BIOL 1114 Practical 3 Frog Anatomy

Nictitating Membrane

A transparent membrane that protects the eye when the frog is submerged; attached to the bottom of the eye

Tympanum

Receives sound waves through vibrations and sends them to the brain for sensory processing; the external eardrum

External Nares

Two small openings that assist in breathing

Glottis

A tube leading to the lungs; aids in breathing and vocalizing

Maxillary Teeth

Small and numerous teeth along the top jaw; angled inward to grip prey and keep it from escaping

Vomerine Teeth

Two teeth on the roof of the mouth used to hold and crush prey; often used to break the hard exoskeleton of insects

Tongue

Sticky and located at the front of the mouth to catch and keep prey; does not help the frog swallow prey

Internal Nares

Connect to the lungs like the glottis; allow the frog to breathe with its mouth closed

Eye Bulges

Push food down the frog's throat to help the frog swallow

Lungs

Used for gas exchange; air enters via buccal pumping; skin also assists in gas exchange via blood vessels

Liver

Has 3 lobes; secretes bile; monitors digested food levels in the blood; stores excess products of digestion

Stomach

Breaks down food mechanically and through acidic secretions that begin chemical digestion

Small Intestine

Finishes the digestive process and is the site where nutrients are absorbed into the blood

Testes

Present in male frogs; produce sperm for reproduction

Vocal Sacs

Present in male frogs; used to call for mates and establish territories

Oviduct

Present in female frogs; coats eggs with a jelly-like material for protection

Olfactory Bulb

Brain region that gives the frog a sense of smell; poorly developed in frogs

Cerebral Hemisphere

Brain region that regulates voluntary actions such as jumping; seat of memory and intelligence and consciousness

Optic Lobe

Brain region that functions in vision

Medulla

Brain region that regulates autonomic (involuntary) functions like respiration and digestion

3

The frog heart has __ chambers