Dentistry: Hypoxia and Cyanosis

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary consequence of hypoxemic hypoxia?

Decreased oxygen content in arterial blood (correct)

Increased partial pressure of O2 in inspired air

Increased affinity of Hb to O2

Increased oxygen content in arterial blood

Which of the following is a cause of anemic hypoxia?

Morphine-induced RC depression

Atrial septal defect

Iron deficiency (correct)

Interstitial pulmonary fibrosis

What is the primary mechanism of CO poisoning in inducing hypoxia?

Decreasing the partial pressure of O2 in inspired air

Inhibiting the diffusion of oxygen across the respiratory membrane

Increasing the affinity of Hb to O2 (correct)

Reducing oxygen content in arterial blood

Which type of hypoxia is characterized by inadequate blood flow to the tissues?

Stagnant hypoxia Signup and view all the answers

What is the primary consequence of stagnant hypoxia?

Inadequate oxygen delivery to the tissues Signup and view all the answers

Which of the following is a cause of hypoxemic hypoxia?

Morphine-induced RC depression Signup and view all the answers

What is the primary difference between hypoxemic and anemic hypoxia?

PaO2 is decreased in hypoxemic hypoxia, but normal in anemic hypoxia Signup and view all the answers

Which type of hypoxia is characterized by a diffusion defect in the respiratory membrane?

Hypoxemic hypoxia Signup and view all the answers

What effect does slow blood flow have in stagnant hypoxia?

It increases the withdrawal of O2 from blood in capillaries Signup and view all the answers

Why is O2 therapy not beneficial in anemic hypoxia?

Because the defect is in the hemoglobin, not the O2 levels Signup and view all the answers

What does an increase in reduced hemoglobin levels in blood cause?

Cyanosis Signup and view all the answers

Which of the following conditions leads to the inability of tissues to utilize O2?

Histotoxic hypoxia Signup and view all the answers

Which symptom is most likely to occur first in moderate hypoxia affecting the brain?

Mental aberration Signup and view all the answers

Why is the PaO2 and O2 content normal in histotoxic hypoxia?

Because the tissues cannot utilize O2 due to a toxic substance Signup and view all the answers

What is the threshold amount of reduced Hb that leads to cyanosis?

5 gm reduced Hb/100 ml blood Signup and view all the answers

Which of the following is not an effect of moderate hypoxia on the brain?

Loss of consciousness Signup and view all the answers

Study Notes

Hypoxia

Hypoxia is defined as O2 deficiency at the tissue level.
Types of hypoxia include:
- Hypoxemic hypoxia: decreased PaO2 in arterial blood, causing decreased O2 content.
- Anemic hypoxia: normal PaO2, but reduced amount of Hb that carries O2.
- Stagnant hypoxia: slow blood flow to tissues, leading to inadequate O2 delivery.
- Histotoxic hypoxia: tissues unable to utilize O2 due to toxic substances.
Causes of hypoxemic hypoxia:
- Decreased partial pressure of O2 in inspired air.
- Intracardiac shunt (right to left shunt).
- Pulmonary diseases (hypoventilation, diffusion defect).
Causes of anemic hypoxia:
- Anemia (deficiency of essential nutrients like iron).
- CO poisoning (formation of carboxyhemoglobin).
Effects of hypoxia:
- Increased rate of ventilation.
- Mental aberration, impaired judgment, drowsiness, excitement, disorientation, loss of time sense, and headache.
- Anorexia, nausea, vomiting, tachycardia, and hypertension.
- Loss of consciousness in severe cases (PO2 < 20 mmHg).

Cyanosis

Defined as a bluish discoloration of skin and mucous membrane due to abnormal increase in reduced Hb in blood.
Threshold of cyanosis: 5 gm reduced Hb/100 ml blood.
Types of hypoxia with cyanosis:
- Hypoxemic hypoxia.
- Anemic hypoxia.
Effectiveness of O2 therapy in treatment of hypoxia:
- Useful in hypoxemic hypoxia.
- Not useful in anemic, stagnant, or histotoxic hypoxia.

Studying That Suits You

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

Description

Learn about hypoxia, its types, causes, and effects, as well as cyanosis, its threshold, and types with and without cyanosis. Undergraduate-level dentistry lecture.