Rattus norvegicus
Norway Rat
Dissection Assignment of Required
Structures
You are to primarily find the following structures and
know something about their physiology by using the assigned vocabulary
assignment and the lab manual for this investigation. Check each item off as
you go along. The following items may be used for a lab practical and/or an
examination at the end of the lab or year. Care, respect, and professionalism
are to be adhered to throughout the lab. You will be graded on how well you
stay on task and on identifying the structures. Be prepared for periodical
questioning throughout the activity.
Note: (right and left) is based on the
specimen (right and left)
External Features: p5
Pinna
Eyelids
Vibrissae
Nares
Anus
* Female urogenital structures: ie vaginal orifice (see p33)
* Male urogenital structures: ie scrotum (see p35)
* Pending on which gender you have, find
someone else in the class who has the opposite and note their anatomy
Skinning the Rat: p4-6 Notes:
No need to worry about (pinning) specimen. If no (hole) in neck, create
your own to beginning the process. Remove as much skin as possible.
Muscular System (Front): p8-13
Masseter
Pectoralis Major
Pectoralis Minor
Triceps Brachii
Linea Alba (thin whitish (non-muscle) membrane down the middle)
Rectus Abdominis
External Oblique
Gracilis
Muscular System
(Back): p15-19
Acromiotrapezius
Biceps Femoris
Fascia (Lumbodorsal) (whitish (non-muscle) membrane)
Throat and Oral
Cavity: p19-22
Lymph Node(s) ; (3-4)
Mandibular Gland(s) ; (2)
Tongue
Teeth
Trachea (note: cut between Mandibular
Glands and muscle to view (contains rings
of cartilage))
Larynx (small whitish box-like structure on top of
trachea (note: may have to cut muscle to see))
Cutting to Expose the Internal Structures: p22 (may
again use p4 as a guide)
Abdominal Cavity and
Digestive System: p22-24
Liver (opt. median, left, right, and caudate lobe);
gall bladder (stores bile) found in humans, not the rat
Stomach (look under liver) [cut the stomach
long-wise and look inside] ; folds inside are called (rugae)
Esophagus
(note: best seen if you look under trachea (note: may with to cut trachea in
half to view))
Pancreas (between small intestine and stomach; delicate,
brown, and (granular))
Spleen
Small Intestine (opt. duodenum, jejunum, ileum)
Peritoneum (clear/thin
membrane between intestines)
Cecum (or Caecum) ; (between small and large intestine)
Large Intestine (
Circulatory System:
p26-31
Thymus Gland (top
of the heart; lightly brown)
Pericardium (clear/
thin membrane over heart) ;
may have fallen to either side of the heart
Atrium or Atria (pl.) ; (r./l.) (opt. pulmonary vein)
Ventricle(s) ; (r./l.) (opt. pulmonary artery) [cut
heart long-wise to see them; blue = r.v. ; red = l.v.]
Anterior (
Posterior (Inferior) Vena Cava Vein (below heart / also look under small/large
intestine)
External Iliac Vein(s) ; (forks off posterior vena cava)
Renal Veins ; (off the kidney)
Aortic Arch (Aorta) [cut away thymus gland to
see]
Thoracic
Aorta Artery (next to posterior vena
cava)
Common Iliac Artery(ies) ; (forks off
thoracic aorta)
Renal Artery(ies) ; (off the
kidney)
Coronary (Heart) (small
vessels on heart)
Respiratory System:
p24-26
Trachea
Larynx
Bronchus (r./l.) [cut heart out to see them]
Lung (note that there are 4 lobes)
Diaphragm (muscle between lungs and the liver) ; (you may have cut it in half by accident)
Urinary Structures:
p32-33
Kidney(s) ; (2)
Ureter(s) ; (2)
Urinary Bladder
Female/Male Genital
Structures: p33-35
* pending on your specimen, find someone with the
other gender to view their structures
|
Female: Ovary (opt. oviducts) Uterus (Uterine Horns) Vagina |
Male: Testis (opt. epididymis) Seminal Vesicles Penis |
Central Nervous
System: p36-39
Spinal Cord [clearly expose
the vertebra; cut vertebra in half to view whitish cord inside]
Brain [remove head and all surrounding tissue;
carefully cut skull to view (not remove) brain]
Cerebral Hemisphere (Cerebrum in humans)
Cerebellar Hemisphere (Cerebellum in humans)
