Transcript Frog Dissection 101

Frog Dissection Review
1. What does a frog’s anatomy have in common
with a human’s?
• Frogs have all the same body systems as
people and most of the same organs!
2. How does a frog’s anatomy differ from a
human’s?
• Frogs have:
a cloaca
three-chambered heart
unique teeth
no external ear
third eyelid
they are also cold blooded
Step One
• Determine frog’s sex: males have thick pads on thumbs;
males are often smaller than females.
• Male is on the right
Step Two
• Locate external features of frog
• Mouth, external nares, tympani, eyes and
nictating membranes
Materials
• Preserved Frog
• Dissecting Tray and Paper Towels
• Dissecting Kit: pins, forceps, scissors,
probe
Step Three
• Cut the hinges of the mouth and open it wide
• Locate the structures inside the mouth: Vomerine teeth,
Maxillary teeth, Internal nares, Tongue, Eustachian
tubes, Esophagus, and Glottis.
Internal nares
Vomerine
Teeth
Glottis
Esophagus
• Look for the opening to the frog’s cloaca, located between the hind
legs. Cut from where hind limbs meet to jaw.
• Then cut through the breast bone and muscle.
Step Five
• Locate organs of digestive system: esophagus,
stomach, small intestine, pancreas, liver, gall
bladder, rectum, cloaca
Rectum
Large
Intestine
Step Six
• Locate the circulatory organs: veins and
arteries, heart with right and left atrium and one
ventricle
Male or Female Reproductive Parts
Fat
Bodies
Clean-Up
• Clean up tools
• Wrap-up frog and organs in a paper towel
• Hold frog and take off gloves and wrap
gloves around frog
• Dispose of frog/gloves in trash can
• Put away tools
• Clean up any remaining debris
• Wash hands
Frog Anatomy Wrap-up
What are the functions of the following organs:
1. Cloaca
Organ that eliminates urine, feces and
sperm/egg
2. Tympanum
External eardrum of the frog; help with
hearing
3. Nictating Membrane
Third eyelid that protects while eating and
under water
4. Vomerine Teeth
Teeth located on roof of mouth that help grab
on to prey
Finished identifying external organs
and organs of the mouth?
• Quiz one another over the organs and
their functions until everyone is familiar
with them
• I will ask students within your group to
either identify the organ or tell me its
function so know your stuff.