Exam 3 respiratory system physiology Flashcards
Carbonic anhydrase
Enzyme found in erythrocytes that catalyze, the formation of carbonic acid. Which then dissociates into bicarbonate and hydrogen ions.
That’s how carbon dioxide can be moved within erythrocytes. Carbon dioxide - carbonic acid - bicarbonate and hydrogen ions
Acidosis
Drop on the pH of blood below 7.3
Where is the brainstem respiratory centers
Pons
Medulla oblongata
Alkalosis
Ph level higher than 7.4
Hypercapnia
excess CO2 in arterial blood
Pneumothorax
Air within the pleura cavity
Alveoli
Gas exchange
150 million
more surface area for a faster rate of diffusion
Alveoli cell types
Squamous (type I) - main cells, gas exchange
Great alveolar (type II) - not involved in gas exchange, repair epithelium. Secrete Surfactant
Alveolar macrophages (dust cells) - Phagocytize dust particles
Surfactant
Has both hydrophilic and hydrophobic ends
prevents alveolars from collapsing and continue to re-inflate
Respiratory membrane
Membrane that gases have to cross for us to have gas exchange.
From lungs to erythrocytes we have to cross squamous alveolar cells
And the basement membrane
Ventilation
inhaling and exhaling
respiratory cycle
Respiratory cycle
a breath in, breath out
Inspiration
Expiration
Respiratory muscles
Diaphram - prime mover for inspiration intercostals - prime mover for inspiration accessory muscles (pectoralis, scalenes) Inspiration and expiration
Boyle’s law
Inverse
Volume goes up, pressure goes down
When we take a breath in the lungs expand the volume increases, the pressure decreases.
That pressure is lower than atmospheric pressure, gas will want to go inside because of the pressure gradient.
Charles Law
Direct
The volume of gas proportional to its temperature
volume goes up, the temperature goes up
The respiratory tract warms the temperature of the gas, the volume of gas expands helping to expand the lungs
During cold months this helps to warm the air before they get to the alveoli
Tidal Volume TV
One cycle of quiet breathing
Inspiratory reserve volume IRV
Amount that can be inhaled beyond TV inhalation
-Restrictive disorder, pulmonary compliance
Expiratory reserve volume ERV
The amount that can be forcefully exhaled beyond TV exhalation
Obstructive respiratory disorder
Residual volume RV
Volume of air that remains even after maximal expiration
Vital capacity
IRV, ERV, TV= total
The maximum amount of air a person can expel from the lungs after a maximum inhalation
Spirometer
used to measure ventilation
Hypocapnia
Pco2 less than 37mmHg
the most common cause of alkalosis
Hyperventilation to compensate for blood being acidic
Hypercapnia
Pco2 greater than 43 mmHg
the most common cause of acidosis
Hypoventilation
3 pairs of respiratory centers
Ventral respiratory group VRG
Dorsal respiratory group DRG
Pontine respiratory group
VRG ventral respiratory group
A pacesetter of the normal respiratory cycle
Inspiratory neurons: Stimulate diaphragm and intercostal
Expiratory neurons: Expire, don’t stimulate anything
DRG dorsal respiratory group
External influence of VRG
Gets info from: Central and peripheral chemoreceptors, stretch receptors, irritant receptors
- After the info is received the DRG influences VRG to change the pattern of breathing
Pontine respiratory group
In the pons
Influences VRG and DRG
modifies breathing to sleep, emotional response, exercise etc
integrates input from higher brain center
Resistance to airflow
Diameter of bronchioles
Pulmonary compliance
Surface tension of alveoli
Measurement of ventilation and respiratory disorders
The method used to determine the respiratory disorder
Restrictive disorder: Restrict the airflow, decrease in pulmonary compliance. IRV, ERV,
Obstructive disorder: obstruction preventing air from flowing. Expiratory Reserve Volume, they can’t push a lot of that air out
Daltons Law
A mix of gases that make up one gas
Add each gas’s pressure to get total pressure
Gas transport of O2
O2: transported on hemoglobin within the erythrocyte
Oxyhemoglobin
Gas transport of Carbon Dioxide
Carbonic Acid within erythrocyte 90% (carbonic anhydrase)
Carbamino compounds - bind to hemoglobin HbCO2
Dissolved gases - dissolved in plasma
Alveolar gas exchange
Opposite of systemic gas exchange
O2 poor blood to lungs and we have gas exchange
we pick up O2 and drop CO2
