Name ______________________________ LABORATORY ANIMAL MANAGEMENT ANATOMY AND CLINICAL TECHNIQUES Contents: I. II. III. IV. Directions Directions Directions Directions for for for for Lab Lab Lab Lab 1 2 3 4 V. Handling and Restraint VI. Ear Notching VII. Injections VIII. Blood Collection IX. Oral dosing/stomach tubing/gavage X. Scalpel Use XI. Suturing XII. Anesthesia XIII. Euthanasia XIV. Dissection XV. Clean up XVI. Ear Notch Code XVII. Anatomy—structures to identify XVIII.Anatomical terms for direction labtech 9/25/2013 Bring directions for labs 1 – 4 to class. You should also bring a copy of the anatomy structures to ID. The remaining sections are to further explain the directions. You may print them or not as you wish. The information is connected by hyperlink. Use control click to move from the highlighted terms to more detailed explanations. 1 I. Lab 1: Safety, animal handling, needle use, suturing. A. Station 1: Rats (Some will be sedated by instructor) 1. Practice tickling: This is a method of gentling the rat. You play with the rat as they would play with each other which gets them used to being handled and makes them less afraid of manipulations used in the lab. 2. Practice sexing 3. Practice handling and restraint techniques (in hands, against body, in pocket). B. Station 2: Mice (Some will be sedated by instructor) 1. Practice sexing. 2. Practice handling and restraint techniques (in hand and on cage top). C. Station 3: Needle use 1. Practice putting together the needle and syringe and filling the syringe to the appropriate level. 2. Practice injection techniques using an orange. 3. Practice SQ and IP injection restraint and placement using a stuffed animal and a dry needle and syringe. 4. Use Koken rat to practice tail vein injections (use the 28 g needle with attached syringe, inject with dI water only). D. Station 4: Scalpel use 1. Practice putting the blade taking the blade off safely. on the handle and E. Station 5: Suturing 1. Practice opening and closing hemostats. Ideally, hemostats should be held by your thumb and 3rd finger with the 2nd finger wrapped around the finger loop and the 1st finger providing support to the shaft. 2. Practice suturing on a glove-wrapped foam pad. Please make sure someone checks your technique. F. Station 6: Anatomy—Study pictures and rabbit model. ALL DISPOSABLE NEEDLES, SYRINGES, AND SCALPEL BLADES MUST GO INTO THE SHARPS CONTAINER. SAVE SUTURE NEEDLES. labtech 9/25/2013 2 II. Lab 2: Anatomy and Clinical techniques (It is recommended that you bring a full page copy of the anatomy terms from the back of this manual on which to take notes. I have also provided a PowerPoint Dissection Guide from which to study.) A. Each group will be provided with 1 each euthanized rat and mouse. We will go over all procedures together. B. Injections 1. Practice restraint techniques for these procedures and get comfortable handling the equipment using both the rat and the mouse. a) SQ b) IP c) Ear notch C. Dissection: Follow along with the instructor. Do not work ahead or you may miss techniques or structures. 1. Note external characteristics of the male and female rat and mouse. 2. Make a mid-line incision from neck to genitalia. Use the scalpel blade for the rat and scissors for the mouse. Separate skin from underlying muscle. 3. Observe the structures in the neck. Practice collecting blood from the jugular vein by inserting a needle through the pectoral muscle. 4. Make a mid-line incision through the peritoneum of the abdominal cavity careful not to cut through the xiphoid process. Cut laterally at the cranial and caudal ends of your incision to open the peritoneal cavity. 5. Observe the in situ position of the abdominal organs. The instructor will go over each system. 6. Enter the thoracic cavity by cutting through the ribs on either side of the sternum and removing the sternum. A wider opening may be made by cracking the ribcage. 7. Observe the in situ position of the thoracic organs and go over them with the instructor. 8. The instructor will demonstrate the method of decapitation using bone shears on the rat and scissors on the mouse. We will then dissect and identify the structures of the brain and head. WASH INSTRUMENTS IN NOLVASAN USING A BRUSH. RINSE THEM, DRY THEM AND PUT THEM AWAY AS DIRECTED ALL NEEDLES AND SYRINGES, SCALPEL BLADES, AND MICROHEMATOCRIT TUBES MUST GO INTO THE SHARPS CONTAINER ALL CARCASSES, ANIMAL TISSUE, AND ITEMS WITH BLOOD ON THEM, MUST BE BAGGED FOR INCINERATION labtech 9/25/2013 3 III. Lab 3--Clinical techniques A. Rats: Each group obtains 1 rat and practice the following: 1. Gavage: Attach a gavage needle to a dry syringe. Measure the needle against the size of the rat. Dip the tip of the needle into sucrose solution. Restrain the rat in your non-dominant hand against your body. Insert the gavage needle into the rat’s mouth and down the esophagus up to the hub of the needle, and then remove it slowly. 2. SQ: Restrain the rat against your upper body to deliver 0.2 cc of saline subcutaneously. 3. IP: Deliver 0.2 cc of saline. 4. Ear notch: Restrain the rat against your upper body and practice ear notching. C. Follow directions in the manual for anesthesia. 1. Calculate the appropriate dosage and administer the anesthesia. 2. Fill out log sheet to monitor anesthesia. 3. Apply eye lubricant to each eye, using a piece of clean gauze, to prevent drying. 4. Inject 10 cc/kg (1 cc/100 g bwt) of sterile saline SQ to prevent dehydration caused by the anesthesia. You will not need to use the restraint technique on the anesthetized animal. 5. Warm a microwavable heating pad (heated 1 - 1½ minutes, 2 minutes for 2 pads) and cover it with a towel. Place the anesthetized animal on the pad to maintain body temperature while under anesthesia and to facilitate vasodilatation for blood collections. D. Site preparation: Shave the rat ventrally, dorsallaterally, on the dorsal surface of the hind legs, and on the proximal surface of the tail. E. ID: Using a 27 g needle, inject 0.05 cc – 0.1 cc/site of saline between the layers of the skin on the dorsallateral surface of the rat. Done correctly, a bleb, or blanching bubble, should form. labtech 9/25/2013 4 F. Lateral saphenous vein: 1. Use a rubber band and hemostat to create a tourniquet at the upper leg joint. 2. Use a 23 g needle held perpendicular to the leg to puncture through the skin and into the vein. Remove the needle. Collect 100 µl of blood from the surface of the skin using a microhematocrit tube. G. IV—Tail vessels (Primary focus—rat vein): 1. To collect from the tail vein, use a rubber band and hemostat to create a tourniquet at the base of the tail. Insert a 25 g needle into the vein and collect 100 µl of blood from the hub of the needle into a microhematocrit tube. 2. You may also try collecting from the tail artery, which lies laterally from the anus to the tip of the tail. Don’t use a tourniquet on the artery. H. Cardiac puncture: Use the xiphoid process as your landmark for point of entry. Use a 23 g, 1-inch needle. Hold the needle at a 20 to 30° angle and direct smoothly into the heart. Collect 0.1 cc to demonstrate correct placement and technique. I. Euthanize the rat using CO2 1. Study the anatomy—be sure you can identify all of the structures on the list at the end of this packet. Look at other animals to observe anatomical variation and the structures of both sexes. 