Frog Dissection Pre Lab
External (Ventral):
External (Dorsal):
External Features
Nictitating Membrane
• Appearance:
Clear or whitish/beige thin membrane.
• Function:
Protects the eye while swimming and attacking
prey.
• Location:
Attached to bottom of the eye.
Tympanic Membranes
• Appearance:
Thin membrane circles on outside of head
• Function:
Transfer sound waves from ear drum to ear
canal for hearing.
• Location:
Sides of head by eyes.
Internal Ears / Eustachian Tubes
• Appearance:
Small, slender tubes
• Function:
Transfers sound waves from the tympanic
membrane to nasal cavity; equalizes air
pressure while swimming
• Location:
Openings visible from inside of upper mouth
Vomerine Teeth
• Appearance:
Small swollen bumps (slimy)
• Function:
Help hold prey in mouth.
• Location:
Roof of mouth by nose.
Maxillary Teeth
• Appearance:
Sharper bumps
• Function:
Crush/hold prey
• Location:
Roof of mouth, outer rim.
Mouth (Teeth):
Nostrils:
Tongue
• Appearance:
Large light colored fleshy
appendage
• Function:
Used to catch prey: Propelled
from the mouth with powerful
muscles; prey sticks to tongue
upon contact.
• Location:
Attached to the FRONT of the
mouth.
Frog Predation Tactics
• https://www.youtube.com/watch?v=wXqK5
QulbJ8
Heart
• Appearance:
Hard, red-brown mass.
• Function:
Circulate blood.
• Location:
Center of chest in between lungs, above liver.
Heart:
Heart:
Lungs
• Appearance:
Brown flaps
• Function:
Bring in oxygen gas, and
release carbon dioxide
gas.
• Location:
Sides of heart within
chest.
Stomach
• Appearance:
Large flesh-colored sack
(tubular).
• Function:
Metabolize/digest food.
• Location:
Left side of frog (your
right side), under liver.
Intestines
• Appearance:
Flesh-colored tube
• Function:
Absorb food nutrients
+ excrete waste
• Location:
Abdomen, connected
to stomach.
Liver
• Appearance:
Gray-ish colored lobes
(large)
• Function:
Metabolize toxins and
fats.
• Location:
Center of chest, under
heart and lungs.
Fat Bodies
• Appearance:
Yellow-ish squiggly
noodles
• Function:
Additional energy
storage + body heat.
• Location:
Sides of body (internal).
Cloaca
• Appearance:
Hole
• Function:
Multipurpose Hole 
Sperm/Eggs, Urine
and Fecal Matter all
come out of here.
• Location:
In between legs.
Male Parts
(Do NOT have to identify)
• Sperm
• Testes
• Cloaca
Female Parts
(Do NOT have to identify)
• Eggs
• Ovaries
• Cloaca
---Dissection Notes--1. Identify external structures.
2. Carefully open mouth and identify types of
teeth + tongue.
3. Lay frog on back.
4. Carefully cut into chest and abdomen:
- Make a vertical incision from throat down
to crotch.
- Make 2 horizontal incisions (one below
throat, and one above crotch).
5. Open + Identify organs.
Cut through the Skin:
Cut through the Muscle:
Frog Dissection Demo
• https://www.youtube.com/watch?v=uLqS5AVRio
• https://www.youtube.com/watch?v=bOJyh
k4QZvc