Transcript Homeostasis Review for regents

HOMEOSTASIS
What it is ALL about – no
really, it’s what this
WHOLE YEAR was
about…
Homeostasis…
• Is the same thing as dynamic
equilibrium
• Is what all your body systems are
working for
• Is necessary for life!!
• Much of homeostasis is getting
energy & ATP!!!
All organisms…
• Need to maintain homeostasis
• Some living things have an
easier time keeping
homeostasis
• Each organisms has its own
homeostatic “levels” that it
works optimally at
Ameobas…
• Need to maintain homeostasis
• Do not need any body systems
to maintain homeostasis
• Simply uses D/O/AT to get
what it needs across the cell
membrane
Plants…
• Need to maintain homeostasis
• Use various organs to
maintain homeostasis
• Roots bring minerals needed
• Guard cells open & closed to
maintain proper water levels
Humans…
• Need to maintain homeostasis
• Use all of our organ systems
• Endocrine and immune system
are very important here
Digestive System…
• Breaks down nutrients into
molecules small enough to
diffuse into the cells
• (HIRTH*) Nutrients in the cells
help maintain energy levels
*”How it relates to homeostasis”
Circulatory System…
• Carries gases and nutrients to
cells
• Removes gases and other
metabolic wastes from the cell
• Maintains proper blood
pressure and heart rate for
homeostasis
Circulatory System
(HIRTH)
• Maintain nutrients levels in
blood, as well as waste
product levels
• Maintain CO2 and O2 levels
(via BP and heart rate)
Respiratory System…
• Physical – supplies the oxygen
• **Breathe faster when you
have too much CO2 (not when
you need oxygen)
• Gas exchange occurs at the
alveoli (with RBC)
Respiratory System
(HIRTH)
• Maintain CO2 and O2 levels
(via increased breathing rate)
• Maintains proper oxygen
levels for cellular respiration to
occur
Excretory System…
• Removes metabolic wastes
Excretory System
(HIRTH)
• Maintain CO2 levels (via the
lungs)
• Maintains proper water levels
(via kidneys)
• Maintains glucose levels (via
kidneys)
Nervous System…
• Regulates your body via
various changes
• Works in close conjunction
with the endocrine system
• Creates “fast” changes
Nervous System
(HIRTH)
• Maintains proper body
temperature (via sweating)
Endocrine System…
• Regulates your body via
various changes
• Works in close conjunction
with the nervous system
• Creates “slow” changes
• Controlled by feedback
Endocrine System
(HIRTH)
• Maintains most the entire body
via hormones
• Maintains glucose levels via
insulin from the pancreas
• Maintains growth levels via the
pituitary gland
Reproductive System…
• Creates reproductive cells
(gametes) via meiosis
• In females, creates
environment for embryo to
develop
Reproductive System
(HIRTH)
• Tells the body when to produce
mature sex cells (via hormones)
• Maintains a viable environment
for the embryo (via hormones)
• Allows mother to “attend” to all
the embryos’ needs (via placenta
and diffusion)
Immune System…
• Primary defense against
pathogens (foreign
substances)
• Works in close conjunction
with the endocrine system and
nervous systems
Immune System
(HIRTH)
• White blood cells attack
pathogens
• WBC produce antibodies that
attack or mark the pathogen
(antibodies are antigen specific)
• Vaccinations “train” and help the
immune system remember
specific pathogens
Immune System
Problems
• Allergies – when the immune system
reacts & releases histamines to
“harmless” substances
• Leukemia – when the immune
system fails to recognize its own cells
and attacks its own organs & such
• Organ rejection – when the immune
systen does not recognize the cells in
a new organ and attacks
DISEASE AS A FAILURE OF
HOMEOSTASIS
• Pathogens – viruses (flu & HIV), bacteria
(strep & food poisoning), fungus (athlete’s
foot & ringworm), parasites (malaria &
tapeworms)
• Cancer – uncontrolled cell growth
• Toxins – lead poisoning, mercury
• Organ failure – diabetes, dialysis
• Poor nutrition – scurvy, goiter