Endocrine System
Major
Hormone
Secreting
Structures
The Endocrine System
• A system containing many glands that
secrete hormones that send messages in
order to maintain homeostasis
•A group of glands that work together with
the nervous system to coordinate all body
functions.
General Information
 Integrates and coordinates activities of
body cells.
 Maintains homeostasis by regulating:
1.
2.
3.
4.
metabolism and energy balance
water, electrolyte & nutrient balance
reproduction, growth and development
mobilization of body against stressors
 Hormones are secreted into interstitial

fluid diffusing into blood or lymph fluid.
Hormones act upon specific target cells.
An Overview of the
functions of the
Endocrine Glands
 Pituitary Gland – the master gland. Called
this b/c it controls all other endocrine glands
and b/c it produces the highest number of
different hormones compared to all other
endocrine glands.
 Hypothalamus – senses the hormone levels
in the blood, then tells the pituitary what to
do with either hormones it produces or by
direct nerve stimulation.
 Pineal Gland – produces a hormone
(melatonin) that helps you go to sleep.
 Thyroid Gland – produces hormones that
influence metabolic rate, decrease blood
calcium and increase bone calcium levels.
 Parathyroid Glands – produces a hormone that
increases blood and decreases bone calcium
levels.
 Thymus Gland – produces a hormone that
stimulates the immune response in children.
 Adrenal Glands – produces hormones help
prepare the body for stress and control blood
pressure.
 Pancreas – produces hormones that control
BSL (blood sugar level).
 Ovaries – produces hormones that control
female characteristics and menstrual cycle.
 Testes – produces a hormone that control
male characteristics and sperm production.
Todays Agenda
 Lab- Tagxedo, word cloud
 Class
Pick up crash course homework due wed
12/16
Take out note packet
Objectives: List all the glands in the endocrine system
Explain how hormones work with target cells.
Distinguish the difference between endocrine glands/ exocrine
glands
List the 4 different types of hormones
Checkpoint
1. List the functions of the endocrine
system.
2. List the major glands in the endocrine
system
3. What is the endocrine system and how
does it interact with the nervous
system?
Functions
 Maintain homeostasis
 Regulate metabolic rate
 Regulate growth and onset of puberty


and menopause
Regulate gametogenesis
Regulate pregnancy, childbirth, and
milk production
Endocrine Glands vs. Exocrine Glands
Endocrine Gland
Exocrine Gland
Exocrine gland:
 a gland that dumps molecules (ex. enzymes or
tears - not hormones) into ducts that generally
lead out of the body or into another organ. It is
a ducted gland (has tubes).
Exocrine glands are NOT part of the
endocrine system
Examples: salivary, milk, and sweat gland, tear
gland, stomach acid,
Sketch the diagram in your notes
Basic Structure of an exocrine gland:
The Endocrine System
Endocrine gland:
 a group of cells organized into a ductless
gland (no tubes) that secretes molecular
messengers (hormones) directly into the
bloodstream.
Glands secrete into blood or interstitial fluid
Examples: pituitary, adrenal and thyroid
***Horomones
Sketch the diagram in your notes
Basic Structure of an endocrine gland:
The Pancreas
 The pancreas is a gland that is part
endocrine and part exocrine.
 The endocrine part of the pancreas
secretes hormones.
 The exocrine part of the pancreas
secretes digestive juices including
enzymes.
Regulation & Communication
 Two systems for regulation:

endocrine system
 ductless glandular epithelium
a.secrete hormones directly into blood
 chemical travels to target tissue
 target cells have receptor proteins
b. slow, long-lasting response
c. Affects metabolic rate of cells
Regulation & Communication
 Two systems for regulation:

