Chapter 9 - Blood, Lymphatic System Flashcards
What is blood mostly composed of
Rbc, wbc and platelets.
What is blood
Connective tissue with a plasma matrix. The protein fibers are only visible when the blood clots.
What are three functions of blood
Transport
Regulation (body temp, water balance, ph balance)
Defense (against pathogens, blood clotting)
What is plasma composed of
Water, proteins and other solutes
What are the formed elements composed of
Platelets, leukocytes and erythrocytes
Describe plasma
Fluid portion with dissolved substances: plasma proteins (albumin, globulins, clotting factors) and gases, nutrients, waste and hormones
What is % of blood volume dependant on
Species and amount of hydration. Cats have smaller rbc than dogs and a higher % of plasma in blood. Hemoconcentration vs. hemodilution
What is the normal yellow color in plasma due to
Bilirubin
Why can blood plasma appear cloudy
Due to postprandial lipemia. (Fat in blood after eating)
How do you avoid postprandial lipemia
Fast before taking a blood sample
What is the difference between serum and plasma
Serum is the same as plasma except it lacks clotting factors
What does supernatant mean
Serum
What is the intrinsic blood coagulation pathway
Surface contact Hageman factor (Active) hageman factor Christmas factor (Active) christmas factor Stable factor Platelet membrane Phospholipid Calcium ions (Active) stable factor P.M.P Calcium ions
Describe the extrinsic blood coagulation pathway
Tissue damage Tissue factor: stable factor Stable factor Platelet membrane phospholipid Calcium ions
Describe the common coagulation pathway
V, platelet membrane, phospholipid Prothrombin Thrombin Fibrin stabilizing factor OR fibrogen Fibrin Stable fibrin clot
What is an anticoagulant
Used to prevent blood clotting (coagulation) in vitro or in vivo. Substance blocks one of clotting factors in pathway
What does edta coagulation do
Binds ca++, used in lab (lavender top)
What does heparin anticoagulant do
Naturally occurring. Used to prevent thrombosis and embolism
What does warfarin anticoagulant do
In 1940: used as rat poison
In 1950: used medicinally as an oral anticoagulant
What are the three formed elements in blood
Erythrocytes
Leukocytes
Thrombocytes
How much percent of blood does plasma compose
55% of blood
What is a Buffy coat and what is it part of
It is leukocytes and thrombocytes, it’s part of the formed elements and its it greater than 1% of whole blood
What is an erythrocyte and what is it part of
It is red blood cells and it composed 45% of whole blood
Wbc are considered what
Complete cells
Describe the physiology of a rbc
Have no nuclei or most other organelles
What are platelets considered
Cell fragments
How long do formed elements last in blood
Survive in bloodstream for a few days with the exception of wbc
Where do blood cells originate
Originate in red bone marrow and do not divide (exception: some wbc)
What is hematopoiesis
The formation of blood cells. It is a continual process: stem cells formed element cells
How long does it take a stem cell to turn into a rbc
15 days
How long do red blood cells survive
100-120 days
What is step 3 in the stem cell conversion to rbc
Proerythroblast turns into basophilic erythroblast
What is the 4th step in the conversion from stem cells to rbc
From a basophilic erythroblast to polychromatic erythroblast.
What is the 7th step of the conversion from stem cell to rbc
From orthochromatic erythroblast to reticulocyte
Describe phase 1 of the development pathway
Ribosome synthesis
What is phase 2 of the development pathway
Hemoglobin accumulation
What is phase 3 in the development pathway
Ejection of nucleus
What is polychromasia
Lavender cytoplasm. Hemoglobin production begins
What does the erythropoietin hormone
Stimulates erythropoiesis, always have a small amount in blood. High rbc or O2 levels depress production. Released by kidneys in response to hypoxia
What are the causes of hypoxia
Decreased rbc numbers due to hemorrhage or increase destruction. Insufficient hemoglobin per rbc (iron deficiency) or reduced availability of o2 (high altitudes)
In early fetus, what organs are responsible for hematopoiesis
Liver and spleen
When fetus ages, what becomes more prominent
Red bone marrow
As an animal ages what happens to red bone marrow
Red bone marrow is reduced to epiphyses and replaced by yellow bone marrow in diaphyses
What does anucleation mean in terms of erythrocytes
Making more space for hemoglobin
What are the benefits of having biconcave disks (erythrocytes)
Higher surface area to transport gases across membrane.
Flexible; can squeeze through small capillaries
What type of respiration do erythrocytes have
Anaerobic
Do erythrocytes have mitochondria ?
No
Do erythrocytes have a nucleus?
Only in non mammalian species
What do red blood cell size and color vary on
Species
How much of the cell does hemoglobin compose
35%
What is hemoglobin composed of
Globular proteins (4 polypeptides) + heme groups (containing iron )
How many O2 can each hemoglobin carry
4 O2
How many hemoglobin. Do we have in our body
250 million hb/rbc
Animals with smaller cells have
More rbc
What are the three types of hemoglobin
Embryonic hemoglobin (HBe) Fetal hemoglobin (HbF) Adult hemoglobin (Hb)
What’s the difference between fetal hemoglobin and adult hemoglobin.
Fetal has a higher affinity to O2 than adult Hb. Very good in low O2 environment
Describe O2 loading in lungs
Produces oxyhemoglobulin (ruby red) Hb+O2 ➡️ HbO2
Describe O2 unloading in tissues
Produces deoxyhemoglobin or empty hemoglobin (dark red)
Hb+o2➡️HbO2
Describe CO2 loading in tissues
20% of CO2 in blood binds to Hb
Hb + CO2 ➡️ HbCO2
What does the lifespan of red blood cells depend on
Varies by species. Large animals have longer living rbc
What does senesce mean
Age
As red blood cells age what happens
Become rounder with less surface area and get trapped in spleen
What happens to old rbc when they get trapped in the spleen
Most are phagocytized by macrophages (wbc) in spleen, some destroyed in blood vessels.
What happens when rbc die
Replaced by young cells from red bone marrow
What happens to globins when they’re separated from heme
Globins are metabolized into amino acids which are sent to liver for production of new proteins
What happens to iron when it’s Seperated from heme and globin
Iron salvaged for reuse; sent to red bone marrow
What happens to heme when it’s Seperated from globin
Heme is degraded to yellow pigment called bilirubin. Sent to liver to be used in bile which is secreted into the small intestine
What happens if liver is unable to process all the bilirubin,
it can collect in the tissues which is jaundice
What is anemia ?
Blood has abnormally low O2 carrying capacity. Low O2 levels cannot support metabolism.
What are the symptoms of anemia
Fatigue, pallor
What is the cause of anemia
Blood loss, decreased erythropoiesis, decreased hemoglobin production
What is polycythemia
Abnormally high number of rbc
What are the three types of polycythemia
Relative polycythemia
Compensatory polycythemia
Polycythemia ruba Vera
Define relative polycythemia
Hemoconcentration (loss of plasma) due to dehydration
Define compensatory polycythemia
Increased erythropoiesis due to hypoxia
Define polycythemia ruba Vera
Rare idiopathic bone marrow disorder
How do you determine amount of cells in blood
❤️Manually count with the hematocytometer slide
❤️Hematocrit or packed cell volume
What does a hematocrit do
Calculate % of rbc (+ Buffy coat plasma)
What are thrombocytes
Platelets that are fragments of larger cells (megakaryocytes)