Review #3
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Fill class evaluation forms on-line
Course overview and web review
Preview of test #3 and a student e-mail note
This course instructor is JP Advis DVM, PhD.
Other courses thought by this instructor are:
System Physiology and Endocrinology in Summer,
Endocrinology and Integrative Physiologygy + Lab in
Fall, and Animal Reproduction and Pathophysiology in
Spring.
Course main “punch line”
“story
line”
1
Basis of Endocrine Physiology
levels of
organization
Basis of Endocrine Physiology
structure
- function
The classical hormones fall into 3 categories:
1- derivatives of the aminoacid tyrosine
2- steroids, which are derived from cholesterol
3- peptides/proteins, which comprise the largest
and most diverse class of hormones.
2
Basis of Endocrine Physiology
homeostatic
regulation
Basis of Endocrine Physiology
integrator
center
homeostatic
regulation
afferent
“story line”
S
sensor
E
diagram for a control system
as that present in
a refrigerator
S
a “reflex arc”
a base for a
control model
negative feedback
“story line”
efferent
“story line”
E
effector
… if story lines are linked through an
integrator, then you have “control”…
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Specific tips for this course
•
Probably the single most important tip for this course is to prepare ten
sentences with what you consider are the main “punch lines” for each
lecture. You should rank your sentences in what you consider is a list
from most to less important ideas presented in each lecture. You
should also edit your sentences, for example, check if more than one
sentence might be combined into a better sentence. Make sure your
sentences cover the whole of the topic presented in the lecture.
•
Use this list to discuss it with fellow students and with your instructor.
•
Please be aware that in order to write a single, concise and informative
sentence you need to understand, rather than memorize, a piece of
information. To test yourself on how good you are doing, check if your
sentence used your own words or if you just borrowed part of a
sentence you read in your textbook. Consider that if you can not
write an idea into a single sentence, you probably have not yet
understood the material.
Websites “punch lines” ideas
1.- Some basic endocrine concepts and the methodologies used to study
a) definition of hormone and of endocrine, neurocrine, paracrine transmission
b) methodologies used in endocrinology (RIAs, RRA, ICC, hybridization, …)
c) how liposoluble and watersoluble hormones are made in general (SER vs RER)
d) hormone story line as a “trick” to think of steps involved in hormone function
2.- A “story line” table for all hormones. Things to look up in the table
a) hormones that are water soluble and those that are lipo soluble
b) hormones involved in hierarchies (gonadal, adrenal, thyroid, …)
c) hormones involved in metabolism (glucose, calcium, sodium, water, …)
d) inputs to endocrine glands and hormone effects on different organs
3.- “Reflex-arc” like-models and the “- Fb” for different hormones
a) inputs, integrators, -Fb in the control of different hormones (the refrigerator)
b) role of the hypothalamus in neuroendocrine control of the endocrine system
c) theoretical components of a control system, homeostasis and rheostasis
d) endocrine and neuroendocrine control and their disruption in pathology
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Websites “punch lines” ideas
4.- Some basic points on mechanism of action of liposoluble hormones
a) intracellular receptors mainly … but also membrane receptors (experiments)
b) effect on protein synthesis mainly, … but some also have membrane receptors
c) cys and trans elements involved in regulation at the promoter level .. integrator
d) permissive effects of some liposoluble hormones (e.g. T3-4, Cortisol, E2,…)
5.- Some basic points on mechanism of action of water soluble hormones
a) plasma membrane receptors … but they also have access to the genome
b) an ultimate effect on channels and enzymes underlies endocrine action
c) GPCR and Tyr-kinase links, different paths to protein phosphorylation
d) Permissive effects of some watersoluble hormones (e.g. Prl on LH receptors)
6.- Some basic points on the hypothalamic pituitary “connection”
a) hypothalamic anterior pituitary portal system (neurohormones, amplification)
b) hypothalamic posterior pituitary system (a good example of neuronal events)
c) the pituitary receives 2/3 of the outputs from PVN (a main brain integrator)
d) the median eminence as a final brain integrator site for endocrine function
Websites “punch lines” ideas
7.- Some basic points on anterior pituitary (AP) hormones
a) most AP hormones are tropic / trophic hormones that act on other endocrine glands
b) all AP hormones are controlled by hypothalamic hypophysiotropic neurohormones
c) the hypothalamic – AP unit acts as an integrator and amplification control unit
d) the hypothalamic – AP link is a vascular one since both tissues have different origin
8.- Some basic points on posterior pituitary (PP) and pineal hormones
a) PP hormones are neurohormones made in the hypothalamus and released in the PP
b) the hypothalamus and PP have the same embryological origin (as opposed to AP)
c) PP hormones are involved in water metabolism and myoepithelial contraction
d) AVP is also released in ME and acts in AP as a CRH, albeit by different mechanism
9.- AVP, OT, and melatonin
a) AP hormones (ACTH, GH, PRL, TSH, LH, FSH, MSH, ßEND)
b) PP hormones (AVP, OT) c) Pineal hormone (Melatonin)
(*)
(*)
(*)
(*) Expand story line for each of these hormones
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From the course website
10.- Calcium hormones
a) PTH
b) vitD
c) calcitonin
11.- Thyroid hormones
a) T3-T4
b) TSH
c) TRH
12.- Catecholamines
a) Cas and the ANS
b) Epi
c) Nepi / DA
(*) Expand story line for each of these hormones following an order such as: origin, stimuli, biosynthesis, release, target, action mechanism, effect, integration, others
S
E
From the course website
13.- GI hormones
a) Gastrin
b) Secretin
c) GLP-1
14.- Pancreas hormones
a) Insulin
b) Glucagon
c) Vit. D
15.- Steroid hormones
a) Mineralocoticoids (Aldosterone
b) Glucocorticoids (Cortisol)
c) Gonadal steroids (E2, P4, T)
(*) Expand story line for each of these hormones following an order such as: origin, stimuli, biosynthesis, release, target, action mechanism, effect, integration, others
S
E
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From the course website
16.- Glucocorticoids
a) Cortisol
b) ACTH
c) CRH
17.- Growth hormones
a) GH
b) IGFs
c) GHRH, SS
18.- Mineralocorticoids
a) Aldosterone
b) Renin
c) Ag II
(*) Expand story line for each of these hormones following an order such as: origin, stimuli, biosynthesis, release, target, action mechanism, effect, integration, others
S
E
From the course website
The start
19.- Integration overview
a) Redundancy
b) Reinforcement
c) Push-pull
d) Modulation
&
The end
20.- Complete table
21.- Complete feedbacks
22.- Complete summaries The story line and the feedback concepts
are the ABC of endocrinology. This is the
minimum you absolutely need to know.
