Endocrine control of osmolarityAntidiuretic hormone (ADH)Aldosterone Atrial natriuretic peptide (ANP)

Osmoregulation: ADH

• Induces H2O conservation

• Released from posterior pituitary

• Peptide hormone

• Activates kidney cells to increase water pores on membrane surface inside collecting duct

• Net effect: water conservation

Figure 45.6a Hormones of the hypothalamus and pituitary glands

Osmoregulation: Vasopressin (ADH)

Osmoregulation: Aldosterone

• Induces Na+ conservation

• Synthesized and released from adrenal cortex

• Steroid hormone (moves in and out of cells by diffusion)

• Acts on kidney cells to increase production of Na+ membrane channels and Na+/K+ pumps

Osmoregulation: Aldosterone

Osmoreg.:Atrial natriuretic peptide• Induces Na+ and water excretion

• Released from the heart when plasma volume is high

• Peptide hormone

• Acts on the kidney to increase Na+ & water excretion, mechanisms not well understood

• Also act as antagonist to vasopressin and aldosterone

Aldosterone & ADH effects on OsM

• If aldosterone rises OsM

increases or decreases?

• If ADH rises OsM

increases or decreases?

Endocrine control of basal metabolic rate

- thyroxine and triiodothyronine

Figure 45.6b Hormones of the hypothalamus and pituitary glands

Thyroid hormones - amines from thyroid that regulate BMR

Anterior pituitary

Hypothalamus Thyroid glands

Thyroid hormone control and function

Primary

thyroid tumor hypersecreting

Secondary

hypothalamic

atrophy due to local stroke

Iodine deficiency

hypothalamus TRH TRH TRH

anterior pituitary TSH TSH TSH

thyroid gland T3 & thyroxine T3 & thyroxine T3 & thyroxine

metabolic rate metabolic rate metabolic rate

Indicate whether level is increased, decreased or no change

Endocrine response to stress- epinephrine and norepinephrine- cortisol

Figure 45.14 Stress and the adrenal gland

Catecholamine hormones - amines that control our response to acute stress

- Cardiac output increases- Blood vessels to skel. muscles dilate- Blood vessels to dig. organs constrict- Liver produces glucose

Cortisol control

CRH

hypothalamus

ACTH

cortisol

( - )

( + )

adrenal cortex

negative feedback

( + )

anterior pituitary

Diurnal rhythm & chronic stress

catabolic effects

Break down proteins and fats to make more plasma glucose