Lesson 2.3: Communication
 Neurons
use impulses to relay
messages from throughout the
body
 What other means do
humans have to provide
communication within in the
body
Chemical Communication using
Hormones
Essential Question
1.
What is a hormone?
Chemical Communication

The glands that secrete hormones are
either
 endocrine

glands
exocrine glands
.

When imbalances in hormone levels occur,
diseases or dysfunctions can result.
Exocrine Glands
 excretes
its essential product by
way of a Duct to some
environment external to itself,
either inside the body or on a
surface of the body.
Exocrine Glands
Sweat
glands
Salivary glands
Mammary glands
Pancreas
Liver
Endocrine System
Endocrine glands release more than 20 major
hormones directly into the bloodstream
without the use of ducts
 or by diffusion into surrounding tissue where it
affects the target cells


http://kidshealth.org/teen/your_body/body_ba
sics/endocrine.html -Discusses the various
glands and their functions
Endocrine System








Hypothalamus
Pituitary gland
Pineal body
Thyroid
Parathyroid
Pancreas
Adrenals
Ovaries and Testes

http://www.nlm.nih.gov/medlineplus/ency/anatom
yvideos/000048.htm
Hypothalamus
 Present
in the
brain and
produces
releasing
hormones and
inhibitory
hormones and
controls
information to
the pituitary
Pituitary gland
a small pea sizes gland
located in the center of the
skull, acting as the Master
Gland controlling
 Releases a number of
hormone that activate
other glands
 List some of them in
Journal noted in this video


Pituitary gland video
medline plus
Pineal Body
A structure of the
diencephalon produces several
hormones including Melatonin
to influence sleep-wake cycles
and sexual development.
 Connects the endocrine
system with the Nervous
system by converting nerve
signals from PNS to hormone
signals

Thyroid Gland
Located in the neck ,
 Secretes T3 and
Thyroxine (T4) that
regulates metabolism
where food is broken
down and converted
to heat or energy
 Secretes Calcitonin
that plays a role in
calcium balance

Thyroid Feedback Loop








hypothalamus senses low levels of T3 and T4Sends message of Thyrotropin-releasing hormone(TRH)
to Pituitary gland to produce TSH
Pituitary send message to Thyroid of TSH
Thyroid get message increases production and release of
T3, T4
Blood levels rise.
Hypothalamus receives Info of increase levels
Communicates this to Pituitary
Pituitary sends message to thyroid to slow production.
CYCLE CONTINUES
Parathyroid
4 pea-sized glands on the
thyroid gland in the neck.
 name is similar to thyroid but
glands are completely different.
 Produce parathyroid hormone
(PTH), helps balance calcium
and phosphorous. Which play
an important role in muscle
contraction and nerve impulse

Pancreas
 Long
narrow gland
located in the
abdomen behind the
stomach and in front
of the spine
 Secretes insulin,
glucagon to help
regulate the body's
use of sugar
Adrenal glands


2 small glands located on
the top of each kidney
SOME Hormones Released
 ARE



corticosteroidsCortisol and
Catecholamine's such as
dopamine, epinephrine to
increase HR and BP during
stress and norepinephrine
Aldostrone that affects
kidney function by
controlling levels of salt and
water in the blood
Also small amounts of
Androgens
Thymus
2 lobes Lies in the
lower part of the
neck or upper
chest behind the
sternum
 Secretes thymus
hormone which
plays an important
role in the
immune system

Ovaries and Testes

Testes Male sex glands that
secrets androgens that
contribute to production
of sperm and the
development of male
characteristics

Ovaries release hormone
estrogen and contribute to
the female characteristics
and regulate menstrual
cycle
Hormones
What does the Endocrine System
Do???
 Once a hormone is secreted, it
travels from the endocrine gland
that produced it through the
bloodstream to the cells designed
to receive its message called
target cells.
Target Cells
target cells have receptors that latch onto only
specific hormones, and that hormone will
communicate only with the target cell that have
receptors for that hormone
 When the hormone reaches its target cell, it
locks onto the cell's specific receptors
 The hormone-receptor combinations transmit
chemical instructions to the inner workings of
the cell.

