Laboratory Techniques and Procedures Objective 4.01: Implement proper techniques for collection and analysis of laboratory samples

Circulatory System Functions Heart, blood, vessels, and lymphatics Functions: ◦ Respiratory – O 2 and CO 2 exchange ◦ Excretory – removes waste from body cells ◦ Protection – clotting and transporting white blood cells to infections ◦ Nutrition – carries energy and food throughout the body ◦ Regulatory – maintain pH and temperature ◦ Hormonal – transfers hormones to organs

Circulatory System Components Heart – muscular, four-chambered pump that drives the circulatory system Pericardium – fibrous sac that encloses the heart Artery – elastic vessel with thick walls to maintain high pressure while carrying blood away from the heart Vein – thin-walled vessel that carries deoxygenated blood to the heart

Capillary – microscopic vessel that forms a network between arteries, veins, and body tissues Lymph system – consists of lymphatic vessels & tissues (tonsils, thymus, spleen, lymph nodes) that play an important role in immunity and disease prevention

Lymph node – bean-shaped structures located throughout the body that produce lymphocytes and monocytes, and filters bacteria, foreign bodies, and malignant cells Spleen – largest lymph organ, produces lymphocytes and monocytes, stores red blood cells and iron, and destroys old red blood cells

Blood Circulation Through the Heart Problems in the right side of the heart will cause the abdomen to fill with fluid (ascites) Problems in the left side of the heart will cause lung congestion Flow of blood through heart in this order: right atrium  right ventricle  pulmonary arteries  lungs  pulmonary veins  left atrium  left atrium  left ventricle  aorta

Cardiac Cycle Video OF6wEnk OF6wEnk

Major Arteries & Veins Aorta – largest artery that sends blood from the heart to the body Brachiocephalic – branches from the aorta to send blood to the head and right side of the body Common carotid arteries – (left & right) run up both side of the neck and supply blood to the head

Coronary arteries – wraps around the exterior of the heart and supply blood to the heart muscle Facial artery – wraps under lower jaw and is used to take the pulse on a horse or cow Femoral artery – runs down the inside hind leg; used to take the pulse on a cat or dog Mesenteric – supplies blood to the intestines

Renal artery – supplies blood to the kidney Pulmonary arteries – carry deoxygenated blood to the lungs Pulmonary veins – carry oxygenated blood to the left atrium Cranial vena cava – returns blood to the heart from the head, neck, and forelegs Caudal vena cava – returns blood to the heart from the thorax, abdomen, and hind legs

Cephalic vein – runs along the front of the foreleg Jugular vein – runs down the neck and returns blood from the head Renal vein – returns blood from the kidney to the caudal vena cava Femoral vein – runs along the inside of the hind leg Saphenous vein – an extension of the femoral vein

Heart

Major Veins

Major Arteries

Structure of Blood Composed of cells and plasma (liquid portion of blood) ◦ 40% cells  Erythrocytes (red blood cells)  Leukocytes (white blood cells)  Platelets ◦ 60% plasma Typically blood volume comprises 6% - 8% of the animal’s total body weight

Blood Cells Hematopoiesis blood formation & development The formation and development of blood cells

Blood Cells All blood cells develop in the bone marrow from one type of cell called a hemocytoblast In young animals blood is produced in all bones In adult animals blood is produced in the pelvis, ribs, vertebrae, femur, and humerus

Erythrocytes (Red Blood Cells) Most abundant blood cell Function: to transport O 2 throughout the body Contains: hemoglobin (a pigment that contains iron and gives blood its red color when combined with O 2 )

In mammals the red blood cell is non-nucleated In reptiles and birds the red blood cell is nucleated Red cell’s life span in dogs and humans is 120 days, but it varies among different species

Leukocytes (White Blood Cells) Colorless, nucleated cells capable of moving throughout the body Function: body defense Divided into two categories: ◦ Granulocytes ◦ Agranulocytes

Granulocytes Produced in the bone marrow Have lobed nuclei and granules in their cytoplasm Neutrophils, basophils, and eosinophils

Neutrophil Has red and blue granules in cytoplasm Function: stop or slow down foreign organisms How they work – 1.Phagocytosis: to eat bacteria and dead cells 2.Bactericidal: kill bacteria How they get to infection site – 1.Sticky and can migrate through vessel walls 2.Release chemicals to attract other neutrophils to the infection site

Basophil Has dark purple granules in cytoplasm Function: phagocytosis, mediate allergic reactions, and produce heparin and histamine

Eosinophil Has orangish-red granules in the cytoplasm Function: moderate the inflammatory response and phagocytosis

Agranulocytes Produced in lymphatic organs Have rounded nuclei, and no granules in the cytoplasm Lymphocytes and monocytes

Lymphocytes Has a round nucleus and plays a vita role in immunity Two categories: 1.T-cells (memory cells) – long-lived; once they are sensitized to an antigen, they remember it so that next time they can fight off that antigen 2.B-cells – encounter an antigen and divide to form many cells that all produce the same antibodies to fight the antigen

