Blood Flashcards
list the 9 functions of blood
- distribution of nutrients
- oxygen transport
- CO2 transport
- transport of waste products
- hormone transport
- body temperature control
- maintain pH of body fluids
- blood loss prevention
- defense of body against disease
list and describe the 3 components of blood
- formed elements: RBCs, WBCs, platelets
- plasma: fluid portion
- buffy coat
what is the main component of plasma?
water
list the 7 components of plasma
- water
- proteins
- nutrients: glucose, fatty acids, vitamins and minerals
- electrolytes: Na+, K+, Ca+
- hormones
- buffers: bicarbonate
- waste products: urea
list the 3 proteins found in plasma and describe if needed
- albumin
- globulins: antibodies are immunoglobulins
- fibinogen: plays a role in clotting
why do you need to include an anticoagulant when collecting plasma?
since it contain fibrinogen, it will clot unless an anticoagulant is present
what is serum?
all components of plasma except fibrinogen, no anticoagulant needed when collecting
list the 3 formed elements
- erythrocytes (RBCs): 45% of blood
- leukocytes (WBCs): 5 types
- thrombocytes (platelets): clotting, cell fragments
what is hematopoiesis?
formation and development of the formed elements of blood in the red bone marrow
what are hematopoietins?
chemical signals that determine the formation of formed elements
describe the structure of erythrocytes
biconcave disks with no nuclei (except for in chickens) meaning they have a finite lifespan
what is hemoglobin?
a major component of RBCs, consists of 1 globin protein and 4 heme groups, with each heme group containing an iron (Fe2+ ferrous) that LOOSELY and REVERSIBLY binds to oxygen
what do erythrocytes do?
transport O2 from lungs throughout body and CO2 from cells in the body to the lungs
when does oxyhemoglobin form?
when O2 binds to hemoglobin in the lungs
when does carbaminohemoglobin form?
when CO2 binds to hemoglobin
when does carboxyhemoglobin form and why is it bad?
when carbon monoxide (CO) binds very tightly to hemoglobin, prevents O2 from binding to hemoglobin = no O2 transport = suffocation
what is nitrate poisoning?
when nitrate converts ferrous iron (Fe2+) to ferric iron (Fe3+), which can’t bind to oxygen, forming methemoglobin, turning blood a chocolate color
where is nitrate found, which can cause nitrate poisoning?
on freshly fertilized pastures
what is erythropoiesis?
formation of erythrocytes
what is erythropoiesis stimulated by?
erythropoietin, which is produced by kidney cells
when is erythropoietin released?
when kidneys sense decreased O2 delivery and release erythropoietin, which stimulates erythropoiesis in red bone marrow, leading to the production of RBCs
how is the release of erythropoietin stopped?
more erythrocytes will deliver O2 to kidneys, which inhibits further release of erythropoietin (negative feedback)
how are erythrocytes removed from circulation (broad)
by macrophages in the liver and spleen, which perform phagocytosis
describe what happens to the globin protein when hemoglobin is broken down
the globin protein is broken down into amino acids that are used for new protein synthesis
describe what happens to the iron from the heme group when hemoglobin is broken down
iron is transported through blood, bound to transferrin, then stored in the liver as ferritin, or used by red bone marrow for erythropoiesis
describe what happens to the heme group when hemoglobin is broken down
the heme group is converted to biliverdin (green), then to bilirubin (yellow), which is then incorporated into bile in the liver
what happens to bile once it leaves the liver?
it is secreted into the small intestine, and then reacts with bacteria in the large intestine, which gives feces it characteristic color, or it leaves the kidneys through urine
list 6 conditions of RBCs
- icterus/jaundice
- hemoglobinemia
- hemoglobinuria
- hemogglutination
- anemia
- polycythemia
describe icterus/jaundice
yellow discoloration of skin and mucus membranes
what causes icterus/jaundice?
bilirubin builds up in blood, caused by liver damage or bile duct damage, or increased rate of erythrocyte destruction
what is hemoglobinemia?
buildup of free hemoglobin from hemolysis
what is hemolysis?
