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CARIBOU ANATOMY

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					    COMPARATIVE
      ANATOMY
    (Excerpted from Nuulluni Qaujisarniq – Learning
           Science away from the classroom)




COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
      On-the-land Comparative Mammalian Dissection

Objective
To study the external and internal anatomy of a mammal for comparison with
other mammals or vertebrates.
Materials
• Adult mammal, freshly killed              • dissecting gloves
• Large tarp                                • hunter’s knives
• Sharp handsaw                             • measuring tape
• cups for scooping blood, etc.             • basins to remove blood and
• garbage bags and bins                       stomach contents
• ball of string                   .        • dissecting scalpels for small mammals
• bone cutters                     .        • water to clean away blood, etc.
• dissecting scissors (surgical scissors)   • permanent marker
• fishing scale or spring scale             • zip-lock bags to carry back organs

Procedure

Part One: External Anatomy
1. Determine the height of the mammal by measuring from front limb extremity
   to shoulder. Record this data in your lab book.

2. Find the length of the mammal from snout to vent (anus). Record this data in
   your lab book.




3. If possible, use the scale to determine the mass of the animal. For larger
   ungulates, estimate the mass.

4. Determine the sex of the mammal by looking between the rear legs. Presence
   or absence of testicles and penis determines gender for some mammals. (For
COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
   marine and rodents you may not be able to tell until you locate the gonads
   internally.) Discuss with the elders and hunters gender identification
   techniques for the species you are examining. Record the sex of the animal
   and the secondary sex characteristics that confirm this.

5. Make an estimate of the mammal’s age, based on the data that you have
   collected. Discuss with the elders and hunters aging techniques for the
   species you are examining. Record the approximate age of the mammal and
   the characteristics upon which you based your estimate.

6. Make an external examination of the mammal to view specific anatomical
   adaptations. See supplemental guides for each mammal.




7. Examine the presence and size of the ears.

8. Check the range of motion of the limbs of the mammal. Draw a diagram to
   show the limits of flexibility of this animal. Consider the use of the limb.

9. Try to touch the base of the skull to the tail of the mammal to investigate the
   flexibility of the spine.

10. Examine and measure the length of the appendages of the mammal. Draw a
    diagram of limb.
COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
11. Locate the parts of the trunk of the mammal where the limbs originate. Find
    the joints and measure the length of the limb. Consider how this relates to
    whether the animal is marine or terrestrial.

12. Examine the fur of the animal. (If you are examining a whale, why do you
    think whales don’t have fur?) Measure the length of the hair. Check whether
    or not there is an undercoat. If so, make note of the difference in length and
    texture of the hairs.

13. Examine the direction of fur growth on the mammal. Make a note of this in
    your lab book.

14. Check for the presence of an oily coating on the hair. Make a note of why or
    why not the mammal has oily fur.

15. Describe the colouring of the mammal. Record any hypotheses about whether
    the animal’s coat colour give it any advantages in its environment.




COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
Part Two: Internal Anatomy


Skinning the mammal
If a hunter is available to demonstrate proper skinning technique, have him or
her cut the skin according to traditional practice. Depending on the intended
use for the hide, the skin can be cut in a variety of ways. If no expertise is
available, follow this procedure:




David Serkoak demonstrating how to skin a caribou so that mitts can be made
from the fur from the legs

1. Lay the mammal on its side.

2. Cut the mammal skin along the ventral midline from anus to jawbone
   (mandible). If the mammal is a male, cut the skin to one side of the testicles
   and penis, if external. If female, make the incision between the bilaterally
   symmetrical placement of the mammary glands. Use caution; hunters’ knives
   and dissecting scalpels are quite sharp. If the animal has a layer of blubber
   between the skin and the peritoneum or ribs, cut through it without
   puncturing the cavities below in order to determine its thickness.

COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
3. Save a sample of the skin including the adipose tissue beneath it as well as
   the fur. Place this sample in a labeled zip-lock bag for further examination
   after the camp.




                      Ringed Seal have a thick layer of blubber


4. Examine the cross section of fur, skin and fat. Measure and record the
   thickness of each layer. Which layer is most responsible for providing
   insulation for the mammal? Consider how this relates to its environment
   (marine or terrestrial.)

