Unit 4 Flashcards
what is rotational stress
increases plasma corticosterone and epinephrine levels but has no effect on norepinephrine
What is footshock
increases plasma corticosterone and decreases hypothalamic NE
What does restraint stress do to corticosterone
Increases plasma corticosterone
What does social disruption do to corticosterone
increases plasma corticosterone
What are The main two neuroendocrine pathways activated in response to stress that control the immune system
-HPA (release of glucocorticoids) and the sympathetic nervous system (release of catecholamines: epinephrine and norepinephrine)
-other neuroendocrine factors that are released following stress that also regulate the immune system including prolactin, growth hormone (GH) and nerve growth factor (NGF).
what causes corticotrophin releasing hormone secretion and where does it come from
stimulation, either physical from the periphery via cytokines or psychological and is secreted from paraventricular nucleus of hypothalamus
T or F: Activation of the sympathetic nervous system results in secretion of acetylcholine from the pre-ganglionic sympathetic fibers in the adrenal medulla
T, This induces secretion of epinephrine into the systemic blood supply
- Norepinephrine is released from the nerve terminals in the vicinity of immune cells.
Where is prolactin secreted from
secreted from the anterior pituitary gland and from many extra-pituitary sites including immune cells
- It is immuno-stimulatory and is proposed to act as a counter measure to glucocorticoids
What does prolactin do in terms of stress
- Prolactin has been shown to be increased by stress (in some not all studies) but is not as well studied as glucocorticoids and catecholamines.
Where is GH secreted from and whats its role in terms of stress
- also secreted from the anterior pituitary gland but can also be produced by immune tissues thereby having an autocrine/paracrine effect on immune cells
- It is also immuno-stimulatory and suggested to counteract the effects of glucocorticoids
Role or nerve growth factor (NGF)
- neurotrophic hormone that can regulate the immune response
- can function through the hypothalamus to activate the HPA axis
- can function as an autocrine/paracrine factor to regulate immune cells
- promotes proliferation and differentiation of T and B lymphocytes and acts as a survival factor for memory B lymphocytes
- shown to be increased following stressful life events.
T or F: stress is detremental to immune system
T, These include changes in lymphocytes populations, in the ratio of helper:suppressor T cells, decreased lymphocyte proliferation, NK cell number and activity, impaired antibody responses and reactivation of latent viral infections.
What is natural killer cells
- type of cytotoxic T lymphocyte that is part of the innate immune system
- They primarily kill viral infected cells and cancer but will also kill bacteria, parasites and fungi.
Describe T lymphocytes
can be divided into subgroups:
1) Cytotoxic T cells (CTL) (also known as CD8+T cells) which destroy cells that are recognized as foreign or non-self
2). Helper T cells (also known as CD4+ T cells) which secrete cytokines and prompt B lymphocytes to synthesize antibodies
3). Memory T cells which are antigen-specific T cells that may be either CD4+ or CD8+
4.) Regulatory T cells (also known as suppressor T cells) which act on helper T cells to suppress antibody production.
T or F: during infection, lymphocytes proliferate
T, The proliferation of lymphocytes following stimulation by a mitogen (blastogenesis) can be used as an in vitro measure of the body’s response to challenge by an infectious agent
