Download Endocrinology - (Chemical signals in animals)

Endocrine control of osmolarity
Antidiuretic 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
Thyroid hormone control and function
Hypothalamus
Anterior
pituitary
Thyroid
glands
Indicate whether level is increased, decreased or no change
Primary
thyroid tumor
hypersecreting
hypothalamus
anterior
pituitary
thyroid gland
TRH
Secondary
hypothalamic
atrophy due to
local stroke
TRH
Iodine
deficiency
TRH
TSH
TSH
TSH
T3 & thyroxine T3 & thyroxine T3 & thyroxine
metabolic rate
metabolic rate
metabolic rate
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
Diurnal rhythm & chronic stress
hypothalamus
CRH
(+)
anterior pituitary
ACTH
negative
feedback
(-)
(+)
adrenal cortex
cortisol
catabolic effects
Break down
proteins and
fats to make
more plasma
glucose