5. At this point you may wish to skin the mammal using traditional methods.
   Otherwise, the skin over the abdomen and thorax may be cut and pulled
   away as flaps.




COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
6. Examine the muscles, connective tissue, tendons and ligaments. Note how
   muscles are positioned in opposing groups, with attachments at bones.




  Skinned Caribou




COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
The Abdominal Cavity and Pelvis

1. Lay the mammal on its right side.

2. Make a small incision along the midline of the mammal, running the blade of
   the knife gently over the tissue until the stomach is visible. This tissue is the
   peritoneal sac that contains the digestive organs, spleen, kidneys and adrenal
   glands. Cut up to, but not beyond the sternum so that the thoracic cavity is
   not opened.

3. Slide three middle fingers of your free hand to lift the connective tissue away
   from the stomach. Turn the knife in the other hand so that the point is inside
   the peritoneum with the blade pointed outwards, cutting towards the anus.
   The stomach and small intestines should spill out. For small mammals, use
   the scissors to make the incision. Continue to open the peritoneal cavity.

4. Identify the spleen, the liver, and the pancreas.




                                                                           Liver

                                                                           Small
                                                                           Intestines

                                                                           Stomach




                                                                           Spleen




Abdominal Cavity of a Ringed Seal, Stomach at cranial end



COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
5. Identify the stomach, small and large intestines.

6. Check to see where the esophagus attaches to the stomach. Without cutting
   into the stomach, try to identify the path that food takes as it travels through
   the gastrointestinal tract, from esophagus to anus.

7. Tie off, with string, the duodenum (just past the stomach) and the rectum to
   ensure that contents remain in place.

8. Carefully cut the esophagus and the rectum and remove the entire GI tract
   including the stomach and intestines. (It may be easier to separate large
   organs, such as a caribou or muskox stomach and later reassemble for
   measurement of the whole tract.)

9. Examine the intestines. Remove the intestines by cutting at the rectum.
   Intestinal tissue is very fine, especially at the rectum, so exercise caution.

10. Separate the coiled mass carefully with a knife and lay it out as a long tube.
    Notice the high degree of vascularization (small blood vessels and lymph
    ducts which connect to the jejunum.) Record your measurements. Identify
    these parts of the small intestine: duodenum (extending from the pyloric
    valve of the stomach to the jejunum,) jejunum, and ileum. Identify these parts
    of the large intestine: caecum, colon and rectum. Calculate the ratio of the GI
    tract length to the snout-to-vent length of the animal.




COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
Ringed Seal Gastro-Intestinal Tract

11. Using the knife or scalpel, separate the stomach from the duodenum above
    the point where the duodenum has been tied off. Carefully section the
    stomach ensuring that the esophagus and the pyloric valve remain together in
    one section.

12. Examine and identify the contents of the stomach. Record your findings.

13. Place the stomach section, which contains the pyloric valve and the
    esophageal opening, into a labeled zip-lock bag for later examination.

14. *Carefully, separate all the intestines from each other. Use the tape measure
    to determine the length of intestinal tract. Record your measurement.

15. Examine the kidneys and locate the adrenal glands. The adrenals are cranial
    to the kidneys, both of which are dorsal to the digestive organs.




COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
                                            Caribou Kidneys

                                            Left and Right Kidneys

                                            Renal Artery and Vein



                                            Descending Aorta

                                            Caudal Vena Cava


                       Caribou kidneys can be embedded in fat


16. In the region of the kidneys, identify the aorta. It is the large muscular artery
    that brings blood from the heart. Find the renal arteries that branch off almost
    at right angles, bringing blood to the kidneys. Find the caudal vena cava, the
    large, thin-walled vein that returns filtered but deoxygenated blood back,
    cranially, to the heart. Find the ureters that bring urine to the bladder.




COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
17. Remove the kidneys and place into a labeled zip-lock bag for later
    examination.

18. Examine the pelvic area of the mammal for genitals. If the animal is a female,
    find the ovaries, uterus and vagina. If the female is pregnant, the fetus will
    aid the identification of the uterus. If the animal is a male, find the penis and
    the testes. (You may have noticed these external organs before the abdomen
    was cut open.) Remove the ovaries or testicles and save these for post-camp
    activities by placing them in a labeled zip-lock bag.




