Ch 16 Endocrine - part 2
Endocrine system
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several separate organs
release hormone into capillaries
hormone transported in blood
endocrine vs exocrine
Endocrine Glands
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Hypothalamus
Pituitary
Pineal gland
Thyroid
Parathyroid
Thymus
Adrenal Cortex
Adrenal Medulla
Pancreas
Ovary
Testes
things to know
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endocrine gland
gland + hormone(s) produced
hormone + its action
diseases
types of hormones
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direct hormones
affect body functions
receptor on body tissues
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tropic hormones
affect other endocrine glands
receptors on “
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releasing hormones
from hypothalamus
stimulating hormones
from pituitary
Thyroid gland
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follicles
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follicular cells
produce thyroid hormone
lumen
stores colloid
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parafollicular (C) cells
produce calcitonin
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thyroid hormone
thyroxine
tri-iodothyronine
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effects:
Thyroid hormone
T4
T3
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calorigenic
stim enzymes of cell respiration
increase basal metabolic rate = heat
catabolize fats, proteins
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growth effects
nervous system development
muscle, skeletal development
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metabolic
protein synthesis
increase heart rate and BP
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see table 16.2
Thyroid hormone synthesis
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thyroglobulin synthesis (colloid)
iodination
I2 added to tyrosine
T4 and T3
stored in colloid
cleavage
T4 and T3 break from colloid
secretion
exocytosis
transport
TBG
thyroxine-binding globulin
control of T4
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stimulus:
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(thyroid stimulating hormone)
low blood T4
low body temp
pregnancy
inhibited by
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TSH
any inhibition of TSH
high blood T4
somatostatin
glucocorticoids
sex hormones (estrogen)
Diseases of Thyroid hormone
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Grave’s Disease
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hyperthyroidism
 BMR ;  HR
weight loss ; sweating
exopthalmos
Myxedema
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hypothyroidism (adult)
fluid accumulation
weakness; lethargy ; mental “sluggishness”
 BMR ; weight gain ; chilled
Cretinism
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hypothyroidism (congenital)
decreased growth; and mental development
Goiter
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thyroid tumor
increased TSH  increase colloid
Calcitonin
decreased I2
= thyrocalcitonin
parafollicular (C) cells
effects:
decrease blood calcium
stimulus:
high blood Calcium
deposit calcium into bone
Parathryroid gland
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Parathyroid hormone
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PTH = parathormone
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effects :
increase blood calcium
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stimulus:
low blood calcium
increase Ca++ absorption
increase Ca++ reabsorption
remove Ca++ from bone
Diseases of Calcium Hormones
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hyperparathyroidism
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from:
parathyroid tumor
20 to kidney condition
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symptoms:
hypercalcemia
osteopenia
(osteitis fibrosa cystica)
hypoparathyroidism
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from:
thyroidectomy
symptoms:
hypocalcemia
muscle spasms
increased nerve excitability
Adrenal gland
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2 separate glands
adrenal cortex
adrenal medulla
outer
inner
Adrenal medulla
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2 catecholamines
epinephrine
norepinephrine
chromaffin cells
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postganglionic sympathetic neurons
“fight or flight”
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effects:
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stimulus:
sympathomimetic
“adrenaline rush”
increase heart rate , BP
bronchodilation
increase blood glucose
increase BMR
increase alertness
Sympathetic nervous system
Adrenal cortex
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3 layers :
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zona glomerulosa outer
mineralcorticoids
zona fasciculata
middle
glucocorticoids
zona reticularis
inner
androgens
Adrenal cortex hormones
hormones:
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mineralcorticoids
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glucocorticoids
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gonadocorticoids
corticosteroids
aldosterone
– Na and K levels
cortisol
– glucose sparing
– anti-inflammatory
androgens
mineralcorticoids
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aldosterone
increases Na levels in blood and tissue fluid
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stim transcription of
Na-K ATPase
reabsorbs Na in kidney (DCT)
excretes K into urine
increase blood volume (water follows Na )
increase BP
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stimulus:
low blood Na
ACTH
renin-angiotensin
glucocorticoids
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“stress hormone”
cortisol
“ glucose sparing”
• increase blood glucose
• fat catabolism
glycogenolysis
gluconeogenesis
protein catabolism
more AA for repair
vasoconstiction
maintains BP
anti-inflammatory
depress immune syst.
affects memory
stimulus:
ACTH
stress
Gonadocorticoids
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androgens :
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males
convert to testosterone
female
convert to estradiol
effects:
puberty
sex drive
minimal compared to gonad production
Diseases of Adrenal Cortex
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Cushing’s
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increased Cortisol
ACTH producing tumor
ant pituitary , lung
pharmaceutical doses
cushingoid features:
Addison’s Disease
moon face : buffalo hump
bruising
steroid diabetes
osteoporosis - fractures
low inflammatory response
decreased Aldosterone , Cortisol
• increase K levels
• low BP
• hypoglycemia
low Na
Diseases of Adrenal Medulla
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pheochromocytoma
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chromaffin cell tumor
increased epinephrine effects
Pancreas
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pancreatic islets
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islets of Langerhans
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alpha (α) cells
glucagon
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beta (β) cells
insulin
somatostatin
Glucagon
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effects:
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increase blood glucose
liver -
glycogenolysis
gluconeogenesis
lipolysis
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stimulus:
low blood glucose
sympathetic n.s.
