Page 217 - Biology_F5

Biology for Advanced Level Secondary Schools

(e) Use fingers to pull the skin aside, digestive structures and draw a well
loosen it from the body wall, stretch labelled diagram.
it and pin it back. (i) When displaying urinogenital system,
(f) Lift the abdominal wall using forceps, the alimentary canal should be removed
make an incision and cut up to the first, followed by the removal of fats
xiphoid cartilage and down to the left from the kidneys using blunt forceps
StomachREADING ONLY
and right ribs. Stretch the body wall and clear the ureter.
and pin it aside (Figure 3.78). Examine (j) In male mouse, open the scrotal sac
the contents of the abdominal cavity by cutting its ventral wall to expose
in undisturbed condition (in situ or the testes, caudal and caput epididymis
visceral/general view) and draw a well as well as the vas deferens. Lay the
labelled diagram. bladder, seminal vesicles, coagulating
glands and prostate glands on one side.
(k) In female mouse/rat grip the clitoris,
Mouth
pull it gently so that the urethra is
Oesophagus
held away from the pelvis, and cut
the ventral part of the girdle. Lift the
oviducts and remove the mesovarium
Liver to expose ureters on both sides, remove
FOR ONLINE
Small Spleen the fat bodies from the kidneys and
intestine ureter, but leave them around the
Pancreas ovaries (the ovaries are enclosed
Large within the thin walled ovarian sac and
intestine
Caecum connected to a very small and much
coiled fallopian tube) and observe the
Rectum very long tube called fallopian tube
near to the uterus.
Anus
Safety precautions

Figure 3.78: General view of the dissected mouse 1. Consider issues such as allergies or
or rat sneezing from loose rat or mouse furs.
(g) To display the digestive system, adjust 2. Rat or mouse may bite a person and
cause pain, so be careful when dealing
the positions of the alimentary canal with live rat or mouse.
by moving the bulk of the intestine to
the left hand side of the specimen to 3. Good hygiene practices should be
observed all the time; keep hands
expose the duodenum and the colon. away from the mouth, nose, eyes
(h) Grip the duodenum and colon, pull and face during and after dissection
them apart to expose hepatic portal and wash hands with antiseptic
vein and turn the bulk of the intestines soap immediately after a dissection
over to untwist them, rearrange the practical session.

Form Five Student’s Book
210