                                                                                  Ringed Seal
                                                                                  kidney
                                                                                  penis
                                                                                  urinary
                                                                                  bladder

                                                                                  testis

                                                                                  rectum




Ringed Seal Uro-genital system. The male genitalia of marine mammals are found internally.




COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
The Thorax

1. Gently cut into the diaphragm at the top side of the abdomen where it
   attaches to the ribcage. If the lungs were not disturbed when the mammal
   was shot, the initial incision into the diaphragm will cause the lungs to
   collapse, and the space around the lungs to fill with air. The pleural sac
   surrounds the lungs. The rib cage, diaphragm and muscles between the ribs,
   called intercostals, hold open the pleural sac, creating a vacuum. When the
   pleural cavity is opened, the lungs collapse like a deflating balloon.

2. Using bone cutters, scissors, a knife or scalpel, carefully remove the ribs to
   open a “window” that arches up to the trachea and back down to the
   diaphragm on the opposite side of the animal.

3. Drain or scoop out the blood as it seeps into the pleural cavity and rinse with
   water.

4. Identify the lungs, the bronchial tubes and the trachea (windpipe.) Notice
   how the trachea is covered by cartilaginous rings that constantly keep it open
   and unblocked.

                                                   Ringed Seal Heart




                                                   Aorta

                                                   Left Atrium


                                                   Left Ventricle


                                                   Right Ventricle (sectioned)




COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
5. Find the heart in the pericardial sac. Carefully cut the sac open. Examine the
   aorta, the pulmonary arteries, the pulmonary veins and the cranial and
   caudal vena cavae. Notice how the aorta, caudal vena cava and esophagus are
   bundled together, projecting caudally to the abdomen. Cut these five large
   blood vessels, and remove the heart. Wash away blood as necessary.
   Place the hearts in a labeled zip-lock bag for post-camp examination. Find
   the mass of the heart using the spring scale.

6. Cut the trachea to remove the lungs, being careful not to cut the lungs
   themselves.

7. Wash off the lungs and try inflating them. See how many exhalations of your
   own lungs it takes to fill the mammal’s lungs. Notice the way the lungs take
   the shape of the pleural cavity when they are fully inflated. Place the lungs in
   a labeled zip-lock bag for later examination. Find the mass of the lungs using
   the spring scale.




                  Inflated ringed seal lungs shortly after extraction


    Ringed Seal Lungs
    What adaptations does the ringed seal have in order to survive underwater yet
    breathe using lungs very much like our own? Why is seal meat and blood so dark?



COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
The Cranium

1.    Carefully remove the eyes with a knife or spoon. Examine the eyeball for the
     optic nerve that should emerge from the back of the eye from the fatty tissue.
     Save the eye for later dissection by placing into a zip-lock bag. Cut through
     the muscles that hold the lower jaw (mandible) to the upper jaw (incisive
     bone and maxilla). Continue cutting through the joints to remove the
     mandible and the tongue.

                                           Caribou Eye




                                           A caribou’s eye can be difficult to
                                           extract, but a spoon is a handy dissection
                                           to. Save the eye for comparative
                                           d          l




COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
2. Use the handsaw to cut through the bridge of the nose (through the frontal
   bone, dorsal to the eyes, and nasal bone rostral to the eyes—closer to the tip
   of the muzzle than the eyes are.) creating a mid-sagittal section. Cut only
   through the skull, not the brain itself.


                                                    Caribou Brain

                                                    Right Cerebral Cortex

                                                    Left Cerebral Cortex

                                                    Cranial Interior




                                                    Hind Brain, including
                                                    Cerebellum,
                                                    Medulla Oblongata,
                                                    Pons
Using a hacksaw to open the cranium of a caribou is a good way to view the
         Picture
undamaged brainNeeded to show the section of the caribou skull showing brain




3. Carefully cut the brain from the spinal chord. *Examine the brain, identifying
   the cerebral hemispheres, the cerebellum, the brain stem regions called the
   medulla oblongata and the pons, the piriform lobe (analogous the thalamus
   and hypothalamus in humans) and the olfactory bulb. Locate the pituitary
   gland. Place the brain carefully in a pre-labeled zip-lock bag.

