Biology - Chapter 11.2: Respiratory System Flashcards
Left lung has ____ lobes and is _____ than the right lung, which has _____ lobes.
2; smaller; 3
Inspiration
- Contraction of diaphragm that pulls lungs downwards
- Causes pressure of the intrapleural space to decrease and the volume of the lungs to increase
Expiration
- Relaxation of the diaphragm, bringing lungs back up the rib cage through elastic recoil
- Causes pressure of the intrapleural space to increase and the volume of the lungs to decrease
Tidal volume
Volume of air that moves through the lungs between a normal inhalation and exhalation
Inspiratory reserve volume
Maximum volume of air that can be inhaled further after a normal inhalation is already taken
Expiratory reserve volume
Maximum volume of air that can be exhaled further after a normal exhalation is already released
Residual volume
Minimum amount of air that needs to be present in the lungs to prevent collapse
Function residual capacity
Entire volume of air still present in the lungs after a normal exhalation
Expiratory reserve volume + residual volume
Vital capacity
Maximum amount of air that can be exhaled after a maximum inhalation
Inspiratory reserve volume + tidal volume + expiratory reserve volume
Total lung capacity
It is that maximum volume the lungs could possibly hold at any given time
Vital capacity + residual volume
Overall Pathway of Air
Nasal cavity –> Pharynx –> Larynx –> Trachea –> Bronchi –> Bronchioles –> Alveoli
Alveoli
Contain:
Type 1 Epithelial cells (structural support)
Type 2 Epithelial cells (produce surfactant)
Hemoglobin
- Tetrameric
- Heme cofactor in each of its subunits
- Can carry up to four oxygen mollecules
Oxyhemoglobin
Transports most of the oxygen traveling in the blood
Cooperativity
Binding of one oxygen molecule to hemoglobin makes it easier for others to bind, due to the change in shape of the hemoglobin polypeptide
Carboxyhemoglobin
Produced when carbon monoxide outcompetes oxygen for hemoglobin binding
Carbaminohemoglobin
Form of hemoglobin that transports CO2. CO2 is very soluble in blood than oxygen, so most of the CO2 is dissolved in blood as bicarbonate anion
Reduced hemoglobin
Produced by H+ ions binding to hemoglobin, outcompeting oxygen and lowering oxygen binding affinity
Myoglobin
- Single peptide with one heme cofactor
- Much higher affinity for oxygen than oxyhemoglobin
- Found within cardiac and skeletal muscle cells to provide oxygen
- Has a hyperbolic oxygen dissociation curve
Oxygen dissociation curve
Relationship between the saturation of hemoglobin with oxygen in the blood and the partial pressure of oxygen.
Right shifted curve
Lowered affinity for oxygen in hemoglobin, caused by:
1) Decreased pH
2) High partial pressure of CO2
3) 2,3-diphosphoglycerate
4) Increased body temperature
Left shifted curve
Increased affinity for oxygen in hemoglobin, caused by:
1) Increased pH
2) Low partial pressure of CO2
3) Fetal hemoglobin
4) Decreased body temperature
CADET, face right!
Carbon dioxide, Acid, 2,3-Diphosphoglycerate, Exercise and Temperature
Cadet Increase –>
Right shifted curve
Bohr Effect
- Hemoglobin has decreased oxygen affinity when CO2 is high
- Carbon dioxide is converted to bicarbonate anions and protons, which produce reduced hemoglobin
Haldane effect
- Hemoglobin has increased CO2 affinity when oxygen is low
- Reduced hemoglobin levels are higher and have a greater affinity for CO2
Bicarbonate buffering system
-Catalyzed by carbonic anhydrase
CO2 + H2O H2CO3 HCO3- + H+
Chloride Shift
As bicarbonate diffuses out of cell, but H+ protons cannot leave. This creates a positive charge within the erythrocyte and Cl- ions diffuse into the blood cell to cancel out the positive charge of protons.
Influx of protons
- Causes the pH to decrease within the erythrocyte, resulting in the conversion of oxyhemoglobin into reduced hemoglobin
- Reduced hemoglobin has lower affinity for O2, leading to the release of O2 into tissues
Breathing is controlled by…
medulla oblongata via central chemoreceptors
Peripheral chemoreceptors
- Surround aortic arch and carotid arteries
- When CO2 is high and oxygen is low, signal to medulla oblangata to iuncrease breathing rate
Respiratory acidosis
lowered blood pH occurs due to inadequate breathing (hypoventilation)
Respiratory alkalosis
increased blood pH occurs due to rapid breathing (hyperventilation)
Metabolic acidosis and metabolic alkalosis
Lowered blood pH, increased blood pH
Occurs as a result of imbalances in carbon dioxide, oxygen, or proton levels
