Chapter 11 Endocrine System
Endocrine System:
• The endocrine system is
made up of the cells,
tissues, and organs that
secrete hormones into
body fluids such as the
blood stream.
• What is its function?
• 1. To enable the
coordination of body
parts communicating
with each other.
• 2. To adjust to
constantly changing
conditions in the body
(homeostasis)
• What is the difference
between an endocrine
gland and an exocrine
gland?
• Endocrine secrets
products into body fluids
to affect target cells
• Exocrine secretes products
into ducts
• What is the tissue called
that hormones affect?
• Target cells
Hormone Action:
Steroid
• _______hormones
are lipid-soluble and can pass
through cell membranes.
• Their receptors are located in the target cell's
_______.
Nucleus
Hormone Action:
• The hormone-receptor complex binds with the
DNA
____________
and activates specific
genes
_________________
that, in turn, direct the
proteins
synthesis of specific _______________.
Non-steroid
• ______________________
hormones combine
membranes
with receptors in target cell _______________.
Hormone Action
• Binding
• The receptors have a ___________________
site
Activity
and a/an _____________________
site.
Hormone Action
• The hormone-receptor complex of
non-steroidal hormones (as first
messenger) triggers a cascade of
biological activity. What happens
after the complex forms?
• What is the name of the most
common second messenger?
• The desired change within the cell
occurs
• The most common second
messenger is cAMP
• Prostaglandins: are
locally-produced lipids
that affect the organ in
which they are
produced with a variety
of effects.
• What are some of these
effects?
• Relax or contract
smooth muscle,
stimulate secretion,
influence blood
pressure
Control of Hormonal Secretions
• There are several ways in which hormone release
is very closely regulated. All of these
mechanisms use negative feedback.
Control of Hormonal Secretions
• The hypothalamus
regulates the
Anterior pituitary gland’s
_____________
release of hormones
Nervous
• The _________system
influences certain
endocrine glands
directly with nerve
impulses.
• Other glands respond
directly to changes in
Blood’s
the ____________
fluid
composition.
• Explain in general how
negative feedback
works. How would this
function in the above
three situations?
Pituitary Gland:
• The pituitary gland is
attached to the base of
the brain and has a front
lobe called the
anterior and a rear
________
lobe called the
posterior
________.
Pituitary Gland
• Releasing hormones
from the ____________
hypothalamus
control the secretions of
the anterior pituitary
and are carried in the
bloodstream by
Hypophyseal portal veins .
__________________
Pituitary Gland
• The posterior pituitary
releases hormones into
the bloodstream in
response to nerve
impulses from the
hypothalamus
_____________.
•
Anterior Pituitary:
• The anterior pituitary
consists mostly of
epithelial
___________________
tissue arranged around
blood vessels and
enclosed in a capsule of
collagenous
connective
_______________tissue
.
Anterior Pituitary:
• How many hormones
does it secrete?
• 6
• What function do most
of them have in
common?
• Several stimulate other
endocrine glands
Anterior Pituitary:
• Growth hormone GH:
• What is the function of
GH?
• What hormones from
the hypothalamus
control the levels of
GH?
• What disorders may
result from a lack of GH
or too much GH?
• It stimulates cells to
increase in size and
divide more frequently
• GH-releasing hormone
and GH-inhibiting
hormone
• Dwarfism
• Gigantism
Dwarfism
Not Mr.
Reyes
Gigantism
Anterior Pituitary:
• Prolactin PRL:
• What is the function of
PRL?
• PRL stimulates and
sustains a woman’s milk
production
• What is its target tissue?
• Mammary glands
• What hypothalamic
hormones affect it?
• PR- Releasing Hormone
Anterior Pituitary:
• Thyroid stimulating
hormone TSH:
• What is the function of
TSH? (What is its
target organ?)
Stimulates the thyroid gland
• What hypothalamic
hormones affect its
release?
How are these hormones
from the hypothalamus
regulated?
As the level of circulating thyroid
hormones fall, the hypothalamus
puts out TRH. When the levels of
circulating thyroid hormones are at
correct level, the hypothalamus
stops putting out TRH.
