1. Hypothalamus: the master gland
Figure The Hypophyseal Portal System and the Blood Supply to the Pituitary Gland
Supraoptic
nuclei
Paraventricular
nuclei
Neurosecretory
neurons
HYPOTHALAMUS
MEDIAN
EMINENCE
Optic
chiasm
Mamillary body
Superior hypophyseal artery
Capillary
beds
Hypothalamus: the master gland
ANTERIOR LOBE
OF PITUITARY GLAND
Infundibulum
Portal vessels
Inferior hypophyseal artery
POSTERIOR LOBE
OF PITUITARY GLAND
Endocrine cells
Hypophyseal veins
p. 605 1

2. Figure 18-8a Feedback Control of Endocrine Secretion
Hypothalamus
Releasing
hormone
(RH)
Hormone 1
(from
pituitary)
Endocrine
target
organ
Hormone 2
(from target
organ)
TRH
TSH
Thyroid
gland
Thyroid
hormones RH
Pituitary
gland
CRH
ACTH
Adrenal
cortex
Gluco-
corticoids
Testes
Inhibin
FSH
Inhibin
Anterior
lobe
Ovaries
Estrogens
GnRH
Progestins
Ovaries LH
Estrogens
Hormone 1
Testes
Androgens
Negative feedback
Endocrine
organ
KEY
Stimulation
Hormone 2
Inhibition
Target cells
p. 606 2

3. Figure 18-8b Feedback Control of Endocrine Secretion
Stimulation
Stimulation
PIH
GH–IH
Inhibition
GH–RH
PRF
Inhibition
Anterior
lobe
Anterior
lobe
Epithelia,
adipose tissue,
liver GH
PRL
Liver
Stimulates
mammary
glands
Somatomedins
Stimulates growth of skeletal muscle,
cartilage, and many other tissues
p. 606 3

4. Figure 18-9 Pituitary Hormones and Their Targets
Hypothalamus
KEY TO PITUITARY HORMONES:
Direct Control
by Nervous
System
Indirect Control through Release
of Regulatory Hormones
ACTH
Adrenocorticotropic hormone
TSH
Thyroid-stimulating hormone
Regulatory hormones are released
into the hypophyseal portal system
for delivery to the anterior lobe of
the pituitary gland GH
Growth hormone
PRL
Prolactin
FSH
Follicle-stimulating hormone LH
Luteinizing hormone
MSH
Melanoctye-stimulating hormone
ADH
Antidiuretic hormone
OXT
Oxytocin
Anterior lobe of
pituitary gland
Adrenal
medulla
Adrenal
gland
ACTH
Adrenal
cortex GH
TSH
Epinephrine and
norepinephrine
Liver
MSH
Thyroid
gland
PRL
FSH LH
Somatomedins
Glucocorticoids
(cortisol,
corticosterone)
Melanocytes (uncertain
significance in healthy
adults)
Bone, muscle,
other tissues
Ovaries
of female
Testes
of male
Mammary
glands
p. 609
Thyroid
hormones (T3, T4)
Inhibin
Testosterone
Estrogen
Progesterone
Inhibin 4

5. Figure 18-9 Pituitary Hormones and Their Targets
KEY TO PITUITARY HORMONES:
Direct Release
of Hormones
ACTH
Adrenocorticotropic hormone
TSH
Thyroid-stimulating hormone
Sensory
stimulation
Osmoreceptor
stimulation GH
Growth hormone
PRL
Prolactin
FSH
Follicle-stimulating hormone LH
Luteinizing hormone
MSH
Melanoctye-stimulating hormone
ADH
Antidiuretic hormone
OXT
Oxytocin
Posterior lobe
of pituitary gland
ADH
Kidneys
OXT
Males: Smooth
muscle in ductus
deferens and
prostate gland
Females: Uterine
smooth muscle and
mammary glands
p. 609 5