Hormone Receptors
Hormone receptors are found either exposed on
the surface of the cell or within the cell, depending
on the type of hormone.
 Three actions of hormones

◦ Endocrine action: the hormone is distributed in blood
and binds to distant target cells.
◦ Paracrine action: the hormone acts locally by diffusing
from its source to target cells in the neighborhood.
◦ Autocrine action: the hormone acts on the same
cell that produced it.
Hormone Levels

When hormone levels reach a certain normal
amount, the endocrine system helps the body to
keep that level of hormone in the blood.
Example,
Thyroid Hormone Feedback Loop.
Disorders related to Hormones

Give examples of disorders involving
hormones.
◦
◦
◦
◦
◦
Hypothyroidism
Hyperthyroidism
Cushing's Syndrome
Addison’s disease
Growth Hormone Deficiency- GHD
Hypothyroidism
Thyroid does not produce
enough thyroid hormone.
 Symptoms include: feeling
tired and weak; cold
intolerance; dry skin and brittle
nails; and constipation.
 Can raise your cholesterol
levels and can make you more
likely to have a stroke or heart
attack.
 It can be treated with thyroid
hormone pills.

Hyperthyroidism
Thyroid is producing too
much thyroid hormone.
 Common symptoms include:
excessive sweating; heat
intolerance; increased
bowel movements;
nervousness or agitation;
and weight loss with
increased appetite.
 Treatments include
antithyroid drugs; ablation
with radioactive iodine; or
surgery to partially remove
the thyroid.

Cushing's Syndrome






Results from excessive
production of Cortisol from
adrenal gland .
Can be the result of tumor
or drug therapy.
Symptoms include fat
deposition in face and
around shoulders. (Buffalo
hump)
Decreased Vit D
activity=bone loss
Emotional frailty.
Hirsuitism-hair growth on
face in females
Addison’s disease
Result from a deficiency
in Cortisol production.
 Can be genetic or the
result of illness or injury.
 Symptoms include low
blood pressure, muscle
weakness, weight loss,
and hyperpigmentation
of skin.
 JFK suffered from this.

Growth Hormone
Deficiency- GHD
Different effects
depending on the age of
onset.
 In infants and childrenhypoglycemia and growth
failure.
 Rarely happens in adults,
but may manifest as bone
loss, loss of muscle mass
and strength.
 Treated by intramuscular
injections of HGH

Gary Coleman Little Rascals and Different Strokes and more
Activity 2.3.1 The Hormone
Connection

Use Inspiration to create a concept map
for Chemical Communication describing
the basic mechanism of hormone action
in the human body.

Share concept maps with class
Feedback Mechanism
(1) A loop system in which the system responds
to perturbation either in the same direction
(positive feedback) or in the opposite direction
(negative feedback).
 (2) A process in which the level of one substance
influences the level of another substance.
 (3) A mechanism or a signal that tends to initiate
(or accelerate) or to inhibit (or slow down) a
process.
 https://www.youtube.com/watch?feature=player_
detailpage&v=_QbD92p_EVs -feedback loop

Essential Questions

2. How do hormones interact with target
cells?

3. What are examples of endocrine
glands and exocrine glands in the human
body?
Essential Questions

4. How do feedback loops help regulate
the action of hormones?

5. How can too little or too much of a
hormone lead to disease?
Activity 2.3.2 Hormones Gone Wild
Part 1

Activity 2.3.2 Part 1 only

Need:
◦ White Poster Board
◦ Markers

What are his Symptoms

What organs and glands are effected

When your team thinks they have the correct
diagnosis- Get Part 2 from your teacher
Activity 2.3.2 Hormones Gone Wild
Part 2
Build the Pituitary Gland on your Manikin
 What is the connection between the
Pituitary Gland and the Hypothalamus
 Build the Thyroid Gland on your Manikin

Example Thyroid Hormone
Feedback Loop
Hypothalamus
The hypothalamus is part of the brain that lies just above the pituitary
gland. It releases hormones that start and stop the release of pituitary
hormones.The hypothalamus controls hormone production in the
pituitary gland through several "releasing" hormones. It functions in
maintaining homeostasis, especially in coordinating the endocrine and
nervous systems; secretes hormones of the posterior pituitary and
releasing factors, which regulate the anterior pituitary.
 These include:

◦
◦
◦
◦
Growth hormone-releasing hormone, or GHRH (controls GH release)
Thyrotropin-releasing hormone, or TRH (controls TSH release)
Corticoptropin-releasing hormone, or CRH (controls ACTH release)
Another hormone made by the hypothalamus is gonadotropin-releasing
hormone (GnRH). It tells the pituitary gland to make luteinizing hormone (LH)
and follicle-stimulating hormone(FSH), which are important for normal puberty
and reproduction.
Pituitary Gland




The pituitary gland is sometimes called the "master gland" because of its
great influence on the other body organs. Its function is complex and
important for overall well-being. It produces hormones that act directly on
the body and that stimulate other endocrine glands to produce their own
hormones.The anterior pituitary (the front part of the pituitary) produces
several types of hormones:
Prolactin: stimulates milk production from a woman's breasts after
childbirth. In pregnant and breastfeeding women, prolactin helps prevent
ovulation (the release of eggs from the ovaries).
Growth hormone (GH): GH stimulates growth in childhood and is
important for maintaining a healthy body composition. In adults it is also
important for maintaining muscle mass and bone mass. GH also affects fat
distribution in the body.
Adrenocorticotropin (ACTH):ACTH stimulates production of cortisol by
the adrenal glands. Cortisol, a so-called "stress hormone," is vital to
survival. It helps maintain blood pressure and blood glucose levels, among
other effects.
Pituitary Gland






Thyroid-stimulating hormone (TSH):TSH stimulates the thyroid gland to
make thyroid hormones, which, in turn, control (regulate) the body's
metabolism, energy, growth and development, and nervous system activity.
Luteinizing hormone (LH): LH regulates testosterone in men and estrogen
in women.
Follicle-stimulating hormone (FSH): FSH stimulates the ovaries to release
eggs (ovulate) in women. LH and FSH work together to allow normal
function of the ovaries or testes, including sperm production.
The posterior pituitary (back part of the pituitary) produces two
hormones:
Oxytocin: Oxytocin causes milk to be released in nursing mothers and
contractions during childbirth.
Antidiuretic hormone (ADH):ADH, also called vasopressin, regulates
water balance. If ADH is not secreted in the right amount, this can lead to
too much or too little sodium (salt) and water in the bloodstream.
Pitutary Tumor
Pituitary Tumor Removal

http://www.skullbaseinstitute.com/video_
pituitary_tumor.htm
Overview of the Endocrine System

http://www.youtube.com/watch?feature=p
layer_detailpage&v=-S_vQZDH9hY
Key Terms
Endocrine Gland
Endocrine System
A gland (as the thyroid or the pituitary) that produces an endocrine
secretion -- called also ductless gland, gland of internal secretion.
The glands and parts of glands that produce endocrine secretions, help to
integrate and control bodily metabolic activity, and include especially the
pituitary, thyroid, parathyroid, adrenals, islets of Langerhans, ovaries, and
testes.
Exocrine Gland
A gland (as a sweat gland, a salivary gland, or a kidney) that releases a
secretion external to or at the surface of an organ by means of a canal or
duct.
Gland
A cell, group of cells, or organ of endothelial origin that selectively
removes materials from the blood, concentrates or alters them, and
secretes them for further use in the body or for elimination from the
body.
Glucagon
A protein hormone that is produced especially by the pancreatic islets of
Langerhans and that promotes an increase in the sugar content of the
blood by increasing the rate of breakdown of glycogen in the liver.
Hormone
Any one of the many circulating chemical signals found in all multicellular
organisms that are formed in specialized cells, travel in body fluids, and
coordinate the various parts of the organism by interacting with target
cells.
Hypothalamus
The ventral part of the vertebrate forebrain; functions in maintaining
homeostasis, especially in coordinating the endocrine and nervous
systems; secretes hormones of the posterior pituitary and releasing
factors, which regulate the anterior pituitary.
Insulin
A vertebrate hormone that lowers blood glucose levels by promoting the
uptake of glucose by most body cells and the synthesis and storage of
glycogen in the liver.
Lesson 2.4 Communication with the
Outside World
Essential Question

1.How do humans communicate with the
world around them?
Communication with the Outside World

How does the Nervous System and Endocrine
System Communicate.
The hypothalamus connects these two important communication
systems.
 The hypothalamus is a tiny collection of nuclei that is responsible
for controlling an astonishing amount of behavior.
 Hypothalamus located at the base of the forebrain, regulates basic
needs such as sleep, hunger, thirst and sex in addition to emotional
and stress responses.
 Hypothalamus controls the pituitary glands, which controls the
release of hormones from other glands in the endocrine system

Essential Questions

2. How does the power of sight allow humans to
communicate with the outside world?
Optical Illusions
Caused by the eye or by the brain
Optical Illusions
A dissociation
between physical
reality and subjective
perception
 The visual illusion is
one of the most
important tools used
by neuroscientists to
understand how the
brain creates its
sense of reality.

A Person with
perfect vision is
still susceptible to
optical illusions
Terms to know about the EYE
Optic Nerve
 Sclera
 Cornea
 Anterior Cavity
 Posterior Cavity
 Tapetum
 Choriod
 Optic Disc or Blind
Spot

Pupil
 Aqueous Humor
 Vitreous Humor
 Iris
 Ciliary Body
 Suspensory
Ligaments
 Lens

http://www.youtube.com/watch
?v=6mNs_TcUyHc
Activity 2.4.1Eye Anatomy

http://www.youtube.com/watch?featur
e=player_embedded&v=0rbCrJoTatE Cow Eye Dissection
Structures of the Eye

Cornea: the clear front window of the eye. The cornea transmits and focuses light
into the eye.

Iris: the colored part of the eye. The iris helps regulate the amount of light that
enters the eye.

Lens: the transparent structure inside the eye that focuses light rays onto the retina.

Macula: a small area in the retina that contains special light-sensitive cells. The
macula allows us to see fine details clearly.

Optic Nerve: the nerve that connects the eye to the brain. The optic nerve carries
the impulses formed by the retina to the brain, which interprets them as images.

Pupil: the dark center in the middle of the iris. The pupil determines how much light
is let into the eye. It changes sizes to accommodate for the amount of light that is
available.

Retina: the nerve layer that lines the back of the eye. The retina senses light and
creates impulses that are sent through the optic nerve to the brain.

Vitreous: the clear, jelly-like substance that fills the middle of the eye.
Essential Questions

3. How is light focused by the eye?

4. How do the eye and the brain work
together to process what we see?

5. How does what we see impact other
human body systems?
Key Terms
Accommodation
The automatic adjustment of the eye for seeing at different
distances affected chiefly by changes in the convexity of the
crystalline lens.
Astigmatism
A defect of an optical system (as a lens) causing rays from a
point to fail to meet in a focal point resulting in a blurred and
imperfect image.
Blind spot
The small circular area in the retina where the optic nerve
enters the eye that is devoid of rods and cones and is
insensitive to light.
Cone
Any of the conical photosensitive receptor cells of the
vertebrate retina that function in color vision.
Cornea
The transparent part of the coat of the eyeball that covers the
iris and pupil and admits light to the interior.
Depth Perception
The ability to judge the distance of objects and the spatial
relationship of objects at different distances.
Key Terms
Hyperopia
Iris
Lens
Myopia
Optic nerve
A condition in which visual images come to a focus behind the
retina of the eye and vision is better for distant than for near
objects -- called also farsightedness.
The opaque muscular contractile diaphragm that is suspended
in the aqueous humor in front of the lens of the eye, is
perforated by the pupil and is continuous peripherally with the
ciliary body, has a deeply pigmented posterior surface which
excludes the entrance of light except through the pupil and a
colored anterior surface which determines the color of the
eyes.
A curved piece of glass or plastic used singly or combined in
eyeglasses or an optical instrument (as a microscope) for
forming an image by focusing rays of light.
A condition in which the visual images come to a focus in front
of the retina of the eye because of defects in the refractive
media of the eye or of abnormal length of the eyeball resulting
especially in defective vision of distant objects -- called also
nearsightedness.
Either of the pair of sensory nerves that comprise the second
pair of cranial nerves, arise from the ventral part of the
diencephalon, form an optic chiasma before passing to the eye
and spreading over the anterior surface of the retina, and
conduct visual stimuli to the brain.
Key Terms
Pupil
The opening in the iris, which admits light into the interior of
the vertebrate eye; muscles in the iris regulate its size.
Refraction
The deflection from a straight path undergone by a light ray or
a wave of energy in passing obliquely from one medium (as air)
into another (as water or glass) in which its velocity is different.
Retina
The sensory membrane that lines most of the large posterior
chamber of the vertebrate eye, is composed of several layers
including one containing the rods and cones, and functions as
the immediate instrument of vision by receiving the image
formed by the lens and converting it into chemical and nervous
signals which reach the brain by way of the optic nerve.
Rod
Any of the long rod-shaped photosensitive receptors in the
retina responsive to faint light.
Visual Perception

It is the ability to interpret the
surrounding environment by processing
information that is contained in visible
light. The resulting perception is also
known as eyesight, sight, or vision
Visual Perception

Predict your dominant eye. Which eye do you think is your
dominant. Next, locate an object 8-10 feet away. Keep both
eyes open and hold your thumb up at arms length. “Cover”
the object with your thumb. Now, close the right eye. If the
thumb appeared to move to the right, the right eye is
dominant. If the thumb did not seem to move, the left eye
is dominant. Poll the class to see how the result matched
their prediction.

Introduce optical illusions and depth perception by showing
hidden image stereograms. You can either bring in books or
have them view the online example at the Magic Eye® site
http://www.magiceye.com/faq_example.htm.
Activity 2.4.2 Visual Perception

Show DVD: Human Body: Pushing the
Limits DVD series. Chapter 2 – 1.11 on
the Sight DVD

http://www.allaboutvision.com/eyeexam/refraction.htm.
Activity 2.4.2 Visual Perception
In pairs make your way through the
eleven stations.
 Only spend about 10 minutes in each
station
 You will need Activity 2.4.2: Student
Response Sheet

Color Vision

The retina of the eye possesses
two special types of nerve cells
known as photoreceptors.
◦ Rods function in dim light and
perceive shades of gray.
◦ Cones function in bright light and
provide sharp, colorful images.

Impulses from rods and cones
pass through nerve cells to the
optic nerve.
Color Vision

There are three different types of cones:
◦ Red cones
◦ Blue cones
◦ Green cones
Each type of cone is sensitive to a different range of
wavelengths of light.
 Different types of cones function together to
interpret colors other than blue, red, and green.
 If any of the cones malfunction, color deficiency or
color blindness occurs.

Depth Perception
Depth perception is the ability to judge the
relative distances between objects in
three dimensions.
 With one eye, the field of vision appears
two-dimensional.
 With two eyes, the eyes see and the brain
processes different views of the same
object.

Accommodation
Two parts of the eye – the cornea and the lens –
focus light on the retina.
 The cornea does most of the work, but it cannot
change shape. Fine adjustments are carried out by
the lens.
 Accommodation is the combination of reflex actions
by which the lens of the eye changes to keep the
focal length, the distance between the center of the
lens and its focal point, constant.
 Ciliary muscles in the eye assist adjustment of the lens.

