Ammonia Toxicity in Liver Failure

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 condition is characterized by high levels of nitrogenous materials in the blood?

Azoturia
Hyperuricemia
Asterixis
Azotemia (correct)

How does excess ammonia (NH3) affect the brain's neurotransmitter balance?

It increases levels of inhibitory neurotransmitters.
It prevents the production of glutamate entirely.
It is converted into glutamate, causing excitation. (correct)
It decreases levels of GABA.

What is the main treatment for asterixis caused by ammonia toxicity?

Intravenous fluids
Lactulose (correct)
Sodium bicarbonate
Increased protein diet

What conversion occurs in the brain due to excess glutamate when ammonia is elevated?

<p>Conversion to GABA (A)</p> Signup and view all the answers

What is the physiological consequence of NH4+ not being able to permeate membranes?

<p>It shifts equilibrium towards NH3, which can cross membranes. (D)</p> Signup and view all the answers

Flashcards

Ammonia toxicity

Ammonia (NH3) builds up in the blood, primarily due to liver failure. This is harmful because it affects brain function.

NH3 permeability

Ammonia (NH3) can pass through cell membranes, unlike ammonium (NH4+).

Brain sensitivity to NH3

The brain is particularly vulnerable to high ammonia levels because it converts ammonia into excitatory neurotransmitters like glutamate, which can cause problems.

Asterixis (Liver Flap)

A flapping tremor, often caused by high ammonia levels damaging brain function.

Signup and view all the flashcards

Lactulose treatment

Lactulose, a sugar, helps reduce ammonia levels by pulling it into the colon and preventing its reabsorption, removing it in the stool.

Signup and view all the flashcards

Study Notes

Ammonia Toxicity

BUN (Blood Urea Nitrogen) measures total nitrogen (urea, NH4+, uric acid, etc.)
Azotemia: high levels of nitrogenous materials in the blood (high BUN)
Azoturia: high levels of nitrogenous materials in urine
Ammonia (NH3) is not membrane permeable, exists in equilibrium with NH4+
NH3 readily passes through membranes
The brain is very sensitive to NH3
Excess NH3 converts to glutamate (excitatory neurotransmitter)
Glutamine: Excess glutamate is normally converted to glutamine by astrocytes
Liver failure: In liver failure, excess glutamate builds up in neurons, converting some to GABA(inhibitory neurotransmitter) and causes effects like Asterixis (flapping tremor, liver flap) and coma
Asterixis treatment: Administering lactulose (galactose + fructose disaccharide) helps bind NH4+ and remove it in the feces as organic acids.

Studying That Suits You

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

Description

This quiz focuses on the effects of ammonia toxicity, particularly in the context of liver failure. It covers related terms such as azotemia and azoturia, and the role of neurotransmitters like glutamate and GABA. Test your understanding of ammonia's impact on brain function and treatment options like lactulose.