Download Endocrine ppt 2014

• The Endocrine System
(the second messenger system of the body)
I. Hormones:
A.Endocrine system produces
hormones (chemical messages)
that are important in
maintaining homeostasis &
regulating reproduction,
metobolic rate, growth &
development plus it mobilizes
the immune system.
I. Hormones:
B. A Hormone is a chemical
messenger produced by a cell
that causes specific changes
in the cellular activity of other
cells (target cells).
Overview of the Endocrine System
• The Role of Target Cell Receptors in Hormonal
Action
Figure 10-2
Overview of the Endocrine System
• Classes of Hormone Receptor
–Extracellular Receptors
• Located in cell membrane
• Targeted by
–Amino acid derivatives
–Peptides
–Eicosanoids
• Operates through a second messenger
such as cyclic-AMP
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Membrane
receptor
First messengers
(E, NE, peptide hormones,
and eicosanoids)
Hormonereceptor
complex
Cell
membrane
G protein G protein
(inactive) (activated)
Activates
adenylate
cyclase
Acts as
cAMP second
messenger
ATP
Cytoplasm
Nuclear envelope
Activates kinase
Nuclear pore
Nucleus
Alterations in
enzyme activity;
opens ion channels
TARGET CELL
RESPONSE
DNA
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10-3(a)
1 of 7
Membrane
receptor
G protein
(inactive)
Cell
membrane
Cytoplasm
Nuclear envelope
Nuclear pore
Nucleus
DNA
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10-3(a)
2 of 7
Membrane
receptor
Hormonereceptor
complex
G protein
(inactive)
First messengers
(E, NE, peptide hormones,
and eicosanoids)
Cell
membrane
Cytoplasm
Nuclear envelope
Nuclear pore
Nucleus
DNA
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10-3(a)
3 of 7
Membrane
receptor
First messengers
(E, NE, peptide hormones,
and eicosanoids)
Hormonereceptor
complex
Cell
membrane
G protein G protein
(inactive) (activated)
Activates
adenylate
cyclase
Cytoplasm
Nuclear envelope
Nuclear pore
Nucleus
DNA
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10-3(a)
4 of 7
Membrane
receptor
First messengers
(E, NE, peptide hormones,
and eicosanoids)
Hormonereceptor
complex
Cell
membrane
G protein G protein
(inactive) (activated)
Activates
adenylate
cyclase
Acts as
cAMP second
messenger
ATP
Cytoplasm
Nuclear envelope
Activates kinase
Nuclear pore
Nucleus
DNA
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10-3(a)
5 of 7
Membrane
receptor
First messengers
(E, NE, peptide hormones,
and eicosanoids)
Hormonereceptor
complex
Cell
membrane
G protein G protein
(inactive) (activated)
Activates
adenylate
cyclase
Acts as
cAMP second
messenger
ATP
Cytoplasm
Nuclear envelope
Activates kinase
Nuclear pore
Nucleus
Alterations in
enzyme activity;
opens ion channels
DNA
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10-3(a)
6 of 7
Membrane
receptor
First messengers
(E, NE, peptide hormones,
and eicosanoids)
Hormonereceptor
complex
Cell
membrane
G protein G protein
(inactive) (activated)
Activates
adenylate
cyclase
Acts as
cAMP second
messenger
ATP
Cytoplasm
Nuclear envelope
Activates kinase
Nuclear pore
Nucleus
Alterations in
enzyme activity;
opens ion channels
TARGET CELL
RESPONSE
DNA
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10-3(a)
7 of 7
C. Unlike exocrine glands that release
their products at the body’s surface
or into body cavities through ducts,
the endocrine glands do not secrete
substances into ducts instead their
hormones are secreted directly into
the surrounding extracellular space
& then diffuse into nearby capillaries
& are transported throughout the
body in the blood.
• D. The endocrine & nervous
systems often work together to
maintain homeostasis.
• E. The nervous system uses
neurotransmitters to act on cells
(which is usually short-lived) to
maintain homeostasis
• F. The endocrine system uses
hormones (whose effects last
longer than neurons) to
produce homeostasis.
