BIOLOGY 1A Lecture Notes - Lecture 34: Autocrine Signalling, Paracrine Signalling, Endocrine System
Overview: endocrine system
Function of hormone signaling in physiology
Growth and development
i.
Homeostasis
ii.
Coordinating response across organ systems
iii.
Metabolism
iv.
Reproduction
v.
a.
Review: Intercellular signaling schemes
Endocrine signaling
Cell releases hormone into blood--> response
1)
Ex. Adrenaline
2)
3)
i.
Paracrine signaling
Secretion of molecule from cell; in proximity if cells have receptor they will respond
to it
1)
Signaling from dorsal lip to differentiate ectoderm to become nervous system
(lecture 29)
2)
3)
ii.
Autocrine signaling
Cell releasing signaling molecule and that cell itself has receptor to respond
1)
Tumor cells; Immune cells
2)
3)
iii.
Synaptic signaling
Exclusive to nervous system; neurons form a synapse so that one neuron is
connected to second cell which can be gland, muscle or another neuron. Releases
neurotransmitters which bind
1)
2)
iv.
Neuroendocrine signaling
Cell that has ability to release chemicals via vesicles into the blood 1)
Neurotransmitters into BLOOD2)
3)
ADH released from hypothalamus
The collecting duct epithelial cells have receptorsa)
4)
v.
b.
Hormone= secreted signaling molecule that travels through the blood, acts at a distance on its
target cells
c.
Hydrophilic and hydrophobic hormones use different signaling pathways
HYDROPHILIC: Water soluble: stored in vesicles, stable in blood, bind to surface receptors i.
HYDROPHOBIC: Lipid soluble: released without vesicles, bind to plasma proteins to blood,
bind to receptors inside the cell
Transported via transport proteins in blood1)
ii.
iii.
d.
Endocrine system
Hypothalamus:
Oxytocin and Vasopressin1)
Releasing and inhibiting hormones2)
i.
Anterior Pituitary:
Growth hormone: stimulates growth and metabolic functions1)
ii.
Posterior Pituitary:
Vasopressin/ADH: promotes retention of water by kidneys--> collecting duct1)
Oxytocin: uterine muscles, birth2)
Long extensions from hypothalamus into posterior pituitary3)
4)
ADH binds, GDP replaced w GTP, G protein binds to adenylyl cyclase which
increases cAMP. cAMP binds to protein kinase A and activates it which
induces cellular response which then results in exocytosis of aquaporins to
make the collecting duct more permeable to water.
a)
5)
iii.
Adrenal medulla:
Epinephrine: raise blood glucose level; increase metabolic activities; constrict
vessels
1)
iv.
Adrenal cortex:
Mineralocorticoids: promote reabsorption of Na+ and excretion of K+ in kidneys1)
v.
Pancreas:
Insulin: lowers blood glucose level1)
Glucagon: raises blood glucose level2)
vi.
e.
Relationship between hypothalamus and pituitary gland
Hypothalamus: receives information from sensors (temp, osmolarity, blood pressure) and
coordinates endocrine response
i.
Posterior pituitary: extension of the hypothalamus (ADH)
Ends of neurons send signals (hormones) through vasculature1)
ii.
Anterior pituitary: separate gland that secretes different hormonesiii.
f.
I.
Homeostatic regulation of blood pressure via the kidney
Blood pressure= the pressure of blood in the vasculature
Contraction of the ventricles in the heart cause an increase in pressure which drives flow
of blood away from the heart through the arteries
No pressure in ur veins1)
Arm is close to your heart so you get accurate measurement 2)
i.
a.
There are two pathways for regulating blood pressure:
Diameter of the arteries influences blood pressure
Vasoconstriction increases blood pressure□
Vasodilation decreases blood pressure□
1.
Blood volume increases blood pressure
Increasing volume of extracellular fluid increases blood volume□
Drinking water increases blood pressure, becoming dehydrated decreases blood
pressure
□
2.
b.
Regulation of blood pressure via the RAAS pathway
Blood pressure and blood volume drops--> sensors(epithelial cells) on JGA
(beginning of nephron) in kidney detect change and secrete renin. Renin leads to
generation of Angiotensin I. ACE (enzyme) converts I into Angiotensin II.
1)
Angiotensin II is a hormone that then binds to smooth muscle around arteries to
constrict so the blood pressure gets higher.
2)
1.
Angiotensin II then binds to adrenal gland which releases the hormone aldosterone
which binds to receptors in distal tubule and gets increased reabsorption of ions
and water.
1)
2.
c.
Summary: RAAS= Renin-Angiotensin-Aldosterone system
Decrease in blood pressure--> increase production of renin1.
Renin--> increases production of angiotensin II2.