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effects:
decrease blood glucose
Insulin
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increase membrane transport of glucose
• increase carrier proteins
increase cell respiration and ATP
increase glycogenesis (storage)
decrease gluconeogenesis
stimulus:
lipolysis
high blood glucose
parasympathetic n.s.
glucagon
somatostatin
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same as hypothalamic hormone (GHIH)
inhibit gastric activity
inhibit TSH (thyroxine)
glucose related hormones
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insulin
decrease blood glucose
glucagon
increase blood glucose
epinephrine
increase blood glucose
cortisol
increase blood glucose (centrally)
growth hormone
increase blood glucose
thyroxine
increase blood glucose
Diseases of Pancreas
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hypoglycemia =
low blood glucose
hyperglycemia
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high blood glucose
• glucosuria
• Polyuria
• Polydipsia
• Polyphagia
Diabetes Mellitus
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type 1
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type 2
hyperglycemia
Insulin dependent
– congenital (autoimmune)
non Insulin dependent
IDDM
decrease Beta cells
NIDDM
– developed
– decrease Insulin receptors on target cells
Thymus
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thymic hormones
maturation of T lymphocytes
Pineal gland
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= epithalamus
melatonin
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circadian rhythms
inhibit RAS
stim by hypothalamus
Ovary
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estradiol
follicle
progesterone
corpus luteum
Ovary
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estradiol
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effects:
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stimulus: FSH
progesterone
follicle
ovum development
uterus development
mammary duct development
corpus luteum , placenta
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effects:
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stimulus: LH, hCG indirectly
inhibin
uterus development
mammary gland development
inhibit FSH, LH
Testes
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testosterone
interstitial cells
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effects:
sperm maturation
accessory sex glands
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stimulus:
ICSH
inhibin
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effects:
sustentacular cells
inhibits FSH
Hypothalamus
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“master gland” of the endocrine system
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direct hormones
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ADH = antidiuretic hormone
urine concentration
oxytocin
uterine contractions
milk secretion
regulatory hormones
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controls Pituitary gland
RH = releasing hormones (factors)
IH = inhibitory hormones
Pituitary
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= Hypophysis
Posterior Pituitary
neurohypophysis
= pars nervosa
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Anterior Pituitary
adenohypophysis
= pars distalis
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infundibulum
stalk connecting to hypothalamus
actually part of neurohypophysis
Posterior Pituitary
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extension of the Hypothalamus
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hypothalamic-hypophyseal tract
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axons from Hypothalamus
hormones made in hypothalamus
released from posterior pituitary
Posterior Pituitary
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ADH
Antidiuretic hormone
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effects:
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stimulus: increase osmolarity
(vasopressin)
increase water reabsorption – kidney
increase BP
oxytocin
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effects:
uterine contractions
milk release
stimulus: stretch of uterus
nursing
Anterior Pituitary
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= adenohypophysis
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hypophyseal portal system
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direct hormones
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stimulating hormones
• vascular system betw hypothalamus and ant. pituitary
specific body responses
control other endocrine glands
Anterior Pituitary – direct hormones
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GH growth hormone =
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PRL prolactin
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FSH follicle stimulating hormone
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LH
somatotropic hormone
• mitosis ; protein synthesis
• stim: GHRH ; low GH ; exercise ; hypoglycemia
• milk production
• stim: estrogen ; nursing ; PRH
• ovum / follicle development
luteinizing hormone
• ovulation ; corpus luteum function
Anterior Pituitary – stimulating hormones
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TSH
thyroid stimulating hormone
ACTH
adrenocorticotropic hormone
MSH
melanocyte stimulating hormone
FSH
follicle stimulating hormone
LH
luteinizing hormone
ICSH
interstitial cell stimulating hormone
increase blood volume
stimulating hormone effect
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anterior pituitary
TSH
ACTH
FSH
LH
ICSH
MSH
other endocrine glands
thyroid
thyroxine
adrenal cortex
cortisol
follicle
estrogen
corpus luteum
progesterone
interstitial cells
testosterone
melanocytes
melanin
hypothalamus – releasing factors
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hypothalamus
growth hormoneRH
prolactin RH
corticotropicRH
thyrotropicRH
gonadotropicRH
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growth hormoneIH
gonadotropicIH
GHRH
PRH
CRH
TRH
GnRH (FHRH)
GnRH (LHRH)
GHIH
GnIH
ant. pituitary
GH
PRL
ACTH
TSH
FSH
LH
inhibit GH
inhibit FSH, LH
** hypothalamus controls all pituitary production there is a regulating hormone from hypothalamus for every pituitary hormone
other endocrine structures
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heart
atrial natriuretic peptide
ANP
brain
brain natriuretic peptide
many neurotransmitters
BNP
kidney
renin
erythropoietin
calcitriol
skin
cholecalciferol (Vitamin D)
liver
angiotensin
digestive tract
gastrin
secretin
cholecystokinin
adipose
estrogens