breakdown of RBCs and release of free hemoglobin
what color is plasma when hemoglobinemia is occurring?
red
what is hemoglobinuria?
excretion of hemoglobin in urine, urine is red
what causes hemoglobinuria? (3)
bacterial toxins, snake venom, parasites
what is hemagglutination?
clumping (agglutination) of RBCs
describe the physiology of why hemagglutination can occur
RBCs have antigens (proteins) on their surface, and animals produce antibodies for proteins/antigens that are not found on the surface of their RBCs, so if a blood transfusion is given to an animal with different antigens on their RBCs than what is given, hemagglutination occurs
what is anemia?
a decrease in the number of functional RBCs
what 3 things can cause anemia?
kidney damage/failure, iron deficiency, bone marrow disease
what is hematocrit/packed cell volume (PCV)
the percentage by volume of whole blood that is erythrocytes
what is a normal PCV?
35-45%
what is polycythemia?
decrease in the fluid portion of blood, less plasma due to dehydration
what are the 2 classes of leukocytes?
- granulocytes
2. agranulocytes
describe how granulocytes are classified, and list all 3
classified based on presence of cytoplasmic granules
- neutrophils
- eosinophils
- basophils
describe how agranulocytes are classified and list both of them
based on the absence of cytoplasmic granules
- lymphocytes
- monocytes
what are neutrophils
the most common WBC, phagocytic cells that cause pus, the first responders during an infection
what are bird neutrophils called?
heterophils
describe what neutrophils look like
segmented , skinny nuclei, clearish cytoplasm
what do eosinophils do?
respond to parasitic infections, release granules to kill parasites
describe what eosinophils look like
pink staining bumpy granules
describe basophils’ function
release granules to kill parasites
what are the least common WBCs?
basophils and eosinophils
describe monocytes
2nd most common WBC, and the largest, enter tissues and become macrophages (phagocytic cells)
what do monocytes look like?
will typically see an indentation in nucleus, very big nucleus, peanutish
list and describe the 2 types of lymphocytes
- T lymphocytes: kill virally infected cells
2. B lymphocytes: produce antibodies
describe what lymphocytes look like
smallest WBC, can’t visually see difference between T and B
what is a Differential WBC Count?
tells percent of each type of WBC in a sample
what are platelets?
fragments of megakaryocytes
what is the function of platelets?
reduce blood loss from injured blood vessels
what is hemostasis?
the stopping of bleeding, 3 steps
what are the 3 steps of hemostasis?
- vasoconstriction
- platelet plug formation (has 7 steps)
- coagulation
describe vasoconstriction
smooth muscle of injured vessel contracts to decrease size of the hole/tear
list the 7 steps of platelet plug formation
- collagen fibers from underlying connective tissue are exposed
- platelets bind to exposed collagen fibers
- platelets become activated and release thromboxane A2
- Thromboxane A2 attracts more platelets to site of injury
- additional platelets bind to activated platelets
- platelets plug up the hole in the injured vessel
- activated platelets express a receptor for fibrinogen
what do healthy epithelial cells release while the platelet plug is forming and what does it do?
they release prostacyclin, which inhibits platelet plug formation as a way to stop the plug once fully formed
describe coagulation
a series of reactions to produce fibrin
what is the main result of coagulation?
fibrinogen binds to activated platelets and reactions occur to activate it to fibrin
list and describe the 2 coagulation pathways
- extrinsic pathway: begins with factors not found in blood
2. intrinsic pathway: begins with factors found in blood
what is needed to start both coagulation pathways?
calcium
what does the fibrinolytic system do?
converts plasminogen to plasmin
what is the function of plasmin?
breaks down fibrin
what 2 things activate the fibrinolytic system?
- presence of fibrin (duh)
2. tissue plasminogen activator
what secretes tissue plasminogen activator?
healthy, intact, epithelial cells
what vitamin is necessary for the synthesis of blood clotting factors?
vitamin K
what prevents proper formation of blood clotting factors? list and give locations of 2 examples
vitamin K antagonists
- dicumarol: found in expired sweet clover
- warfarin: common agent in rat poison
what is fibrin?
the activated form of fibrinogen
