Download Endocrine System

Endocrine System
Endocrine System—General Info
• Works WITH the Nervous system
• Main function is to produce hormones—
chemical messenger influencing other
tissues/organs.
• Differs from NS with regard to speed
– NS—body will make rapid adjustments to
changes
– ES—uses chemical messengers (hormones) to
affect change. Hormones travel via
bloodstream. Generally longer lasting.
Endocrine vs Exocrine glands
• Endocrine glands—secrete hormones directly
into the blood
– anterior pituitary
– thyroid
– adrenal
• Exocrine glands—deliver hormones into the
blood via tubes leading from the gland
– sweat glands
– salivary glands
– mammary glands
Major body processes regulated by
ES
• Reproduction
• Growth and development
• Maintaining homeostasis of electrolytes,
water and nutrients
• Regulation of cellular metabolism
Endocrine System—transport
hormones…
• Hormones travel through the blood and bind
to receptor proteins
– Steroid hormones (cholesterol derived)
• Are lipid soluble and cross the plasma membrane,
bind to receptors inside the cell and affect DNA
transcription.
– Animation
– Non-steroid hormones (protein based)
• Bind to specific membrane receptors and trigger a
signaling cascade inside the target cell which
activates necessary enzymes.
– Animation…
Target cells and controlling the ES
• Hormones travels through the entire body
via the blood, but only affect specific target
tissues.
• The body primarily uses negative feedback
loops to determine when to turn on/shut off
hormone production.
• Other ways the body controls the ES is
through the nervous system and biorhythms.
Negative Feedback loops
• Works like a thermostat in your house
to maintain a constant environment of
68oF.
– Turns on the furnace to produce
heat if the temperature is too cold
and off when the desired temp is
reached.
– Turns on AC to cool the house if
temp is too high and shuts it off
when back to the desired time..
http://www.endocrinesurgeon.co.uk/endocrine_conditions/What-is-negative-feedback.html
Homeostasis
• Negative
feedback loops
ensure the body
returns to
“normal”
conditions after
stimulus.
www.mdmaterials.com
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Glucose Regulation
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Biology, Campbell. 1987. pg 896
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ENDOCRINE REGULATION
A fuzzy balancing act
Receive, Reaction, Refine
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Endocrine Regulation
RECEIVE
Stimulation –
regulation of release /triggered release
– "sensory" input
• response to substance in the blood (Iodine,
glucose)
– hormonal regulation
• responds to upstream gland regulation (TSH,
LH...)
– neural regulation
• response short term stress
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Endocrine System
Regulation
• Hypothalamus
receives input and
reacts to stimulate
specific organs to
achieve the desired
effect.
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Pituitary Function
The MASTER gland
• The pituitary gland
secretes hormones that
regulate other glands in
the body and therefore
is referred to as the
Master Gland.
waukesha.uwc.edu
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Endocrine Regulation
REACT
Mechanism of Release
– Steroids
• Lipid soluble - readily enter cells
– stimulus leads to biosynthesis
– transport in blood assisted by carrier proteins
(serum albumin)
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Endocrine Regulation
REACT
Mechanism of Release
– Hormones that are NOT steroids or lipids
• Water Soluble –
interact with membrane receptors
– synthesized, packaged into vesicles via golgi
– vesicles migrate to and collect at release site
– activated release, exocytosis to dump contents
– typically Ca++ sensitive; regulate Ca++ /
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regulate release
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Endocrine Regulation
Endocrine System
Endocrine
System
REFINE
• Down Regulation-Negative Feedback loop
Blood Ca++ levels Decrease
stimulates
Parathymus
+
-
PH
Blood Ca++ levels Increase
Bone is
degraded
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Endocrine Regulation
Endocrine
System
REFINE
Removal of hormones
•The bulk of hormone is cleared by the liver and kidneys
•Only a small fraction is removed by target tissue
– protein and amine hormones bind to receptors and are
internalized and degraded
• action and elimination is usually quicker (minutes)
– Steroid and thyroid hormones are degraded after hormonereceptor complex binds to nuclear chromatin
• action and elimination are slower (hours-days)
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Endocrine Control
• Feedback system
for the control of
ovulation
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Biology:An Exploration of Life, McFadden&Keeton. 1995. pg 546
Endocrine Disorders
Endocrine
Problems
Dwarfism
Characteristics
-Short
stature
Short
stature,
can be caused by any one of more
(proportional)
than 200
conditions, most of which are genetic
and result in disproportionate body structure.
