The Respiratory System Overview
30 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of the conducting zone in the respiratory system?

  • Transport of oxygen molecules
  • Warming and humidifying air (correct)
  • Gas exchange
  • Regulation of breathing rate

Which property of the lungs allows them to return to their original size after expansion?

  • Elasticity (correct)
  • Compliance
  • Surface tension
  • Resistance

How does gas exchange primarily occur in the alveoli?

  • Using specialized proteins for gas transport
  • By active transport mechanisms
  • Through diffusion due to temperature changes
  • Via gradients of partial pressures (correct)

What is the role of surfactants in the alveoli?

<p>To prevent alveolar collapse (A)</p> Signup and view all the answers

Which muscles are primarily involved in the process of inspiration?

<p>Diaphragm and external intercostals (D)</p> Signup and view all the answers

What term describes the volume of air remaining in the lungs after maximum expiration?

<p>Residual volume (B)</p> Signup and view all the answers

What primarily drives the neural control of breathing?

<p>Changes in thoracic cavity volume (B)</p> Signup and view all the answers

What is the approximate partial pressure of oxygen (PO2) in alveolar air?

<p>105 mm Hg (A)</p> Signup and view all the answers

What is the approximate partial pressure of O2 in the air?

<p>160 mm Hg (A)</p> Signup and view all the answers

What percentage of oxygen is transported bound to hemoglobin in red blood cells?

<p>97% (A)</p> Signup and view all the answers

Which component of hemoglobin actually binds oxygen?

<p>Heme (A)</p> Signup and view all the answers

What physiological condition favors the release of oxygen from hemoglobin in tissues?

<p>High temperature and low pH (A)</p> Signup and view all the answers

What is the role of 2,3-diphosphoglycerate (DPG) in oxygen transport?

<p>It decreases the affinity of hemoglobin for oxygen. (D)</p> Signup and view all the answers

Which of the following increases oxygen binding to hemoglobin?

<p>High pH (C)</p> Signup and view all the answers

What happens to deoxyhemoglobin when oxygen binds to it?

<p>It becomes oxyhemoglobin. (A)</p> Signup and view all the answers

Which factor is NOT associated with oxygen release at tissues?

<p>High pH (D)</p> Signup and view all the answers

What is the primary form in which carbon dioxide is transported in the blood?

<p>Converted to bicarbonate (B)</p> Signup and view all the answers

Which enzyme facilitates the conversion of carbon dioxide to bicarbonate in red blood cells?

<p>Carbonic anhydrase (D)</p> Signup and view all the answers

What condition causes low pH in the blood?

<p>High CO2 concentration (D)</p> Signup and view all the answers

What role does the medulla oblongata play in the regulation of breathing?

<p>Activates motoneurons for inspiration (A)</p> Signup and view all the answers

Which type of chemoreceptors are sensitive to pH changes in the cerebrospinal fluid?

<p>Central chemoreceptors (D)</p> Signup and view all the answers

How does carbon monoxide affect hemoglobin compared to oxygen?

<p>Binds with 250 times stronger affinity than O2 (B)</p> Signup and view all the answers

Which center in the pons promotes inspiration?

<p>Apneustic center (B)</p> Signup and view all the answers

Where does the majority of carbon dioxide transport occur after being converted to bicarbonate?

<p>In the red blood cells (C)</p> Signup and view all the answers

Which factor does not influence the regulation of breathing?

<p>Oxygen binding affinity (A)</p> Signup and view all the answers

What happens to bicarbonate after it exits the red blood cell?

<p>It moves into the plasma (C)</p> Signup and view all the answers

What effect does cutting the vagus nerve have on the duration of inspiration?

<p>It prolongs inspiration (D)</p> Signup and view all the answers

Which response occurs when CO2 levels in the blood rise?

<p>Increased respiratory rate (C)</p> Signup and view all the answers

What leads to the inhibition of inspiration during the Hering-Breuer reflex?

<p>Activation of stretch receptors (A)</p> Signup and view all the answers

Which phenomenon does not enhance CO2 diffusion out of the blood in the lungs?

<p>High oxygen saturation of hemoglobin (A)</p> Signup and view all the answers

Flashcards

Lung Compliance

The ability of the lungs to stretch and expand during inspiration.

Lung Elasticity

The tendency of the lungs to return to their original size after being stretched.

Alveolar Surface Tension

The force that causes the surface of the alveoli to collapse inwards due to the attraction between water molecules.

Surfactant

A substance secreted by certain cells in the alveoli that reduces surface tension, preventing the alveoli from collapsing.

Signup and view all the flashcards

Inspiration

The process of breathing in.

Signup and view all the flashcards

Expiration

The process of breathing out.

Signup and view all the flashcards

Tidal Volume

The amount of air that moves into or out of the lungs during a normal breath.

Signup and view all the flashcards

Residual Volume

The amount of air remaining in the lungs after a maximal exhalation.

Signup and view all the flashcards

What is PO2?

Partial pressure of oxygen (PO2) is the pressure exerted by oxygen in a mixture of gases. In this case, it refers to the partial pressure of oxygen in the air we breathe.

Signup and view all the flashcards

What is PCO2?

Partial pressure of carbon dioxide (PCO2) is the pressure exerted by carbon dioxide in a mixture of gases. In this case, it refers to the partial pressure of carbon dioxide in the air we breathe.

Signup and view all the flashcards

What is hemoglobin?

Hemoglobin is a protein found in red blood cells that binds to oxygen and carries it throughout the body. It has four subunits, each containing a heme group. Each heme group contains an iron atom that can bind to one oxygen molecule.

Signup and view all the flashcards

What is deoxyhemoglobin?

Deoxyhemoglobin refers to hemoglobin that is not bound to oxygen. It is the form of hemoglobin in the blood when oxygen is released to the tissues.

Signup and view all the flashcards

What is oxyhemoglobin?

Oxyhemoglobin refers to hemoglobin that is bound to oxygen. It is the form of hemoglobin in the blood when it is carrying oxygen from the lungs to the tissues.

Signup and view all the flashcards

What is the Bohr effect?

The Bohr effect describes the decrease in the affinity of hemoglobin for oxygen when the pH of the blood decreases. This effect helps to ensure that oxygen is released to tissues that need it most, such as those that are metabolically active.

Signup and view all the flashcards

What is 2,3-diphosphoglycerate (DPG)?

2,3-diphosphoglycerate (DPG) is a molecule that binds to hemoglobin and decreases its affinity for oxygen. This effect helps to ensure that oxygen is released to tissues that need it most, such as those that are metabolically active.

Signup and view all the flashcards

What factors favor the release of oxygen from hemoglobin?

The release of oxygen from hemoglobin is favored under conditions of low PO2, low pH, high temperature, and the presence of 2,3-diphosphoglycerate (DPG). These conditions are typically found in tissues that are metabolically active.

Signup and view all the flashcards

CO's affinity to Hb

Carbon monoxide (CO) binds to hemoglobin (Hb) approximately 250 times more strongly than oxygen (O2), effectively displacing oxygen from Hb molecules.

Signup and view all the flashcards

How CO reduces oxygen transport

The inability of CO-bound Hb, known as carboxyhemoglobin, to carry oxygen significantly reduces oxygen transport in the blood, leading to tissue oxygen deprivation.

Signup and view all the flashcards

Carboxyhemoglobin

The form of Hb where CO is bound to all four heme groups is called carboxyhemoglobin.

Signup and view all the flashcards

CO2 transport in plasma

Approximately 10% of CO2 is dissolved in plasma.

Signup and view all the flashcards

Carbaminohemoglobin

Around 20% of CO2 binds to amino groups on alpha and beta chains of hemoglobin, forming carbaminohemoglobin.

Signup and view all the flashcards

Bicarbonate formation

The majority (70%) of CO2 is converted to bicarbonate ions (HCO3-), primarily within red blood cells.

Signup and view all the flashcards

Carbonic anhydrase's role

The enzyme carbonic anhydrase facilitates the conversion of CO2 to bicarbonate, accelerating the process.

Signup and view all the flashcards

CO2 gradient

The movement of CO2 from tissues to the lungs occurs due to a concentration gradient.

Signup and view all the flashcards

Bicarbonate transport

Some CO2 remains in the plasma, forming bicarbonate, which then moves out of the red blood cells through a specific transporter.

Signup and view all the flashcards

CO2 diffusion at the lungs

At the lungs, CO2 diffuses out of the blood into the alveoli, moving down its concentration gradient.

Signup and view all the flashcards

Medulla oblongata's role in breathing

The medulla oblongata, a region in the brainstem, acts as the rhythmicity center, controlling the basic pattern of breathing.

Signup and view all the flashcards

Hering-Breuer reflex

The hering-breuer reflex, triggered by stretch receptors in the bronchi and bronchioles, helps regulate the length of inspiration by inhibiting further inhalation.

Signup and view all the flashcards

Pons pneumotaxic center

The pons pneumotaxic center in the brainstem regulates transitioning from inspiration to expiration, shortening inspiration in its presence.

Signup and view all the flashcards

Chemoreceptors' role in breathing

Chemoreceptors monitor blood pH levels to control breathing rate and depth.

Signup and view all the flashcards

Central chemoreceptors

Central chemoreceptors, located in the medulla oblongata, are sensitive to pH changes in cerebrospinal fluid (CSF), reflecting changes in blood CO2 levels.

Signup and view all the flashcards

Peripheral chemoreceptors

Peripheral chemoreceptors, found in aortic bodies and carotid bodies, respond to pH changes in the blood, triggering increased breathing in response to high CO2 or low pH.

Signup and view all the flashcards

Study Notes

The Respiratory System

  • The respiratory system includes structure and properties, mechanics of breathing, gas exchange, transport of gases, and regulation of breathing.

  • A mammalian lung is composed of multiple lobes, lobar bronchi, main bronchi, segmental bronchi, pleurae and pleural space.

  • The pleura is a double-layered membrane surrounding the lungs. The parietal pleura lines the thoracic cavity, while the visceral pleura covers the lungs.

  • A mammalian lung also contains an esophagus, trachea, diaphragm, and ribs.

  • The conducting zone prepares air for gas exchange by warming, humidifying and filtering it (through mucus and cilia).

  • The respiratory zone (respiratory bronchioles and alveoli) facilitates gas exchange.

  • Alveoli are tiny air sacs in the lungs

  • A capillary network surrounds the alveoli to facilitate gas exchange.

Physical Properties of Lungs

  • Lungs have compliance (stretch ability) and elasticity (return to original size).
  • Surface tension at the inner surface of alveoli is reduced by surfactant. This prevents alveolar collapse.

Respiratory Proteins

  • Type I and II pneumocytes are types of cells in the alveoli.

  • Pulmonary surfactant is a layer covering the alveoli.

  • DPPC (dipalmitoyl phosphatidylcholine) and other lipids are key components of pulmonary surfactant.

Mechanics of Breathing

  • Breathing has two phases: Inspiration (inhalation) and expiration (exhalation).

  • Changes in thoracic cavity volume drive breathing.

  • Inspiration involves the diaphragm and external intercostals muscles expanding the thoracic cavity.

  • Expiration is usually passive, with relaxation of inspiratory muscles and recoil of the chest wall.

Gas Exchange

  • Gas exchange is driven by partial pressure gradients. Gases move from high to low pressure regions.

  • Composition of air: H₂O (variable), N₂ (~590 mmHg), O₂ (~160mmHg), CO₂ (~10mmHg)

  • Atmospheric pressure is ~760 mmHg.

  • Alveolar air is saturated with water (H₂O), and PO2 is ~105 mmHg and PCO2 is ~40mmHg.

Transport of Respiratory Gases

  • Oxygen (O2): ~3% dissolved in plasma, ~97% bound to hemoglobin in red blood cells (RBCs).

  • Hemoglobin is a protein with 4 subunits (2 alpha and 2 beta). Each subunit contains a heme pigment with iron (Fe++), binding to one O2 molecule.

Factors Affecting Oxygen Binding to Hemoglobin

  • Low temperature, high partial pressure of O2 (high PO2) and high pH favor oxygen binding to hemoglobin.

  • High temperature, low partial pressure of O2 (low PO2) and low pH favor oxygen release from hemoglobin.

  • Organic phosphate compounds (e.g., DPG) decrease hemoglobin's O2 affinity.

Carbon Monoxide (CO)

  • CO binds to hemoglobin ~250 times more strongly than O2 reducing O2 transport significantly.

Carbon Dioxide (CO2) Transport

  • ~10% of CO2 is dissolved in plasma, ~20% is bound to hemoglobin (carbaminohemoglobin). ~70% is transported as bicarbonate in red blood cells (RBCs), mediated by carbonic anhydrase.

Regulation of Breathing

  • The medulla oblongata acts as the rhythmicity center, generating rhythmic breathing patterns.

  • E neurons inhibit inspiratory motor neurons, resulting in expiration.

  • Herning-Breuer reflex involves stretch receptors in bronchi and bronchioles for regulating the length of inspiration.

  • Pons centers (pneumotaxic and apneustic) further modulate breathing patterns.

  • Higher brain centers influence breathing as well.

Regulation of Breathing: pH and CO2 Influence

  • Central chemoreceptors in the medulla oblongata are sensitive to changes in CSF pH (related to PCO2).
  • Peripheral chemoreceptors (in carotid and aortic bodies) are sensitive to changes in blood pH and PO2.
  • Changes in PO2 are only detected by peripheral chemoreceptors in very low O2 conditions.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

The Respiratory System PDF

Description

This quiz covers the structure and functions of the respiratory system, including the mechanics of breathing and gas exchange. Explore the components of mammalian lungs, the roles of pleurae, and the physical properties essential for effective respiration.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser