Respiratory I PT2 BETA

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson
Download our mobile app to listen on the go
Get App

Questions and Answers

What is the primary benefit of a large surface area in the lungs for gas exchange?

  • It allows for a greater amount of gas to diffuse across in a given time period. (correct)
  • It decreases the efficiency of ventilation-perfusion coupling.
  • It increases the speed of blood flow through the pulmonary capillaries.
  • It reduces the amount of oxygen that can dissolve in the plasma.

Decreasing the surface area in the lungs will optimize gas exchange.

False (B)

How is oxygen primarily transported in the blood, and what percentage does this method account for?

Oxygen is primarily transported bound to hemoglobin, accounting for approximately 98.5% of the oxygen carried from the lungs to tissues.

In scenarios with poor ventilation and good perfusion in the alveoli, there is a(n) ______ in Oâ‚‚ and a(n) ______ in COâ‚‚.

<p>decrease, increase</p> Signup and view all the answers

Match the following conditions with their corresponding effects on Hb-Oâ‚‚ affinity:

<p>Increased temperature = Decreased affinity Increased blood pH = Increased affinity Increased PCOâ‚‚ = Decreased affinity Decreased blood pH = Decreased affinity</p> Signup and view all the answers

Which of the following best describes the effect of increased body temperature on the affinity of hemoglobin for oxygen?

<p>Decreased affinity, causing hemoglobin to release oxygen more readily. (C)</p> Signup and view all the answers

Increasing the concentration of carbon dioxide (COâ‚‚) in the blood increases the affinity of hemoglobin for oxygen.

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

Describe the relationship between ventilation, perfusion, and vasoconstriction in the lungs when ventilation is poor but perfusion is good.

<p>Poor ventilation and good perfusion causes vasoconstriction, which decreases perfusion.</p> Signup and view all the answers

The condition in which body cells are unable to use oxygen even when enough is delivered, often due to cyanide poisoning, is known as ______ hypoxia.

<p>histotoxic</p> Signup and view all the answers

Which of the following is the most accurate description of ventilation-perfusion coupling in the lungs?

<p>The matching of the amount of gas flowing into the alveoli with the blood flow in the pulmonary capillaries. (A)</p> Signup and view all the answers

Only 1.5% of oxygen is dissolved in plasma, so if that was the only way Oâ‚‚ was carried, our cardiac output would need to be 5x what it is normally.

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

Explain the process of how carbon dioxide is transported from the tissues to the blood, mentioning the role of carbonic anhydrase and bicarbonate ions.

<p>Carbon dioxide diffuses from tissues into the blood, where it reacts with water to form carbonic acid, a reaction catalyzed by carbonic anhydrase. Carbonic acid then dissociates into hydrogen ions and bicarbonate ions, with the bicarbonate ions being transported in the plasma to the lungs.</p> Signup and view all the answers

When oxygen binds to the iron in hemoglobin in RBCs; this forms ______.

<p>oxyhemoglobin</p> Signup and view all the answers

How does carbon dioxide bind to hemoglobin?

<p>Binds to globin chains to form carbaminohemoglobin (B)</p> Signup and view all the answers

Explain what happens to hemoglobin in the lungs and in tissues, regarding percent oxygen saturation.

<p>In the lungs, hemoglobin is 100% saturated with oxygen. As blood flows through systemic capillaries, some oxygen is released, and hemoglobin is approximately 75% saturated.</p> Signup and view all the answers

When blood flows through capillaries, it releases some Oâ‚‚, and hemoglobin is approximately ______ percent saturated.

<p>75</p> Signup and view all the answers

Match the type of hypoxia with its primary cause:

<p>Anemic hypoxia = Too few RBCs or abnormal/reduced Hb Ischemic hypoxia = Impaired or blocked blood circulation Histotoxic hypoxia = Body cells unable to use oxygen Hypoxemic hypoxia = Reduced arterial POâ‚‚</p> Signup and view all the answers

Which type of hypoxia results from the inability of body cells to utilize oxygen, even though adequate oxygen is delivered?

<p>Histotoxic hypoxia (C)</p> Signup and view all the answers

In histotoxic hypoxia, the body is unable to deliver enough oxygen.

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

Describe the mechanisms that influence hemoglobins's affinity for oxygen.

<p>Hb-Oâ‚‚ affinity is influenced by Temperature, Blood PH, and PCOâ‚‚. As Temperature increases, affinity decreases. As Blood PH increases, affinity decreases, and as PCOâ‚‚ increases, affinity decreases. These mechanisms help split oxygen to tissues that need it.</p> Signup and view all the answers

Flashcards

Surface Area Importance

Gas exchange optimization in the lungs is improved by a large surface area.

Ventilation-Perfusion Coupling

This is the matching of air flow into alveoli with blood flow in pulmonary capillaries.

Poor Ventilation, Good Perfusion

↓ O₂ and ↑ CO₂ in alveoli, occurring when ventilation is poor but perfusion is good.

Good Ventilation, Poor Perfusion

↑ O₂ and ↓ CO₂ in alveoli, caused by good ventilation but poor blood flow.

Signup and view all the flashcards

Vasoconstriction Effect

Decreased vessel diameter reduces blood flow when ventilation is poor.

Signup and view all the flashcards

Vasodilation Effect

Increased vessel diameter boosts blood flow when ventilation is good.

Signup and view all the flashcards

How is O2 transported?

  1. Dissolved in plasma (1.5%) 2. Bound to hemoglobin (98.5%)
Signup and view all the flashcards

Hemoglobin (Hb)

The iron-containing protein in red blood cells that binds to oxygen.

Signup and view all the flashcards

Oxyhemoglobin

Hemoglobin fully loaded with oxygen

Signup and view all the flashcards

Deoxyhemoglobin

Hemoglobin that has released oxygen.

Signup and view all the flashcards

Carbaminohemoglobin

Hemoglobin with carbon dioxide attached

Signup and view all the flashcards

O2 Saturation Levels

Hb is fully saturated with O2 in the lungs, 75% in systemic capillaries

Signup and view all the flashcards

Hb-O2 Affinity

Indicates how tightly hemoglobin binds oxygen.

Signup and view all the flashcards

Temperature on Hb-O2 Affinity

Decreases affinity, splits to tissues that need it.

Signup and view all the flashcards

Blood pH and O2 affinity

Lower pH decreases Hb-Oâ‚‚ affinity.

Signup and view all the flashcards

PCO2 and Hb-O2 affinity

Increased carbon dioxide decreases Hb-Oâ‚‚ affinity.

Signup and view all the flashcards

Ways CO2 is Transported

  1. Dissolved in plasma (7-10%) 2. Bound to Hb (~20%) 3. As bicarbonate ions (~70%)
Signup and view all the flashcards

Hypoxia

Inadequate oxygen to body tissues.

Signup and view all the flashcards

Anemic Hypoxia

Too few or abnormal red blood cells or reduced Hb.

Signup and view all the flashcards

Ischemic Hypoxia

Impaired or blocked blood circulation.

Signup and view all the flashcards

Study Notes

  • BIO 269 discusses respiration (pt2) focused on gas exchange.

Lecture Goals

  • Optimize gases in the lungs by grasping the importance of surface area.
  • Comprehend ventilation-perfusion coupling.
  • Detail the different ways oxygen (O2) is transported in the blood.
  • Explain how hemoglobin (Hb) functions in transporting both O2 and carbon dioxide (CO2).
  • Explain the O2 saturation curve and the different factors impacting O2's affinity for Hb.
  • Detail the transport mechanisms of CO2 including the chemistry involved.
  • Identify the different types of hypoxia.

Surface Area

  • Surface area is important in optimizing gas exchange in the lungs.
  • Increasing surface area facilitates greater gas diffusion within a given time frame, enhancing gas exchange.
  • The human lung has a surface area of 70m².
  • Emphysema (where the volume is unchanged) and tumors or mucus accumulation can decrease surface area.

Ventilation-Perfusion Coupling

  • Ventilation refers to the amount of gas flowing into and out of the alveoli.
  • Perfusion refers to the blood flow within the pulmonary capillaries.
  • Poor ventilation with good perfusion results in decreased O2 and increased CO2 levels in the alveoli, with blood removing O2 faster than ventilation can replenish it.
  • Poor perfusion with good ventilation causes an increase in O2 and a decrease in CO2, as O2 does not move into the blood and CO2 does not diffuse into the alveoli quickly enough due to limited blood flow.
  • Optimal gas exchange requires a close match between ventilation and perfusion.
  • Poor ventilation coupled with good perfusion results in vasoconstriction to decrease perfusion.
  • Good ventilation coupled with poor perfusion results in vasodilation that increases perfusion.

Oxygen Transport

  • O2 is transported in two primary ways: dissolved in plasma and bound to hemoglobin.
  • Only approximately 1.5% of O2 is transported dissolved in the plasma due to its poor solubility.
  • About 98.5% of O2 is transported by binding to hemoglobin (Hb).

Hemoglobin (Hb)

  • Red blood cells are full of hemoglobin (Hb).
  • Hemoglobin (Hb) consists of 4 iron (Fe2+)-containing heme groups and 4 globin chains.
  • Oxygen-deficient blood circulates through lungs.
  • Oxygen diffuses from the lungs into the blood and into RBCs
  • In RBCs, oxygen binds to the iron in hemoglobin to form oxyhemoglobin.
  • Oxygen detaches from iron as deoxyhemoglobin and diffuses from the blood into tissue cells, upon delivery to body tissue.
  • CO2 binds to the globin chains to form carbaminohemoglobin.

Oxygen Transport in Blood

  • Hemoglobin is 100% saturated with oxygen in the lungs, meaning all four iron molecules are bound to O2.
  • As blood flows through systemic capillaries, Hb releases some O2 and becomes approximately 75% saturated.
  • A substantial amount of O2 remains in venous circulation.

Hemoglobin-O2 Affinity

  • Hemoglobin-O2 affinity refers to the binding strength between Hb and O2, which determines how readily O2 is released to tissues.
  • Increased affinity means Hb and O2 are more tightly bound, making Hb more likely to hold onto O2.
  • Decreased affinity means Hb and O2 are less tightly bound, making it more likely to split.
  • Factors that change the affinity of Hb for O2 include temperature, blood pH, and partial pressure of CO2 (PCO2).
  • Higher temperature results in decreased affinity.
  • Higher H+ concentration (lower pH) results in decreased affinity.
  • Higher PCO2 results in decreased affinity.
  • Decreased affinity results in lower percent saturation of Hb, where more O2 detaches from Hb.

Carbon Dioxide Transport

  • CO2 is transported in the blood in three main forms: dissolved in plasma, bound to Hb, and as bicarbonate ions.
  • Only 7-10% of CO2 is transported dissolved in the plasma.
  • Around 20% of CO2 is transported bound to Hb.
  • Approximately 70% of CO2 is transported as bicarbonate ions (HCO3-) in the plasma.

Types of Hypoxia

  • Hypoxia is defined as inadequate O2 delivery to tissues
  • Anemic hypoxia involves too few RBCs or RBCs that are abnormal or have reduced Hb.
  • Ischemic hypoxia involves impaired or blocked blood circulation.
  • Histotoxic hypoxia occurs when body cells are unable to use O2, even when enough is delivered (as in cyanide poisoning).
  • Hypoxemic hypoxia is marked by reduced arterial PO2, which can result from impaired ventilation or CO poisoning.

Studying That Suits You

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

Quiz Team

Related Documents

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser