These are not my flashcards but I refuse to pay for quizlet premium just to use the learn function
Blood is the only...
fluid tissue (connective) in the body having both a solid and liquid component.
What causes the colour of blood to vary?
Oxygen levels.
What is the pH of blood?
7.35-7.45
What is the temperature of blood?
38 degrees Celsius
What is the volume of blood in a healthy adult?
5-6 litres.
What percentage of a healthy adults body weight is made up of blood?
8%
What percentage of a blood sample is made up of plasma?
approx. 55%
What percentage of a blood sample is made up of the formed elements?
approx. 45%
What are the components of plasma?
- water
- salts (electrolytes)
- plasma proteins
- substances transported by blood
What are the formed elements?
- erythrocytes
- leukocytes
- basophils
- eosinophils
- neutrophils
- monocytes
- lymphocytes
- platelets
Hematopoiesis
- The process of blood cell formation
- Occurs in red bone marrow
All blood cells are derived from a common stem cell, what is it?
hemocytoblast/ pluripotential stem cells
What are the 3 phases of hematopoiesis?
1. Mesoblastic
2. Hepatic
3. Medullary (Myeloid)
Mesoblastic phase
Begins around the 19th day of embryonic development. Forms the primitive RBC's and eventually early blood vessels.
Hepatic phase
5-7 weeks - characterized by recognizable clusters of developing cells. Represents definitive hematopoiesis. The liver is the main site.
Medullary (Myeloid) Phase
4-5 month of fetal development, the bone marrow takes over cell production. Becomes the main site of hematopoiesis.
Erythropoiesis
Red blood cell development/ production.
Granulopoiesis
Granulocyte development/production.
Neutrophils, Eosinophils, Basophils
Thrombopoiesis
Platelet development/production.
Why do RBCs differ from other blood cells?
- anucleate
- contain few organelles; lack mitochondria
- make ATP by anaerobic means
- essentially a sack of hemoglobin
- shaped like biconcave discs
How is the shape of RBCs beneficial?
The biconcave shape gives the cell a high surface to volume ratio which is essential for gas exchange.
What is the life span of RBCs?
120 days.
What are reticulocytes?
young RBCs which enter the blood to become oxygen - transporting erythrocytes.
Polychromasia
Young RBCs still contain residual RNA, therefore on the blood smear they appear lavender/purple in colour.
Erythropoietin
The hormone that controls the rate of RBC production.
Kidneys produce most erythropoietin as a response to reduced oxygen levels in the blood.
5 steps that maintain homeostasis: normal blood oxygen levels
1. Stimulus - Low blood oxygen carrying ability
2. Kidneys (and liver, to a smaller extent) release erythropoietin.
3. Erythropoietin stimulates red bone marrow.
4. Enhanced erythropoiesis increases RBC count.
5. Oxygen carrying ability of blood increases.
Factors that could lead to low blood oxygen carrying ability
Decreased RBC count
Decreased amount of hemoglobin
Decreased availability of oxygen
Hemoglobin
Iron bearing protein that binds oxygen.
How many oxygen molecules can one hemoglobin bind to?
4
Anemia
Decrease in the normal number of RBCs in circulation.
Abnormal or deficient amount of hemoglobin in the cells.
Not a disease, but the result of an underlying condition.
Anisocytosis
Variation in cell size
Erythrocyte sizes
Normocytic- