Respiratory 3 Flashcards
Mastery
Diffusion Depends on
4 things
AFTER
Fick’s law of diffusion
DAGS
Concentration gradient
Diffusion distance
Solubility
Surface area
* alveoli
Thickness and Surface Area of the Respiratory Membrane
Respiratory membranes
- … thickness
- …. total surface area (40 X that of skin)
- … if lungs become …
- leading to(….), and gas exchange …,
- … surface area with emphysema, walls of adjacent alveoli…
Respiratory membranes
0.5 to 1 μm thick
Large total surface area (40 X that of skin)
Thicken if lungs become waterlogged
(edema), and gas exchange ↓
↓ surface area with emphysema
walls of adjacent alveoli break down
Partial Pressure Gradients
Partial pressure gradient for O2 in lungs is steep
Venous blood Po2 = … mm Hg
Alveolar Po2 = …. mm Hg
* O2 partial pressures reach equilibrium of …mm Hg in ~0.25 seconds, about 1/3 the time a red blood cell is in a pulmonary capillary
Partial pressure gradient for CO2 in the lungs is less steep:
Venous blood Pco2 = … mm Hg
Alveolar Pco2 = …. mm Hg
BUT CO2 is … times …. soluble in
plasma than oxygen
CO2 diffuses in equal amounts with oxygen
Internal Respiration
Capillary gas exchange in body tissues
Partial pressures and diffusion gradients are
… compared to external respiration
Po2 in tissue is always …. than in systemic
arterial blood
Po2 of venous blood is … mm Hg and Pco2 is
… mm Hg
Partial pressure gradient for O2 in lungs is steep
Venous blood Po2 = 40 mm Hg
Alveolar Po2 = 104 mm Hg
* O2 partial pressures reach equilibrium of 104 mm Hg in
~0.25 seconds, about 1/3 the time a red blood cell is in a
pulmonary capillary
Partial pressure gradient for CO2 in the lungs is less steep:
Venous blood Pco2 = 46 mm Hg
Alveolar Pco2 = 40 mm Hg
BUT CO2 is 20 times more soluble in
plasma than oxygen
CO2 diffuses in equal amounts with oxygen
Internal Respiration
Capillary gas exchange in body tissues
Partial pressures and diffusion gradients are
reversed compared to external respiration
Po2 in tissue is always lower than in systemic
arterial blood
Po2 of venous blood is 40 mm Hg and Pco2 is 46 mm Hg
JUST KNOW MCQ for this
Ventilation-Perfusion Coupling
Ventilation: …
Perfusion: …
Ventilation and perfusion: …
Ventilation-Perfusion Coupling
Carbon Dioxide - Bronchioles
… CO2 causes bronchiole dilation
… CO2 causes bronchoconstriction
Oxygen – Alveoli
… O2 causes vasodilation
… O2 causes vasoconstriction
Ventilation-Perfusion Coupling
Ventilation: amount of gas reaching the
alveoli
Perfusion: blood flow reaching the alveoli
Ventilation and perfusion must be matched
(coupled) for efficient gas exchange
Ventilation-Perfusion Coupling
Carbon Dioxide - Bronchioles
↑ CO2 causes bronchiole dilation
↓ CO2 causes bronchoconstriction
Oxygen – Alveoli
↑ O2 causes vasodilation
↓ O2 causes vasoconstriction
O2 Transport in Blood
Molecular O2 is carried in the blood
…% dissolved in plasma
…% loosely bound to each Fe of hemoglobin
(Hb) in RBCs
… O2 per Hb
Most oxygen in the blood is transported bound to ….
… + … ↔ …
Molecular O2 is carried in the blood
1.5% dissolved in plasma
98.5% loosely bound to each Fe of hemoglobin
(Hb) in RBCs
4 O2 per Hb
Most oxygen in the blood is transported bound to hemoglobin.
Hb + O2 ↔ HbO2
Gas Transport: oxygen
At level of gas exchange surface (where the PO2 is … mmHg) – Hb quickly becomes … with oxygen
At the level of the tissue (where the PO2 is … mmHg) – Hb unloads …% of its oxygen – which diffuses into tissue
O2 and Hemoglobin
Rate of loading and unloading of O2 is regulated by
-
-
-
-
-
At level of gas exchange surface (where the PO2 is 100 mmHg) – Hb quickly becomes saturated with oxygen -
Gas Transport: oxygen
At the level of the tissue (where the PO2 is 30-40 mmHg) – Hb unloads 25-30% of its oxygen – which diffuses into tissue
Rate of loading and unloading of O2 is regulated by
Po2
Temperature
Blood pH
Pco2
Concentration of DPG
4 things that affect oxyhemoglobin curve
when does it shift right
pH, temp, CO2, fetal
fetal shifts left, very effecient
shifts right in exercise, more pH, more CO2, higher temp, unload O2.
Hypoxia
what is it?
Due to a variety of causes
* Not enough … (eg. …)
* Too few …
* Abnormal or ….
* Blocked or poor …
* Metabolic …
* … disease
* Carbon …
Inadequate O2 delivery to tissues
- Not enough oxygen (eg. High altitude)
- Too few RBCs
- Abnormal or too little Hb
- Blocked or poor circulation
- Metabolic poisons
- Pulmonary disease
- Carbon monoxide
TEST TEST TEST
Carbon Monoxide Poisoning
what is it and what happens?
CO2 Transport
CO2 is transported in the blood in three
forms
… to …% dissolved in …
….% bound to globin of …. (…)
…% transported as …. (…–) in plasma
whats the equation?
CO has 200x the affinity for Hb
Binds Hb and doesn’t let go
Blocks sites from oxygen
CO2 Transport
CO2 is transported in the blood in three forms
7 to 10% dissolved in plasma
20% bound to globin of hemoglobin
(carbaminohemoglobin)
70% transported as bicarbonate ions (HCO3–) in
plasma
Acid-Base Conditions
Respiratory Acidosis
If ventilation is … (e.g. …),
CO2 may…
* CO2 combines with water (carbonic acid equation)
… will also build up
This will drop …
If breathing can’t be corrected, the ….
will actively work to correct H+ levels
Respiratory Alkalosis
E.g. ….
…. breathing will cause excessive … of …
* Also loss of …
This will cause the body to be ….
Seen in … conditions as well
Metabolic Acidosis
Eg. … acid (… pH) due to … or a … or … problem
Will trigger … breathing to help reduce …
* Will reduce …
Metabolic Alkalosis
Low …
Breathing will … to try and build … and … levels
Respiratory Acidosis
If ventilation is hindered (e.g. emphysema),
CO2 may build-up
* CO2 combines with water (carbonic acid equation)
H+ will also build up
This will drop pH
If breathing can’t be corrected, the kidney
will actively work to correct H+ levels
Respiratory Alkalosis
E.g. Hyperventilation
Fast breathing will cause excessive loss of CO2
* Also loss of H+
This will cause the body to be alkalotic
Seen in high altitude conditions as well
Metabolic Acidosis
Eg. High acid (low pH) due to exercise or a
kidney or buffer problem
Will trigger faster breathing to help reduce CO2
* Will reduce H+
Metabolic Alkalosis
Low H+
Breathing will slow down to try and build H+ and CO2 levels
Upper respiratory infections
Colds and flu
* Caused by …
* … not effective
Pneumonia: … of the lungs
* May be caused by ….
* High mortality rate in seniors
* Treatment depends on ….
Tuberculosis
- … infection that scars the …
* May be active with symptoms, or dormant and will
reactivate later
* Treatment: …
Botulism: …. by bacterial toxin
* how do you get it?
* Causes … of skeletal muscles including … and …
* … failure
Upper respiratory infections
Colds and flu
* Caused by viruses
* Antibiotics not effective
Pneumonia: infection of the lungs
* May be caused by bacteria or viruses
* High mortality rate in seniors
* Treatment depends on cause
Tuberculosis
bacterial infection that scars the lungs
* May be active with symptoms, or dormant and will
reactivate later
* Treatment: antibiotics
Botulism: poisoning by bacterial toxin
* Toxin consumed in improperly preserved foods
* Causes paralysis of skeletal muscles including
intercostals and diaphragm
* Respiratory failure
Lung Cancer
…. growth of … cells
Impairs …, …, …
…% of all U.S. cancer deaths
Causes
…% of cases associated with smoking
… gas
Workplace chemicals such as …
Uncontrolled growth of abnormal cells
Impairs air flow, gas exchange, blood flow
One-third of all U.S. cancer deaths
Causes
90% of cases associated with smoking
Radon gas
Workplace chemicals such as asbestos
