Do Now
Aim: How can an immune
response be a breakdown in
homeostasis?
Agenda
•Do Now
•Self-guided topics 1-5 review
•Correct work using the answer key
•Reflection
•Castle Learning or Quizlet review
Topic 1 Diabetes
The first few slides review
the endocrine system and
homeostasis…
Feedback mechanism or loop
•In the winter, what
happens when the
temperature in your
house goes to low?
•Thermostat detects a
decrease and sends a
signal to the furnace
to go on. Once the
temp is back to
normal the furnace
turns off
Feedback mechanisms
•Human organ
systems maintain
homeostasis by
using:
Feedback
loops or
mechanisms
Sending Signals
•What are the primary
agents that the brain
uses to communicate
with other cells?
•Hormones
•Neurotransmitters
(Nerve chemicals)
Receiving Signals
Receptor molecules
•How do cells in
the body receive
signals from the
brain?
•Receptor
molecules on
their cell
membrane
Feedback Loop Example
1.
1
2.
4
2
3.
4.
3
Brain detects a decrease
in temperature
The brain releases
chemical signals to
muscles beneath the skin
surface.
These muscle cells receive
the signal through
receptor molecules and
begin to shiver.
Brain stops sending signal
once temp is back to
normal
Insulin
Protein- Long and folded
molecule with a shape
•The hormone
produced by the
pancreas gland
to lower
Blood sugar
levels
Diabetes
•When the
pancreas fails
to produce or
properly use
Insulin
Two types of diabetes
•Type 1- Develops
in children before
the age of 15
•Type 2- Develops
in people after
the age of 30
Hormone and Receptor molecule must
fit in order to work
Pancre
as
Gland
Receptor
molecule
Hormone
Failure of hormone to work
means either the
1. Hormone is not
produced
2. Receptor
molecule is the
wrong shape
3. The hormone is
the wrong
shape
Another living example of a feedback
mechanism
•When sugar levels
rise the brain detects
rise, then sends a
signal to pancreas to
release insulin.
When sugar levels
are normal pancreas
stops secreting
insulin
Feedback
What could cause diabetes?
1. Person not producing
enough insulin
2. The target cell
cannot receive signal
because of a
defective
- Receptor molecule
- Hormone
Brain Pop
•http://www.brainpop.com/health/diseasesinj
uriesandconditions/diabetes/
•Username: bufsd
•Password: bufsd
Topic 2 Allergies
Allergic reaction
•What is an allergic
reaction?
•Is an immune
response to a
harmless
substance like
peanuts
Antigens triggers the allergy
•What human
organ system is
responsible for an
allergic reaction?
The immune
system
Explain how it
works
Antigens are specific
Walnut
• Why are some
people allergic to
one type of food
but not another?
•The shape of
surface proteins
are different
Peanut
Topic 3 Organ
Transplants
Organ transplant
When an organ is
replaced with an organ
from another person.
The organ can
sometimes be seen as a
“foreign invader” from
the immune system
Cell surface proteins
Transplanted organs
have different or foreign
antigens on their cells.
This is similar to how the
immune system sees a
virus or bacteria cell
Different cell proteins
Donor cell proteins
Receiver’s cell proteins
These cells are not a match for an organ
transplant
Organ transplant rejection
• Organ transplant will reject if proteins
do not match
• Immune system will trigger white
blood cells to attack the transplanted
organ
Immunosuppressants
Immuno - immune system
suppressants - lower
Immunosuppressants are drugs that
lower the immune systems response to
transplanted organs.
Topic 4 Immune
Response
Bacteria
•Bacteria are singlecelled organisms.
•They are alive because
they can carryout the
characteristics of life
without needing the
help for another
organism
Bacterial infections
•How are bacterial
infections treated
or cured?
•They are treated
with antibiotics
prescribed by a
Doctor
Viruses
•Viruses are noncellular (not a cell)
•They are dead because
they cannot performs]
the characteristics of
life without having a
host.
•The infects to cause
illness and death.
Vaccine
•What is in a
vaccine that
makes it
effective?
Dead or
weakened
microbe
Cures and Treatment
•Diseases caused by a bacteria can be cured
because the bacteria can be killed.
•Doctors inject a person with antibiotics to kill
the bacteria
•Viruses cannot be killed because they are
NOT alive so there is NO cured for them
•Vaccines can PREVENT viruses from infecting
Vaccines
Vaccinations use dead or weakened microbes
(virus) to stimulate the first production of
antibodies
They are not as strong as the disease so the
person does not get sick
Helps organisms build a memory of
antibodies.
Vaccine Process
1. A dead or weaken virus is injected into an
organism
2. The immune systems recognizes the virus
and synthesizes antibodies
3. The immune system makes a memory of the
virus so when the real virus (not a dead or
weak one) comes it can use the antibodies
to stop it immediately.
Topic 5 Homeostasis in
Plants
Stomata (One open and one
closed)
Guard cell opens the stomata
when the plant needs nutrients
and closes stomata when at
equilibrium
Plant Homeostasis
Reflection
Answer the reflection questions on the last
page and then work on any missing castle
learning assignments
Regents Questions