2. Practice suturing on the rat skin and abdominal muscle. IMPORTANT: Wash instruments in Nolvasan using a toothbrush. dry them and put them away as directed. ALL NEEDLES AND SYRINGES, SCALPEL BLADES, AND SUTURE NEEDLES MUST GO INTO THE SHARPS CONTAINER. labtech 9/25/2013 Rinse them, DISPOSABLE 5 IV. Lab 4: Comparative Handling and Clinical Techniques A. Station 1: Mice: Techniques are similar to the rat; however, the mouse may be restrained in one hand. 1. Gavage: Use an appropriate sized gavage needle. 2. SQ: Restrain the mouse against a cage top to deliver 0.1 cc of saline. 3. IP: Deliver 0.1 cc of saline. 4. Ear notch: Scruff the mouse and ear notch. 5. Lateral saphenous vein: Restrain the mouse in an adapted syringe case. Pinch the leg in the groin to extend the leg and to occlude blood flow. Use small clippers to shave the outside of the leg. Use a 23 g needle held perpendicular to the leg to puncture through the skin and into the vein, then remove the needle and collect the blood pooling on the surface. Collect 100 µl of blood in a microhematocrit tube. 6. Submandibular vein: Use a 5 mm lancet to puncture the blood vessels located at the junction of the mandible and maxillary cheek bones. Collect 100 µl of blood from the surface of the cheek into a microhematocrit tube. 7. Cardiac puncture: This technique requires anesthesia; alternatively, blood may be collected immediately after euthanasia. Use a 25 g, 5/8” needle. Use the xiphoid process as your landmark for point of entry. Hold the needle at a 20 to 30° angle and direct smoothly into the heart. B. Station 2: Rabbit 1. Handling and sexing a) Practice picking up the rabbit, holding the rabbit in a “football” hold, and returning the rabbit to its container. b) Practice flipping the rabbit. Identify the sex of the rabbit and note the external genitalia (on both sexes if available). 2. SQ Injection: Inject 1 cc of sterile saline anywhere along the dorsal side (back) of the animal using a 20 g needle and a 1 cc syringe. 3. Blood collection: Collect 100 µl of blood from the marginal ear vein (auricular vein). C. Station 3: Guinea pigs and/or hamsters 1. If these species are available, practice handling and sexing these animals. labtech 9/25/2013 6 V. Handling A. Mice and rats—handling Back to Lab 1 1. Pick animals up by the base of the tail. That is the side of the tail closest to the body. Picking them up by the tip of the tail makes them feel insecure, they are more likely to bite, and there is the potential for stripping off the skin of the tail if animals are handled this way. B. Mice—restraint Back to Lab 1 1. Mice are scruffed in the non-dominant hand. 2. Hold the mouse by the tail using your dominant hand. This is usually done on the cage top; it should always be done on a rough surface. 3. Using your non-dominant hand, slide your thumb and first finger (or knuckle) on either side of the mouse’s neck and down along the jaw line. Close your fingers grasping the skin, and then pull it taut up over the back of the head and neck of the mouse. You should have enough skin so that the head cannot turn. 4. Position the body of the mouse against your thumb. Use your second finger to pull skin from the mouse’s back taut against the thumb. 5. Grasp the tail between your little finger and the heel of your hand. The mouse should be supported all along its body. The tail should always be restrained. If the tail is loose, it will pull the mouse’s body loose. C. Rat—restraint Back to Lab 1 1. Rats are restrained using the “V” technique. Place your first and second finger on either side of the rat’s head and wrap your thumb and last 2 fingers under the forelimbs. The hand used depends on your goal; learn the technique in both hands. Always support the hindquarters when using this technique. Adult rats are too heavy to hold in one hand. You may use your other hand or hold the rat against your body for this additional support. labtech 9/25/2013 7 2. 3. 4. labtech 9/25/2013 To restrain for a subcutaneous injection, you will position the rat perpendicular to your body against your chest. a) Grab the rat in a V hold in your non-dominant hand. b) Pull the rat away from your body, grab the tail, wrap the tail to the top of your nondominant arm, and place the rat against your chest so that it is parallel to the floor. Press the rat against your body along its length using your hand and arm. c) Place your thumb on the rat’s shoulder blade. Move your index finger over the rat’s head to the far side of its body, and pinch the skin up between your fingers to make a tent. Remember to continue pushing down on the rat’s head with your fingers as you pinch. To restrain the rat for gavage, use the V hold in your non-dominant hand. a) Stretch the rat out by grasping the tail and hindquarters and pulling them away from your body so that the rat’s hind feet are not underneath it, and then positioning the rat vertically against your chest. Use your hand and arm to press the rat into your body. b) In this hold, your first two fingers will pull gently on the jaw line of the rat elevating its head and straightening out its body. The thumb and last 2 fingers may pull the forelimbs back as well. The goal is to achieve a straight body so that the feeding tube may slide down the esophagus unimpeded. To restrain the rat for an intraperitoneal injection, use the pocket technique. Start with the rat in the V hold in your dominant hand. a) Position the rat head down and tail up over your nondominant pocket. Pull your pocket out with your nondominant hand and slide the rat down into the pocket. b) Transfer your hold from your dominant to nondominant hand by placing your non-dominant hand over the top of the pocket and pressing the rat into your hip or leg. Slide your 8 c) D. labtech 9/25/2013 dominant hand out of the pocket as your nondominant hand rolls up to cover the rat. Slide the non-dominant hand up to the rump of the rat so that you may use your thumb to push the rat down into the pocket. Continue to push the rat into your body and cup your fingers around the rat’s body so that it can’t turn in your pocket. Position the leg and tail between your thumb and hand and roll the rat’s hindquarters away from your body to visualize the abdomen. Rabbit—handling Back to Lab 3 1. Pick the rabbit up by the scruff; however, this is not as cranial a position as it is on the mice. It is easiest to grasp the skin over the shoulder blades. You may use either hand, but it is most comfortable in your dominant hand. When you have a firm grip on the scruff, place your other (nondominant) hand under the hindquarters and lift the rabbit. Once the rabbit is out of its container and in your arms, wrap your non-dominant hand around the rabbit’s body, placing the rump in your hand and tucking the rabbit’s head under your arm. This is called the “football” hold and is used for transporting rabbits for short distances. 