Cause
shortage of GH (hypophysial dwarfism)
or defective receptor (Laron Syndrome).
www.blogsmonroe.com
Endocrine Disorders
Gigantism
CharacteristicsExtreme height
(8-9 ft, proportional structures)
CauseExcessive GH during
development
Gigantism is extremely rare (only a few hundred known cases total).
Cause of excess of GH excess varies but often is linked to21Acromegaly
www.endotext.org
Endocrine Disorders
Endocrine
Problems
AcromegalyAcromegalyCharacteristics
Causeexcess
GH
in adulthood.joint aches
abnormal
bone
growth
thick coarse
oily skin
Usually
benign
adenoma impaired vision
excessive sweating
sleep apnea
abnormal menstruation
skin odor
erectile dysfunction
headaches
fatigue and weakness
decreased libido
enlarged lips nose and tongue
skin tags
www.addamsfamily.com
Endocrine Disorders
Hypothyroidisim
CharacteristicsCause
- Not enough thyroid hormone.
Fatigue, weakness, weight gain or
resistance to weight loss, course dry hair,
Hasimoto’s
dry roughdiseasepale skin, autoimmune
hair loss, cold disease
intolerance, muscle cramps and aches,
constipation, depression, irritability,
Medical
treatmentsremoval,
damage or
memory
loss, abnormal
menstruation,
pituitary
deficiency.
decreased
libido.
thyroid.about.com
High TSH
with low T3/T4.
subclinical
hypothyroidism
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www.datiskharrazian.com
Endocrine Disorders
–CausesHyperthyroidism
Characteristicspalpitations, heat
Graves’
Disease, autoimmune
disease
intolerance,
nervousness,
insomnia,
(antibodies
attach
to thyroid
and over
breathlessness,
increased BM, decreased
stimulate
T3 production)
menstruation, fatigue, fast heart rate,
trembling,
weight
loss,
muscle
Benign
tumornodule
(few
cells)weakness,
warm moist skin, hair loss, staring gaze.
out of regulation
pro.corbis.com
Low TSHtemporary swelling
Thyroiditishigh
T3/T4(postpartum)
levels
– of gland
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www.avondalevet.com
Endocrine Disorders
Cushing’s Disease
Characteristicscentral body obesity
glucose intolerance
Hypertension
menstrual irregularity
“Buffalo hump”
Osteoporosis
kidney stones
excess hair growth
emotional liability
“moon” face
Cause- Excess Cortisol
tumor of the lungs, pituitary or adrenal glands
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www.netterimages.com
ourlatinamerica.blogspot.com
Endocrine Disorders
DiabetesMost common Endocrine disorder
Consistent elevated blood sugar
Characteristics- frequent hunger, thirst, urination,
blurred vision, fatigue, weight loss, poor wound
healing, dry mouth, dry itchy skin, impotence,
recurrent infections. Erratic blood sugar.
– normal blood glucose: 80-120mg/100 ml,
– diabetes: as much as 600mg/100ml of blood
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www.malluworld.org
Endocrine Disorders
Diabetes
CausesType 1 -insulin deficiency
Type 2 -insulin resistance
hormone disturbance
Agromegaly
Cushing’s
Gestational diabetes- temporary condition caused
by pregnancy
placenta metabolizes insulin quickly.
