Download endocrine1

Wednesday, 14 September
Chapter 11 The Endocrine System
•
•
•
•
•
•
•
•
Classes of hormones
The adrenal gland
Fates of hormones
Control of hormone secretion
Hormone interactions (permissive effects)
Hypothalamus & Pituitary
The story of Aunt Dot
Endocrine disorders (lab next week)
1QQ # 4 8:30 am
1. What changes in hepatocyte metabolism are
produced by glucagon?
2. A) What advise would you give to a person who
is a reactive hypoglycemic and B) provide the
reasons for your advise.
3. Your patients plasma glucose level is 45 mg/dl.
A) What hormone is responsible for her rapid
heart rate, pale clammy skin, and irritability? B)
Why does she have a headache?
1QQ # 4 9:30 am
1. Explain in some detail how beta cells of the Islets of
Langerhans are affected by anticipating an excellent
meal.
2. A) Describe a situation that would lead to the activation
of the sympathetic nervous system. B) How does
sympathetic stimulation affect the secretion from beta
cells in the Islets of Langerhans? C) Why is this
beneficial for the person in terms of fuel supply?
3. After an overnight fast, a patient arrives for an Oral
Glucose Tolerance Test. The first blood sample (even
before ingestion of the Tru-Glu cola shows a plasma
glucose concentration of 150 mg/dl. A) Do you have
the patient drink the Tru-Glu? Why or why not? B)
What might you do next to determine what is “wrong”
with your patient?
Class activity
• 24 students were hormones and we
classified these hormones as amines,
peptides or steroids, considered how they
are synthesized and stored (or not) in
secretory cells, transported in the plasma,
the locations of their receptors in/on target
cells, the nature of the response in target
cells (latency & duration),
24 Hormones, 24 Students
•
•
•
•
•
•
•
•
•
•
•
•
Corticosterone
Testosterone
Estriol
Cortisol
Aldosterone
Estrone
TSH
ADH
CRH
TRH
PTH
LH
•
•
•
•
•
•
•
•
•
•
•
•
Glucagon
DA
EPI
NE
T3
Insulin
T4
GH
ACTH
FSH
EPO
CCK
Endocrine Organs (Table 11-1)
•
•
•
•
•
•
•
•
•
•
Hormone
Pituitary Gland
Paracrine agent
Thyroid Gland
Autocrine agent
Pancreas
Neurotransmitter
Gonads
Neuromodulator
Gastrointestinal Tract
Heart
Hormone: chemical messengers
carried by blood to target cells
Kidney
upon which they act.
Hypothalamus
Liver
Only those cells having receptors
Etc.
Can respond to a given hormone
3 Chemical Classes of
Hormones
• 1:
–
–
• 2:
• 3:
Amine hormones (from amino acid tyrosine)
Thyroid hormones
Adrenal medullary hormones (catecholamines)
Peptide hormones (peptides & proteins)
Steroid Hormones (derivatives of cholesterol)
Amine
Hormones
Fig. 11.01
Thyroid
Hormones
Not soluble
in plasma,
bound & free
Adrenal
medulla
NT
Catecholamines
soluble in
plasma
NT
Steroid hormones
Fig. 11.03
not soluble in plasma, not storable in vesicles
Bound & Free
Target cells have intracellular receptors.
Changes is gene expression.
Timecourse: longer latency, longer lasting
Peptide Hormones
Fig. 11.02
Soluble in plasma
e.g.
Beta cell
Guess peptide!
Cell surface receptors on target cells
Examples of
Peptide Hormones:
Insulin,
glucagon
prolactin,
erythropoietin,
parathyroid
hormone,
gastrin,
leptin,
growth hormone,
oxytocin,
vasopressin,
FSH,
LH,
GHRH, and
many more!
Know Table 11-2 p 319
•
•
•
•
•
Hormone class
Major form in plasma
Location of receptors
Signal transduction mechanisms
Rate of excretion / metabolism
Fig. 11.05
Steroids
Catecholamines
Adrenal Gland
Part of Sympathetic Nervous System
Hormones of the Adrenal Cortex
Androgens
DHEA
“Andro”
Glucocorticoids
Mineralicorticoid
What regulates the secretion of cortisol and aldosterone?
Fig.
Gonadal Steroids
11.06
(not adrenal cortex)
Estrogens
King DS, Sharp RL, Vukovich MD, Brown GA, Reifenrath TA, Uhl NL,
Parsons KA . Effect of oral androstenedione on serum testosterone and
adaptations to resistance training in young men: a randomized controlled
trial. JAMA 1999; 281(21):2020-8
What happens to hormones once released?
Be able to give
Examples.
Ex: Renin
Fast if free
Slow if bound
T4 to T3 and Testosterone to Estradiol
Factors that affect hormone secretion
Na+, K+, Ca++, etc.
NE, ACh, etc.
TRH, TSH, DA, etc.
Integrator!
Recall example:
beta cells of Islets of Langerhans
Secretion is usually pulsative, may be diurnal.
Fig. 11.08
Permissive
effect
Thyroid hormone stimulates production of beta-adrenergic receptors,
which increases the target cell’s responsiveness to EPI.