nervous system
 system of neurons
a. transmits “electrical” signal &
release neurotransmitters to
target tissue (action potentials)
b. fast, short-lasting response
c. Affects:3 types of muscles and glands
Regulation by chemical messengers
 Neurotransmitters released by neurons
 Hormones release by endocrine glands
endocrine gland
neurotransmitter
axon
hormone
carried by blood
receptor proteins
receptor proteins
target cell
Lock & Key
system
Hormone
 A chemical that acts like a messenger;
a protein or steroid that causes a
response in a target cell or organ
 About 50 hormones in the human body.
Powerful chemicals that work at low
concentrations
 Produced by endocrine glands, NOT
exocrine glands.
 Basal level =lowest level of hormones
Examples: ADH (Antidiuretic hormone),
testosterone, thyroxin
Classes of Hormones
 Steroids ex.
 Protein ex.
 Biogenic amine ex.
 Flcosonoids ex.
insulin
Agenda 12-16
 Check point
 Quiz
 Grade Quiz
 Notes on target cells and negative
feedback
Check Point
1. Explain the main difference between
the endocrine and exocrine glands
2. List the major difference between the
nervous system and the endocrine
system
3. What is a hormone?
12-17
 Finish looking up hormones action- 10
mins
 20 minutes of notes on target cells and
negative feedback
 10 mins for chart activity
 LAB: you may use your extra time to
finish any of the tasks above
 Finish Tagxedo,
concussion testing
Turn in HW Crash Course
Activity
 Using page 322-323 in your text book
 Fill out the information of chemistry of
hormones and steroid hormones and
non steroid hormones (10 mins)
Classes of Hormones
 Protein-based hormones

polypeptides
 small proteins: insulin, ADH

insulin
glycoproteins
 large proteins + carbohydrate: FSH, LH

amines
 modified amino acids: epinephrine, melatonin
 Lipid-based hormones

steroids
 modified cholesterol: sex hormones, aldosterone
Steroid Hormones
 Lipid soluble




(hydrophobic)
Synthesized from
cholesterol
Transported by a
protein in bloodstream.
Diffuses inside, binds
with DNA to transcribe
gene.
Full effect could be
minutes to days.
Animation –
Intracellular Receptor
Model
Protein Hormones
 Water soluble (hydrophilic)
 Binds to receptors on




target cell membranes. No
diffusion!
Causes second
messengers (cAMP) to be
activated inside cell.
Cascading effect: a single
molecule can activate
hundreds of second
messengers each which
activates thousands of
reactions.
Rapid response
Multiplier effect!
Animation – Second
Messenger cAMP
Target Cell
 Virtually all cells in the body are exposed to
circulating hormones but only certain cells
respond to a given hormone
 A cell that a hormone is specifically directed
towards.
Example: ADH works on the collecting
tube in the nephron.
 Target cells contain molecules on their
surface called receptors, to which hormones
can bind. Target cells do their job when
hormones are bound to their receptors.
Target Cells
 Located on surface of cell membranes
 Inside target cells
 Ex. Increases/decreases rate of cell
division
 Ex. Increases/ decreases synthesis and
secretion
of material
Target Cells
 Responsiveness can depend on:
1. Hormone concentration
2. Amount of receptors
a. up-regulation (increasing # of receptors)
b. down-regulation (decreasing # of receptors)
3. Influence of other hormones
Synergistic effect vs. Antagonistic effect
(Glucagon + epinephrine)
(Insulin and Glucagon)
Target Cells
 In order for a hormone to cause a
response, its’ shape must match the
shape of its’ target cell’s receptors.
 If the hormone and the cell’s receptors do
not match, the cell will not be affected and
no response by the cell will occur.
 It’s like the lock and key model
Target Cells
 Target cell receptors locations:
 Example:
http://www.ftmguide.org/images/receptors.gif
Control of Hormone
Secretion
Hormone Regulation
 Hormone secretion is controlled by:
1. Neural stimuli
2. Humoral stimuli (blood chemistry)
3. Hormonal stimuli
 Process used to regulate:
FEEDBACK LOOPS!
Negative Feedback
 Negative Feedback – is when an activity
alters a condition in the body, and this
triggers a series of events that reverses
the altered condition
Ex. Body temperature
- When body temp. goes up, we sweat
- When body temp. goes down, we shiver
Negative Feedback
Ex. Blood sugar levels
- When blood sugar goes up, insulin
lowers blood sugar
- When blood sugar goes down, glucagon
raises blood sugar
Homeostasis of Blood Glucose
Gland A secretes a
hormone that
stimulates gland B to
increase secretion of
another hormone. The
hormone from gland B
alters its target cells
and inhibits activity of
gland A.
Endocrine System Control
Feedback
Regulation of Blood Sugar
islets of Langerhans
insulin
beta islet cells
liver stores
glycogen
body
cells take
up sugar
from blood
pancreas
liver
high
blood sugar level
(90mg/100ml)
low
triggers
hunger
liver
releases
glucose
liver
pancreas
glucagon
islets of Langerhans
alpha islet cells
reduces
appetite
Agenda 12-18
 Check Point
 Chart Activity (4 people)
 Group Work (4 People)
 LAB:
Work on your Poster Presentation 
Check Point
 What is a target cell, and how do they
work?
 How does negative feedback work?
 Explain the difference between steroid
hormone action and protein horomone
action
Agenda 12-22
 Period 3/4 Waffle Day
House Episode
Secret Santa Exchange
Period 2
Quiz
Grade quiz
Chart activity time/ project time
Agenda 12/23
Happy Holidays
Time to work on your poster
presentations use this time to your
advantage!
1-4-16 Happy New Year
 Take out note packet pick up group work
activity, Gland list, endocrine system lab
 Notes on endocrine glands
 Group work activity
 Lab- Time to work on your poster
presentation
Check Point:
Meet with the person (Shoulder to Shoulder)
next to you take 5 mins to discuss what we
have learned about the endocrine system
Endocrine Glands
Section 39-1
Hypothalamus
The hypothalamus makes
hormones that control the
pituitary gland. In addition, it
makes hormones that are stored
in the pituitary gland.
Pituitary gland
The pituitary gland produces
hormones that regulate many of the
other endocrine glands.
Parathyroid glands
These four glands release
parathyroid hormone, which
regulate the level of calcium
in the blood.
Thymus
During childhood, the thymus
releases thymosin, which
stimulates Tcell development.
Adrenal glands
The adrenal glands release
epinephrine and nonepinephrine,
which help the body deal with stress.
Pineal gland
The pineal gland releases melatonin, which
is involved in rhythmic activities, such as
daily sleep-wake cycles.
Thyroid
The thyroid produces thyroxine, which
regulates metabolism.
Pancreas
The pancreas produces insulin and glucagon, which
regulate the level of glucose in the blood.
Ovary
The ovaries produce estrogen and progesterone.
Estrogen is required for the development of secondary
sex characteristics and for the development of eggs.
Progesterone prepares the uterus for a fertilized egg.
Testis
The testes produce testosterone,
which is responsible for sperm
production and the development of
male secondary sex characteristics
Hypothalamus
 Part of brain and attached to pituitary
 Controls pituitary secretions
 Secretes several hormones control the
release of other hormones known as
releasing hormones
Anterior Pituitary Gland
 nickname: Master gland


Controls the other
endocrine glands
Secretes 7 hormones
 Growth Hormone (GH) –
increases metabolic rate
 Too much – gigantism
 Too little – dwarfism
 Prolactin: initiate milk
production during
pregnancy
Posterior Pituitary Gland
 Comprises 25 % of gland
 Neurons secrete these hormones (2)
 Oxytocin: allows milk secretion and
contractions in uterus
 Antidiuretic hormone (ADH):decreases
urine
production
THYROID GLAND (Butterfly Shaped)
 Located anterior to the neck just
anterior to the larynx and trachea
 Regulates
Metabolism and energy balance
 Secretes 2 hormones:
 thyroxine: regulates metabolism
 Calcitonin:
Decreases Ca in the
blood

1-5-16
 Take out note packet and pick up lab
from front desk
 Notes on parathyroid to Pancreas
 Check Point:
1. Which gland is butterflied
shape and produces calcitonin?
1. Which gland releases growth releasing
hormone?
2. If you drink alcohol which hormone
will be inhibited?
Parathyroid Gland
-
-
Embedded in the back of the thyroid
Secretes parathyroid hormone which
controls metabolism of calcium and
phosphate
Adrenal Gland
 Releases hormones to deal with stress
-
Located on top of the kidneys
Secrete adrenaline which helps deal with
stress and accelerates the heart and
breathing rates
Adrenal Gland Cont.
 Cortex




Produces more than
2 dozen steroid
hormones
Aldosterone
Cortisol
corticosteriods
 Medulla



“fight or flight”
Made up of
postganglionic
neurons
Epinephrine and
Pancreas
 Located in abdominal cavity
 Secretes 4 hormones
 Insulin
 glucagon
Ovaries
Female gonads are called ovaries
produce gametes via meiosis
- Located in the pelvic region
- Secrete estrogen and progesterone
which regulate
female secondary
sex characteristics
-
Testes
Male gonads are called testes
- Secrete 2 hormones
- Located in the scrotum
- Secrete testosterone
which regulates male
secondary sex characteristics
- Inhibin- inhibits the release of
Menstrual cycle hormones
-
Pineal
 Rounded gland in midbrain region
 Secretes 1 hormone- Melatonin:
Controls the body’s internal clock
affects: jet lag, insomnia
Thymus
 Small mass located anterior to the
heart.
 Secretes 4 hormones
 Thymosin- promotes maturity of T
cells: destroys microbes
Heart
 Secretes 1 hormone
 Atrial matriuretic peptide (ANP)decreases blood pressure
Kidneys
 Secretes 2 hormones
 Renin: combines w/ other hormones

Regulates BP
Erythropoietin (EPO):new blood cells
Hormone Disorders
 Most involve the
HYPOSECRETION or
HYPERSECRETION of a
hormone.
 Hypersecretion most likely due
to a tumor on the gland.
 Few cases involve faulty
hormone receptors or reduction
of receptors.
Diabetes





D. Insipidus
“tasteless”
Hyposecretion of
ADH
Extreme thirst
Dehydration
Excessive
urination






D. Mellitus
“Sweet tasting”
Hyposecretion of
insulin (type 1)
Blood glucose
build up
Weight loss
Excessive
urination
Sweet smelling
breath
Diabetes Mellitus
 Group of related disorders that result in
hyperglycemia
Type I
 Juvenile
 Insulin cells are destroyed by own
immune system
Type II
 Adult
 Loose ability to respond to insulin
Diabetes Insipidus
 Under secretion of ADH
 Symptoms: lots of urine, thirst,
dehydration
 Bed wetting in children
 Treatment:
Injection/
nasal
spray
Grave’s Disease
Hyperthyroidism
Symptoms:
Intolerance to heat
Heart palpitations
Sensitivity to light
Weight loss
Appetite increase
Easily agitated
Protruding eyes
Hypothyroidism or Myxedema
Early symptoms:
Being more sensitive to cold
Constipation
Depression
Fatigue or feeling slowed down
Heavier menstrual periods
Joint or muscle pain
Paleness or dry skin
Thin, brittle hair or fingernails
Weakness
Weight gain (unintentional)
Cretinism – lack
of thyroxine
during fetal life
Late symptoms, if left untreated:
Decreased taste and smell
Hoarseness
Puffy face, hands, and feet
Slow speech
Thickening of the skin
Thinning of eyebrows
Acromegaly
 hypersecretion of GH during
adulthood, usually a pituitary tumor.
Only certain bony regions in face, feet
and hands are affected by excessive
bone deposition.
Goiter
Iodine deficiency causes thyroid to enlarge as it
tries to produce thyroxine
+
tyrosine
+
iodine
AP Biology
✗
✗
thyroxines
Gigantism
Hypersecretion of GH during childhood
If left untreated, acromegaly will occur.
Pituitary Dwarfism
 Hyposecretion of


GH, can be
corrected by
giving GH
hormone
Must be diagnosed
before growth
plates have closed.
Can be tumor
related
Gigantism vs. Dwarfism
Adrenal Gland Disorders





Cushing’s
Excess Cortisol
Weight gain
Rounded moon face
Fatty hump on back
Fatigue





Addison’s
Hyposecretion of
glucocorticoids and
mineralcorticoids
Mouth lesions
Hypoglycemia
Strange skin
pigmentation
Salt craving
Adipose and Leptin
 Leptin is hormone that

causes you to feel full.
Obesity may be due to
no leptin or not enough
or hypothalamus
becomes leptin
resistant.