1. Amphibian Anatomy

2. The External Parts of a Frog
Head
Front Legs
Fingers
Palm
Wrist
Lower Arm
Upper Arm
Elbow
Trunk
Hind Legs
Thigh
Knee
Ankle
Sole
Webbing
Toes

3. The External Parts Functions
The Frog body is divided into a head, a short neck and a trunk. The head contains a mouth, eyes, ears, nose, and, of course, a brain.
Since their necks are so short they can’t move their heads much.

5. Salamander

6. Skeletal anatomy of a frog

7. The Internal Parts of a Frog
Male
Large Intestine
Small Intestine
Lung Lobes
Liver Lobes
Heart
Stomach
Gall Bladder
Testis
Fat body
Urinary bladder
Female
Liver Lobes
Heart
Ovary with eggs
Gall Bladder
Small Intestine
Stomach
Oviduct

8. Digestive system
The frog's digestive system starts in the mouth with its tongue.
For the most part, frog tongues are attached near the back of the jaw and folded on the base of the mouth with the tip of the tongue pointing back toward its throat. Their tongues can be flipped out very rapidly and accurately in order to catch an insect.
Most frogs do have tooth-like structures which are attached to the jaw and aid in breaking up the food so that it can be digested.
The food then goes down their short esophagus into the stomach, where the food is digested. The waste goes into the coiled, winding intestines where it can be later removed.

9. Cardiovascular system
They have a 3-chambered heart, arteries, veins, and lymphatics.
A prominent ventral abdominal vein is present in amphibians
Some mixing of oxygenated and deoxygenated blood occurs in ventricle

10. Reparatory System They have four modalities of respiration:
1.- Branchial
2.- Boccopharyngeal
3.- Cutaneous
4.- Pulmonic
Amphibian lungs are paired

11. Gas exchange occurs through lungs, gills, and/or the skin
Some salamanders have no lungs (secondarily lost)
Adults have double circulation
Both a pulmonary and a systemic circuit

12. Excretory system
The kidney of amphibians is mesonephric and empties into a urinary bladder.
The urinary blader of some amphibians may be biolobate.

13. Reproductive system
Amphibians have paired internal gonads that are hormonally regulated.
The testes of the frog are collection of seminiferous tubules connected to the mesenteric by collecting ducts.
The amphibian ovaries are located in proximity to the kidneys as seen in higher vertebrates.
Eggs are funneled into the osteum of the oviduct and then passed to the cloaca

14. Gender Determination Most not sexually dimorphic -Size -Color
Observe courtship
Candling abdomen for eggs
Swelling = repro active male salamanders
observe the actual courtship - morphology and behavior.
male’s vocal sacs become more prominent during breeding
Xenopus leaves females have larger ventral flaps and a larger body than males
Male Xenopus have black surfaces on the inner aspect of the forelimbs & larger digits during the breeding season. In bullfrogs the tympanic m. is = diameter as the eye female and in males 2x > eye. 14

15. Gender Determination Females More rotund body shape

16. Gender Determination Males
Caudata Crests, bright colors, tail swellings in some during breeding season
Anura Vocal sacs, nuptial pads during breeding season

17. Males are smaller than females

18. Resources
Frog Biology -
Frog Biology -
Anatomy of Amphibians -
Images -