1. Dissecting the Frog
Follow and fill in your notes as we read together. You may have your notes on you at the time of dissection

2. Review – Terms of OrientationL
Review – Terms of Orientation D M
Anterior
Front end
Posterior
Back end
Dorsal
Upper surface or back
Ventral
Under surface
Medial
Lies close to the mid-line of the body
Lateral
Away from the mid-line A P V

3. External Anatomy Skin Dorsal – green/brown Ventral – off white
Purpose?
Ventral – off white
Thin and flexible
Water can pass through it
Veins in skin
Can get O2 in the winter
Have mucus glands
Some produce toxins to ward off predators
Keeps skin moist
                                                                                                                        

4. External Anatomy Head External nostrils Eyes Tympanums
Upper and lower eyelids
Nictitating membrane
Purpose?
Tympanums
Function?

6. External Anatomy Trunk 2 front limbs 2 hind limbs Upper arm Fore arm
Wrist
Hand – four digits
2 hind limbs
Thigh
Shank
Ankle
Foot – five digits
Webbed
Function?

7. External Anatomy Cloacal Opening Waste products exit
Urine from the kidneys
Fecal matter from the intestines
Reproductive products exit
Egg
sperm

9. External Anatomy Mouth Top of mouth Rear of mouth Internal nostrils
Vomerine teeth
Maxillary teeth
Rear of mouth
Esophagus (gullet opening)
leads to stomach
Glottis
Leads to trachea and lungs

10. External Anatomy Mouth Tongue Eustachian tubes Vocal sacs
Large, fleshy
Attached at front of mouth
Eustachian tubes
Attach to the eardrums (tympanums)
Equalize air pressure (same function in humans)
Vocal sacs
Only in males
Used for mating calls

11. In Order to Observe the Mouth, you have to cut the jaws with a scissor.

12. Internal Anatomy Place frog on dorsal side
Pin it at the wrist and ankles (angle pins away from frog)
Make incisions through the skin as shown in the diagram

13. Skin first, then cut away muscle that’s underneath

14. Internal Anatomy Major organs to dissect Heart Liver Stomach
Small intestine
Large intestine
Gall bladder
Lungs
Kidneys
Spleen

17. Tough organs to find – kidney and spleen (fat bodies can be taken out and thrown away)

18. Dissecting tools Dissecting Pan Scalpel Forceps Dissecting Needle
Dissecting Probe
Scissors
Metric Ruler
Dropper
Dissecting Pins