6. Hypothalamus: the master gland
© 2012 Pearson Education, Inc.
1) Direct neuronal innervation of adrenal medulla (come back to)
2) Neuronal innervation of posterior pituitary
3) Portal system release to anterior pituitary
2A) Pathway: Supraoptic neurons → posterior pituitary → ADH → kidneys
Affect: ↑ H2O reabsorption in distal convoluted tubule (DCT) & collecting duct (CD)
~5% daily urine output
Release
stimulated by: ↑ osmotic pressure (↑ solute = ↓ H2O)-detected in hypothalamus
↓ blood pressure &/or volume-detected in heart called osmoreceptors
Notes: EtOH ↓ ADH release = ↑ urine output
diabetes insipidus: central-don’t make ADH; nephrogenic-don’t respond to ADH
2B) Pathway: Paraventricular neurons → posterior pituitary → oxytocin → uterus/mammary gland [female] OR vas deferens/prostate [male]
Affect: female: uterine contractions during labor (+ feedback); contractions during breastfeeding (let down)
male: contractions during emission-get sperm out
stimulated by: pressure on cervix; nipple stimulation
sexual arousal
List hormone produced by hypothalamus that goes to anterior pituitary
List hormone produced by anterior pituitary
List target organ
Effects
3A) weirdo-pars intermedia-secretes melanocyte stimulating hormone (MSH); secretion inhibited by dopamine
blood levels nearly 0 in humans except:
1) fetal development 2) young children 3) pregnant women 4) disease state
also released by skin after sun exposure = paracrine effect
The rest follow pathway to pars distalis portion of anterior pituitary
3B) prolactin release factor (dopamine acts as inhibitor)
prolactin → breasts→ development and milk production (also involves additional hormones for dev. Esp estrogen)
3C) Gonadotropin Releasing Hormone (GnRH)
Lutenizing Hormone (LH) → ovaries → ovulation; estrogen & progesterone release
→ testes → androgen release
Follicle Stimulating Hormone (FSH) → ovaries → estrogen release; follicle development/maturation
→ testes → sperm development/maturation
3D) Growth Hormone Releasing Hormone (GHRH) & Growth Hormone Inhibiting Hormone (GHIH)
Growth Hormone (GH) → kidney/liver → somatomedins → ↑ amino acid uptake/protein synthesis everywhere
epithelial/CT → cell division & differentiation
adipose → b.d. triglycerides → fatty acid → ATP synthesis
liver → b.d. glycogen → ↑ [glucose] in blood
all together = growth!
depends on genetics and diet too (also increase: exercise, non-REM sleep, thyroid and sex hormones = increase GH release)
imbalances: hypo-pituitary dwarfism-small stature, normal brain; Rx inject GH
hyper-gigantism before growth plates close; acromegaly after growth plates close
3E) Corticotropic Releasing Hormone (CRH)
Adrenocorticotropic Hormone (ACTH) → adrenal cortex → glucocorticoids (cortisol) [come back to w/stress]
3F) Thyrotopin Releasing Hormone (TRH)
Thyroid Stimulating Hormone (TSH) → thyroid → T3/T4
p. 619
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

7. Figure 18-10a The Thyroid Gland
Hyoid bone
Superior
thyroid artery
Thyroid cartilage
of larynx
Internal
jugular vein
Superior
thyroid vein
Cricoid cartilage
of larynx
Common
carotid artery
Left lobe of
thyroid gland
Right lobe of
thyroid gland
Isthmus of
thyroid gland
Middle thyroid vein
Inferior
thyroid artery
Thyrocervical trunk
Inferior
thyroid
veins
Trachea
Outline of clavicle
p. 611
Outline of sternum
Location and anatomy of the thyroid gland 7

8. Figure 18-10c The Thyroid Gland
Capillary
Capsule
C cell
Cuboidal
epithelium
of follicle
Follicle
cavities
Thyroid
follicle
Thyroid
follicle
Thyroglobulin
stored in colloid
of follicle
C cell
Follicles of the thyroid gland
LM  260
Histological details of the thyroid gland showing thyroid follicles and both of the cell
types in the follicular epithelium ATLAS: Plate 18c
p. 611 8

9. Figure 18-11a The Thyroid Follicles
cavity
Thyroglobulin
(contains T3 and T4)
FOLLICLE CAVITY
Endocytosis
Thyroglobulin
Iodide
(I+)
Lysosomal
digestion
Other amino acids
Tyrosine T4 T3
Diffusion
Diffusion
TSH-
sensitive
ion pump
FOLLICLE CELL
CAPILLARY
Iodide (I–)
TBG, transthryretin,
or albumin
T4 & T3
p. 612
The synthesis, storage, and secretion of thyroid hormones. 9

