Transcript Dissecting_the_Frog - T. Schor Middle School

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
Review – Terms of Orientation
D
• Anterior
– Front end
• Posterior
P
– 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
L
M
A
V
External Anatomy
• Skin
– Dorsal – green/brown
• Purpose?
– Ventral – off white
• Purpose?
– 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
External Anatomy
• Head
– External nostrils
– Eyes
• Upper and lower
eyelids
• Nictitating
membrane
– Purpose?
– Tympanums
• Function?
External Anatomy
• Trunk
– 2 front limbs
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Upper arm
Fore arm
Wrist
Hand – four digits
– 2 hind limbs
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Thigh
Shank
Ankle
Foot – five digits
– Webbed
– Function?
External Anatomy
• Cloacal Opening
– Waste products exit
• Urine from the kidneys
• Fecal matter from the
intestines
– Reproductive products
exit
• Egg
• sperm
External Anatomy
• Mouth
– Top of mouth
• Internal nostrils
• Vomerine teeth
• Maxillary teeth
– Rear of mouth
• Esophagus (gullet opening)
– leads to stomach
• Glottis
– Leads to trachea and lungs
External Anatomy
• Mouth
– Tongue
• 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
In Order to Observe the Mouth, you
have to cut the jaws with a scissor.
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
Skin first, then cut away muscle
that’s underneath
Internal Anatomy
• Major organs to dissect
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Heart
Liver
Stomach
Small intestine
Large intestine
Gall bladder
Lungs
Kidneys
Spleen
Tough organs to find – kidney and spleen (fat
bodies can be taken out and thrown away)
Dissecting tools
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Dissecting Pan
Scalpel
Forceps
Dissecting Needle
Dissecting Probe
Scissors
Metric Ruler
Dropper
Dissecting Pins