2. When returning rabbits to their cage or box, always put them in rump first and head towards your body. This is to prevent them from jumping out of your arms, which could result injury. 3. Rabbits may be flipped to visualize their ventral side. a) Scruff the rabbit with your dominant hand and pull the rabbit away from your body. b) Using your non-dominant hand, roll the rump around your dominant arm, then bring the rabbit back to your body so that the belly is up and the rabbit is caught between your dominant arm and your body. c) You may hold the rabbit on your dominant arm to examine the head and teeth. Use your hold on the scruff to pull the head back. d) You may transfer the hold to the non-dominant arm to examine the abdomen and hind feet and to sex the rabbit. Wrap your non-dominant 9 arm around the rabbit and place its rump into your hand. To sex the rabbit, pull down on the tail. E. F. G. labtech 9/25/2013 Rabbit restraint 1. Rabbits do not generally require a firm restraint for subcutaneous injections. We place the rabbit in a box to keep in a small space. 2. Rabbits are placed into a restrainer for more invasive procedures such as blood collections. This is important to prevent the rabbit from trying to jump, and in doing so, breaking its back. We will use a cat bag to restrain the rabbit. Hamster handling Back to Lab 3 1. Hamsters have almost no tail and so all handling and restraint must be done using a full body scruff. 2. Press the hamster into the cage with your nondominant hand. Grasp the skin along the back between your thumb on one side and your fingers on the other. Make sure you have the skin along the back and behind the head pulled taut so that the hamster cannot turn within its skin. Then lift the hamster. Guinea pig handling 1. Guinea pigs are never scruffed. They are picked up by wrapping one hand around their body about the level of the shoulder blades. Use the other hand to scoop up the hind quarters and lift the guinea pig. 10 VI. Ear Notching Back to Lab 2 A. Use the chart in back to learn the Ear Notch Code for Cole B. This is not a universal numbering system, but we will use this system for both rats and mice in this class. Note that the chart is looking from the back of the animal’s head with the right ear on the right. B. Mice 1. Restrain your mouse using the scruffing technique described above (use your non-dominant hand). With the head immobilized and the tail restrained, place the mouse onto a cage top with the mouse pressed up against the right side of the cage top. If done correctly, the mouse should be unable to turn its head to the right. 2. Grasp the ear notcher in your dominant hand holding near the tip of the ear notcher. 3. Slide the tip of the ear notcher over the margin of the mouse’s ear. Depress the tip of the notcher to clip a ½-circle of tissue from the margin of the mouse’s ear. (For some numbers, you will have to move toward the center of the ear and clip a whole circle.) C. Rats 1. Restrain the rat in a V-hold in your non-dominant hand. Hold the rat against your body, pressing the head close to your body. You may wrap the rat in a towel for this restraint if needed. 2. As with the mice, slide the tip of the ear notcher over the margin of the ear and clip a ½-circle of tissue from the ear. VII. Injections Back to Lab 1 A. Needle safety website: http://safetyservices.ucdavis.edu/snfn/safetynets/snml/ sn3/SN3pdf labtech 9/25/2013 11 B. Needle use Needle Size Recommendations for Class Procedures Needles 20 g, 1-inch 23 g, 1-inch Rat SQ IP IC L. Saphenous Mouse L. Saphenous. Rabbit SQ 25 g, 5/8-inch IV (tail blood collection) SQ IP IV (tail) IC IV (ear vein) 27 g, 1/2-inch 28 g, 1/2-inch 1. 2. 3. 4. labtech 9/25/2013 ID IV (tail vein injection) IV (tail vein injection) - Capping needles: To cap a needle lay the cap on the table and slide the needle into the cap. If a firm seal is desired, lift the syringe and press into the table to seal the cap. Always lay needles in the cap when setting them on the table— it keeps the needles clean and prevents accidents. Beveled edge: Insert the needle with the angled surface up to direct the needle parallel to vessel. Aspirate: Draw back on plunger to check location of needle. a) For anything other than an IV procedure, aspiration of blood is an indication of an improperly placed needle. You may have entered an organ, in which case injection of fluid may cause tissue damage. If blood appears, the needle should be pulled out and repositioned. Note: Aspiration is not necessary for an ID injection. b) If urine or feces are aspirated (yellow, green, or brown), the needle, syringe and solution are contaminated and must be discarded to prevent infection. Disposal: Needles and syringes must be discarded into a Sharps container. Do not cap needles prior to disposal. Do not remove the needle from the syringe. Have a Sharps container close to where you are working. 12 C. Syringe use 1. Milliliter (ml) and cubic centimeter (cc) are equivalent volumes and may be used interchangeably. 2. For injection, chose a syringe that will accurately measure the volume you need. You can only measure to one 100th of a ml in the 1 or 0.5 cc syringe and even then not very accurately. Dilute solutions for more precise measurements. 3. For blood collections, use small syringes for small blood vessels or choose a collection device that uses capillary action (microhematocrit tube). Too much vacuum will collapse the vessel. 4. Read the syringe where the black edge of the plunger touches the liquid in the syringe. 5. When inserting the syringe into the animal, keep your thumb off of the plunger to avoid premature delivery. Move your thumb to the plunger after aspirating. D. Subcutaneous (SQ): Used in all rodents and rabbits. Used primarily for slow release dosing as with fluid replacement or hormone administration. Rabbits are often given sedatives and anesthetics subcutaneously. Ease of administration makes up for the slightly slower uptake. Back to Lab 3 1. General technique a) Usually given in scruff of neck, but when multiple sites are needed, injections may be given along the back. b) Skin should be tented, or pinched up away from the body, and the needle positioned close to the body but between the skin and the underlying muscle. c) Aspirate. Resistance indicates correct positioning. If the plunger pulls back easily, you have probably gone through the skin and out the other side. 2. Mice are scruffed (always hold the tail), and then placed in a ventral position on a cage top. Use a 25 g, 5/8-inch needle. Deliver 0.1 cc of saline to practice. 