• G. Hormones are classified into 2
basic categories: peptides
(including amino acids,
polypeptides, & proteins) &
steroids (complex rings of carbon
& hydrogen atoms) synthesized
by cholesterol. Ex. Gonadal
hormones & adrenocortical
hormones
Now we are going to look at each
gland individually:
• These next few slides will
be copied onto your paper
but do not have blanks to
fill in
• H. Pituitary – found in sella turcia
pea-size, gland. It is also called the
Master Gland. The Anterior
pituitary is hormone production
glandular portion. Ex. GH (bone &
muscle) & TSH (growth of thyroid)
• The Posterior pituitary is the neural
portion & extension of
hypothalamus. Ex. Oxytocin (milk
release) & ADH ( increase H O & BP)
Hormones of the Anterior Pituitary
• Pituitary Hormones and Their Targets
The Pituitary Gland
Figure 10-8
Hormones of the Posterior Pituitary
• I. Thyroid-Found in anterior throat
overlying inferior border of larynx.
One of the largest endocrine glands
& has a heavy blood supply. Ex.
Thyroid hormone T3 & T4 contain
iodine.
• J. T3-T4 Function to 1) accelerate
cellular metabolism, 2) tissue
growth, 3) skeletal reproductive &
nervous system development.
Calcitonin lowers blood calcium
levels.
• K. Thyroid gland unique because it
can store & slowly release its
hormones (up to 3 months worth)
Goiter=
iodine or T3 / T4
deficiency
L. Over active & under active thyroid can
cause severe disturbances. Ex. Hypothroid
syndrome – goiter or cretinism; Severe
hyperthyroidism – Graves disease
(autoimmune disorder that attacks the
thyroid)-most common.
M. Parathyroid – 4 to 8 embedded in
posterior aspect of thyroid gland. Ex. PTH
important in controlling level of calcium
in blood.
• N. Hyperparathyroidism- rare result of
PTH deficiency untreated death may
occur. Kidney stones, reflexes & skeletal
muscle weakness.
The Parathyroid Glands
Figure 10-11
• O. Adrenal glands almond size atop
the kidneys.
1. Adrenal Medulla (inner)epinephrine & norepinephrine
2. Adrenal cortex (outer)- Makes
steroid hormones called
Corticosteroids. Ex. Mineralcotricoids,
Glucocorticoids, & Androgens
Adrenal Medulla
 Produces two similar hormones
1. Epinephrine – aka Adrenaline;
associated w/the fight or flight
system. Axons stimulate hormone
secretion. Increases heart rate and
force, releases glucose, fatty acids
into blood, opens airways
Epinephrine
Adrenal Medulla
 Produces two similar hormones
2. Norepinephrine: aka.
Noradrenaline- associated w/the
rest & digest system. Is the
antagonist to epinephrine.
 These hormones prepare the
body to deal with short-term
stress
Norepinephrine – Rest & Digest
Adrenal Cortex-Mineralcorticoids
(mainly aldosterone)
 Produced in outer adrenal cortex
 Regulate mineral content in blood,
water, and electrolyte balance
 Target organ is the kidney
 Production stimulated by renin and
aldosterone
Adrenal Cortex:
 Glucocorticoids (including
cortisone and cortisol)
 Promote normal cell
metabolism
 Help resist long-term stressors
 Released in response to
increased blood levels of ACTH
Adrenal Cortex:
Sex hormones
 Produced in the inner layer
of the adrenal cortex
 Androgens (male hormones)
and some estrogen (female
hormones)
Adrenal Gland Response to Stress
• P. Pancreas- located partially
behind the stomach. Mixed gland
so has both endocrine & exocrine
capabilities.
• Islets of Langerhans-minute
clusters of cells that produce
pancreatic hormones. Ex. Insulinlowers blood sugar level &
Glucagon –increases blood sugar
P. Pancreas:
–Islet cells secrete insulin and
glucagon
•Insulin produced by beta cells
•Glucagon produced by alpha
cells
–Exocrine cells secrete enzymerich digestive fluid
• Actions of Insulin and Glucagon
–Insulin
•Lowers blood glucose concentration
•Increases glucose uptake, storage,
and use by target cells
•Targets liver, muscle, fat cells
–Glucagon
•Raises blood glucose concentration
•Increases glycogen breakdown and
glucose synthesis
•Targets liver cells
The Pancreas
Figure 10-13(a)
rd
3
Q. Pineal Gland: located in the
ventricle of the brain secretes
Melatonin associated w/sleep &
wake cycles.
