Chapter 13 Flashcards
(26 cards)
What was the brain traditionally believed to be in terms of immune response?
An “immune privileged organ” not affected by immune responses or inflammation.
What protects the brain from external molecules and immune cells?
The blood-brain barrier, formed by specialized endothelial cells.
What recent discovery changed our understanding of brain immunity?
The brain does respond to immune system signals and participates in immune responses.
What is neuroimmunology?
A field of research studying the interactions between the nervous and immune systems.
What are common invaders that activate the immune system?
Viruses, bacteria, yeast.
What is the local response to infection or injury?
Swelling, pain, changes in blood flow, and release of inflammatory molecules.
Which cells and proteins are activated during a general immune response?
Leucocytes, macrophages, and acute phase proteins.
What are the general symptoms of the acute phase response?
Fever, aches, sleepiness, loss of appetite, and disinterest.
What brain region regulates fever, sleep, and appetite during illness?
The hypothalamus.
What types of signals reach the brain from infected or injured tissue?
Neural (via sensory nerves or vagus nerve) and humoral (circulating molecules).
What molecules might signal the brain during immune responses?
Prostaglandins, complement proteins, and cytokines.
What are cytokines?
Proteins that mediate immune and inflammatory responses.
Name some types of cytokines.
Interferons, interleukins, tumor necrosis factors, chemokines.
How are cytokines activated?
By infection, injury, toxins, or low oxygen levels.
How does the brain control cytokine production?
Through sympathetic nervous signals and hormones like cortisol.
What do cytokines stimulate in the liver?
Production of acute phase proteins.
Do all cytokines have the same effect?
No; some are pro-inflammatory, others are anti-inflammatory.
How can stress affect the immune system?
It can suppress or sometimes enhance immune function.
Which type of stress is most harmful to immunity?
Chronic, uncontrollable stress (e.g., excessive workload, major tragedies).
What brain protein is increased during stress?
Corticotrophin releasing factor (CRF).
What is the pathway from brain to cortisol release?
CRF → Pituitary gland releases ACTH → Adrenal gland releases cortisol.
What is cortisol’s effect on the immune system?
It suppresses immune function and inflammation.
What diseases involve overproduction of immune molecules in the brain?
Multiple sclerosis, stroke, Alzheimer’s disease.
How might cytokines contribute to brain damage?
Excessive cytokine activity can damage neurons.
