean?
The blood flow through the pulmonary capillaries.
Is all alveoli ventilated equally in inhalation?
No, alveoli at the base of the lungs receive more air
What part of the lungs receive the least amount of air?
The apex (Top) of the lungs receive the least amount of air. ~ 50% difference.
What is the respiratory zone of the lungs?
- Respiratory bronchioles
- Alveolar ducts
- Alveolar sacs
- Alveoli
- The alveolar duct controls the
flow of air to the alveoli
What do we use to find the difference in perfusion?
Perfusion is also greater at the base of the lung
* Again, gravity results in more blood flowing in the lower sections
of the lungs
* We use the ratio of ventilation to perfusion to determine how
equally-matched they are
▫ V/Q
V = ventilation
Q = perfusion
What is the V/Q ratio in an apex of the lung in a healthy person?
2.1 because of greater ventilation
What is the V/Q ratio in the middle of the lung in a healthy person?
1, because ventilation matches perfusion.
What is the V/Q ratio in the base of the lung in a healthy person?
0.3, this is because of greater perfusion.
Is the volume of blood pumped through the systemic circuit and the pulmonary circuit the same?
Yes.
However, the dynamics are different
How does the systemic circuit pump blood?
- Systemic circuit
▫ High-pressure system
▫ Vascular resistance regulates blood flow
How does the pulmonary circuit pump blood?
- Pulmonary circuit
▫ Low-pressure system
▫ Parallel pathways for blood to flow
▫ Low vascular resistance – 1/10th of systemic
What are some restrictive pulmonary disorders?
Pulmonary fibrosis, pulmonary oedema.
What are some obstructive pulmonary disorders?
Asthma, chronic bronchitis, emphysema.
What are masses in the lungs?
Tumours or scar tissue.
What is pulmonary fibrosis?
- Scarring of lung tissue
▫ Normal tissue replaced by fibrotic
tissue - Reduces lung compliance
- Inhibits oxygen diffusion
- Often caused by autoimmune
disorders - Causes also include:
▫ Tuberculosis
▫ Asbestosis and silicosis
What is pulmonary oedema?
Most commonly caused by heart problems
* Congestive heart failure
▫ Left ventricle and/or left AV valve
dysfunction
▫ Blood backs up on left side of heart as it
cannot be pumped effectively into systemic
circuit
▫ Increased pressure in pulmonary blood
vessels forces fluid out
▫ Fluid collects in alveoli
* Hypertensive crisis
▫ Increased afterload inhibits left ventricular
stroke volume
* Pulmonary capillary membrane damage
▫ Makes capillaries more permeable to fluids
▫ Can be caused by infection such as
pneumonia
▫ Also irritants such as toxic gases from
industrial welding, sulphur dioxide and
chlorine gas
What is asthma?
- Asthma is associated with chronic inflammation of the bronchial
tubes - Characterised by bronchospasms, increased mucus secretion and airway obstruction
- Caused by genetic and environmental factors
- Environmental factors include:
▫ Allergens
▫ Pollutants
▫ Drugs including aspirin
▫ Sulphates used as preservatives in wine, beer etc
What is chronic bronchitis?
Chronic bronchitis is an inflammatory condition resulting in:
▫ Excess thick mucus secretion
▫ Loss of ciliary function
▫ Increased risk of infection
What is emphysema?
- Causes the loss of alveolar walls
- Results in:
▫ Large air spaces that remain full of air after exhalation
▫ This prevents new, oxygen-rich air from entering lungs
What is the normal pH range for blood?
7.35 -7.45
What causes acidosis?
-pH Below 7.35
What are the different types of acidosis?
- Respiratory acidosis.
- Metabolic acidosis
What causes alkalosis?
- pH above 7.45
What are the different types of alkalosis?
- Respiratory alkalosis
- Metabolic Alkalosis
How is blood pH maintained?
- The three mechanisms used are:
- Buffering systems (quickest)
▫ Rapid but do not remove H+ from the body - Removal of carbon dioxide (minutes)
▫ Increasing pulmonary ventilation rate and depth to remove excess CO2 - Excretion of H+ by the kidneys (slowest)
▫ Only mechanism that eliminates H+ from the body
How does the body respond to exercise?
- Exercise is a regular activity that places a major demand on the
body
▫ Increased O2 consumption and CO2 production - To met these demands:
▫ Pulmonary ventilation and perfusion are increased
▫ Vasodilation occurs in working muscles to increase blood flow
▫ PO2 and PCO2 drive diffusion in both external and internal respiration
VENTILATION - Anticipation of exercise stimulates increased breathing rate and
depth
▫ Driven by the limbic system - Breathing pattern then dependant on exercise intensity
▫ Via feedback from chemoreceptors measuring PO2, PCO2 and H+
PERFUSION
Increased pulmonary perfusion
▫ Cardiac output increases in both the systemic and pulmonary circuits
– same stroke volume in each ventricle - Pulmonary perfusion rises
- Increases the O2 diffusing capacity 3x
Due to pulmonary capillaries being fully perfused
What are the changes in epithelium in the bronchial tubes?
- Primary, secondary and tertiary bronchi
▫ Pseudostratified ciliated columnar epithelium with goblet (mucus
secreting) cells - Large bronchioles
▫ Simple ciliated with some goblet cells - Smaller bronchioles
▫ Simple ciliated with few goblet cells - Terminal bronchioles
▫ Simple cuboidal
What are the changes in cartilage and smooth muscle in the bronchial tubes?
As bronchial tubes get smaller, plates of cartilage replace
incomplete rings
* Smooth muscle content increases as cartilage decreases
▫ Smooth muscle present in spiral bands
▫ Helps keep bronchial tubes open
▫ Influenced by catecholamines
Epinephrine and norepinephrine relaxes this muscle and causes
bronchodilation
▫ Muscle spasms may close off bronchial tubes
This occurs during an asthma attack
How are alveoli structured?
Alveoli are constructed using simple squamous epithelial cells
(known as type I cells)
* The alveolar wall and capillary wall form the respiratory
membrane
▫ Gases must diffuse across this
▫ Very thin – 0.5 μm to aid speed of diffusion (copy paper is 100 μm)
* Also contain type II cells (septal cells)
▫ Small cuboidal cells with microvilli
▫ These secrete alveolar fluid - surfactant to reduce surface tension
How many alveoli are in the lungs?
~ 300 million
What are the factors that affect pulmonary ventilation?
Alveolar surface tension, Lung compliance, Airway resistance
How does alveolar surface tension affect pulmonary ventilation?
▫ Water molecules are bound by hydrogen bonds
▫ Stronger attraction to each other than to gas molecules in the air
▫ This surface tension pulls the alveoli slightly inwards
Reduces their volume
▫ Must be overcome to expand the volume of each alveolus
▫ Surfactant secreted by Type II cells helps reduce this
How does Lung compliance affect pulmonary ventilation?
▫ Describes the ease of lung expansion
Caused by the difference between intrapleural and alveolar pressures
▫ High compliance = easy to expand per unit change of pressure
▫ Low compliance = difficult to expand per unit change of pressure
* Low compliance may be caused by:
▫ Scarring of alveoli usually caused by diseases such as tuberculosis
▫ Increased fluid in lung tissue – pulmonary oedema
▫ Deficiency of surfactant – increased surface tension
How does airway resistance affect pulmonary ventilation?
▫ Resistance caused by walls of the bronchial
tubes
▫ Normally dilated during inhalation and
constrict a little during exhalation
▫ Also modulated by the ANS
▫ Any narrowing or obstruction to airways
increases resistance
▫ Seen in asthma and chronic bronchitis
How many breaths does an average adult take a minute?
12 (500 ml of air per breath), volume can increase by 50% during peak exercise over resting values.
- volume increases per breath
- Number of breaths/min increases.
What is the mixture of gases in the air?
▫ N2 - 78.6%
▫ O2 - 20.9%
▫ Ar - 0.093%
▫ CO2 - 0.04%
▫ H2O & others 0.367%
Where is the partial pressure of oxygen higher? Why?
The Alveoli, this is because solutes diffuse from a higher concentration to a lower concentration (higher gradients = faster diffusion rates), therefore if the PP of oxygen is higher in the alveoli, it ensures the oxygen diffuses into the blood.
Where is the partial pressure of Carbon Dioxide higher? Why?
In pulmonary capillary blood, this is because solutes diffuse from a higher concentration to a lower concentration (higher gradients = faster diffusion rates), therefore if the PP of CO2 is higher in the PCB the CO2 will diffuse out of the blood and into our lung.
Why are there differences in the partial pressure of the respiratory system?
▫ Small tidal volume used in quiet breathing
▫ O2 constantly diffusing into blood
▫ CO2 high in residual and expiratory reserve volumes
What are the partial pressures of alveolar air in external respiration?
- PO2 = 104 mmHg
- PCO2 = 40 mmHg
What are the partial pressures of pulmonary capillary blood (oxygen poor) in external respiration?
- PO2 = 40 mmHg
- PCO2 = 45 mmHg
What are the partial pressures of oxygen-rich blood (systemic capillary) in internal respiration?
- PO2 = 100 mmHg
- PCO2 = 40 mmHg
What are the partial pressures of tissue cell in internal respiration?
- PO2 = 40 mmHg
- PCO2 = 45 mmHg
Why is there a difference in alveolar ventilation?
- The weight of fluid in the plural cavity is greatest at the base of
the lung
▫ Due to the force of gravity - This increases the intrapleural pressure
▫ Pressure within the pleural cavity - The alveoli here are less expanded and have a higher compliance
- Therefore, they can be filled with more air
What is the mean pressures of the pulmonary circulation?
mmHg
- Pulmonary artery = 15
- Beginning of capillary = 12
- End of capillary = 9
- Left atrium = 8
- Net driving pressure = 15 - 8 = 7
What is the mean pressures of the Systemic circulation?
mmHg
- Aorta = 95
- Beginning of capillary = 35
- End of capillary = 15
- Right atrium = 2
- Net driving pressure = 95 - 2 = 93
To obtain the maximum gas exchange, how do we modulate perfusion and air flow in the lungs?
- Low alveolar oxygen content
▫ Pulmonary vasoconstriction
▫ Limits blood flow to these alveoli
▫ Blood shunted to alveoli with higher oxygen content
▫ Bronchioles dilate to flow more air to increase oxygen delivery - High alveolar carbon dioxide content
▫ Bronchioles dilate to flow more air to increase carbon dioxide and
oxygen diffusion
How does the air flow through conducting airways?
- Airflow follows similar principles to blood flow
- Pressure difference drives flow
- Resistance from airway walls
- 10% reduction in airway radius =
▫ 52% increase in resistance
▫ 35% decrease in airflow
Flow = pressure gradient/resistance
What are the modulators of airway diameter?
Smooth muscle in airways contains receptors to:
▫ Neurotransmitters
▫ Hormones
* Muscarinic receptors bind acetylcholine
▫ Causes bronchoconstriction
* Β adrenergic receptors bind adrenaline (epinephrine)
▫ Causes bronchodilation
▫ Also bind sympathomimetics:
Albuterol (salbutamol/Ventolin) and salmetrol
Used by asthmatics to cause bronchodilation
What are the effects of acidosis?
- results in depression of the central nervous system.
- caused by loss of synaptic transmission.
- pH below 7 leads to disorientation.
- Possible coma and death.
What are the effects of alkalosis?
- Alkalosis causes overexcitement of the central and peripheral nervous systems.
- Nervousness
- Muscle spasms and convulsions
- Death
Name the characteristics of respiratory acidosis and the causes
▫ Result of high CO2 concentrations above 45 mmHg
▫ ↑ CO2 forms more H2CO3 = ↑ H+
▫ Failure to maintain adequate alveolar ventilation and/or perfusion to remove CO2
* Causes include:
▫ Lung diseases
▫ Damage to respiratory muscles or innervation
▫ Drugs that may reduce ventilation rate
Name the characteristics of metabolic acidosis and the causes
▫ Too much acid is produced by working cells
▫ Failure of the kidneys to remove H+ from blood
* Causes include:
▫ Kidney disease
▫ Diabetic acidosis – ketoacidosis
▫ Lactic acidosis – ineffective oxidative metabolism
▫ Loss of bicarbonate ions due to severe diarrhea
▫ Poisoning – aspirin, methanol
Name the characteristics of respiratory alkalosis and the causes
- Respiratory alkalosis
▫ Blood PCO2 below 35 mmHg
▫ Results in an increase in pH
↓ in H2CO3 formation and subsequent H+ concentration - Causes include:
▫ Hyperventilation – removal of too much CO2 by the respiratory system
Anxiety, high altitude oxygen deficiency etc.
Name the characteristics of metabolic alkalosis and the causes
- Metabolic alkalosis
▫ High systemic blood concentration of HCO3-
▫ Binds more H+ and reduces acidity - Causes include:
▫ High intake of alkaline drugs e.g. sodium bicarbonate
▫ Extreme vomiting – loss of gastric acids (HCL)
How does the carbonic acid - bicarbonate buffering system work?
The primary buffering system in the body is the carbonic acid-
bicarbonate buffer system
* H2CO3 - carbonic acid
▫ Acts as a weak acid
* HCO3- - bicarbonate ion
▫ Acts as a weak base
▫ Kidneys can synthesise and resorb HCO3-
* Can adjust both an excess or shortage of H+
If there is a drop in pH (↑ H+), bicarbonate ions are used to bind free H+
H+ + HCO3- → H2CO3 → H2O + CO2
* CO2 can then be removed during exhalation
* If there is an increase in pH (↓H+), carbonic acid (H2CO3) can add H+
H2CO3 → H+ + HCO3-
Carbonic acid → hydrogen ion → Bicarbonate ion
What cardiac output do you see during exercise in which the intensity is continuously increased?
Increases in heart rate, O2 consumption, Stroke Volume and Cardiac Output.
How does age affect the respiratory system?
- Increasing age has a negative effect on the respiratory system
- Elasticity is lost from the airways down to the alveoli
- Alveoli become ‘baggy’
- Chest wall also becomes more rigid
- Results in a loss of vital capacity of up to 35%
- Loss of bronchial tube ciliary function and reduction in alveolar
macrophages increase risk of infection and disease