Thyrotropin-Releasing Hormone (TRH)
Anterior Pituitary:
• Adrenocorticotropic
hormone ACTH:
• What is the target organ
for ACTH?
• What hormone does it
affect the release of?
• What is the name of the
hormone from the
hypothalamus that
controls ACTH’s release?
• Adrenal cortex
• Cortisol
• Corticotropin-releasing
Hormone (CRH)
Anterior Pituitary:
• Follicle stimulating
hormone FSH:
• What are the target
organs for FSH?
• Gonads
• What effect does it have
on the males?
• Testes start to produce
sperm
• On females?
• Ovaries begin to produce
eggs and to produce and
release estrogens
• Gonadotropin-Releasing
Hormones
• What hormone from the
hypothalamus affects its
release?
Anterior Pituitary:
• Luteinizing hormone
LH:
• What does it do?
• Causes ovulation and
formation of corpus
luteum in the ovary
which then begins to
release estrogen and
progesterone
Anterior Pituitary:
• Luteinizing hormone
LH:
• How is it different in
males than in females?
• In males it stimulates
the testes to release
testosterone
• In females stimulates
the follicle to release
the egg (ovulation).
Anterior Pituitary:
• Luteinizing hormone
LH:
• What is its controlling
hormone from the
hypothalamus called?
• Gonadotropinreleasing hormone
GnRH
Posterior Pituitary:
• The posterior lobe
consists of
Nerve
________________
fibers and supporting
Neuroglia
_________________
cells arising in the
hypothalamus.
• What structure actually
produces the hormones
released by the posterior
pituitary?
hypothalamus
Posterior Pituitary:
• Antidiuretic hormone
ADH:
• What is the function of
this hormone?
• What disorder may
result if enough ADH is
not secreted?
• ADH is a chemical that
decreases urine
production
• Diabetes insipidus
Posterior Pituitary:
• Oxytocin:
• What are the functions
of this hormone ?
• causes contraction of
the uterus walls during
childbirth
• milk-letdown during
breast feeding
Thyroid Gland:
• The thyroid gland is
located below the
larynx
_______________
and
consists of two broad
lobes
____________
connected by an
isthmus
________________.
Thyroid Gland
• The thyroid consists of
secretory parts called
___________________
follicles
filled with hormonestoring
colloid
_________________.
Thyroid Gland
• Thyroxine T4:
• How many iodines does it contain? 4
• Triiodothyronine T3: How many iodines? 3
• What is the function of these two hormones?
Regulate Metabolism
• How does TSH affect their release?
Stimulates the Thyroid Gland to release
• How do they affect the release of TSH?
Increased T3 and T4 levels cause the pituitary gland to stop releasing them
• What is a goiter and what may cause one?
Low levels of Iodine or thyroid inability to produce T3 and/or T4
Thyroid Gland
• Calcitonin:
• What is the function of
this hormone?
• What part of the
thyroid secretes it?
• Inhibits osteoclasts
(breakdown of bone)
and increases kidneys
excretion of calcium
and phosphate ions
resulting in lower
calcium levels in blood
• Parafollicular cells
Parathyroid Glands:
•
•
•
•
How many are there
and where are they
found?
Parathyroid hormone
PTH: What is the
function of this
hormone?
How does it achieve
this function?
• Four: located on the back
of the thyroid gland
• Increases blood calcium
levels
• Stimulates osteoclasts to
breakdown bone tissue
and release calcium in the
blood. Also makes kidney
conserve calcium
Parathyroid
• How is it related to
calcitonin from the
thyroid?
• PTH and Calcitonin have
opposite effects and
work together to
maintain the correct
levels of calcium ions in
the blood
Adrenal Gland:
• The adrenal glands sit atop
the __________________
kidneys
enclosed in a layer of
Adipose
tssue
__________.
• Adrenal medulla: The
adrenal medulla is made
up of modified
Postganglionic neurons
_____________________
___ that are connected to
the _____________
Sympatheic division of
the autonomic
nervous system.
Adrenal Gland:
• The hormones secreted
are the same as
neurotransmitters of this
system but are called
hormones because they
are secreted into the
body fluids and blood stream.
__________________.
Adrenal Gland:
• Epinephrine &
norepinephrine:
• What affect do these
have on the body?
• What are they secreted
in response to?
Similar effects to those of
the sympathetic division
of the autonomic nervous
system
• Stress and “fight or
flight” situations
Adrenal Gland:
• Adrenal cortex: The
adrenal cortex makes up
most of the adrenal
glands and consists of
___________cells
in
Epithelial_
three layers: an outer,
middle, and an inner
zone. Several groups of
hormones are secreted
by the cortex.
Adrenal Gland:
• Mineralocorticoids - aldosterone:
sodium ions by
• This hormone controls the levels of _______
conserving them in the _______.
kidneys
• This causes the conservation of water
Adrenal Gland:
• Why is this important?
• Which zone secretes
mineralocorticoids?
• Important in
homeostasis of the
body
• Outer zone
• Glucocorticoids:
• These hormones influence the metabolism of
glucose, protein, and fat in response to conditions
Stress
that __________
the body and require a greater
supply of _________________
in the bloodstream.
glucose
• How does negative feedback control the release of
these hormones?
Decrease in sodium
• What else can trigger their release?
Decrease in blood pressure
• Name an important glucocorticoid.
Cortisol
• Which zone secretes these hormones?
Adrenal Cortex
• Sex hormones: Sex
hormones, produced in
inner
the ____________zone,
are mostly of the
male
___________
type but
can be converted to
female
________________
hormones in the skin,
liver, and adipose
tissues.
• These hormones
supplement those
released by the gonads
and may stimulate early
development of
reproductive organs.
Pancreas:
• The pancreas secretes
hormones as an
__________________
endocrine
gland, and digestive
juices to the digestive
tract as an
exocrine___
___________
gland.
• Where is the pancreas
located?
Behind and beneath the stomach
Pancreas:
• Its endocrine portions
are the islets of
langerhans__that
__________
include two cell types-alpha
________
cells that
secrete glucagon, and
______________
cells
beta
that secrete insulin.
Pancreas:
increases
• Glucagon __________
the blood levels of
glucose by stimulating
the breakdown of
glucogen
_____________and
the
conversion of
noncarbohydrates into
glucose
___________________
____.
Pancreas:
• What controls the levels of
glucagons in the blood?
• Declining blood sugar
levels
• Insulin _________
decreases the
blood levels of glucose by
stimulating the liver to
glycogen
form ________increasing
__________________
protein
synthesis, and stimulating
adipose cells to store
________________.
fat
• What controls the blood
levels of insulin?
High blood sugars
Pineal Gland:
• The pineal gland, near
the upper portion of the
thalamus, secretes
melatonin
_________________-,
which is involved in the
regulation of
circadian
____________
rhythms
of the body.
Thymus Gland:
• The thymus gland, lying
between the lungs under
the
sternum
__________________,
secretes
thymosin
___________________
that affect production
and differentiation of T
lymphocytes that are
important in
______________.
immunit
y
Reproductive Glands:
• The ovaries produce
what two hormones?
• What does the placenta
produce?
• The testes produce
• Estrogen and
progesterone
• Estrogen, progesterone,
and gonadotropin
• testosterone
Digestive Glands Other Hormone
Producing Organs:
• The digestive glands
secrete hormones
associated with the
processes of digestion.
heart
• The ________________
secretes atrial natriuretic
peptide affecting sodium
and the kidneys secrete
erythropoietin
______________ for
blood cell production.
Stress:
• Factors that serve as
stressors to the body
produce stress and
threaten
homeostasis
__________________.
• Stress may be physical,
psychological, or some
combination of the two.
• What effects on the
body does physical
stress have?
Threatens the survival of
tissues
Stress:
• What does psychological
stress result from?
• Real or perceived dangers
• Responses to stress are
designed to maintain
homeostasis.
• The
_______________________
hypothalamus
controls the general stress
syndrome, which involves
increased sympathetic
activity and increased
secretion of which
hormones?
Cortisol, glucagon, growth hormone, and antidiuretic
hormone