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Endocrine Disorders
ENDOCRINE
DISORDERS
Adrenal disorders:
Adrenal insufficiency
Addison's disease
Congenital adrenal hyperplasia
Mineralocorticoid deficiency
Conn's syndrome
Cushing's syndrome
adrenogenital syndrome
Pheochromocytoma
Adrenocortical carcinoma
GRA/Glucocorticoid remediable
aldosteronism
Glucose homeostasis disorders:
Diabetes mellitus
Hypoglycemia
Idiopathic hypoglycemia
Insulinoma
Metabolic bone disease:
Osteoporosis
Osteitis deformans (Paget's
disease of bone)
Rickets and osteomalacia
Pituitary gland disorders:
Diabetes insipidus
Hypopituitarism
Pituitary tumors
Pituitary adenomas
Prolactinoma
Acromegaly, gigantism
Cushing's disease
Parathyroid gland disorders:
Primary hyperparathyroidism
Secondary hyperparathyroidism
Tertiary hyperparathyroidism
Hypoparathyroidism
Pseudohypoparathyroidism
Sex hormone disorders:
Disorders of sex development or
intersex disorders
Hermaphroditism
Gonadal dysgenesis
Androgen insensitivity syndromes
Hypogonadism
Gonadotropin deficiency
Kallmann syndrome
Klinefelter syndrome
Ovarian failure
Testicular failure
Turner syndrome
Disorders of Gender
Gender identity disorder
Disorders of Puberty
Delayed puberty
recocious puberty
Menstrual function or fertility
disorders
Amenorrhea
Polycystic ovary syndrome
Thyroid disorders:
Goiter
Hyperthyroidism and GravesBasedow disease
Hypothyroidism
Thyroiditis
Thyroid cancer
Tumours of the endocrine glands
not mentioned elsewhere
Multiple endocrine neoplasia
MEN type 1
MEN type 2a and
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Endocrine System
• Glands and the hormones they
produce…you will need to know these for
the test.
• Study earlier rather than later!
Review of Endocrine
System
• Quick review of
info…
Pituitary
• Known as the master gland as it is not only
responsible for many hormones, it also acts
as a regulator for other glands in the
endocrine system.
Pituitary Gland Hormones
• ADH
(Antidiuretic
Hormone)
–Responsible for
maintaining
water balance
in your body.
Pituitary Gland Hormones
• Oxytocin
–Responsible
for causing
uterine
contractions
during and
after birth.
Pituitary Gland Hormones
• GH (Growth Hormone)
–Causes growth in humans…big
surprise huh?
Pituitary Gland Hormones
• TSH
(Thyroid
Stimulating
Hormone)
–Influences
your
thyroid
gland
Pituitary Gland Hormones
• ACTH
(Adrenocorticotropic
Hormone)
–Regulates the
adrenal glands
Pineal Gland
Pineal Gland Hormone
• Melatonin
–Helps your
body adjust to
various
amounts of
daylight
Thyroid Gland
• Location:
Surrounds
windpipe
Thyroid Hormones
• Thyroxine
–If iodine is
present, it will
control the
metabolism of
glucose in the
body.
Thyroid Hormones
• Calcitonin
–Responsible
for depositing
blood calcium
into bones
Parathyroid Glands
• Location—
attached behind
the thyroid
– Years ago, they used to
remove the
parathyroids with the
thyroid if the thyroid
was damaged. This
lead to death in
patients…OOPS!
Parathyroid Hormone
• PTH (Parathyroid
hormone)
– Responsible for
pulling calcium
from bones and
depositing it into
the bloodstream.
Thymus Gland
• Location:
Longish gland in
the middle of
your chest.
Thymus Hormone
• Thymosin
–Assists the immune
system
Adrenal Glands
• Location:
Located right
on top of
kidneys
Adrenal hormones
• Aldosterone
–Maintain
blood salts
(primarily
Na+, K+)
Adrenal hormones
• Cortisone:
– Kicks in to help
body with long
term stress.
Adrenal hormones
• Epinephrine
– Kicks in when
body undergoes
short term stress
– Test-taking, car
accident, caught
in a lie…etc.
Pancreas
• Location:
Found right
behind the
stomach
Pancreas hormones
• Insulin
–Decreases
blood sugar
Pancreas hormones
• Glucagon
–Increases
blood sugar
Ovaries
• Small, almond shaped organs on
the ends of the fallopian tubes.
Ovary hormones
• Estrogen and
Progesterone
– Responsible for
sex characteristics
and controlling
the menstrual
cycle
Testes
• Testosterone
– Responsible for male secondary sex
characteristics
Other structures and the ES
• Heart
– ANP will increase the
Na+ excretion and
inhibit smooth muscle
contraction
Other structures and the ES
• Kidney
– Renin will cause
vasoconstriction of the
blood vessels (increases
blood pressure)
Other structures and the ES
• G.I. Tract
– There are many
polypeptide
hormones that act on
the GI tract.
– Most hormones will
increase intestine
motion and enzyme
production
Other structures and the ES
• Placenta
–HCG: maintains embryo growth
in first 90 days gestation
Other structures and the ES
• Placenta
–Estrogen and Progesterone help
maintain uterus health
–Lactogenic Growth hormone
help with milk production after
birth of baby
www.abbottdiagnostics.com.
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