L6: Cortisol Flashcards
cortisol
secreted from the adrenal cortex, stress hormone that plays a direct role in the mediation of long-term stress
the control pathways for cortisol secretion
HPA pathway
HPA pathway
corticotropin-releasing hormone (CRH)
adrenocorticotropic hormone (ACTH)
cortisol
most important metabolic effect of cortisol
protection against hypoglycemia
when blood glucose levels drop
the pancreas secretes glucagon to promote gluconeogenesis and glycogen breakdown
in the absence of cortisol,
glucagon is unable to respond adequately to hypoglycemic challenge
cortisol has a permissive effect on
glucagon and catecholamine activity
cortisol is essential for life
animals whose adrenal glands have been removed die if exposed to any significant environment stress
the permissive action on reactivity to catecholamines by cortisol also affects
blood pressure
cortisol has permissive action on the reactivity to catecholamines by
smooth muscle cells that surround arterioles
cortisol supresses
the immune system through multiple pathways
in what ways does cortisol affect the immune system
cortisol prevents cytokine release and antibody production by white blood cells and cortisol inhibit the inflammatory response by decreasing leukocyte mobility and migration
cortisol has been used as
anti-inflammatory drug for treating a variety of conditions: bee stings, pollen allergies and transplantation of organs
common HPA pathologies
hormone deficiency (hypocortisolism) and hormone excess (hypercortisolism)
uncommon cause of adrenal steroid disorders
abnormal tissue responsiveness
symptoms of hypercortisolism
excess gluconeogenesis, hyperglycemia, muscle protein breakdown, lipolysis, tissue wasting, thin arms and legs, extra fat in the trunk and face, increased appetite and food intake, moon face, striations
three types of hypercortisolism
primary, secondary, iatrogenic (physician-caused)
primary hypercortisolism
caused by an adrenal tumor that autonomously secretes cortisol, there tumors are not under the control of pituitary ACTH
secondary hypercortisolism
caused by a pituitary tumor that autonomously secretes ACTH, the tumor does not respond to negative feedback
iatrogenic hypercortisolism
occurs secondary to cortisol therapy for some other condition
hyposecretion of cortisol is __ than hypersecretion
much less common
primary adrenal insufficiency
also known as Addison’s disease, results from the autoimmune destruction of the adrenal cortex
Addison’s disease results in
the hyposecretion of all adrenal steroid hormones including aldosterone, resulting in an imbalance in Na+, K+ and water in the blood possibly leading to hypotension
a characteristic of Addison’s disease
the elevation of serum ACTH levels due to the loss of negative feedback by cortisol
in response to stress
the usual physiological functions of cortisol are enhanced as cortisol concentration in the plasma increase
cortisol concentrations in the plasma lead to
gluconeogenesis, lipolysis, inhibition of insulin actions increase
high cortisol concentrations also inhibit
nonessential processes, such as reproduction, during stressful situations and inhibit immune function
Cushing’s syndrome
the result of chronically elevated plasma cortisol concentration
