Gas Exchange & Respiration

Question 1

Respiration

Answer 1

The transport of oxygen to cells, involves three diff processes

Question 2

Ventilation

Answer 2

exchange of air between the lungs and environment (the physical act of breathing)

Question 2

Gas Exchange

Answer 2

exchange of O2 and CO2 in alveoli and bloodstream (occurs passively in diffusion)

Question 2

Cell Respiration

Answer 2

the act of the cells using O2 to make ATP

Question 3

Diaphragm

Answer 3

muscle at the bottom of the ribs that is responsible for the act of breathing; drops down when contracting to increase volume and decrease pressure

Question 3

Which muscles contract in inhalation?

Answer 3

Diaphragm and external intercostal muscles

Question 3

Features of Alveoli

Answer 3

TRIM
T- thin wall, made of single-layer squamous cells
R-rich capillary network, allows for better gas exchange
I- Increased SA: Volume ratio, allows for optimization of O2 transfer
M- moist, prevents alveoli from collapsing and allows gases to dissolve

Question 3

Type 1 Pneumocyte

Answer 3

Type of alveoli cell responsible for gas exchange, made of squamous cells and is 95% of alveoli surface

Question 4

Intercostal Muscles

Answer 4

Muscles that are found on the inside and outside of the rib cage, responsible for inhalation

Question 4

Dalton’s Law of Partial Pressure

Answer 4

Law that states that the total pressure in a system is proportional to the amount of pressure being enacted by each individual component (ie. air pressure is composed of pressure from O2, nitrogen, and more)

Question 4

Type 2 Pneumocyte

Answer 4

Type of alveoli cell that secretes surfactants to keep a moist environment and prevent alveolus from sticking to each other

Question 5

Why is it hard to breathe at high altitudes?

Answer 5

The total environmental pressure is lower, so while the concentration of O2 is the same, the partial pressure of O2 is lower, and therefore there’s less force pushing the oxygen into the lungs, leading to a lack of oxygen

Question 6

Structure of hemoglobin

Answer 6

4 globular units, 2 alpha and 2 beta structures, and each polypeptide has an iron containing heme group that O2 binds to

Question 7

Oxygen affinity

Answer 7

Refers to how well hemoglobin picks up and keeps the oxygen

Question 8

Cooperative Binding

Answer 8

Process by which the hemoglobin undergoes a conformational change when an oxygen is bound to it, which means that when you gain an oxygen, it becomes easier and easier to pick up oxygen the more oxygen molecules are already bound to the hemoglobin

Question 9

Factors that Effect the Oxygen Dissociation Curve

Answer 9

Higher temperature and a lower pH move the oxygen dissociation curve to the right, because the hemoglobin protein is destabilized and releases the O2 more readily

Question 10

Why is the oxygen dissociation curve an S curve?

Answer 10

Because of cooperative binding, oxygen does not bind to hemoglobin at a linear rate

Question 11

How is fetal hemoglobin different?

Answer 11

It contains a gamma instead of a beta subunit, and has a higher affinity for oxygen so it can take oxygen from mother’s hemoglobin through passive diffusion

Question 12

Myoglobin

Answer 12

Contains 1 heme group, and can only contain one oxygen. Type of oxygen transport molecule found in the muscles as backup during exercise. Has a high affinity for oxygen, so will only release it when conditions are dire

Question 13

Why is Dalton’s Law important?

Answer 13

Because gases with a larger gradient between partial pressures will diffuse faster than those with a smaller gradient. At high altitudes, the partial pressure of the air outside and the air in the capilliaries is closer than at sea level, so it diffuses slower and we get less oxygen

Question 14

Bohr Effect

Answer 14

The drop in pH in the blood due to CO2 and increased presence of acids, which then shifts the oxygen dissociation curve to the right.

The presence of CO2 also reduces hemoglobin’s affinity for oxygen, and the acidity caused by the HCO3- also destabilizes the protein

Question 15

Process of bohr effect + CO2

Answer 15

1. CO2 moves from cells into the blood stream, and 70% is diffused into an RBC
2. CO2 combines with H20 to form carbonic acid (H2CO3)
3. Carbonic acid (H2CO3) immediately dissociates and loses an H+ ion, forming bicarbonate ions (HCO3-)
4. Production of H+ ions increases acidity of blood
5. HCO3- moves out of RBC and Cl- moves in (chloride shift) to keep the erythrocyte a neutral charge
6. HCO3- binds with loose Na+ to form NaHCO3 (sodium bicarbonate) which prevents HCO3- from liberating another H+ ion

Question 16

Haldane Effect

Answer 16

Says that oxygen displaces CO2 carried by hemoglobin to allow for oxygenation and gas exchange in the lungs

Question 17

Anhydrase

Answer 17

Reverts carbonic acid back into CO2 and H2O

Question 18

Aortic and Carotid bodies

Answer 18

Chemoreceptors that detect the pH of the blood and send signals to the brain to either increase heart rate and breathing or to slow it down

Question 19

Medulla Oblongata

Answer 19

Area of the brain responsible for modulating how quickly the heart beats and the lungs breathe, part of the brainstem

Question 20

Asthma

Answer 20

A common, chronic inflammation in airways of the lungs

Question 21

Symptoms of Asthma

Answer 21

shortness of breath, tightness in chest, wheezing, coughing

Question 22

Asthma Triggers

Answer 22

ASS FACE
A- allergies
S- smoking
S- stress & anxiety
F- food preservatives and medications
A- arthropods (dust mites)
C- cold air
E- exercise

Question 23

Symptoms of high altitude sickness/hypoxia

Answer 23

fatigue, breathlessness, rapid pulse, nausea, headaches

Question 24

How does the body acclimatize to high altitudes?

Answer 24

Short term-
Diaphragm learns to drop lower
Increased production of RBCs and hemoglobin
Increased Vascularization of muscles
Kidneys secrete alkaline wine, increase lactate clearance in the body

Long term-
Larger/wider chest (barrel chest)
Greater lung surface area

Question 25

Cause of COPD

Answer 25

Irritants creating chronic inflammation and bronchitis from excess mucus buildup, and the destruction of alveoli (emphysema) by irritants that dissolve the alveoli walls and reduce surface area

Question 26

Symptoms of COPD

Answer 26

Difficulty breathing, coughing, loss of ability to exercise and walk, necessity of breathing in tube oxygen

Question 27

Risk factors for COPD

Answer 27

Smoking (including second-hand)
long term exposure to irritants (ie. asbestos)
pre-term birth (pre-32 weeks)
genetic factors (AAT deficiency, prevents formation of protein that protects lung tissue from enzymes)

Question 28

Risk factors for lung cancer

Answer 28

Smoking (including second hand)
Family History
Chemicals (like asbestos)
Air Polution
Radon Exposure
HIV

Question 29

Symptoms of lung cancer

Answer 29

Chronic cough
Chest pain
Trouble breathing
Appetite loss
Weight loss
Coughing blood
Hoarseness
Face Swelling
Tiredness

Question 30

Vital capacity

Answer 30

the max volume of air you are physically able to take in and exhale

Question 31

Tidal volume

Answer 31

the normal volume of air you usually take in, completely automatic

Question 32

Residual Volume

Answer 32

the little volume of air left behind after exhale to keep alveoli open and prevent lung collapse