The integration paradigms presented in
the final lectures are an attempt to provide
examples of “real life” examples were
multiple endocrine systems interact.
S
E
7
From the course website
23.- Sex development
a) Story lines
b) Feedbacks
c) Puberty
24.- Menstrual cycle
a) Story lines
b) Feedbacks
c) Menstrual cycle
Basic concepts from
these lectures were
used in the last two
lectures (biological
clocks and aging).
S
E
From the course website
25.- Food intake
a) Story lines
b) Feedbacks
c) Food intake
26.- Immunology
a) Story lines
b) Feedbacks
c) Stress response
Basic concepts
from these lectures
were used to
reinforce the
“balance” idea
behind integration.
S
E
Pro-inflamatory
response
Th1 / Th2
Anti-inflamatory
response
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From the course website
gonadal
hierarchy
27.- Biological Rhytms
a) Story lines
b) Feedbacks
c) Clocks & entrainment
E2
P4
receptor
28.- Reproductive Aging
a) Story lines
b) Feedbacks
c) Menopause
S
CS
E
GnRH
Young
AP
Basic concepts from
these lectures were
used to show how
homeostatic control
systems my fail with
age (“timing failure”).
Middle - Aged
gonad
S
E
E2 / P4
From the course website
Overview of the course based on some essay questions, or which would
be the questions of your final exam if such exam was an essay test. The
basic elements presented in this course were summarized in 3 main
thrusts:
a) story lines for each hormone involved in communication issues; b) feedback systems used to regulate the multiple hormone functions; and c) mechanisms of action by which enzymes / channels respond to hormones Having these elements in mind attempt to organize and to answer the
questions described below (each question deals with an issue used in the
final section of the course to review and to integrate all material covered in
this course). 9
From the course website
Control of food intake. The neuroendocrine control of
food intake involves neurotransmitters and
neuropeptides as inputs and outputs to an integrator
located in the PVN. From a conceptual view of nerve
cell connectivity and function, describe a possible
circuitry consisting of neuronal and endocrine signals
(to and from the PVN integrator) operating during the
two opposite metabolic conditions of feeding / satiety
(hypermetabolic condition) and fasting / starvation
(hypometabolic condition). From the course website
The menstrual cycle. Gonadotropin release is thought to be
controlled by an hypothalamic network of LHRH or GnRH
neurons, delivering its hypophysiotropic peptide to primary portal
vessels at the median eminence, which regulate gonadotropinproducing cells in the anterior pituitary. From a conceptual view of
nerve cell connectivity and function, describe a mechanism that
would allow an hypothalamic network of LHRH or GnRH neurons
(or two subnetworks, e.g. tonic vs phasic) to synchronize both its
tonic (or basal pulsatile gonadotropin release) and its phasic (or
preovulatory surge-like release of gonadotropin) operation, as it is
observed during the menstrual cycle. In addition, consider how
the pulsatile output of such hypothalamic network might affect the
anterior pituitary release of gonadotropins.
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From the course website
The stress response. The response to stress
involves neurotransmitters and neuropeptides
as inputs and outputs to an integrator located in
the PVN. From a conceptual view of nerve cell
connectivity and function, describe a possible
circuitry consisting of neuronal and endocrine
signals (to and from the PVN integrator)
operating during the stress response.
From the course website
An example of integration at the CNS level.
An anovulatory syndrome is associated with
endocrine events involving the interface
between stress and reproduction, as for
example in ballet dancers, marathon runners,
aging and psychological stress. Provide an
explanation for one of such anovulatory events
based on the three basic elements presented in
this course.
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From the course website
Another example of integration at the CNS level.
How do you envision that rhythm–related signals
may play a role in the neuroendocrine control of
reproduction and / or food intake (you may select
only one or compare both). Consider a potential role
involving SCN and entrainment signals as well as
hypothalamic and non-hypothalamic neuroendocrine
pathways participating in their control circuitry. A student e-mail after test 2
Hi,
Today after I had handed in my exam, I
noticed something that really frustrated me
and another student, who was walking out at
about the same time as me. There was a
student who had a pile of notes on the ground
and was paging through them looking for
answers for the exam. I don’t want to be
considered as someone to rat one out, but I
studied a lot for this exam and I am sure
everyone would have liked to have their notes
with them. Sorry but this got me really
upset and just wanted to touch base with you
on the matter.
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