1. Students
Get handout – Ch 45 Guided Notes
Turn in Case Study – box
Any speciation papers?
Phones in bin….muted or off…please & thank you!

2. } Chapter 45: Hormones and the Endocrine System
What is the difference between paracrine & endocrine?
Paracrine – local signaling between neighboring cells
Endocrine – distance signaling thereby using the circulatory system
Review Ch 11: Cell communication
Reception
G protein-linked receptors
Tyrosine kinase receptors
Ion channel receptors
Steroid hormone receptors – intracellular
Transduction
2nd messengers – Ca+2 ions, cAMP, IP3 & DAG
Phosphorylation cascades – protein kinases
Response
Gene activation aka transcription
Enzyme activation
Cell division }
Membrane bound

3. Figure 45.3 Mechanisms of hormonal signaling: a review
SECRETORY
CELL
Hormone
molecule
VIA
BLOOD
Signal receptor
TARGET
Signal
transduction
pathway
Cytoplasmic
response
Nuclear
NUCLEUS
DNA OR
receptor
and response
mRNA
Synthesis of
specific proteins
(a) Receptor in plasma membrane
(b) Receptor in cell nucleus

4. Chapter 45: Hormones and the Endocrine System
What is the difference between paracrine & endocrine?
What are the 3 general types of signaling pathways?
Simple endocrine
Simple neurohormone
Simple neuroendocrine

5. Figure 45.2 Basic patterns of simple hormonal control pathways
Example
Stimulus
Low blood
glucose
Receptor
protein
Pancreas
secretes
glucagon ( )
Endocrine
cell
Blood
vessel
Liver
Target
effectors
Response
Suckling
Sensory
neuron
Hypothalamus/
posterior pituitary
Neurosecretory
Posterior pituitary
secretes oxytocin
( )
Smooth muscle
in breast
Milk release
Hypothalamic
neurohormone
released in
response to
neural and
hormonal
signals
Hypothalamus
secretes prolactin-
releasing
hormone ( )
Anterior
pituitary
prolactin ( )
Mammary glands
Milk production
(c) Simple neuroendocrine pathway
(b) Simple neurohormone pathway
(a) Simple endocrine pathway
Glycogen breakdown, glucose release into blood

6. Chapter 45: Hormones and the Endocrine System
What is the difference between paracrine & endocrine?
What are the 3 general types of signaling pathways?
How can 1 ligand cause different effects?
Different receptor types on different cells
Different intracellular signal molecules (relay proteins)

7. Figure 45.4 One chemical signal, different effects
Different receptors
different cell responses
Epinephrine
a receptor
b receptor
Vessel
constricts
dilates
Glycogen
breaks down
and glucose
is released
from cell
Intestinal blood vessel
(a)
Skeletal muscle
blood vessel
(b)
Liver cell
(c)
Different intracellular proteins
Glycogen deposits

8. Figure 45.6 Human endocrine glands surveyed in this chapter
Hypothalamus
Pineal gland
Pituitary gland
Thyroid gland
Parathyroid glands
Adrenal glands
Pancreas
Ovary
(female)
Testis
(male)

9. Chapter 45: Hormones and the Endocrine System
What is the difference between paracrine & endocrine?
What are the 3 general types of signaling pathways?
How can 1 ligand cause different effects?
What are some common endocrine glands?
How does the hypothalamus control the anterior & posterior pituitary
differently?
- posterior – directly via neurohormones
- anterior – indirectly via releasing hormones (tropic hormones)
 tropic hormones = hormones that influence other glands to release
other hormones

10. Figure 45.7 Production and release of posterior pituitary hormones
Hypothalamus
Neurosecretory
cells of the
hypothalamus
Axon
Anterior
pituitary
Posterior
HORMONE
ADH
Oxytocin
TARGET
Kidney tubules
Mammary glands,
uterine muscles

11. Figure 44.16 Hormonal control of the kidney by negative feedback circuits
ALCOHOL =
Inhibits ADH release 
decreased H2O reabsorption 
increased H2O release 
dehydration 
hangover!

