Hormone

Report
Anatomy and
Physiology
The Endocrine System
 The
endocrine system includes anything that
secretes hormones directly into body fluids.
 Endocrine
glands include: the thyroid, parathyroid,
adrenal, kidney, hypothalamus, pituitary, pineal,
pancreas, ovaries, testes, and thymus glands.
 The
function of the endocrine systems is to regulate
metabolic pathways (chemical rxns, electrolyte
balance, membrane transport, reproduction, &
digestion) by secreting hormones.
http://www.worsleyschool.net/science/files/ho
rmones/mainpic.gif
Some terms:
 Hormone:
a biochemical that affects a specific
metabolic pathway in another cell.
 These
are secreted into body fluids & blood.
 These
are mostly steroids and made from
cholesterol but some are amines, peptides,
proteins, and glycoproteins.
 Target
cells (or organs): cells or organs that receive
the hormone (cell that is affected). These cells have
binding sites (a.k.a. receptors) for specific
hormones.
 Hormones
are placed in 2 groups: Steroid hormones
and Nonsteroid hormones.
 Steroid
Hormones: lipid soluble, meaning they easily
pass (diffuse) thru membranes. These are formed
from cholesterol usually.
 Nonsteroid
hormones must bind to receptors of
target cells (do not diffuse thru membranes). These
are amines, peptides, proteins, and glycoproteins.
Hormonal Secretion Control:
 This
is done by negative feedback control.
 Mechanism
that regulates the production of
hormones based on the accumulation of
another substance along a metabolic
pathway.
For example:
 The adrenal gland produces chemical A
which continues a pathway:
A BC D E
 When
E is accumulated, it prevents (or
inhibits) the adrenal gland from producing A.
This is a negative feedback mechanism.
http://faculty.clintoncc.suny.edu/faculty/Michael.G
regory/files/Bio%20102/Bio%20102%20lectures/e
ndocrine%20system/cortisol.gif
http://www.google.com/imgres
The Endocrine
Glands and
Their Hormones
The Pituitary Gland:

found in the base of the brain

has 2 parts: anterior and posterior (based on the lobe of the
brain in which it is found).

controlled by the hypothalamus (by releasing hormones)
http://images.encarta.msn.com/xrefmedia/aencmed/targets/illus
/ilt/T012393A.gif
The Pituitary Hormones:
Anterior Pituitary Hormones:
 Growth Hormone (GH): stimulates growth of
cells (increase in size & cell division).
 Prolactin
(PRL): stimulates and sustains the
milk production in new mothers.
 Thyroid-Stimulating
Hormone (TSH): controls
thyroid gland secretions and is partially
regulated by the hypothalamus.
Anterior Pituitary Hormones (cont’d):
 Adrenocorticotropic hormone (ACTH):
controls the hormone production of the
adrenal cortex. Stress may increase ACTH.

Follicle-stimulating hormone (FSH) and
luteinizing hormone (LH): are released in
the gonads (testes and ovaries). These are
called gonadotropins.
The Posterior Hormones:
 Antidiuretic hormone (ADH): decreases urine
production by regulating the amount of
water the kidneys excrete; therefore,
regulating [water] in body fluids.
 Oxytocin
(OT): considered an antidiuretic; it
stimulates the uterine muscles to contract
(causing contractions & birth), lactation b/c
it stimulates milk-producing glands, and milk
ejection.
The Thyroid Gland and its hormones:
 This
is located on both sides of the larynx and in front
of the trachea.
 Thyroxine
(a.k.a. T4 or tetraiodothyronine) has 4
atoms of iodine and Triiodothyronine (a.k.a. T3) has
3 atoms of iodine (is 5 times stronger). Both regulate
the metabolism of carbs (stimulate their use),
proteins (stimulate their production), & lipids
(stimulate their breakdown).
 Calcitonin:
not technically a thyroid hormone (b/c
of the location of production). This regulates the
[Ca] and [phosphate ions] in the blood.
Thyroid
http://stb.msn.com/i/D8/DF6013611CDFDC22A8FB8E28C1DFF.jpg
The Parathyroid Glands and their hormones:
 These
4 are found on the thyroid gland.
 These
secrete parathyroid hormone (PTH): increases
blood [Ca++] and decreases blood [phosphate ion],
affecting the kidneys, bones & intestines. This works
with calcitonin and is regulated by the [ ] of these
ions in the blood.
http://stb.msn.com/i/BD/F8BC26E3251ABD2F3FEA4
607A1D47.jpg
The Adrenal Glands and their hormones:
 This
is located on top
of the kidneys and
contains 2 portions:
 adrenal
medulla
(central portion)
 adrenal
portion).
cortex (outer
http://www.massgeneral.org/cancer/crr/types/endocrine/images/
adrenal_gland.jpg
The Adrenal Cortical Hormones:

Aldosterone: regulates the [mineral] in the
blood, stimulating water retention and
sustaining b.p. and volume.

