1. Frog

2. External Structures Eye
Iris- enlarges or reduces the size of the pupil in response to varying amounts of light
Pupil- opening for light to come in
Nictitating membrane- extra transparent eyelid at the bottom of the eye
Nostrils on top of mouth open into frog’s mouth
Tympanic membrane- serves as an eardrum, transmitting sound vibrations to the ear cavity

3. Digestion Gullet Short esophagus
Stomach- enlarged portion of the digestive tract that serves as a storage sac and site of preliminary digestion
Pylorus- narrow region of stomach containing a muscular pyloric valve which controls the further passage of food
Small intestine consisting of the duodenum and then the ileum absorbs dissolved food into the bloodstream
Colon or large intestine
Short tubular cloaca- common passageway for solid and liquid waste as well as eggs and sperm during reproduction
Tadpoles are herbivores
Adult frogs are carnivores

4. Mouth Large sticky tongue attached at the front of the mouth
Internal nostril openings in roof of mouth
Openings to eustachian tubes unite the ear cavity with the mouth, located at the back corners of the mouth
Gullet- passage to the digestive tract, opening to esophagus
Glottis- swelling with slender opening leading to the lungs
Males have openings in the back of the lower jaw that lead to the vocal sacs
Teeth- grasping not chewing
Ridge of tiny maxillary teeth in the upper jaw
Two sets of vomerine teeth between the internal nostril openings

5. Digestion
Liver- 3 lobed gland, produces bile which aids in digestion, also stores some digested food
Gallbladder- stores excess bile
Pancreas- this gland is a small strip of tissue near the stomach, produces digestive enzymes
Bile duct- secretions from the liver, gallbladder, and pancreas are passed to the small intestine through the bile duct
Mesenteries- transparent membranes that enclose all the digestive organs and connect the organs to the dorsal body wall, contain blood vessels

6. Respiration
Frog obtains oxygen by using its skin, mouth lining, and lungs.
Frog does not have muscles needed to inhale and exhale like humans do. Frog essentially swallows the air.
Mouth
Glottis
Trachea
Lungs

7. Circulation

8. Excretion
Kidneys
long red brown structures against the dorsal body wall
Filters waste and excess water from the blood and concentrates it into urine
Urinary bladder
Cloaca

9. Reproduction
Female
Ovaries- produce eggs
Oviducts- long coiled tubes lined with cilia
Uterus- stores eggs
Cloaca- ejects eggs during mating
Male
Testes- produce sperm
Vasa efferentia- passageway for sperm from testes through kidneys to cloaca
Amplexus- male clasps or wraps around the female which stimulates the female to release her eggs. As they exit the females cloaca they are covered by the male in milt which contains sperm.

10. Nervous System Central nervous system Peripheral nervous system
Brain- encased in skull
Spinal cord- encased in spinal column
Peripheral nervous system
Nerves that transmit impulses between the central nervous system and the frog’s muscles and sensory organs
Divisions of the Five major lobes of the brain, from anterior to posterior:
Olfactory lobes ~ receive impulses from the smell receptors of the nostrils
Cerebrum ~ controls voluntary muscle activity
Optic lobes ~ Receives impulses from the eyes
Cerebellum ~ coordinates muscle activity and some involuntary activities
Medulla oblongata ~ transports impulses to and from the spinal cord, including some reflexes.

11. Nervous System Nervous system contains: Brain Spinal cord
Cranial nerves (branch from the brain)
Spinal nerves (branch from the spinal cord)
Sensory organs( eyes, ears, taste buds)
Divisions of the Five major lobes of the brain, from anterior to posterior:
Olfactory lobes ~ receive impulses from the smell receptors of the nostrils
Cerebrum ~ controls voluntary muscle activity
Optic lobes ~ Receives impulses from the eyes
Cerebellum ~ coordinates muscle activity and some involuntary activities
Medulla oblongata ~ transports impulses to and from the spinal cord, including some reflexes.
Nervous System