12. Figure 45.8 Production and release of anterior pituitary hormones
Tropic Effects Only
FSH, follicle-stimulating hormone
LH, luteinizing hormone
TSH, thyroid-stimulating hormone
ACTH, adrenocorticotropic hormone
Nontropic Effects Only
Prolactin
MSH, melanocyte-stimulating hormone
Endorphin
Nontropic and Tropic Effects
Growth hormone
Neurosecretory cells
of the hypothalamus
Portal vessels
Endocrine cells of the
anterior pituitary
Hypothalamic
releasing
hormones
(red dots)
HORMONE
FSH and LH
TSH
ACTH
MSH
TARGET
Testes or
ovaries
Thyroid
Adrenal
cortex
Mammary
glands
Melanocytes
Pain receptors
in the brain
Liver
Bones
Pituitary hormones (blue dots)

13. Chapter 45: Hormones and the Endocrine System
What is the difference between paracrine & endocrine?
What are the 3 general types of signaling pathways?
How can 1 ligand cause different effects?
What are some common endocrine glands?
How does the hypothalamus control the anterior & posterior pituitary
differently?
How is the thyroid regulated?
Regulates metabolism
T3 & T4 hormones
Triiodothyronine (T3) & thyroxine (T4) have 3 or 4 iodine atoms

14. Figure 45.9 Feedback regulation of T3 and T4 secretion from the thyroid gland
Hypothalamus
Anterior
pituitary
TSH
Thyroid T3 T4 +
TRH
What happens with a lack of iodine in the diet?
Pg 33

15. Chapter 45: Hormones and the Endocrine System
What is the difference between paracrine & endocrine?
What are the 3 general types of signaling pathways?
How can 1 ligand cause different effects?
What are some common endocrine glands?
How does the hypothalamus control the anterior & posterior pituitary
differently?
How is the thyroid regulated?
How is homeostasis of blood calcium achieved?
Thyroid & parathyroid glands
Calcitonin & PTH

16. Figure 45.11 Hormonal control of calcium homeostasis in mammals
Calcitonin
Thyroid gland
releases
calcitonin.
Stimulates
Ca2+ deposition
in bones
Reduces
Ca2+ uptake
in kidneys
STIMULUS:
Rising blood
Ca2+ level
Blood Ca2+
level declines
to set point
Homeostasis:
Blood Ca2+ level
(about 10 mg/100 mL)
level rises
Falling blood
Ca2+ release
from bones
Parathyroid
gland
Increases
in intestines
Active
vitamin D
Stimulates Ca2+
uptake in kidneys
PTH

17. Chapter 45: Hormones and the Endocrine System
What is the difference between paracrine & endocrine?
What are the 3 general types of signaling pathways?
How can 1 ligand cause different effects?
What are some common endocrine glands?
How does the hypothalamus control the anterior & posterior pituitary
differently?
How is the thyroid regulated?
How is homeostasis of blood calcium achieved?
How is homeostasis of blood glucose achieved?
Pancreas
Insulin and glucagon

18. Figure 45.12 Maintenance of glucose homeostasis by insulin and glucagon
Beta cells of
pancreas are stimulated
to release insulin
into the blood.
Insulin
Liver takes
up glucose
and stores it
as glycogen.
Body cells
take up more
glucose.
Blood glucose level
declines to set point;
stimulus for insulin
release diminishes.
STIMULUS:
Rising blood glucose
level (for instance, after
eating a carbohydrate-
rich meal)
Homeostasis:
(about 90 mg/100 mL)
rises to set point;
stimulus for glucagon
Dropping blood glucose
skipping a meal)
Alpha cells of pancreas
are stimulated to release
glucagon into the blood.
Liver breaks
down glycogen
and releases
glucose into
blood.
Glucagon

19. Chapter 45: Hormones and the Endocrine System
What is the difference between paracrine & endocrine?
What are the 3 general types of signaling pathways?
How can 1 ligand cause different effects?
What are some common endocrine glands?
How does the hypothalamus control the anterior & posterior pituitary
differently?
How is the thyroid regulated?
How is homeostasis of blood calcium achieved?
How is homeostasis of blood glucose achieved?
How does the body respond to short-term stress, ie fight or flight?
- epinephrine & norepinephrine

20. Figure 45.13 Stress and the adrenal gland
Spinal cord
(cross section)
Nerve
signals
cell
Releasing
hormone
Stress
Hypothalamus
Anterior pituitary
Blood vessel
ACTH
Adrenal
gland
Kidney
Adrenal medulla
secretes epinephrine
and norepinephrine.
Adrenal cortex
secretes
mineralocorticoids
and glucocorticoids.
Effects of epinephrine and norepinephrine:
1. Glycogen broken down to glucose; increased
blood glucose
2. Increased blood pressure
3. Increased breathing rate
4. Increased metabolic rate
5. Change in blood flow patterns, leading to
increased alertness and decreased digestive
and kidney activity
Effects of
mineralocorticoids:
Retention of sodium
ions and water by
kidneys
Increased blood
volume and blood
pressure 1. 2.
glucocorticoids:
Proteins and fats
broken down and
converted to glucose,
leading to increased
Immune system may
be suppressed
(b) Long-term stress response
(a) Short-term stress response
Nerve cell

21. Table 45.1 Major Human Endocrine Glands and Some of Their Hormones

22. Table 45.1