3. Rats are held horizontally against the body using the hand, wrist, and arm of the non-dominant hand. Use a 23 g, 1-inch. Deliver 0.2 cc of saline to practice, or give 10 cc/kg to hydrate during anesthesia. 13 labtech 9/25/2013 4. Rabbits are placed in a box; they do not require restrain for this procedure. Pinch the skin to make a tent anywhere over the back. Use a 20 g, 1-inch needle. Inject 1 cc of saline. E. Intraperitoneal (IP): Used in all rodents; can be used in the rabbit, but the restraint is difficult. Uptake is more rapid than SQ. Back to Lab 3 1. General technique a) Hold the animal with its head down. This allows the abdominal organs to fall cranially decreasing the risk of incorrect penetration. b) This injection is given in the lower abdomen about the level of the knee joint on the right side of the animal’s body (this may be to your left). c) This injection is going into the abdominal, or intraperitoneal, cavity. Position the needle at about a 30 degree angle from the surface of the body. Do not insert parallel to the body or your needle may penetrate the skin, but not the muscle layer. d) Aspiration is particularly important. (1) Blood indicates improper placement into an organ. Remove needle and reposition. (2) Urine or feces indicates improper placement into the bladder or GI tract. Remove needle and place needle and syringe into the sharps container. 2. Mice are scruffed and held head down. Use a 25 g, 5/8-inch needle. Deliver 0.1 cc of saline to practice the injection. 3. Rats are restrained using the pocket technique. Use a 23 g, 1-inch needle. Deliver 0.2 cc of saline to practice or the appropriate dose of anesthesia. F. Intradermal (ID): Used in antibody research, the injected material is usually an antigen, or foreign protein, coupled with an adjuvant, a material used to increase irritation, thus producing an antibody response. Tuberculin tests use this type of injection. ID injections are performed primarily in GP and rabbits, but we will practice on an anesthetized rat. 1. Hair is shaved off of the back, lateral to midline to avoid injecting over the spinal cord. 2. Use a 27 g, ½-inch needle and a 1 cc syringe. labtech 9/25/2013 14 3. 4. 5. The skin is pinched between the thumb and finger forming a tent. Hold the syringe at the hub and brace the index finger of each hand together to allow for a strong force with a small, controlled movement. Slide the needle along the top of the tent inserting it within the layers of skin. Once the needle is inserted, drop the skin so that you can visualize the delivery. Deliver 0.05 – 0.1 cc of sterile saline per injection site. Try several sites on the back. A small bubble that blanches white will appear at the injection site. This bubble is called a bleb. Back to Lab 4 G. Intramuscular (IM): Seldom done in the mouse or rat, common site in guinea pigs and rabbits. Muscle masses commonly used are quadriceps muscle of the leg or lumbar muscles of the back. We will not practice this. H. Intravenous (IV): Often difficult on rodents, but very common in rabbits. Used for very rapid absorption, usually medicinal. Practice on the Koken rat. You may also practice on your anesthetized mouse and rat if you wish. Back to Lab 1 1. Always inject into veins. An injection into an artery may damage tissue as the fluid injected passes through the small capillaries at the distal end of the appendage. An injection into a vein travels through the large vessels to the heart and is diluted before reaching the capillaries. 2. Use a 28 g needle attached to a ½ cc syringe and inject 0.1 cc of saline into the tail vein of the rat and mouse. 3. Hold the tail in your non-dominant hand across the first three fingers and under your little finger to form a plateau. Squeeze the tail gently between your thumb and first two fingers to stabilize. 4. Always direct the needle towards the body. 5. Hold the syringe at the hub and with fingers on top and sides, not underneath as this raises the syringe and puts the needle in at too steep an angle. Use only the fingers to slide the needle labtech 9/25/2013 15 6. 7. in. Stabilize your hand, by placing the little finger against the fingers holding the tail. Do not aspirate. Inject the saline and look for clearance of blood along the vein. A bubble forming in the tail at the site indicates that you are not in the vein. Make your first injection about half way down the tail and move up the tail as you make further attempts (distal to proximal). VIII. Blood Collection: Back to Lab 4 A. General procedures 1. Vasodilatation a) This facilitates blood flow reducing stress to both the animal and the technician. It may be accomplished with chemical (acepromazine) or mechanical means (heat or topical irritants). b) We will produce vasodilatation with heat. (1) Obtain a microwavable gel pack and heat in the microwave (1½ minutes) (2) Place the animal on the pack, with a towel between the pack and the animal. A second towel may be used to cover the animal. (3) The temperature within the toweling should be about 30ºC. Rapid breathing, panting or drooling are indications of hyperthermia. If this occurs, remove the rat from the heating pad. 2. Site preparation a) For most blood collections, you will clip the hair prior to beginning. We will use clippers, but you may also use a scalpel blade or a depilatory. It is not necessary to clip prior to cardiac puncture. b) If hair is clipped, site is usually cleansed to remove debris that may be picked up in the sample. However, excessive cleaning will cause irritation so limit it to a quick wipe with dry gauze or gauze wet with EtOH or warm water or use masking tape to pick up hair. 3. labtech 9/25/2013 When collection is complete a) Remove the needle, and the tourniquet, if one is used. b) Press a clean gauze pad over the point of entry. Apply firm, but gentle pressure. Do 16 c) d) B. Blood collection guidelines from IACUC campus policies: http://safetyservices.ucdavis.edu/ps/a/IACUC/po/bloodVo lumes 1. 2. C. labtech 9/25/2013 not hold so tight as to stop blood flow to the site. Hold continuously for 30 seconds. Do not dab or wipe during this time. Observe the animal for an additional 30 seconds to assure that bleeding has stopped. 1% of body weight collected every 2 weeks. (Body weight is in grams; blood volume in milliliters.) Exp: 200 g rat x 1% = 2 ml Lateral Saphenous vein: Anesthesia is not required, but may be used. BACK 1. Mice may be restrained in a 20 cc syringe case; rats may be restrained in a towel. 