stress and anxiety

hypopituitarism leads to decreased production of ______, decreased stimulation of the __________ __________, and less _________ production

ACTH; adrenal glands; CORT

what activates the anterior pituitary to release ACTH

CRH

prolonged release of ACTH leads to:

enlarged adrenal cortex

types of corticosteroid hormones

glucocorticoids & mineralocorticoids

cortisol ____________ blood glucose levels

increases

cortisol is released by the adrenal gland but regulated by the:

pituitary gland

long term ACTH deficiency leads to:

shrinkage of adrenal cortex

where does CRH bind

to receptors of the anterior pituitary gland

what is *responsible for the neuroendocrine adaptation component of the stress response*

*HPA axis*

when a stressor is detected through our senses, where is the information sent to

*amygdala*

2 parts of adrenal glands

*cortex & medulla*

the major pathway of the HPA axis *results in the production and secretion of what*

*cortisol*

if the information that the amygdala interprets is dangerous, where does it send a "distress signal" to

*hypothalamus*

(memorize) activation of stress response - when someone experiences a stressful event:

1. amygdala sends distress signal to hypothalamus 2. hypothalamus activates SNS (which triggers the fight-or-flight response by sending signals through the autonomic nerves to the adrenal glands) 3. adrenal glands respond by pumping the hormone epinephrine into bloodstream 4. epinephrine triggers the release of blood sugar & fats from temporary storage sites in the body 5. as the initial surge of epinephrine subsides, the hypothalamus activates the second component of the stress response system - known as the *HPA axis*

(memorize) HPA axis activation:

1. hypothalamus releases corticotropin-releasing hormone in response to stress 2. CRH acts on the pituitary gland, causing it to release ACTH 3. ACTH acts on adrenal gland, causing it to release cortisol 4. cortisol causes the release of glucose into bloodstream in order to facilitate flight or fight response

what act synergistically to mediate the stress response

CRH & vasopressin (ADH)

the feedback mechanism signals the hypothalamus & the anterior pituitary gland to inhibit:

HPA axis activity & the synthesis of CRH & ACTH

what is cortisol

a stress hormone

location of the hypothalamus

above the brainstem

the chemicals released from the adrenal medulla after SNS activation that help us deal with stress include:

adrenaline (epinephrine), noradrenaline, & dopamine (a small amount)

during stress, what does the pituitary release

adrenocorticotropic hormone (ACTH) & beta endorphins into bloodstream

what does chronic stress cause in the paraventricular nucleus neurons & other brain areas

anatomical changes

what is the intersection of worry & stress

anxiety

neuropeptide/morphine like hormone released during stress

beta endorphins

suppressed CORT levels ___________ inhibit continued HPA activation through GR-mediated negative feedback

cannot

link between the endocrine & nervous system

command center of hypothalamus

the adrenal cortex releases _____________ hormones & _________ ______________ at small amounts

corticosteroid; sex steroids

upon activation, what does the hypothalamus release

corticotropin releasing factor (CRF also known as CRH)

what does the cortex of adrenal glands produce

cortisol

glucocorticoid receptor agonist

dexamethasone

what systems work as our *stress response*

endocrine, nervous, & immune systems

what does the medulla of adrenal glands produce

epinephrine (adrenaline)

T/F - worry, anxiety, and stress are synonymous

false

T/F - beta endorphins boost pain & reduce pleasure

false - reduce pain & boost pleasure

what is the hypothalamus responsible for? (4 f's and 2 h's)

fighting, fleeing, feeding, & fornication homeostasis & hormones

what lobe of the brain does worry take place

frontal lobe

which type of receptors regulate cortisol levels after a stressful event (mostly located in PVN)

glucocorticoid (type II) receptors

what does traumatic brain injury induce

hypopituitarism

long term stress response

hypothalamic pituitary adrenal (HPA) axis

what controls the pituitary gland

hypothalamus

glucocorticoids are triggered by:

hypothalamus & pituitary gland (e.g. hydrocortisone, corticosterone, cortisol)

