Animal Systems
THE SKELETAL SYSTEM
The skeletal system is made up of ______________, ______________, and ______________.
The skeletal system has two functions: to ______________ ______________ ______________ and give
______________. It works hand in hand with the muscular system. The bones can't ______________ on their
______________. Muscles provide the ______________ that animals need to produce ______________.
They're attached by tough rubbery ______________. When the muscle ______________ the bone will move.
Muscles that cause movement work in ______________ or ______________ ______________. When a
muscle contracts, it ______________ on the bone it's attached to. One muscle group pulls the leg
______________, the other muscle group pulls the leg ______________.
Before any of that can happen, the brain gets an ______________ ______________ ______________ and tells
the brain to move, and the muscles ______________, pulling the ______________ that pull the leg up and
down.
THE RESPIRATORY AND CIRCULATORY SYSTEM
The respiratory system involves the ______________ and all of its passageways, which performs an exchange
of ______________.
The circulatory system involves the ______________ and all the ______________ ______________.
Animals breathe through their nose and mouth. The air travels to its ______________ through tiny branches
called ______________. Those branches empty into these very thin walled air sacs called ______________.
The walls of alveoli are so thin that gasses like ______________ and ______________ ______________ can
pass through them.
______________ begins when oxygen-poor blood enters the ______________. The heart notices and sends
the blood to the lungs, where it becomes oxygen-rich. The oxygen-rich blood pumps back to the heart.
The heart needs ______________ so the blood goes to the small intestine and picks up nutrients. Now that it's
nutrient and oxygen-rich, it can be delivered to any other body part, and then it goes through that circle again.
The blood travels in the ______________ and ______________ (tiny vessels). The dissolved nutrients can pass
through their thin walls and enter the ______________.
Cells pass their ______________ ______________ back through those capillaries and they get in the blood,
which becomes oxygen-poor again, and it keeps going through the cycle.
There are ______________ and ______________ circulatory systems.
All vertebrates and some other animals have closed circulatory systems: ______________ ______________
______________.
Arthropods, mollusks, and other invertebrates have open systems: ______________ ______________
______________.
THE DIGESTIVE SYSTEM
The digestive system is where all an animal’s food is broken down into ______________ and that's how animals
get the ______________ they need.
The animal chews its food with its teeth, and its ______________ breaks down the food so it’s small enough to
travel down his ______________.
NOTE: Saliva is made of 99% water. This is no surprise considering the body is made of 60% water. The
remaining 1% of saliva contains digestive enzymes, uric acid, electrolytes, mucus-forming proteins, and
cholesterol.
As it travels down the ______________, it's going to enter the ______________. The ______________ will hold
the food until it's partially ______________. The strong ______________ ______________ break down the
food.
The esophagus gets the food to the stomach using a ______________ motion. It's like an ______________ that
______________ and ______________ and it pushes food all the way down into the stomach.
After it's been digested, the food is going to empty into the ______________.
______________ ______________ are produced by the ______________ and the ______________ to break
down the ______________, the ______________, and ______________ into nutrients that are then absorbed
by the ______________ ______________.
NOTE: Digestive or gastric juice is made up of digestive enzymes, hydrochloric acid, and other substances that
are important for absorbing nutrients.
This is where the food that becomes the ______________ get into the ______________. As blood travels from
the ______________ down to the small intestine and picks nutrients up.
The ______________ ______________ absorbs all the ______________ and the ______________ parts.
The ______________ ______________ goes to the small intestine and the ______________ goes into the
large intestine. It becomes more solid and travels to the ______________ and out.
THE EXCRETORY SYSTEM
The ______________ system ______________ ______________ ______________ from the body, too. It
removes excess ______________ and ______________.
Cells create waste, including ______________ ______________ and ______________. ______________
______________ is removed through the ______________. The nitrogen waste is sent through the
______________ from the ______________ to the ______________.
The liver breaks it down into ______________.
Note: A toxin is a ______________ substance.
The kidneys filter the waste from the blood using tiny filters called ______________. The ______________
separates ______________ from ______________ ______________.
Useful substances are allowed to go back into the ______________ and nephrons collect the waste.
______________ is the collected waste from the nephrons. Urine travels from the ______________ to the
______________ and once it's full, the ______________ carries urine from the bladder outside of the body.
THE NERVOUS AND ENDOCRINE SYSTEM
The ______________ system in a vertebrate includes the ______________, ______________, the
______________ ______________, and ______________ ______________.
It works with the ______________ system which contains all of the ______________. Hormones are
______________ that are released into the bloodstream that change how the body acts.
If a rabbit saw a predator it might decide that it needs to run. Its nerves would relay that message. The nerves in
its eyes spot the predator, nerves carry the signals to the brain, the brain sends the signal through nerves to the
muscles, telling them to move. As it runs it senses that it needs to run faster. The ______________
______________ would send out a ______________: ______________. Adrenaline increases the heart rate
and that sends extra blood to the muscles. That gets it running faster and gets the rabbit’s body ready for
anything.
THE SKELETAL SYSTEM
bones
shortens
electric nerve signal
power
opposing groups
protect soft organs structure
tendons
move, own
pulls
up
movement
ligaments
tendons
pair
down
contract
THE DIGESTIVE SYSTEM
nutrients
esophagus
nourishment
stomach acids
contracts
accordion
saliva
stomach
good stuff
esophagus
sugars
expands
digested
stomach
rectum
squeezing
small intestine
fats
liver
pancreas
intestines
the proteins
digestive juices
water
nutrients
waste
bloodstream
undigested
large intestine
heart
THE EXCRETORY SYSTEM
kidneys
excretory
salt
nephrons
liver
carbon dioxide
removes waste products
lungs
carbon dioxide
water
kidneys
bladder
nephron
urine
poisonous
useful material
blood
nitrogen
urethra
toxins
waste
blood
THE RESPIRATORY AND CIRCULATORY
SYSTEM
lungs
blood vessels
gasses
bronchi
heart
veins
nutrients
lungs
blood carried in blood vessels
alveoli
heart
oxygen
capillaries
open
carbon dioxide
blood moves in an open cavity
cells
circulation
closed
waste materials
THE NERVOUS AND ENDOCRINE
SYSTEM
brain
endocrine
chemicals
adrenaline
nerves
sense organs
hormones
nerve cord
endocrine system
nervous
hormone