Angiotensin II -->causes vasoconstriction by binding to receptors on muscle surrounding
arteries
3.
Angiotensin II--> causes release of aldosterone by binding to receptors on the adrenal
gland
4.
Aldosterone--> increases blood volume by promoting reabsorption of ions and water by
binding to receptors on the epithelial cells that line the distal tubule of the nephron
5.
d.
Blood pressure control medication targets RAAS pathway : want 140 systolic
Drugs that limit production of angiotensin II (such as ACE inhibitors)
Less angiotensin II leads to vasodilation□
Less angiotensin II leads to drop in blood volume□
Both of these lowers blood pressure□
§
ARBs= angiotensin II receptor blockers
Same am't of angiotensin II but it can't bind to the receptors□
§
Aldosterone inhibitors
Work on kidneys to prevent reabsorption of water and ions□
§
e.
II.
Growth hormones produced by the anterior pituitary
Tropic hormones are hormones that target other endocrine glandsa.
b.
Stimulates protein synthesis and growth of muscles and connective tissuesc.
Stimulates production of insulin-like growth factors d.
Overproduction or underproduction of IGFs leads to body size differencee.
IGFs signals via RTKs
Growth factor binds to receptor1.
Dimerization2.
Phosphorylation cascade3.
Then transcription factors drive transcription of genes which leads to growth4.
f.
III.
Lecture 34- Hormones and the Endocrine System
Overview: endocrine system
Function of hormone signaling in physiology
Growth and development
i.
Homeostasis
ii.
Coordinating response across organ systems
iii.
Metabolism
iv.
Reproduction
v.
a.
Review: Intercellular signaling schemes
Endocrine signaling
Cell releases hormone into blood--> response
1)
Ex. Adrenaline
2)
3)
i.
Paracrine signaling
Secretion of molecule from cell; in proximity if cells have receptor they will respond
to it
1)
Signaling from dorsal lip to differentiate ectoderm to become nervous system
(lecture 29)
2)
3)
ii.
Autocrine signaling
Cell releasing signaling molecule and that cell itself has receptor to respond
1)
Tumor cells; Immune cells
2)
3)
iii.
Synaptic signaling
Exclusive to nervous system; neurons form a synapse so that one neuron is
connected to second cell which can be gland, muscle or another neuron. Releases
neurotransmitters which bind
1)
2)
iv.
Neuroendocrine signaling
Cell that has ability to release chemicals via vesicles into the blood 1)
Neurotransmitters into BLOOD2)
3)
ADH released from hypothalamus
The collecting duct epithelial cells have receptorsa)
4)
v.
b.
Hormone= secreted signaling molecule that travels through the blood, acts at a distance on its
target cells
c.
Hydrophilic and hydrophobic hormones use different signaling pathways
HYDROPHILIC: Water soluble: stored in vesicles, stable in blood, bind to surface receptors i.
HYDROPHOBIC: Lipid soluble: released without vesicles, bind to plasma proteins to blood,
bind to receptors inside the cell
Transported via transport proteins in blood1)
ii.
iii.
d.
Endocrine system
Hypothalamus:
Oxytocin and Vasopressin1)
Releasing and inhibiting hormones2)
i.
Anterior Pituitary:
Growth hormone: stimulates growth and metabolic functions1)
ii.
Posterior Pituitary:
Vasopressin/ADH: promotes retention of water by kidneys--> collecting duct1)
Oxytocin: uterine muscles, birth2)
Long extensions from hypothalamus into posterior pituitary3)
4)
ADH binds, GDP replaced w GTP, G protein binds to adenylyl cyclase which
increases cAMP. cAMP binds to protein kinase A and activates it which
induces cellular response which then results in exocytosis of aquaporins to
make the collecting duct more permeable to water.
a)
5)
iii.
Adrenal medulla:
Epinephrine: raise blood glucose level; increase metabolic activities; constrict
vessels
1)
iv.
Adrenal cortex:
Mineralocorticoids: promote reabsorption of Na+ and excretion of K+ in kidneys1)
v.
Pancreas:
Insulin: lowers blood glucose level1)
Glucagon: raises blood glucose level2)
vi.
e.
Relationship between hypothalamus and pituitary gland
Hypothalamus: receives information from sensors (temp, osmolarity, blood pressure) and
coordinates endocrine response
i.
Posterior pituitary: extension of the hypothalamus (ADH)
Ends of neurons send signals (hormones) through vasculature1)
ii.
Anterior pituitary: separate gland that secretes different hormonesiii.
f.
I.
Homeostatic regulation of blood pressure via the kidney
Blood pressure= the pressure of blood in the vasculature
Contraction of the ventricles in the heart cause an increase in pressure which drives flow
of blood away from the heart through the arteries
No pressure in ur veins1)
Arm is close to your heart so you get accurate measurement 2)
i.
a.
