ENDOCRINE SYSTEM
January 27-28, 2016
Endocrine Disorders
Gigantism
excess growth hormone during childhood
Endocrine Disorders
Acromegaly
excess growth hormone after closure of
epiphiseal plates
Endocrine Disorders
Growth Hormone Deficiency
(pituitary dwarfism)
underproduction of growth hormone as a child
Endocrine Disorders
Grave’s Disease
excess thyroid hormones
Endocrine Disorders
Hypothyroidism
underproduction of thyroid hormones
Endocrine Disorders
Cushing’s Syndrome–
excessive cortisol
Endocrine Disorders
Addison’s Disease–
underproduction of cortisol
Endocrine System
Controls and regulates the body through hormones
• Hormones are chemical messengers that travel through
the blood to one or more target organs
• Major processes regulated include
• Growth
• Reproduction
• Stress response
• Water / nutrient / electrolyte balance
• Metabolism
Hormones
Are produced by a gland
travel through bloodstream
bind to /enter cells of target organ(s)
change cell function of target organ(s)
Hormones
How do hormones change target cells?
• Change membrane permeability / electrical state
• Promote synthesis of certain proteins
• Activate or inactivate enzymes
• Stimulate mitosis (cell division)
Major Types of Hormones
1. Steroids
• Diffuse across cell membrane and nuclear membrane (lipid-
soluble!)
• Bind to a receptor protein in nucleus
• Receptor – steroid complex increases transcription of certain
genes, resulting in the production of certain proteins
Examples: sex hormones, corticosteroids
Major Types of Hormones
2. Amino-acid based (amines, peptides, and proteins)
• Bind to a receptor protein on cell membrane
• Receptor starts a series of events that produce a specific
change in the function of the cell
Examples: insulin, oxytocin, GH, melatonin, calcitonin, etc.
Non-steroidal hormones
always use second
messenger molecules –
molecules that are
produced within the target
cell as a result of the
binding of the hormone
with the receptor
Quick Review
1. What are the two types of hormones, and what is the
major difference between them?
• steroids – can cross cell membrane, bind to receptor
inside nucleus
• nonsteroidal (amino-acid based) – cannot cross cell membrane, bind to
receptor on cell membrane
2. Which type of hormone produces second messenger
molecules?
• Nonsteroidal (amino-acid based) produce second messenger
molecules. After binding to a receptor on the cell membrane, an
enzyme catalyzes the production of the second messenger, which in
turn, brings about the cellular changes.
Quick Review
Wait a minute, then show with fingers
3. Which of the following is NOT one of the major
processes controlled by hormones?
a.
b.
c.
d.
Body coordination
Growth and development
Electrolyte balance
Cellular metabolism
Quick Review
Wait a minute, then show with fingers
4. Which of the following is NOT a typical effect of
hormones on target cells?
a. Mitosis is stimulated
b. Enzymes are activated
c. Proteins are synthesized
d. Cellular mutations develop
Control of Hormone Release
Hormones regulate body functions by producing specific
effects in target cells. Disorders can develop if too much or
too little hormone is secreted.
How does the body determine when/how much hormones to
release?
The release of nearly all hormones occurs as part of
negative feedback mechanisms.
Review: Compare and Contrast Negative
and Positive Feedback Mechanisms
Negative feedback mechanisms maintain the levels of a
variable (e.g. body temperature) within a narrow range.
 The output acts to change the direction of the stimulus.
 Example: Body temperature regulation
Positive feedback mechanisms dramatically increase a
variable (e.g. contractions) until a certain endpoint (e.g.
childbirth) is reached.
 The output acts to increase the stimulus
 Example: labor contractions
Example: Blood Sugar Regulation
Example:
Blood
Calcium
Regulation
Stimulus of Hormone Release
Even when glands are part of a negative feedback loop, there
must be some stimulus that triggers the release of hormones.
What was stimulus in the previous two examples?
Blood sugar level and calcium level. Non-hormonal
chemicals like these are called humoral stimuli.
There are three basic types of stimuli that cause the release of
hormones.
1. Humoral stimuli (non-hormone chemicals in the blood
and body fluids)
2.
3.
??
??
Stimulus of Hormone Release
Even when glands are part of a negative feedback loop, there must
be some stimulus that triggers the release of hormones.
What was stimulus in the previous two examples?
Blood sugar level and calcium level. Non-hormonal
chemicals like these are called humoral stimuli.
There are three basic types of stimuli that cause the release of
hormones.
1. Humoral stimuli (non-hormone chemicals in the blood and
body fluids)
2. Hormonal stimuli (other hormones – e.g. TSH, ACTH, FSH,
LH, PRL)
3. Neuronal stimuli (e.g.
Often glands respond to multiple
release of ep. /
stimuli (Ex: release of
nor-ep by adrenals)
aldosterol by adrenal glands)
Example of
Multiple
Stimuli:
Aldosterone
release
Diabetes Mellitus
Diabetes is a disorder characterized by abnormally
high levels of blood sugar (hypoglycemia)
Facts
• 347 people world-wide have diabetes.
• 7th leading cause of death in the US
• Leading cause of kidney failure, non-traumatic limb
amputation, and adult-onset blindness in US
• Major contributor to heart attack and stroke
Major Types of Diabetes
Type I (juvenile-onset)
• Occurs when the immune system attacks the insulinproducing cells of the pancreas, which means that little to no
insulin can be produced
• Genetic risk factors and environmental triggers
• ~5% of cases
Gestational diabetes occurs in ~5% of
•Type II (adult-onset)
pregnant women. Disease usually
disappears when pregnancy is over.
• Too little insulin is produced and/or cells become insulin-
resistant
• Obesity and inactivity are major risk factors, but genetics
also play a role
• ~90% of cases
Symptoms of Diabetes
Symptoms develop more
rapidly and are more
severe for Type I
diabetes.
Additional symptoms
found with Type 1
diabetes include:
• Acetone smell to breath
• Lethargy
• Deep, labored breathing
Complications of Diabetes
Hyperglycemia (high blood sugar) damages blood vessels and nerves,
leading to the major complications listed below.
Note: it’s the high blood sugar that causes the damage. The better blood
sugar is controlled, the less complications will arise.
Treatment of Diabetes
•Type I diabetes
• Healthy diet and exercise
• Blood glucose monitoring (multiple times a day)
• Insulin injections (multiple times a day) or pump
•Type II diabetes
• Weight loss
• Healthy diet and exercise
• Blood glucose monitoring
• Medicines to increase the body’s production of insulin
• Medicines to combat insulin resistance and help glucose enter cells
• Insulin injections
Many new treatments in the development stage,
including
• Pancreas transplants
Watch me!
• Stem cells
• More convenient glucose monitoring and insulin
delivery
Game!
• Round 1:
• Bet on 1, 2, 3, 4, 5, or 6
• On your mark …
• Round 2:
• Bet on blue, yellow, gray, green, or red.
• Ready, set, go!
Closure
• What were our objectives, and what did you learn about
them?
• What was our learner profile trait and how did we exemplify
it?
• How does what we did today address our unit question?