2. Occlude the blood vessel. a) Mouse: The hind leg is extended and held between the thumb and Mouse finger. Pinching the skin in the groin helps to extend the leg and to occlude the vein. The hair is shaved using clippers. b) Rat: Wrap the rubber band once around the leg and catch the ends of the band with the hemostats. Rat Twist the hemostats to tighten the band and occlude the vein. 3. The lateral saphenous vein runs over the top of the foot, along the outside of the calf muscle just above the ankle, and up the back of the leg. 4. A 23 g, 1-inch needle is inserted perpendicularly into the muscle to puncture the saphenous vein. The needle is removed and blood is collected from the surface of the skin in a 100 l capillary tube. Collect no more than 100 l to demonstrate 17 5. success. Then cover the puncture with a gauze pad and compressed until bleeding stops. Flexing the foot may also help. If the first puncture is not successful, move closer to the foot and try again. Blood flows from the foot up the leg, so if the vein is damaged, moving upstream is more likely to produce a successful blood collection. D. Submandibular area—Mice only: Blood flows better in an unanesthetized mouse, but the technique requires a very secure restraint. You may choose to try it with or without anesthesia. BACK 1. Directions with pictures: 2. http://www.medipoint.com/html/mouse_phlebotomy.htm l 3. http://www.youtube.com/watch?v=niTVnEAHOko 4. Scruff the mouse and orient it so that you are looking at the cheek. Locate the junction of the mandible and maxillary cheek bones. This is also the junction of the lower facial vein and the submandibular vein. The actual location is not easy to see so we will use the “freckle” as our landmark and move slightly dorsal and caudal from that mark. 5. Using a 5 mm lancet, puncture the skin at that point. Although not visible through the skin, the concentration of vessels makes it relatively easy to find and penetrate a vein. 6. Blood will pool on the cheek. Use a microhematocrit tube to collect blood. 7. Cover the puncture with a gauze pad and compress until bleeding stops. E. Tail vessels: Anesthesia is not required, but we will use to prevent pain to the animal while you are learning a difficult procedure. This technique is a relatively non-invasive way to collect blood from the mouse or rat, but it takes practice, particularly in a pigmented animal. BACK 1. Vasodilatation--the animal must be warm. If you have not already done so, place your rat on a towel-wrapped microwavable gel pack for 5-15 minutes until the veins in the tail are distended. Continue to work with rat on the hot pack during the blood collection. 18 labtech 9/25/2013 2. 3. 4. 5. 6. labtech 9/25/2013 Positioning and tourniquet: a) To collect from one of the tail veins, place the rat in lateral recumbency (on its side). Make a tourniquet by wrapping a rubber band once around the tail, grasping both ends with a hemostat, and twisting the hemostat several turns. This allows the tourniquet to be easily removed. b) To collect from the tail artery, place the rat in dorsal recumbency (on its back) and look for the artery on the ventral surface of the tail from the anus to the tip of the tail. Do not use a tourniquet. Using your non-dominant hand, drape the tail across your first three fingers and under your little finger to form a plateau. Squeeze the tail at each side gently between your thumb and first two fingers to stabilize. Use a 25 g needle without a syringe. Holding the needle by the sides of the hub, insert the needle beveled edge up. It should be parallel to the tail and very superficial. If blood appears in the hub of the needle, use a microhematocrit tube to collect a maximum of 100 µl. If you fail to get blood, move a short distance to try again. a) When collecting from the vein, move distal (away from the body) because blood flow comes from the tip of the tail. b) When collecting from the artery, move proximal (toward the body) because blood flow is coming from the body. Once you fill your microhematocrit tube, remove the needle, and the tourniquet, and use a gauze pad to apply pressure until bleeding stops. 19 F. Cardiac Puncture: Always done under anesthesia and a terminal procedure on mice, rats, and rabbits, it allows for collections of large quantities of blood (approximately 5 to 6% of body weight or 5 - 6 ml/100 g bwt in the rat). Use a 23 g, 1 to 1 ½-inch needle and a 1 cc syringe for the rat, a 25 g, 5/8-inch needle for the mouse. Back to Lab_4 1. Palpate the notch between the xiphoid process and the last rib. This is your point of entry. 2. Insert the needle into the notch, parallel to midline and at a 30 angle. Insert smoothly; hesitation may cause the needle to deflect the heart. Insert until the hub is slightly underneath the last rib 3. Pull back on the plunger to form a vacuum. If blood does not flow into the syringe, keeping the plunger pulled out about 0.1 cc, pull the needle out slowly. If the needle went through the heart, it may reenter. If blood still doesn’t flow, remove the needle completely and start again. Keep the needle moving in a straight line. Excess movement in the chest cavity could lacerate organs. 4. Collect a minimum of 0.1 cc to demonstrate correct placement. Then, remove the needle. 5. This is a terminal procedure due to the risk of thoracic bleeding. G. Auricular (Ear) vessels (rabbit only) BACK 1. Blood collections do not require sedation, but a sedative will make the procedure easier on both the animal and the technician. Acepromazine is commonly used because it provides vasodilatation as well as sedation. A topical analgesic is often used, either in place of, or in addition to the sedative. 2. The marginal ear vein can provide up to 5 cc. We will practice this technique, collection 100 µl per attempt. a) Clip hair to improve visibility. b) Apply prilocaine, a topical analgesic. Allow this to sit on the ear about 5 minutes. Then wipe it off before inserting the needle. labtech 9/25/2013 20 c) 3. IX. Use a paper clip on gauze placed proximal to the point of entry as a tourniquet. d) Hold a roll of gauze under the ear to stabilize. e) Insert a 25 g needle into the vein. Needle should be inserted parallel to the ear; the vein sits above the surface of the skin. f) Pull blood from the hub of the needle into a microhematocrit tube for small volumes. g) If larger volumes are needed, you would use a 22 g needle and a small syringe. Draw back slowly to prevent the vein from collapsing. The central artery can be used for volumes up to 50 ccs. We will not attempt this technique in class. a) Don't use a tourniquet. b) Use a 20 g needle with a Vacutainer tube or break the hub off of the needle and allow blood to drip from the end of the needle into a test tube. Oral dosing/stomach tubing/gavage Back to Lab 3 A. This is a technique used to deliver fluids directly into the stomach. It allows for a measured dose to be delivered at a specified time. It is also used when solutions are unpalatable or degraded by enzymes in the mouth. B. A stomach tube (feeding tube or gavage needle) is a needle with a ball on the end. A properly sized needle will have a ball which allows easy passage into the esophagus but which is too large to pass through the larynx into the trachea. C. Feeding tubes come in straight or curved and in stainless steel or plastic. We will use plastic because it tends less traumatic to the animal, but it is possible for the animal to chew the tube. Try to prevent this by not hesitating once you have inserted the tube. However, this is not always possible to prevent. If chewing occurs, the tube may be rough and cause trauma to the esophagus or the tube may break and the animal may swallow part of it. If the tube becomes rough, replace it. If the animal swallows part of the tube, let me know. It may regurgitate the tube, but if not we will euthanize the animal. labtech 9/25/2013 21 D. labtech 9/25/2013 Technique for stomach tubing--You may practice this technique on a lightly sedated animal but not on an animal that has been heavily sedated. The muscles of the trachea in a heavily sedated or anesthetized animal are too relaxed to prevent entry of the tube into the lungs, which could result in trauma. 1. Attach a gavage needle to an empty syringe. 2. Measure the tube. The needle should extend from approximately the tip of the nose to the last rib. 3. Dip the tip of the needle into the sucrose solution to trigger the swallowing reflex and to increase the animal’s acceptance of the tube. 4. Restrain the rat and hold against your body leaving your dominant hand free. The mouse does not need to be held against your body—a single hand hold is sufficient. 5. Insert the tube into the mouth by sliding it into the diastema and then pulling it to the front of the mouth. Straighten your first 2 fingers against the animal’s jaw to pull its head back. Use the tube as a lever to tip the animal's head back forming a straight line from the mouth to the esophagus. 6. Pass the tube along the palate to the larynx. Time entry into the esophagus with the swallowing reflex. 7. Slide the tube down the esophagus into the stomach. When the hub of the needle is at the mouth, the end should be in the stomach. 8. If you were delivering a sample, you would depress the plunger on the syringe at this point to deliver the correct dose. 9. Remove the needle carefully. Observe the animal for signs of distress. Resistance on the needle or struggling from the animal could mean improper placement. Remove the tube and try again. 22 X. Scalpel Use Back to Lab 1 A. Loading and unloading the scalpel blade onto the handle. 1. Open the package and pick up the blade with a pair of hemostats. Position the blade in the hemostats so that the blade faces away from your hand. 2. Slide the opening of the blade over the raised portion of the handle until it clicks into position. 3. To unload, turn the handle over so the raised portion faces the counter. Hold the handle over the sharps container. Use the hemostats to pop the blade off into the sharps container. B. Scalpel grip 1. Pencil grip--hold the scalpel handle as a pencil. This allows for greater precision over short distances. Most appropriate grip for our work. 2. Fingertip grip--hold the scalpel handle between fingertips and thump tip. Allows for greater control with a longer range of motion. May be more comfortable for rat dissections. C. Incision technique 1. Use one hand to exert tension on the skin longitudinally and laterally to stretch the cutting surface by placing the first finger and thumb on either side of the incision line. This hand will move as the blade progresses to keep enough tension to see the cutting edge. 2. The scalpel blade is place behind (not between) the fingers. The blade slides in a straight line. Enough pressure should be exerted to cut through the skin, but not the underlying muscle layer. Try not to lift the scalpel blade until the incision is finished. labtech 9/25/2013 23 XI. Suturing Back to Lab 1 A. Suture needles 1. Round needles are used for soft tissue. 2. Cutting needles with a triangular cross-section are used for tough tissues like skin. B. Suture material 1. Non-absorbable suture is used primarily for skin where it can be removed. If left in the body, it will become encapsulated in fibrous tissue. The most common material is braided silk although nylon and even stainless steel may be used. 2. Absorbable suture loses tensile strength and then breaks down and is absorbed by the body, usually within 60 days. Examples include catgut, chromic gut, and Vicryl. These are used for internal sutures. C. Suture size 1. Largest diameter 5 (0.7 mm) to smallest 11/0 (0.01 mm) (11/0 is pronounced 11 “ought”) 2. In mice and rats is 3/0 or 4/0 is most common. D. Hemostat 1. The loops of the hemostat should be around your thumb and 3rd finger. 2. Your first finger guides the tip. Your second finger guides the base. E. Simple interrupted sutures 1. Position the needle in your left-hand hemostat. Hold the needle between the center of the curve and the swag (threaded end). Pick up one side of the incision with a pair of rat-toothed forceps and insert the needle in, taking a “bite” of about 5-8 mm. Pick up the opposing side of the incision directly opposite the first and insert the needle in it. (You can sometimes pick up both sides at once but watch for slipping.) 2. Switch to a hemostat in your right hand, use it to grasp the needle and pull it through the tissue holding your left hand hemostat against the incision as a brace if needed. Pull the suture material until only 2-3 cm is left on the left side of the incision. 3. Let go of the needle and move the hemostat in your right hand to a point in the suture material about 10 cm from the right side of the incision. Alternatively, you may use your hand to hold the suture material instead of a hemostat. labtech 9/25/2013 24 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. F. labtech 9/25/2013 Wrap the suture material in your right hand (long end) around the closed tip of the hemostat in you left hand twice forming two loops. This wrap is counter-clockwise; over the top and to the center. Grab the short end of the suture material with the hemostat in your left hand. Pull the short end of suture through the two loops and tighten by crossing your right hand over your left; continue in the same direction as your wrap. Do not let go of the suture in your right hemostat (or hand) or change the position of your hands at this point. Let go of the suture in the left hemostat and staying “inside the V,” wrap the long end of suture around the hemostat once. This wrap is clockwise; over the top and toward the center. Using the left hemostats, again grasp the loose, or short, end of suture. Pull it through the loop and uncross your hands to tighten the knot (again continuing in the same direction as your wrap). You have now completed a square knot Do not let go of the suture in your right hemostat (or hand) or change the position of your hands. To make a locking stitch, let go of the suture in the left hemostat and staying “inside the V,” wrap the long end of suture around the hemostat once. This wrap is counter-clockwise. Pick up the short end of suture, pull it through the loop and cross your hands to tighten. Cut the suture ends to about 5 mm in length. Make your next stitch about 8-10 mm away. You may reverse this procedure, by driving the needle in from right to left, however, you will have to wrap the opposite directions and cross left over right to tighten the knot. 1. Always wrap over to under. 