Lec 7 Flashcards
What does psychosomatic mean?
physical illness with an apparently psychological etiology
What is affected when you are stressed?
- -immunity, digestion, and the cardiovascular system
- -When you are stressed, every single cell in your body is affected
What is sickness behaviour?
The behavioral and cognitive changes that accompany physical illness
- -Ignore food and beverages.
- -Lose interest in social interaction.
- -Have excess or fragmented sleep.
- -Feel depressed and irritable.
- -Have impaired attention and memory
What might sickness behaviour be good for?
may represent a motivational state responsible for helping individuals cope with infection
What is psychoneuroimmunology?
The study of the interaction between the mind, brain, and immune system.
What can our psychological state interact with? Why are these interactions important?
- -can interact with the immune system and the immune system can interact with the brain
- -These interactions are important for everything from the common cold to cancer.
The brain and immune system have a ____________ communication
bidirectional
What did psychoneuroimmunology advance?
advanced earlier viewpoints that saw infectious diseases as strictly physical phenomena
What is the immune system?
- -responsible for protecting your body from microbial overgrowth.
- -monitors the internal environment for signs of invasion by bacteria or viruses, as well as evidence of tissue damage
- -is extremely powerful, and is highly regulated in order to maintain optimal levels of function
Why is the immune system decentralized?
– decentralized because it is all over the body to attack any bad bacteria/microbes
What regulates the immune system?
the HPA axis
What acts as factories and repositories for immune cells?
- -spleen
- -lymph nodes
- -thymus
- -bone marrow
The immune system relies on ___________________
on chemical communication to organize its functions
What are the two basic divisions of the immune system?
Innate immune system: coded by DNA (fight off diseases that affected your ancestors)
Adaptive immune system: as you encounter viruses or bacteria, you develop immunity to them (develop antibodies to them)
–Cell-mediated immunity (T cells)
–Antibody-mediated immunity (B cells)
Your innate immune system is activated and it may or may not manage it. If it can’t manage it, then it activates the two branches of the adaptive immune system (T cells B cells)
What are cytokines?
- -Cytokines are like hormones for immune signaling
- -Cytokines are molecules that coordinate the immune response, and tell the body that it is under attack.
What is the innate immune system?
- -used for “general purpose” immunity, and is sensitive to molecules that are universally present on bacteria.
- -macrophages have receptors on their membranes that bind to pathogens and trigger phagocytosis
- -When activated, cells of the innate immune system (such as macrophages) release cytokines into circulation
How do macrophages identify pathogens?
use TLR’s (toll-like receptors) to identify pathogens
What is the adaptive immune system?
- -is activated by cytokines, and involves two systems of leukocytes (white blood cells)
- ->cell mediated immunity (T-cells) developed in thymus
- ->antibody mediated immunity (B-cells) developed in bone marrow
What do T-cells do?
T cells are activated by cytokine signals and interaction with macrophages. Once activated, T cells proliferate and develop into a form that attacks body cells that have been infected
What do B cells do?
- -Develop antibodies which bind to antigens on pathogens to kill or deactivate them. When you have the antibody it recognizes the antigen of that infector and kills it off. Unless you have the antibody, you won’t be able to fight it off necessarily.
- -B cells that produce antibodies are also called plasma cells
- -Memory B cells survive in the body for ages
- -B-cells involved in fighting viruses.
How are cytokines released?
- -After ingesting pathogens, macrophages release cytokines such as interleukin-1 (IL-1)
- -IL-1 stimulates T helper cells (lymphocytes) to release IL-2.
- -IL-2 induces the proliferation and development of antibody producing B cells (plasma cells) and cytotoxic T cells.
What do cytokines do?
- -Trigger an inflammatory response (redness, fever, aches, etc.)
- -Attract more innate immune cells.
- -Activate the adaptive immune system.
How do cytokines interact with the brain?
- -Cytokines are like ‘sickness hormones’, so it makes sense that they can communicate with the brain
- -Cytokines like IL-1 signal sickness to the brain through a variety of mechanisms
- —>The vagus nerve connecting the brain to the abdominal organs
- —>Receptors on blood vessels in the brain detect circulating IL-1 or pathogens and stimulate cytokine production in the brain
- —>Circulating IL-1 can be actively transported into the brain
Cytokines in the brain are linked to _________ behaviour
sickness; by informing the brain of infection, cytokines allow the animal to make appropriate adjustments to its behavior.
