Download Excretory/Urinary System Notes - Flipped Out Science with Mrs

Toxic Waste?!
So now we’ve eaten…we have to get
rid of the waste!
Excretory/Urinary System Notes
Continuation of digestion – food is transferred into nutrients and passes through
the body as waste
7.7B transformation of energy within an organism, for example to transfer from
chemical energy to heat and thermal energy in digestion
You may use this notes page:
Food! Nutrients in the Body
• So we eat food to survive, right?
• What do we do with this food though?
Our food is chemical energy. As the body breaks it
down, these molecules are sent to all part of the
body. The cells, depending on what type of cell it is,
then use those molecules for different processes.
Law of Conservation of Energy
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Remember this one?
Energy cannot be created nor destroyed!
Therefore, energy just changes forms.
The energy stored in food changes to chemical
energy, which is then changed into either
thermal energy or mechanical energy
• Why thermal?
Examples of energy transformations in
the human body
Chemical Energy in the Body
• Carbohydrates and fats are utilized for energy.
• This energy is not only used for movement and to
keep us warm, it is also used for biological
processes within cells.
How?
• All molecules are made up of atoms which are
joined together by bonds.
Chemical Energy in the Body
• The bonds which join atoms contain energy.
• the bonds between different atoms will vary in
their strength and amount of energy.
• The cells in your body function by
manipulating and rearranging molecules to
form new bonds or break old ones, in a
process called metabolism.
From absorption and energy, and
then…to waste!
• So we know how nutrients go into the body,
how do we get rid of the things we don’t
want?
• Excretion is the process of removing wastes
from the body
• Three systems in your body work to get rid of
wastes
Body Systems that remove wastes:
1. The integumentary system releases waste
products and water when you sweat
2. The respiratory system releases carbon
dioxide and water when you exhale
3. The urinary or excretory system contains
organs that remove liquid and solid waste
products from your body
Label on your page:
Main
structures:
• kidneys,
ureters,
bladder and
urethra
Functions of the excretory system:
• Removes wastes produced by the activities of
cells that have been filtered by the blood
stream
• Removes toxic nitrogen waste
• Maintains water balance which is crucial to
maintaining homeostasis.
• Homeostasis is maintained by getting rid of
wastes such as salt and urea
More on Homeostasis:
• Your cells have to maintain a certain level of
salt and water to function properly
• The excretory system works with the
endocrine system to help maintain
homeostasis
• Chemical massagers, called hormones, signal
the kidneys to filter more or less water or salt,
depending on the current levels in your body
How the kidneys work to clean our
blood!:
1. The kidneys filter the blood of waste using tiny
structures called nephrons
a. Nephron consists of two parts – glomerulus and
renal tubule
b. Includes a network of arterioles and venules
c. Unfiltered blood from an artery enters kidney
and passes through nephrons, removing waste
d. Nephrons collect waste and release to ureters
e. Filtered blood returns to bloodstream in veins
Label the one in your notes
2. Ureters: tubes that carry
urine from each kidney
to the urinary bladder
3. Bladder: stores urine
until it is released from
the body
4. Urethra: carries urine
from the bladder to the
outside of the body
a. Males have common exit
for both urine and sperm
b. Females have a single exit
for urine
3
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Other Excretory Organs
• Skin = releases
perspiration (water
& salts) to cool off
body
Other Excretory Organs
• Lungs = release carbon dioxide from the
body
Excretory System
• Crash Course:
• https://www.youtube.com/watch?v=WtrYotjY
vtU
Excretory System Lab
• Let’s read through the directions and then you
will work with your group to follow
procedures and clean up when you are done.