Cortisol: a.ka. hydrocortisone, affects
glucose, protein & fat metabolism.

Adrenal Sex Hormones: in males, a.k.a.
adrenal androgens; in females, a.k.a.
estrogens. These supplement sex
hormones & stimulate gonad
development.
The Adrenal Medulla Hormones:
 Epinephrine
(a.k.a. adrenaline) and
norepinephrine (a.k.a. noradrenaline) are
released simultaneously. These increase the
heart rate, increase heart contractions,
increase breathing rate, increase b.p.,
increase blood glucose levels, & decrease
digestion causing the typical “fight or flight
reaction”
The Pancreas and its Hormones:
 This is found by the
stomach and has 2
functions: exocrine
gland (secretes
digestive juices) and
endocrine (releasing
hormones).
 The endocrine
section contains
groups of cells known
as the Islets of
Langerhans which
contain alpha cells
(secrete glucagon)
and beta cells
(secrete insulin).
http://www.pancreatic.org/atf/cf/%7BA69EE36
7-5C5C-4B26-A09464E9EA47D990%7D/image001.jpg
The Pancreatic Hormones:
 Glucagon: produced by alpha cells;
stimulates the breakdown of glycogen and
amino acids. It raises [blood sugar] and is
regulated by a low blood sugar
(hypoglycemia).
 Insulin:
produced by beta cells; stimulates the
liver to make glycogen, promotes the
transport of glucose into cells, stimulates
protein synthesis and stimulates fat storage;
thus, it decreases [blood sugar] and is
regulated by a high blood sugar
(hyperglycemia).
Blood
Sugar
Regulation:
http://www.endocrineweb.com/images/su
gar.gif
Other
Endocrine
Glands
Pineal Glands:
 This is found in the
brain on the upper
portion of the
thalamus.
 This
secretes
melatonin which
regulates circadian
rhythms (response to
light and dark
conditions of the
environment. These
rhythms dictate sleep
patterns & seasonal
cycles of fertility in
some mammals.
http://training.seer.cancer.gov/module_anatomy/images/illu_pituitary_
pineal_glands.jpg
Thymus Gland:
 This is found between the
lungs (shrinks with age).
 This
secretes thymosins
which regulate the
production &
differentiation of white
blood cells, specifically
T cells (T lymphocytes)
http://www.besthealth.com/besthealth/bodyguide/reftex
t/images/Thymus_spleen.jpg
Reproductive Glands:
 Ovaries: produce estrogens & progesterone
 Testes: produce testosterone
 Placenta: produces estrogens, progesterone
& gonadotropin
http://www.nlm.nih.gov/medlineplus/enc
y/images/ency/fullsize/17122.jpg
http://www.actionhealthinc.org/teenzone/ima
ges/female.jpg
http://www.malecontraceptives.org/methods/im
ages/heat.jpg
 Heart:
produces atrial natriuretic peptide
(stimulates urinary Na secretion).
 Kidneys:
produce erythropoietin (stimulates
the production of rbc’s).
http://www.nhlbi.nih.gov/health/dci/images/heart_interior.gif
http://www.healthline.com/blogs/health_observances/upl
oaded_images/kidney-713543.jpg
Stress and Health:
 Stress
is defined as a
condition that causes
change in the internal
environment (a
physiological response
that alters homeostasis).
A
stressor is a factor that
causes stress.
http://www.google.com/imgres
Stress and Health:
There are types of
stressors:
 physical which can be
temperature changes
internally or externally,
[O2] changes, injury,
illness (infections),
exercise, noise, etc.
 psychological factors
which include emotions,
feelings (anger, joy, fear,
grief, anxiety, depression,
etc.), thoughts, losses,
unpleasant and pleasant
encounters, and sexual
arousals/encounters.
http://www.google.com/imgres
Response to stress: These are physiological
responses, called general stress syndrome,
which is an adaptation to general stress.
 This
is controlled by the hypothalamus which
activates fight or flight rxns (increases
epinephrine output).
The physical responses include:
 Increased
[blood glucose] levels
 increased
heart rate
 increased
rate of breathing
 increased
b.p.
 air
passage dilation
http://www.google.com/imgres
 Other
hormones are increased in output as
well: glucagons, GH (both increase use of
energy sources) and ADH (decrease urine
output, conserving water, & maintaining
blood volume).
 In
addition, cortisol is increased which
decreases the # of lymphocytes (increasing
risk of infection/illness by lowering
resistance and increasing the risk of high
b.p., GI ulcers and atherosclerosis).
 Look
up online or in text!
 Know the following:
dwarfism, gigantism, acromegaly, diabetes
insipidus, goiters, Grave’s disease, cretinism,
exophthalmos, tetany, Addison’s disease,
Cushing’s syndrome, diabetes mellitus, ketosis,
polyuria, polydipsia, polyphagia, insulin
resistance, and menopause.

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