Monocyte Has an irregular shaped nucleus Largest cell in the blood Function: phagocytosis

Thrombocytes (platelets) Main function: hemostasis (clotting) Platelets are 1/3 the size of a red blood cell Stop bleeding by adhering to damaged vessels and clumping together and releasing proteins that help form a clot Average life span: 10 days

Hematology Study of the structure of blood and the tissues that produce blood Lab tests most commonly performed in vet medicine: ◦ PCV or hematocrit ◦ White cell count ◦ TPP (total plasma protein) ◦ Blood film evaluation

PCV – Packed Cell Volume Measures percentage of red blood cells in the total blood volume Capillary tube is filled with fresh anticoagulated blood, sealed with clay, and centrifuged for five minutes Results read using special scale Animal with PCV below normal is said to have anemia

Normal PCV values: Dog: 37 – 55 Cat: 30 – 45 Horse: 32 – 48 Bovine: 24 – 46

TPP – Total Plasma Protein Measurement of proteins produced mainly by the liver Measured using a capillary tube of blood, broken at the plasma layer, plasma placed on a refractometer Elevated TPP is a sign of inflammation, infection, or dehydration Decreased TPP occurs normally in newborns and pregnant animals

Blood Film Evaluation Used to determine size, color, and shape of cells and abnormalities in their formation Used to look for blood parasites such as microfilaria of the heartworm

Prepared by spreading a drop of blood on a slide, drying the slide, staining with Wright’s stain Evaluated by scanning under high power for abnormalities Abnormalities appear in the RBC as color changes in the cell, abnormal cell shape and size, and foreign bodies within the cell

Blood Chemistry Procedures Vacutainer tubes have a vacuum created to place a needle and syringe into a rubber plunger Different tubes for specific requirements – different colors to identify

Red Top – sterile or no anticoagulant that contains a gel separator Tiger Stripe – contains no silicone, gel separators, anticoagulants, or additives of any kind Lavender Top – sterile, contains EDTA as the anticoagulant Green Top – sterile, contains lithium heparin as the anticoagulant Light Blue Top – sterile, contains sodium citrate as the anticoagulant Gray Top – sterile, contains potassium oxalate and sodium fluoride as the anticoagulant

Each test requires a specific amount of blood, serum, or plasma to run the sample Allow the samples that require centrifuging at least 30 minutes to clot prior to spinning but not more than 60 minutes

Specific Procedures Complete Blood Count – evaluates the different types of WBCs Blood Smear – evaluates blood cell morphology

Specific Procedures PCV – measurement of the percentage of RBCs in whole or unclotted blood (also a hematocrit) Plasma Protein (total protein) – measures the ratio of protein within the blood and checks the hydration of the patient

Videos Veterinary Blood Testing: U2sqRtU U2sqRtU Vet Tech Training-Basic Blood Collection: DIQ91c DIQ91c

Urinary System Major organs: ◦ Kidneys ◦ Ureters ◦ Urinary bladder ◦ Urethra Function: to extract and remove waste from the blood

Kidneys Responsible for extracting and collecting waste Paired organs located on both sides of the spinal column Bean-shaped in most species of animals Kidneys of cattle have several lobes

Parts of the kidney Cortex Medulla Renal pelvis Nephrons ◦ Located throughout the cortex and medulla ◦ Functioning units of the kidneys ◦ Responsible for filtering and collection of waste from the blood ◦ Collecting ducts run through medulla and drain into renal pelvis

Ureters Urine then passes into the ureters and proceeds to the bladder Smooth muscled tubes that extend from each kidney Use peristalsis to move urine to the bladder Urine is pushed into the bladder every seconds depending on the species Flows in spurts rather than continuously

Bladder Smooth muscle, extremely elastic sac Capable of holding large volumes of urine Has three openings ◦ Two that receive urine from ureters ◦ One used to excrete urine to the urethra

Urethra Carries urine from the bladder to the exterior Varies in length and circumference in males and females ◦ Female urethra is shorter in length and runs directly from bladder to the exterior ◦ Males have narrower urethra that is longer to extend through the accessory sex glands and exit through the penis

3 Phases of Urine Production 1. Filtration 2. Reabsorption 3. Secretion Occur in the nephrons

Filtration Blood enters the glomerulus through the afferent arteriole Under various pressures, water, salt, and small molecules move out of the glomerulus and into Bowman’s capsule

Reabsorption Occurs in the proximal convoluted tubule and the loop of Henle Substances needed by the body such as water and electrolytes will be reabsorbed by the body from the loop of Henle

Secretion Substances are secreted into the collecting tubules and transported to the renal pelvis Urine Production: 5iwTQvM 5iwTQvM

Urinalysis Provides information about how the kidneys are functioning and if wastes are being properly filtered from the body Specimen Collection ◦ Free Catch ◦ Manual Expression ◦ Catheterization ◦ Cystocentesis