R. Inhibits reproductive function
S. Protects neural tissue from free
radicals
T. Its’ complete function is still
unclear.
Q. Pineal Gland: located in brain
Thymus Gland
 Located posterior to the sternum
 Largest in infants and children
 Produces thymosin
 Matures some types of white
blood cells
 Important in developing the
immune system
Reproductive Glands: Ovaries
 Estrogen Hormone:
 Produced by Graafian follicles or the
placenta
 Stimulates the development of secondary
female characteristics
 Matures female reproductive organs
 Helps prepare the uterus to receive a
fertilized egg
 Helps maintain pregnancy
 Prepares the breasts to produce milk
Reproductive Glands: Ovaries
 Progesterone
 Produced by the corpus luteum
 Acts with estrogen to bring about
the menstrual cycle
 Helps in the implantation of an
embryo in the uterus
Reproductive Glands: Testes
 Interstitial cells of testes are hormoneproducing
 Produce several androgens (sex
hormones)
Reproductive Glands: Testes
 Testosterone (hormone) is the most
important androgen
 Responsible for adult male
secondary sex characteristics
 Promotes growth and maturation
of male reproductive system
 Required for sperm cell
production
Other Hormone Producing Tissues &
Organs:
 Parts of the small intestine Secretes
hormones to control digestion
 Parts of the stomach
–Kidneys Secretes three hormones
• Calcitriol—Stimulates calcium and phosphate absorption in
intestine
• Erythropoietin (EPO)—Stimulates red blood cell production by
bone marrow
• Renin—Enzyme that leads to angiotensin II that triggers
aldosterone from adrenal cortex
Other Hormone Producing Tissues &
Organs:
 Heart Specialized muscle cells secrete atrial natriuretic
peptide (ANP) to lower blood volume or blood pressure
• Adipose tissue (fat cells)
– Secretes leptin to control appetite
– Secretes resistin to reduce insulin response
 Many other areas have scattered
endocrine cells
Endocrine Functions of the Placenta
 Produces hormones that maintain
the pregnancy
 Some hormones play a part in the
delivery of the baby
 Produces HCG in addition to
estrogen, progesterone, and other
hormones
Patterns of Hormonal Interaction
• Kinds of Interaction between Hormones
–Antagonistic (opposing effect)
• E.g., calcitonin versus PTH
–Synergistic (additive effect)
• E.g., hGH and cortisol on glucose sparing
–Permissive effect
• E.g., epinephrine and thyroid hormones
–Integrative effect
• E.g., calcitriol and PTH on calcium levels
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Patterns of Hormonal Interaction
• Hormones Needed for Normal Growth
–Growth Hormone
–Thyroid Hormones
–Insulin
–Parathyroid Hormone
–Calcitriol
–Reproductive Hormones
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Patterns of Hormonal Interaction
• Hormones and Stress
• Stress—Any condition that threatens
homeostasis
• General Adaptation Syndrome to stress
–Alarm phase (sympathetic ANS
response)
–Resistance phase (glucocorticoid
response)
–Exhaustion phase (organ system failure)
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Development of the Endocrine System
 Most endocrine organs operate
smoothly until old age
 Menopause is brought about by lack
of efficiency of the ovaries
 Problems associated with reduced
estrogen are common
 Growth hormone production declines
with age
 Many endocrine glands decrease
output with age
• The information on the
next slides will be found
on your notes papers
II. Hormone Action
• C. Hormones activate target cells by 1 of
2 methods, depending upon the
chemical nature of the hormone:
• 1) peptide hormones {water soluble}
that bind to a receptor protein on the
plasma membrane of the cell. The
receptor protein, then stimulates the
production of a second messenger
(either cAMP or calcium.)
II. Hormone Action
• 2) steroid hormones {lipid soluble}
that diffuse through the plasma
membrane of the target cell & bind
to receptor protein present in the
cytoplasm that activates a DNA
segment that turns on specific genes
III. Control of Hormone Production
• A. Endocrine glands release
hormones in response to 1 or more
of the following stimuli:
•
1. Hormones form other
endocrine glands
•
2. Chemical characteristics of the
blood
•
3. Neural stimulation
III. Control of Hormone Production
• 4. most hormone production is regulated by
negative feedback system.
•
a. negative feedback: hormones
secretion is triggered by some internal or
external stimulus, then rising hormones levels
inhibit further hormone release resulting in
blood levels of many hormones varying only
within a very narrow margin.
