The Frog: circulatory system
• Frogs have a closed
circulatory system that is
broken into two loops:
• 1. Pulmonary circulation:
blood is pumped from the heart
to the lungs & back to the heart
• 2. Systemic circulation:
blood is pumped from the heart
to the rest of the body & back
again
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• The heart has three
chambers: two atria
& one ventricle
The Frog: respiration
• Larval amphibians breathe through their
gills & skin
• As frogs mature, the gills are lost &
respiration occurs through the skin & lungs
• Respiration through the lungs is called
pulmonary respiration
• Respiration though the skin is called
cutaneous respiration
The Frog: Digestive system
• Food is captured by a sticky tongue &
taken into the mouth
• It is then swallowed & moves through
the pharynx & elastic esophagus to
the stomach
• Once in the stomach, gastric digestive
juices are secreted by glands that line
the stomach
• A muscle at the base of the stomach
opens & allows the food to move into
the first section of the intestines: the
duodenum
• From the duodenum it moves to the
ileum where the nutrients released
from the food is absorbed into the
bloodstream
• The duodenum and the ileum make up
the small intestine
• The indigestible parts of the food move
into the large intestine where any
extra water is reabsorbed & the leftover
waste is pushed into the cloaca & out
through the vent
• The intestines are held in place by a
thin but strong membrane called the
mesentery
• The frog has many accessory glands
like humans that aid the digestion
process
• Liver: produces bile which breaks
down fat
• Gallbladder: bile is stored here until it
is needed
• Pancreas: secretes enzymes that help
further digest the food
The Frog: Excretory system
• The kidneys are the primary excretory
organs
• They lie on either side of the lower
spinal column against the dorsal body
wall
• The kidneys filter wastes from the blood
& excretes it from the body as urine
The Frog: Nervous system
• The brain consists of the following parts:
• Olfactory lobe: center for the sense of smell & is
found at the anterior of the brain
• Cerebrum: regulates behavior & learning & is found
behind the olfactory lobe
• Optic lobe: center for the sense of sight & lies
behind the cerebrum
• Cerebellum:
coordinates
muscular movement
• Medulla
oblongata: found
at the posterior of
the brain & controls
organ functions
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Frog & Toad Myths
• They will NOT give you warts!
• Their urine is NOT toxic!
• If you kiss frogs, they will
NOT turn into princes!!
(sorry girls)
Froggy Facts
• Because frogs come out in the rain people
used to think that they fell to earth in the rain
and in the 1800’s people tried to prove it by
catching them!
• At first it was thought that frogs could not
throw up, but then it was discovered on a
space mission that a frog can throw up. The
frog throws up its stomach first, so the
stomach is dangling out of its mouth. The
frog then uses its forearms to dig out all of
the stomach's contents and then swallows
the stomach back down again. (GROSS!)
“It’s Not Easy Being
Green”
-Kermit
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The End