Adrenal Gland and Stress Hormones lec 10

Flashcards about the adrenal gland and stress response.

Adrenal Gland

Located on top of the kidneys, composed of the cortex and medulla.

Cortical Hormones

Aldosterone, Cortisol, androgens, estrogens

Medullary Hormones

Epinephrine (adrenaline), Norepinephrine (noradrenaline)

Mineralocorticoids

Hormones from Zona glomerulosa

Glucocorticoids

Hormones from Zona Fasialata

Catecholamines

Hormones from Medulla

Hypothalamus

Releases CRF (corticotropin-releasing factor) stimulating pituitary gland

Pituitary Gland

Produces POMC which is cleaved into ACTH.

ACTH

Stimulates the adrenal cortex to secrete mineralocorticoids, glucocorticoids and androgens.

Adrenaline (Epinephrine)

Increases heart rate, cardiac output, enhances glucose production, causes vasodilation.

Noradrenaline (Norepinephrine)

Primarily increases blood pressure by causing vasoconstriction

Adrenomedullin

Peptide involved in vasodilation and blood pressure regulation

HPA Axis Stimulation

Hypothalamus releases CRF which stimulates conversion of POMC in pituitary to ACTH.

Stress

Anything that changes our internal environment.

Response to Stress

Collaboration between CNS and PNS, Endocrine system activity via hypothalamic-pituitary-adrenal axis.

Hypothalamus (in stress response)

Detects stress and sends a signal to the pituitary gland.

Pituitary Gland (in stress response)

Releases adrenocorticotropic hormone (ACTH).

Adrenal Glands (in stress response)

Releases cortisol, often referred to as the "stress hormone."

Adrenaline (Effects)

Increases heart rate, elevates blood pressure, and redirects blood flow to essential muscles and organs.

Chronic Stress (Effects)

Continuous activation of the HPA axis can lead to adrenal fatigue.

Cortisol

Key hormone of the adrenal gland

Cortisol Binding Globulin

Inhibitory cortisol binding protein

Sex Hormone Binding Globulin (SHBG)

True transporter protein which loosely binds cortisol and protects it

Glucocorticoid Receptor (GR)

Cortisol in cytosole binds to what?

GRs

Trigger transcriptional changes increasing/decreasing production of specific protein

Catecholamines

Reactions to acute stress - Fight or Flight

Advenomeduline

Acts as a vasodilator increasing blood flow

ADH (Vasopressin)

Nonapeptide stored and released from posterior pituitary

ADH Function

Reabsorption of water from distal tubule and collecting ducts

Triggers activation of atrial osmoreceptors

Increased plasma osmolarity

ADH receptors

V2 receptor in kidney, V3 in pituitary, V1 in blood vessel

ADH from Pituitary

Increases the reabsorption from kidneys ofH20+Urine

Renin - angiotensin - aldosterone (RAA)

Regulation of circulating blood in kidney

Renin release from macula densa

Drop in Capillary pressure Causes what

angiotensinogen converting enzyme

Liver protein to angiotensin 1

Renin

Kidney realeases _

Regulates what in RAA cycle?

Blood pressure and fluid/electrolyte balance in kidney