There are two pathways for regulating blood pressure:
Diameter of the arteries influences blood pressure
Vasoconstriction increases blood pressure□
Vasodilation decreases blood pressure□
1.
Blood volume increases blood pressure
Increasing volume of extracellular fluid increases blood volume□
Drinking water increases blood pressure, becoming dehydrated decreases blood
pressure
□
2.
b.
Regulation of blood pressure via the RAAS pathway
Blood pressure and blood volume drops--> sensors(epithelial cells) on JGA
(beginning of nephron) in kidney detect change and secrete renin. Renin leads to
generation of Angiotensin I. ACE (enzyme) converts I into Angiotensin II.
1)
Angiotensin II is a hormone that then binds to smooth muscle around arteries to
constrict so the blood pressure gets higher.
2)
1.
Angiotensin II then binds to adrenal gland which releases the hormone aldosterone
which binds to receptors in distal tubule and gets increased reabsorption of ions
and water.
1)
2.
c.
Summary: RAAS= Renin-Angiotensin-Aldosterone system
Decrease in blood pressure--> increase production of renin1.
Renin--> increases production of angiotensin II2.
Angiotensin II -->causes vasoconstriction by binding to receptors on muscle surrounding
arteries
3.
Angiotensin II--> causes release of aldosterone by binding to receptors on the adrenal
gland
4.
Aldosterone--> increases blood volume by promoting reabsorption of ions and water by
binding to receptors on the epithelial cells that line the distal tubule of the nephron
5.
d.
Blood pressure control medication targets RAAS pathway : want 140 systolic
Drugs that limit production of angiotensin II (such as ACE inhibitors)
Less angiotensin II leads to vasodilation□
Less angiotensin II leads to drop in blood volume□
Both of these lowers blood pressure□
§
ARBs= angiotensin II receptor blockers
Same am't of angiotensin II but it can't bind to the receptors□
§
Aldosterone inhibitors
Work on kidneys to prevent reabsorption of water and ions□
§
e.
II.
Growth hormones produced by the anterior pituitary
Tropic hormones are hormones that target other endocrine glandsa.
b.
Stimulates protein synthesis and growth of muscles and connective tissuesc.
Stimulates production of insulin-like growth factors d.
Overproduction or underproduction of IGFs leads to body size differencee.
IGFs signals via RTKs
Growth factor binds to receptor1.
Dimerization2.
Phosphorylation cascade3.
Then transcription factors drive transcription of genes which leads to growth4.
f.
III.
Lecture 34- Hormones and the Endocrine System
Overview: endocrine system
Function of hormone signaling in physiology
Growth and developmenti.
Homeostasisii.
Coordinating response across organ systemsiii.
Metabolismiv.
Reproductionv.
a.
Review: Intercellular signaling schemes
Endocrine signaling
Cell releases hormone into blood--> response1)
Ex. Adrenaline2)
3)
i.
Paracrine signaling
Secretion of molecule from cell; in proximity if cells have receptor they will respond
to it
1)
Signaling from dorsal lip to differentiate ectoderm to become nervous system
(lecture 29)
2)
3)
ii.
Autocrine signaling
Cell releasing signaling molecule and that cell itself has receptor to respond1)
Tumor cells; Immune cells2)
3)
iii.
Synaptic signaling
Exclusive to nervous system; neurons form a synapse so that one neuron is
connected to second cell which can be gland, muscle or another neuron. Releases
neurotransmitters which bind
1)
2)
iv.
Neuroendocrine signaling
Cell that has ability to release chemicals via vesicles into the blood
1)
Neurotransmitters into BLOOD
2)
3)
ADH released from hypothalamus
The collecting duct epithelial cells have receptors
a)
4)
v.
b.
Hormone= secreted signaling molecule that travels through the blood, acts at a distance on its
target cells
c.
Hydrophilic and hydrophobic hormones use different signaling pathways
HYDROPHILIC: Water soluble: stored in vesicles, stable in blood, bind to surface receptors
i.
HYDROPHOBIC: Lipid soluble: released without vesicles, bind to plasma proteins to blood,
bind to receptors inside the cell
Transported via transport proteins in blood
1)
ii.
iii.
d.
Endocrine system
Hypothalamus:
Oxytocin and Vasopressin1)
Releasing and inhibiting hormones2)
i.
Anterior Pituitary:
Growth hormone: stimulates growth and metabolic functions1)
ii.
