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Endocrinology - _Chemical signals in animals_

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					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




                 Anterior       Thyroid
Hypothalamus
                 pituitary      glands
   Indicate whether level is increased, decreased or no change
                   Primary      Secondary         Iodine
                thyroid tumor hypothalamic      deficiency
                hypersecretin atrophy due to
                      g        local stroke
hypothalamu         TRH            TRH             TRH
s
anterior
pituitary           TSH            TSH             TSH
thyroid gland       T3 &      T3 & thyroxine T3 & thyroxine
                  thyroxine
                metabolic rate metabolic rate metabolic rate
Endocrine response to stress
 - epinephrine and norepinephrin
 - 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
                       (+)      negative
                                feedback
anterior pituitary
                 ACTH           (-)        Break down
                        (+)                proteins and
                                           fats to make
adrenal cortex       cortisol              more plasma
                                           glucose
               catabolic effects

				
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posted:7/24/2013
language:Latin
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