Page 207 - Biology_F5

Biology for Advanced Level Secondary Schools

Lung Heart
FOR ONLINE READING ONLY
Gall bladder Liver
Anterior part of anterior Stomach
abdominal vein
Ileum Duodenum
Rectum
Posterior part of anterior Bladder
abdominal vein

Figure 3.69: General view (visceral) of the dissected frog or toad

(p) In displaying the digestive system, pin (r) In case of a female frog; pin the right
out the stomach to either side of the ovary on top of the left ovary, loosen
animal. Pin out the lungs, and turn the and pin out the right oviduct and pin
liver lobes forward and hold them in the bladder aside.
place with pins and grip the ileum to (s) For the nervous system; remove
cut the mesentery and loosen the coils, the pins from the skin of the head
but do not cut the mesentery of the and remove the floor of the mouth
duodenum and rectum. Rearrange the by cutting through angle of the jaw
duodenum in position to expose the to expose the first spinal nerve (the
pancreas and pin out the ileum to your hypoglossal nerve) which curves
right hand side to make all features the pharynx and proceeds forward
visible. ventrally around the floor of the mouth
to supply the tongue.
(q) In displaying the urinogenital system, (t) Remove the flesh from both fore limbs
the cloaca should be opened by around the shoulders and remove the
removing the ventral portion of the pins from the lungs and the stomach.
pelvic girdles. This should be done Cut through the oesophagus and
by inserting one blade of the scissors remove the lungs, heart, stomach and
through the girdle, followed by cutting other parts of the alimentary canal.
through the girdle as near to the mid (u) Remove the reproductive and excretory
line as possible, and lastly cutting on parts, when removing the kidney. Take
each side and removing the central care not to cut the aorta.
portion of the girdle. Care should (v) Remove any remaining membranes
be taken to avoid cutting the blood surrounding the abdominal lymph sacs
vessels. in order to expose the second spinal
nerve called the brachial nerve (which

Form Five Student’s Book
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