Posterior Pituitary:
Vasopressin/ADH: promotes retention of water by kidneys--> collecting duct1)
Oxytocin: uterine muscles, birth2)
Long extensions from hypothalamus into posterior pituitary3)
4)
ADH binds, GDP replaced w GTP, G protein binds to adenylyl cyclase which
increases cAMP. cAMP binds to protein kinase A and activates it which
induces cellular response which then results in exocytosis of aquaporins to
make the collecting duct more permeable to water.
a)
5)
iii.
Adrenal medulla:
Epinephrine: raise blood glucose level; increase metabolic activities; constrict
vessels
1)
iv.
Adrenal cortex:
Mineralocorticoids: promote reabsorption of Na+ and excretion of K+ in kidneys1)
v.
Pancreas:
Insulin: lowers blood glucose level1)
Glucagon: raises blood glucose level2)
vi.
e.
Relationship between hypothalamus and pituitary gland
Hypothalamus: receives information from sensors (temp, osmolarity, blood pressure) and
coordinates endocrine response
i.
Posterior pituitary: extension of the hypothalamus (ADH)
Ends of neurons send signals (hormones) through vasculature1)
ii.
Anterior pituitary: separate gland that secretes different hormonesiii.
f.
I.
Homeostatic regulation of blood pressure via the kidney
Blood pressure= the pressure of blood in the vasculature
Contraction of the ventricles in the heart cause an increase in pressure which drives flow
of blood away from the heart through the arteries
No pressure in ur veins1)
Arm is close to your heart so you get accurate measurement 2)
i.
a.
There are two pathways for regulating blood pressure:
Diameter of the arteries influences blood pressure
Vasoconstriction increases blood pressure□
Vasodilation decreases blood pressure□
1.
Blood volume increases blood pressure
Increasing volume of extracellular fluid increases blood volume□
Drinking water increases blood pressure, becoming dehydrated decreases blood
pressure
□
2.
b.
Regulation of blood pressure via the RAAS pathway
Blood pressure and blood volume drops--> sensors(epithelial cells) on JGA
(beginning of nephron) in kidney detect change and secrete renin. Renin leads to
generation of Angiotensin I. ACE (enzyme) converts I into Angiotensin II.
1)
Angiotensin II is a hormone that then binds to smooth muscle around arteries to
constrict so the blood pressure gets higher.
2)
1.
Angiotensin II then binds to adrenal gland which releases the hormone aldosterone
which binds to receptors in distal tubule and gets increased reabsorption of ions
and water.
1)
2.
c.
Summary: RAAS= Renin-Angiotensin-Aldosterone system
Decrease in blood pressure--> increase production of renin1.
Renin--> increases production of angiotensin II2.
Angiotensin II -->causes vasoconstriction by binding to receptors on muscle surrounding
arteries
3.
Angiotensin II--> causes release of aldosterone by binding to receptors on the adrenal
gland
4.
Aldosterone--> increases blood volume by promoting reabsorption of ions and water by
binding to receptors on the epithelial cells that line the distal tubule of the nephron
5.
d.
Blood pressure control medication targets RAAS pathway : want 140 systolic
Drugs that limit production of angiotensin II (such as ACE inhibitors)
Less angiotensin II leads to vasodilation□
Less angiotensin II leads to drop in blood volume□
Both of these lowers blood pressure□
§
ARBs= angiotensin II receptor blockers
Same am't of angiotensin II but it can't bind to the receptors□
§
Aldosterone inhibitors
Work on kidneys to prevent reabsorption of water and ions□
§
e.
II.
Growth hormones produced by the anterior pituitary
Tropic hormones are hormones that target other endocrine glandsa.
b.
Stimulates protein synthesis and growth of muscles and connective tissuesc.
Stimulates production of insulin-like growth factors d.
Overproduction or underproduction of IGFs leads to body size differencee.
IGFs signals via RTKs
Growth factor binds to receptor1.
Dimerization2.
Phosphorylation cascade3.
Then transcription factors drive transcription of genes which leads to growth4.
f.
III.
Lecture 34- Hormones and the Endocrine System
Document Summary
Function of hormone signaling in physiology i. ii. iii. iv. v. Secretion of molecule from cell; in proximity if cells have receptor they to it. Signaling from dorsal lip to differentiate ectoderm to become nervous (lecture 29) Cell releasing signaling molecule and that cell itself has receptor to resp. Exclusive to nervous system; neurons form a synapse so that one neuro they will respond ous system respond euron is. Exclusive to nervous system; neurons form a synapse so that one neuro connected to second cell which can be gland, muscle or another neuron neurotransmitters which bind. Cell that has ability to release chemicals via vesicles into the blood. The collecting duct epithelial cells have receptors c. d. Hormone= secreted signaling molecule that travels through the blood, acts at a distan target cells. Hydrophilic and hydrophobic hormones use different signaling pathways i. ii. Hydrophilic: water soluble: stored in vesicles, stable in blood, bind to surfac.