Astigmatism




Astigmatism is a condition in which the cornea or the lens is
irregularly shaped.
This shape change causes incoming light rays to refract and
converge improperly.
The light rays do not focus at a specific point on the retina,
resulting in a blurry or distorted image.
Astigmatism may be corrected with eyeglasses, contact lenses,
or refractive surgery.
Blind Spot
The optic nerve exits the eye at the retina on
its way to the brain.
 Since this area of the retina does not have
receptors that respond to light, it is referred
to as the blind spot. An image that falls on this
area can not be seen.
 Normally people do not recognize the blind
spot because the eyes are always on the move
and the brain ignores this “hole” in visual
input.

Peripheral Vision
Peripheral vision is the ability to see things that
fall outside of the direct line of vision.
 Due to their proximity to the edge of the
retina, rods are responsible for this aspect of
vision.
 Peripheral vision is better for detecting
movement than for processing sharp images,
and is most often stronger in the dark.

Optical Illusions
Optical illusions are visual tricks that actually
take place in the brain rather than the eye.
 The visual cortex of the brain deciphers
images sent from the eye, however
surrounding objects, intense colors,
distortions of expected patterns, and
preconceptions can cause the mind to “see”
and interpret an image differently.

Afterimages




Afterimages are optical illusions that occur when looking
away after staring intently at a fixed image or color.
The constant light stimulating the retina causes the cones
in that area to become fatigued.
After looking away from the image, the less-stimulated
cones, which are not fatigued, still function.
The resulting image lasts briefly and because it comes
only from the less-fatigued cones, is perceived as a
negative image.
Essential Questions


6. What is visual perception?
7. What does it mean to have 20/20
vision?
Essential Questions

8.How can corrective lenses be used to
refocus light and resolve myopia and
hyperopia?

9. How does the eye perceive depth,
color and optical illusions?
The Day I Quit Driving

http://www.exploratorium.edu/seeing/notf
adeaway/site/quitdriving.html
Disorders of the Eye
RETINITIS
PIGMENTOSA
HYPEROPIA
MYOPIA
GLAUCOMA
REVIEW QUESTIONS
RETINIS PIGMENTOSA

Refers to a group of
inherited disorders that
slowly lead to blindness
due to abnormalities of
the photoreceptors in
the retina.
MYOPIA




near- sightedness
short-sightedness
A vision condition in which
close objects are seen clearly,
but objects farther away
appear blurred.
Myopia occurs if the eyeball
is too long or the cornea, the
clear front cover of the eye,
has too much curvature. As a
result, the light entering the
eye isn’t focused correctly
and distant objects look
blurred.
HYPEROPIA (farsightedness)

A defect of vision caused by an
imperfection in the eye (often
when the eyeball is too short
lengthwise or when the lens can’t
become round enough causing
inability to focus on near objects)

As an object approaches the eye,
the eye must increase its power to
keep the image in focus on the
retina.

In hyperopia the power of the
cornea and lens is insufficient so
the image appears blurred.
GLAUCOMA

Glaucoma is an eye
disease that affects the
pressure of the eye,
resulting in optic nerve
damage. The aqueous and
vitreous humor expand,
which then covers the
optic nerve, which leads
to vision loss. Glaucoma
is the second leading
cause of blindness.
Essential Question

10. How does an error in the structure
or function of the eye relate to disease or
dysfunction?

11. How is life impacted by a vision
disorder?
Essential Question

12. What are the tests and procedures in
a routine eye exam?
Activity 2.4.4 Eye Care
Professionals

Part 1

Create a handout titled “What You Need
to Know about an Eye Exam”.
Activity 2.4.4 Eye Care
Professionals

Career Journal:
◦ Opthamologist
◦ Optometrist
◦ Optician

Describe a Scenario of why a a patient
would see this type of eye doctor in
addition to the information listed on your
Career Journal Rubric.