4. Examine the inside of the cranium cavity. Locate the foramen magnum (the
   largest hole at the base of the skull through which the spinal cord projects.)
   Examine the sutures on the exterior of the cranium.

5. Place the brain on a scale to determine its mass. Record your answer.

Musculo-Skeletal Examination

6. If the animal is a good source of meat, have an elder or hunter cut up the
   meat.
7. Collect the femur (the proximal bone of the lower limb) or any other large
   bone from the animal. Save this in a labeled zip-lock bag.
COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
Supplementary Information about Caribou - Inuit
Qaujimajatuqangit and Scientific Knowledge

In many Arctic and Subarctic households these days, caribou is the most likely
meat to be served for the main meal of the day. Inuit elders in the Baffin speak of
their childhood when there were few caribou, but at that time their own
grandparents told them not to worry because the caribou would be plentiful
again when the grandchildren became old. In many communities in the Baffin
today, hunters do not have to go far to find an abundance of caribou.
Hunters and elders talk of the times when every part of the caribou, except for
the adrenal glands, had a use. Skins were and are still used for parkas, mitts,
kamiik uppers, sometimes for tents and for bedding when camping. The stomach
chambers and bladder could be used as vessels to carry collected berries, water
or anything else that we use plastic grocery bags for now.
When a caribou was freshly killed, the heat coming from its still warm body,
would not only be used for warming the hunter as he skinned and butchered the
animal outdoors with his bare hands, but also to melt snow for drinking.

                                                               Freshly killed
                                                               young buck ready
                                                               for dissection and
                                                               butchering




COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
Bones and antlers from the caribou are frequently carved into works of art, but
traditionally a great number of tools were made from these materials. Caribou
legs, when frozen, were used as napuit, or cross pieces on qamutiit (sleds) where
wood is always used now. Caribou meat is lean, but in times when there was
little marine mammal blubber around, caribou fat too could be rendered to make
uqsuq, fuel for the qulliq (stone lamp.) The runners of the sled could be fashioned
in very cold weather from caribou skins soaked in water and wrapped around
frozen fish, molding the frozen skins into the same shape that wooden runners
have nowadays. Inuit of the past were ingenious with the few resources that the




land, sky and sea provided.
  Peter Hardy, left, wisely wore a caribou skin parka when travelling with the Arctic
  Millenium Expedition, presenting the Globe program in Pond Inlet to Karen



The fall skins of the caribou were important for making parkas: hunters’ wives
would instruct husbands exactly what age and gender of caribou to get. These
men would cut hide in a way so that the colour and thickness of the fur would fit
into the design of the parka. The hide on the legs could be cut differently
depending on whether it was intended for mittens or for the upper section of
kamiks. Men were expected to bring back the skins cut to their wives’
specifications. Caribou clothing is still the best for spending extended periods of
time outdoors during the long winter. Because of its tremendous insulating
capacity, caribou skins are still an essential part of a hunter’s gear, serving as the
flooring between the mattress and snow floor of a tent or igloo, or as emergency
blankets. Hides were often sewn together to make tents in the past.
COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin
Before Europeans and southern Canadians first traded lumber, iron and steel in
the Arctic, bones from all animals were carved into knives, scapers, needles, sun
goggles and countless other tools. Caribou bone and antler figured prominently
as the raw materials for tool, sled and sometimes even housing construction. The
shape and strength of antler and bone from caribou are properties not unlike
wood.
Much of the caribou flesh is edible: the meat, brain, liver, tongue, ribs, kidneys,
stomach wall and even the stomach contents were eaten in the past. Inuit elders
who demonstrate their traditional hunting skills are also incredible at cutting
through the joints, the bones, tendons and ligaments of the animal. They can
carve up the animal into cuts of meat with surgical precision. A deep
understanding of the anatomy of the caribou underlies these hunters’ ability to
cut the animal’s joints as they preserve buried lengths of tendon to be used as
rope or thread. In times when there were few caribou, all the animal’s meat
might be reserved for the elders.




The large four-chambered ruminant stomach of the caribou



COMPARATIVE ANATOMY
from “Nuulluni Qaujisarniq – Learning Science away from the classroom”
Project coordinated by E. Maltin

				
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