IV. Communication b/w the
Hypothalamus & Pituitary Glands
• A. Communication b/w the
hypothalamus & the Anterior Pituitary
Gland occurs through chemicals that are
produced by the hypothalamus &
delivered to the ant. pituitary through
blood vessels.
IV. Communication b/w the
Hypothalamus & Pituitary Glands
• B. Communication b/w the
hypothalamus & the Posterior Pituitary
Gland occurs through neurosecretory
cells that connect the 2 glands.
V. Antagonistic Hormones
• A. When the body hormone levels drop
below normal homeostasis levels the
antagonistic hormones are secreted to bring
the body back to homeostasis.
• B. Ex. Bundles of cells in the pancreas called
the islets of Langerhans contain 2 kinds of
cells alpha (secrete glucagons) & beta
(secrete insulin) cells, that control blood
glucose concentrations by producing the
antagonistic hormones insulin & glucagon
VI. Major Endocrine Organs
Gland
Hormone Released
Target Tissue/Organ
Chief Function of
Hormone
Pineal
Melatonin
Various Tissues
Involved in daily
rhythms; possibly
involved in
maturation of sex
organs
Hypothalamus
Hypothalamic-releasing
& release-inhibiting
hormones
Anterior pituitary
Regulate anterior
pituitary hormones
Anterior Pituitary
Growth hormone (GH)
Soft tissues, bones
Mammary glnds
Ovary, testes
Gonads
Adrenal cortex
Thyroid
Skin & Melanocytes
Stimulates protein
synth. & bone growth
Prolactin; (LTH)
Luteininzing Hormone;
Follicle stimulating
hormone (FSH);
Adrenocorticotropic
hormone (ACTH)
Thyroid stimulating
(TSH)
MSH (Melanocyte
stimulating Hormone)
Stimulates milk
production & secretion
Reg. Oogenesis &
spermatogenesis
Same as LH
Stimulate secretion of
gluco-corticoids
Stimulate secretion of
T &T
VI. Major Endocrine Organs
Gland
Hormone Released
Target Tissue/Organ
Chief Function of
Hormone
Posterior Pituitary
Oxytocin
Uterus,mammary
glands
Uterine contractions,
release of milk
Increases water
retention & BP
Increases metabolic
rate; helps to result.
growth &
development
Lowers blood calcium
levels
Increases rate of cellular
metabolism
Raises blood calcium
levels
Thyroid
Antidiuretic Hormone
(ADH);
Thyroxin (T4)
Calcitonin
Triiodothyronine (T3)
Kidneys, sweat glands
All tissues
Bones, kidneys,
intestine
Bone
Parathyroid
Parathyroid hormone
(PTH)
Bones, kidneys,
intestine
Thymus
Thymosins
T lymphocytes
Stimulates
maturation of T
lymphocytes
VI. Major Endocrine Organs
Gland
Hormone Released
Target Tissue/
Organ
Chief Function of
Hormone
Adrenal Medulla
Epinephrine &
Norepinephrine
Cardiac & other
muscles
Stimulate “fight-orfight” reaction; raise
blood glucose lvl.
Adrenal Cortex
Glucocorticoids ex.
Cortisol
Mineralcorticoids
ex. Aldosterone
Androgens ex.
DHEA
All tissues
Kidneys
Sex organs, skin,
muscles
Pancreas
Insulin
Glucagon
Liver, muscles,
adipose tissues
Liver
Raises blood glucose
level
Increase
reabsorption of Na+
& to excrete K+
Stimulate onset of
puberty, female sex
drive
Lowers blood
glucose levels
Increases blood
glucose levels
Adrenal Glands
VI. Major Endocrine Organs
Gland
Hormone Released
Target Tissue/ Organ
Chief Function of
Hormone
Ovaries
Estrogen
Progesterone
Relaxin
Inhibin
Uterus
Uterus
Pelvis, cervix
pituitary
Testes
Testosterone
Inhibin
Testes
Pituitary
Regulates menstrual
cycle, secondary sex
characteristics.
Reg.menstrual cycle,
pregnancy
Dilates cervix & birth
canal
Inhibits FSH release
Regult.
spermatogenesis,
secondary sex
characteristics
inhibits FSH release
Gonads
• THE END!!!!