the HPA axis is the cooperation of what 3 endocrine glands

hypothalamus, pituitary gland, & adrenal gland

the chemicals released from the adrenal medulla ______________ cardiac output, skeletal muscle flow, glucose levels, & sodium retention

increase

under normal conditions, the GR antagonist would _____________ cortisol levels

increase

the 2 types of receptors that detect cortisol levels are activated upon ______________ cortisol levels

increased

decreased CORT is associated with _______________ ________________, thus injury-induced suppression of the HPA axis depicts a mechanism through which post-TBI consequences may occur

increased inflammation

the GR agonist ____________ cortisol production by inhibiting HPA axis activation

inhibits

the HPA axis is a term used to represent the _____________ between the hypothalamus, pituitary gland, and adrenal glands

interaction

when are cortisol levels highest

just before waking

cortisol synthesis inhibitors

ketoconazole & metyrapone

mineralocorticoids are triggered by:

kidney (e.g. aldosterone)

what does cortisol aid in

metabolism of fats, proteins, carbs, & increases glucose levels in blood providing additional energy for muscles

when are cortisol levels lowest?

midnight

glucocorticoid receptor antagonist

mifepristone

which type of receptors help to maintain normal daily cortisol fluctuations in the blood

mineralocorticoid (type I) receptors

what 2 types of receptors detect cortisol levels & initiate the negative feedback mechanism

mineralocorticoid (type I) receptors (MR) & glucocorticoid (type II) receptors (GR)

when cortisol in the blood reaches a certain concentration, what is triggered

negative-feedback mechanism

beta endorphins act on the _____________ receptors in our brains to reduce pain

opiate

what is the amygdala

our emotional processing center

what is stress a threat to

our homeostasis (our ability to adjust and respond to internal & external stimuli in order to maintain balance)

the ______________ ____________ of the hypothalamus projects directly to the anterior pituitary

paraventricular nucleus

what structure of the hypothalamus secretes vasopressin and CRH

paraventricular nucleus

"master gland" that controls the activity of most hormone secreting glands

pituitary gland

hypothalamus sends information to the:

pituitary gland

how does the HPA axis work

positive & negative feedback

what does the pituitary gland produce

prolactin, growth hormone, thyroid stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), luteinizing hormone (LH), follicle stimulating hormone (FSH), oxytocin, antidiuretic hormone

where does ACTH bind after traveling down to kidneys

receptors of the adrenal cortex

the chemicals released from the adrenal medulla _____________ intestinal motility

reduce

mifepristone is used as a treatment to do what

reduce HPA hyperactivity due to dysregulation of negative feedback

main functions of the HPA axis

regulate cortisol levels & maintain energy/homeostasis

main role of the adrenal glands

release of hormones that regulate metabolism, immune systems, blood pressure, & response to stress

what does the hypothalamus produce

releasing & inhibiting hormones; e.g. growth hormone, somatostatin, gonadotrophin-releasing hormone, thyrotropin-releasing

what involves the physiological process, fight or flight response by the ANS, and is hormonal

stress

what does traumatic brain injury result in

suppressed HPA activation in response to a stressor

chronic stress results in:

sustained activation of HPA axis, ineffective negative feedback to the HPA axis, linked to type 2 diabetes, obesity, & CVD, high cortisol levels implicated in mood disorders, & link between early life trauma & overactive HPA axis later in life (increased anxiety, metabolic effects, insulin resistance)

what does the hypothalamus activate by sending signals through the autonomic nerves to the adrenal glands & HPA axis

sympathetic nervous system

short term stress response

sympatho-adrenomedullary (SAM) axis

what do healthy cortisol levels ensure

that the hypothalamus & the pituitary gland maintain the appropriate level of sensitivity to negative feedback of cortisol in response to stressors

what does the negative feedback loop protect the body from

the prolonged release of cortisol via the HPA axis, ensuring the return to homeostasis

main function of beta endorphins

to reduce pain during stress

potential causes of HPA axis disturbances

traumatic brain injury, prenatal stress, early life stress, genetic background, current stress, & neurodegenerative disease

T/F - cortisol is helpful in the short term by acting to restore homeostasis & harmful in the long-term by weakening the immune system

true

what involves thought process

worry