2. Always tighten in the same direction in which you are wrapping. 25 XII. Anesthesia A. Drugs we will use for pain management Drugs Acepromazine Ketamine Lidocaine 1% Prilocaine Xylazine B. Actions Sedative, Vasodilator Dissociative anesthetic Local anesthetic Topical analgesic Sedative, Analgesic Muscle relaxant BACK to Lab 4 Commercial Concentration 10 mg/ml 100 mg/ml 10 mg/ml 25 mg/g 20 mg/ml 100 mg/ml Drug dosages 1. Drug dosages are given in a formulary put out by various veterinary organizations. Dosages are usually expressed as a range and may vary from one formulary to another. Your choice within the range may depend on the procedure, as well as the line, age, sex, etc., of the animal. 2. Formulary dosages are expressed in mg/kg. The actual delivery dosage will be in ml/kg and must be calculated based on the commercial concentration of the drug (from above table). The drugs are sold in differing concentrations so read the label carefully to be sure you have the correct concentration. Formulary dose x 1/conc. = delivery dose Species/ Drug Formulary dose Inverted Delivery Use Used in lab Commercial Dose Conc Rat & mouse/ Acepromazine 0.5 mg/kg 1 ml/10 mg 0.05 ml/kg Sedation Rat & mouse/ Clinical Ketamine Xylazine (100 mg/ml) Acepromazine Rat/Surgical 3. labtech 9/25/2013 Ketamine Xylazine 50 mg/kg 1 ml/100 mg 0.5 ml/kg 5 mg/kg 1 ml/100 mg 0.05 ml/kg 0.5 mg/kg 1 ml/10 mg 0.05 ml/kg 1 ml/100 mg 1 ml/20 mg 0.9 ml/kg 0.45 ml/kg 90 mg/kg 9 mg/kg Note that some of the delivery doses are too small to accurately measure when calculated for an animal that weighs less than 1 kg. 26 C. Dilution 1. Drugs often come in concentrations too high to accurately measure when drawing up volumes for small rodents. We correct for this by diluting drugs with sterile water, saline, or another appropriate vehicle. The drugs we use in this class will be diluted with sterile water. 2. Acepromazine is diluted to different volumes for rats and mice because of their 10-fold weight difference. Concentration of drug x volume concentrated drug/total volume = diluted concentration Diluted concentration (inverted) x formulary dose = diluted delivery dose Species/ Use Rat sedation Mouse sedation Commercial Conc. 10 mg/ml Dilution factor* 1:10 Diluted conc 1 mg/ml Formulary dose 0.5 mg/kg Del Dose (dilute) 0.5 ml/kg 10 mg/ml 1:100 0.1 mg/ml 0.5 mg/kg 5 ml/kg *Dilution factor = 1:n+1 where n+1 equals total volume Dilution ratio = 1:n (ratio of solute to solvent) D. Drug combinations for balanced anesthesia 1. Acepromazine alone (above): Instructors will use in lab 1 to produce light sedation for handling of mice or rats. This drug will calm the animal but the animal will remain conscious. 2. labtech 9/25/2013 Ketamine:Xylazine:Acepromazine: This cocktail will provide anesthesia for clinical techniques. Ketamine is an anesthetic. Xylazine and acepromazine are sedatives. Adding sedatives will calm the animal thereby reducing the amount of anesthesia required. Ace is also a vasodilator making it easier to collect blood. In the table below, we are mixing drugs and diluting with water to make a cocktail that will provide balanced anesthesia in an easily measurable dosage. Animals will lose consciousness and will not feel pain; however, they may not lose the toe pinch reflex. 27 Set delivery dose Target Dilution: Dilution Factor: Cocktail volume: dilution factor. so all drugs are equal in volume divide delivery dose by formulary dose Multiply target dilution by concentration Determine the required total volume and divide by the Drug Delivery dose Ket Xyl Ace Water 1 ml/kg 50 mg/kg 1 ml/50 mg 100 mg/ml 1 ml/kg 5 mg/kg 1 ml/5 mg 20 mg/ml 1 ml/kg 0.5 mg/kg 1 ml/0.5 mg 10 mg/ml Water or solvent needed to reach total volume 3. Target dilution Concentration Dilution Factor 2 4 20 Total volume 20 ml 10 ml 5 ml 1 ml 4 ml Calculate the delivery dose of the pre-mixed cocktail for rats. a) Weight the rat and convert to kilograms Kg = g bwt/1000 b) 4. Formulary dose Multiply the weight in kg times the delivery dose of 1 ml/kg 1 ml/kg x __________ kg = ________ ml Mice: Mice require a higher dilution of the ket:xyl:ace cocktail since a typical mouse weighs about 30 grams and the rat dose would be 1 ml/kg x 0.03 kg (30 gram) = 0.03 ml which is impossible to measure accurately with our syringes. We will dilute the rat anesthesia 1:10 for mouse anesthesia. The dose will be 10 ml/kg (0.1 ml/10 grams) so the delivery dose for a 30 g mouse will be 0.3 ml. a) Weigh the mouse in grams. b) Calculate the delivery dose of the pre-mixed cocktail for mice: 0.1 ml/10 grams x _______ grams = ________ ml labtech 9/25/2013 28 5. Ketamine plus xylazine (rats): This will provide a surgical plane of anesthesia for surgical procedures in lab 6. Ketamine is again the anesthetic. We will continue to use xylazine as the sedative and a muscle relaxant to prevent trauma caused by surgical manipulations. Both will be at higher dosages to maintain a prolonged period of anesthesia. We will not use acepromazine as vasodilatation is contra-indicted in a surgical procedure. In this case, we are adding 1 ml of xylazine to a 10 ml bottle of ketamine. Drug Delivery dose Formulary dose Target dilution Concentration Dilution Factor Ket Xyl 1 ml/kg 1 ml/kg 90 mg/kg 9 mg/kg 1 ml/90 mg 1 ml/9 mg 100 mg/ml 100 mg/ml 1.1 11 Total volume 11 ml 10 1 E. Draw up dose and administer the anesthetic: 1. Use a 1 ml syringe with the appropriate needle—23 gauge for rats, 25 gauge for mice. 2. Note: If your calculations give you a final volume of more than 1 cc, please check your calculations. 3. Once you have completed your calculations, see the instructor or TA for the anesthesia. 4. Inject the anesthesia IP. 5. Record dose and time on the anesthesia log sheet provided in lab. F. Monitoring anesthesia: Monitor the depth of anesthesia throughout the procedure and administer a supplemental dose if the animal becomes light. 1. Pedal withdrawal or toe pinch reflex: The best method of monitoring rodents for a surgical plane of anesthesia is by using the spinal cord reflex of the toe. When you pinch the toe (using your fingernail or a pair of forceps), the foot withdraws away from the stimulus. Since reflexes are reflexes are suppressed from head to toe under anesthesia, the toe pinch reflex is one of the last reflexes lost. Note: It is not necessary for this reflex to be suppressed for clinical techniques and it may not disappear with the light anesthesia. It should disappear with the heavy anesthesia used for surgery in lab 6. labtech 9/25/2013 29 2. 3. 4. 5. Purposeful movement or vocalizations, those in response to touch or painful stimuli, indicate that the animal is light. Muscle tone: An increase in tone, as demonstrated by chewing or whisker movement, means animal is light. Breathing patterns: Rapid and shallow if light; slow and gasping if deep. Color of mucus membranes (O2 levels)--blue or clear if too deep. G. Supplemental doses: Although the loss of the pedal withdrawal reflex is our major sign that the animal has reached a surgical plane, it may not disappear under the light anesthesia dose. The animal should be unconscious and unresponsive to stimulus before you begin your procedures. If your rat does not achieve this level from the initial dose, or if it becomes light during your procedures, supplement with ketamine only (no acepromazine or xylazine unless directed to by the instructor or TA). 1. Supplemental Ketamine: This should be administered at a dose of 1/3 to 1/2 of the original dose. Use a 1/3 dose when toe pinch reflex is slight. Use a 1/2 dose when toe pinch reflex is strong or animal still exhibits the righting reflex. You may need to use the 1/2 cc syringe to accurately measure this dose for smaller animals. Syringe units: 50 units = 0.5 ml Low dose (1/3 x 0.9 ml): 0.3 ml/kg High dose (1/2 x 0.9 ml): 0.5 ml/kg H. Record keeping: Record all drugs administered on the Anesthesia Log (provided in class). 5. Surgical records are required by the AWA and PHS. 2. Ketamine is a controlled substance (Schedule III) and records of its use are required by the FDA. XIII. Euthanasia A. Ask for assistance in using the CO2 chamber. If you prefer, you may ask the instructor or TA to euthanize your animal for you. If you do not need to use the euthanized animal, leave it in a cage with a cage top on the back counter and we will euthanize the animals in a group. B. Place the animal to be euthanized in the CO2 chamber located in the back of the room. labtech 9/25/2013 30 C. D. E. Turn on the gas using the large knob on top of the tank to start the flow. Turn counterclockwise. Then use the small round knob on the regulator to release the gas into the chamber. Euthanasia will take 2-3 minutes for a mouse, 3-5 minutes for a rat. Look for cessation of breathing. Leave the animal in the chamber for 1 minute after all signs of life have disappeared. If the animal is not being dissected, insert a scalpel blade into the thoracic cavity (thoracic punch) to assure death. Back to Lab 4 XIV. Dissection: BACK to Lab 2 A. Use the following websites to prepare for lab and to study for tests. There are also several good books on anatomy at the Health Sciences Library. See the recommended resources on the class website for some suggestions. 1. Virtual necropsy: http://tvmouse.compmed.ucdavis.edu/ 2. Labeled dissection: http://www.utm.edu/staff/rirwin/public_html/RatAna t.htm B. Locate the organs and landmarks in the abdominal and thoracic cavities and in the neck that are found on your list of anatomical structures to identify. Note: The heart will beat for several minutes following death. This is because the sinoatrial node will stimulate beating as long as there is ATP in the cells. XV. C. Obtain the bone shears to decapitate your rat or ask for help with this procedure. Examine the brain and find the structures on your list. D. Look at animals from other groups to note anatomical variation between sexes and individuals. Clean up. BACK A. Dispose of animal carcasses and tissue in the appropriate bag for incineration. Include any bloodcontaminated material, i.e., gloves or gauze, in the bag. labtech 9/25/2013 31 B. Dispose of sharps (disposable suture needles, injection needles and syringes, scalpel blades) in Sharps container. C. Scrub your instruments using Nolvasan and a brush. Rinse and dry them. Then sort them as directed. DO NOT PUT WET INSTRUMENTS AWAY. They will rust. D. If a heating pad has been used, wash it with either hand soap or Nolvasan, dry it, and return it to the Styrofoam container. E. Return your lab coat and any appropriate bag to be laundered. F. Wash your hands before leaving. labtech 9/25/2013 cloth towels to the 32 XVI Back to Ear Notching Ear Notch Code for Cole B labtech 9/25/2013 33 XVII Anatomy: Be sure that you can identify the following structures in dissected animals, the rabbit model, and in diagrams. Back to Lab 2 Blood vessels Reproductive--female Thoracic cavity Lateral saphenous vein Cervix Lungs Tail vein (mouse/rat) Uterine horns Heart Tail artery (mouse/rat) Oviduct Diaphragm Auricular artery (rabbit) Ovary Thymus Reproductive-male Neck Peritoneal cavity Preputial gland Salivary glands Xiphoid Process Testes Trachea Stomach (Pyloric) Epididymus Esophagus Stomach (Cardiac) Gubernaculum Thyroid Duodenum Pampiniform plexus Masseter muscle Pancreas Vas deferens Small Intestine Seminal vesicles Head Cecum Coagulating gland Cerebral hemispheres Large intestine Prostate gland Cerebellum Liver Penis Pineal gland Auricular vein (rabbit) Gallbladder (mouse/rabbit) Olfactory nerves Urinary Bladder Optic nerve & chiasm Kidney Hypothalamus Adrenal gland Pituitary (Ant. & Post.) Spleen Harderian gland labtech 9/25/2013 34 XVIII ANATOMICAL TERMS FOR DIRECTION Cranial Caudal Toward the head Toward the tail Dorsal Ventral Toward the back or top Toward the abdomen Back to Lab 2 Anterior Toward the head Posterior Opposite to the head Superior Inferior Above Below Medial Lateral Toward the middle or midline of the body Toward the side or away from the middle or midline Proximal Distal Nearer the long axis of the body or a reference point Away from the long axis of the body or reference point Palmar Plantar Relating to the palm of the forelimb Relating to the sole of the hindlimb Oral Concerning the mouth Rostral Toward the nose Recumbency: Position in which an animal is lying Sternal recumbency: lying on its abdomen Lateral recumbency: lying on its side Dorsal recumbency: lying on its back labtech 9/25/2013 35 Superior Dorsal Cranial Anterior Caudal Posterior Superior Anterior Cranial Inferior Ventral Ventral lateral medial Proximal labtech 9/25/2013 Dorsal Distal Caudal Posterior 36 Inferior Crossword puzzle to study anatomical directions—Answers are posted separately. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Across Down 1. 3. 6. 8. 11. 12. 14. 15. 16. 2. 4. 5. 7. 9. 10. 13. Toward the tail Relating to the sole of the hindlimb Relating to the palm of the forelimb Away from the midline of the body Concerning the mouth Closer to a specific point on the body Above Toward the head Toward the rear labtech 9/25/2013 Further from a specific point on the body Toward the abdomen Toward the midline of the body Toward the front Toward the nose Toward the back Below From Techtalk Vol.15, No.4 Aug 2011 37
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