10. Figure 18-11b The Thyroid Follicles
Hypothalamus
releases TRH
Homeostasis
Disturbed
Decreased T3 and
T4 concentrations
in blood or low
body temperature
TRH
Anterior
lobe
Pituitary
gland
HOMEOSTASIS
Normal T3 and T4
concentrations,
normal body
temperature
Anterior
lobe
TSH
Homeostasis
Restored
Increased T3 and
T4 concentrations
in blood
Thyroid
gland
Thyroid follicles
release T3 and T4
p. 612
The regulation of thyroid secretion 10

11. © 2012 Pearson Education, Inc.
601
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
© 2012 Pearson Education, Inc.

12. © 2012 Pearson Education, Inc.
The Thyroid Gland
Very nice chart!
Regulation usually negative ↑ T3 & T4 = ↓ TRH
Extremely cold weather = ↑ TRH [in kids]
Extreme anxiety/excitement = ↓ TRH [counteract sympathetic NS stimulation]
Imbalances: hypo-extreme = cretinism
mental & physical retardation (diff from ↓ GH)
hypo-not so bad = myxedema
low BMR = lethargic, confused
generalized edema, increased cholesterol
hyper-extreme = thyrotoxicosis
>160% normal BMR- hungry, weight loss, nervous/edgy
Grave’s disease: immune system antibodies to receptor for TSH therefore chronically stimulate TSH receptors = ↑ production of T3 & T4
p. 613
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
© 2012 Pearson Education, Inc.

13. Figure 18-10c The Thyroid Gland
Capillary
Capsule
C cell
Cuboidal
epithelium
of follicle
Follicle
cavities
Thyroid
follicle
Thyroid
follicle
Thyroglobulin
stored in colloid
of follicle
C cell
Follicles of the thyroid gland
LM  260
Histological details of the thyroid gland showing thyroid follicles and both of the cell
types in the follicular epithelium ATLAS: Plate 18c
p. 611 13

14. Figure 18-12a The Parathyroid Glands
Left lobe of
thyroid gland
Parathyroid
glands
Posterior view of the
thyroid gland showing
the parathyroid glands.
p. 614 14

15. Figure 18-12c The Parathyroid Glands
(chief) cells
Oxyphil
cells
Parathyroid cells and oxyphil cells
LM  600
Parathyroid gland cells
p. 614 15

16. Figure 18-13 The Homeostatic Regulation of Calcium Ion Concentrations
Increased
excretion
of calcium
by kidneys
Thyroid gland
produces
calcitonin
Calcium
deposition
in bone
HOMEOSTASIS
RESTORED
HOMEOSTASIS
DISTURBED
Rising levels of blood calcium
Blood calcium
levels decline
Rising calcium
levels in blood
HOMEOSTASIS
Normal blood
calcium levels
(8.5–11 mg/dL)
p. 615 16

17. Figure 18-13 The Homeostatic Regulation of Calcium Ion Concentrations
HOMEOSTASIS
Normal blood
calcium levels
(8.5–11 mg/dL)
Falling levels of blood calcium
HOMEOSTASIS
DISTURBED
HOMEOSTASIS
RESTORED
Falling calcium
levels in blood
Blood calcium
levels increase
Increased
reabsorption of
calcium by
kidneys
Parathyroid
glands secrete
parathyroid
hormone (PTH)
Calcium release
from bone
Increased calcitriol
production causes
Ca2+ absorption
by digestive
system
p. 615 17

18. Figure 18-15 The Pineal Gland
Pinealocytes
p. 619
Pineal gland
LM  450 18

19. © 2012 Pearson Education, Inc.
Pineal gland-epithalamus-secretes melatonin
Serotonin converted to melatonin during the dark part of day
This conversion is inhibited during the day
SAD due to increased melatonin production
Inhibits puberty in humans; levels fall just before puberty; tumors that prevent it’s release lead to precocious puberty
Involved with circadian and annual rhythms
Acts as an anti-oxidant in the CNS to prevent damage to tissue
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
© 2012 Pearson Education, Inc.