Respiratory III

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Questions and Answers

What is the primary factor affecting the amount of oxygen carried by hemoglobin?

Altitude

Concentration of Hb (correct)

pH levels

Temperature

Anemia does not affect oxygen transport in the bloodstream.

False

What effect does an increase in metabolism have on hemoglobin's affinity for oxygen?

It decreases hemoglobin's affinity for oxygen.

Hemoglobin carries _____ times more dissolved oxygen than carbon dioxide.

20 Signup and view all the answers

Match the following forms of CO2 transport in the blood with their percentage of total content:

Physical solution = 5-10% Carbamino compounds = 15-20% Bicarbonate = 70-75% Signup and view all the answers

What percentage of oxygen in the blood is reversibly bound to hemoglobin?

97% Signup and view all the answers

At a usual arterial pressure of 100 mm Hg, 3 ml of O2 is dissolved in each liter of blood.

True Signup and view all the answers

What is the significance of hemoglobin's ability to bind 4 molecules of oxygen?

It increases the oxygen-carrying capacity of the blood. Signup and view all the answers

What regulates the contraction of respiratory muscles?

Motor neurons Signup and view all the answers

The amount of gas dissolved is directly proportional to ____________ of that gas.

partial pressure Signup and view all the answers

What happens to oxygen saturation as blood passes through tissue capillaries?

Decreases Signup and view all the answers

True or False: The rhythmic nature of breathing originates solely from chemoreceptors.

False Signup and view all the answers

What is the most important factor that leads to an increase in ventilation?

pCO2 Signup and view all the answers

Match the following terms related to oxygen transport with their descriptions:

PaO2 = Partial pressure of arterial oxygen Hb = Hemoglobin O2 saturation = Amount of oxygen carried divided by total capacity Henry's Law = Gas solubility is proportional to its partial pressure Signup and view all the answers

Hypoxia is a deficit in O2 supply to the ______.

cells Signup and view all the answers

What does a 100% saturation of hemoglobin indicate?

All binding sites of hemoglobin are occupied by oxygen. Signup and view all the answers

A greyhound consumes 4500 ml of O2 per minute during rest.

False Signup and view all the answers

Match the following respiratory components with their functions:

Central chemoreceptors = Detect changes in pCO2 indirectly Peripheral chemoreceptors = Detect direct arterial changes in pO2 Inspiratory neurons = Stimulate motor neurons for muscle contraction Stretch receptors = Regulate inspiratory neuron activity based on lung stretch Signup and view all the answers

Which of the following symptoms is NOT associated with hypoxia?

Increased heart rate Signup and view all the answers

True or False: In birds, both inspiration and expiration are passive processes.

False Signup and view all the answers

What is the remedy for hypoxia?

Inhalation of pure O2 Signup and view all the answers

Study Notes

Oxygen Transport in Blood

Most of the oxygen in blood (>97%) is bound to hemoglobin
Oxygen dissolved in blood follows Henry’s Law: amount of gas dissolved is directly proportional to partial pressure of that gas
Solubility of O2 very low in blood
At a usual arterial pressure (PaO2=100mm Hg): 3 ml of O2 per L of blood is dissolved
Blood leaving the lungs contains ~200 ml O2 per liter, 197 ml/liter is bound to hemoglobin
Hemoglobin contains 4 heme groups, each with 1 iron atom that can bind 1 molecule of O2
Oxygen saturation is the amount of oxygen carried divided by the total oxygen capacity of blood
When all 4 binding sites of hemoglobin are occupied: 100% saturation
When half the binding sites are occupied: 50% saturation

Factors Affecting Hb Saturation

pH: increase in H+ decreases affinity of Hb for O2, curve shifts to the right, need higher pO2 for saturation, unloading occurs more rapidly
Temperature: increase in metabolism = increase in heat, similar effect as pH
2,3DPG (diphosphoglycerate): binds to Hb, similar effect as pH
The pO2 in the lung is generally sufficient to maintain 100% saturation, pH, T and DPG mainly affect the unloading of oxygen

Blood Transport of CO2

Carbon dioxide in blood is carried in three forms: physical solution, carbamino compounds, and bicarbonate
Physical solution (5-10%) = dissolved in blood
Carbamino compounds (bound to proteins) bind to –NH groups on proteins, especially hemoglobin, stronger affinity for deoxyhemoglobin
Bicarbonate (HCO3-), 70%-75% of total carbon dioxide content, CO2 + H2O  H2CO3  HCO3- + H+

Regulation of Respiration

Respiratory muscles contract rhythmically
Respiratory center in the brain stem (medulla oblongata) originates rhythmic nature of breathing
Inspiratory neurons stimulate motor neurons in the spinal cord  contraction of respiratory muscles
Inspiratory neurons are controlled by Central Pattern Generator (CPG)
Respiratory center is influenced by pO2, pCO2 and H+ concentrations
Stretch receptor in lung, bronchiole, and muscles influence Inspiratory neurons

Chemoreceptors

Chemoreceptors detect O2, CO2 and H+
Central chemoreceptors: in brain stem, indirectly detect changes in pCO2 in the blood
Peripheral chemoreceptors: in carotid and the aorta, detect direct arterial changes in pO2, pCO2 and H+
Information sent to the respiratory centers:  pCO2,  H+ or  pO2  increase ventilation
pCO2 most important factor leads to increase in H+

Hypoxia

Deficit in O2 supply to the cells
Symptoms: confusion, hallucination, loss of consciousness
Causes: low arterial pO2 from pulmonary diseases/failure, high altitude, reduced transport capacity, reduced blood flow to tissues, impaired cell metabolism
Remedy: inhalation pure O2

Respiration in Birds

Gas exchange identical to mammals
Ventilation different
Lungs relatively small and rigid; do not change in volume during inspiration/expiration
Air sacs communicate with the lungs and the bronchi
Inspiration and expiration are active processes
Possess unidirectional parabronchi that runs in the lung.

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Description

This quiz explores the mechanisms of oxygen transport in blood, focusing on hemoglobin's role in carrying oxygen. Learn about factors affecting hemoglobin saturation, such as pH and temperature, and understand how these factors influence oxygen delivery in the body. Test your knowledge on key concepts like Henry's Law and the solubility of O2 in blood.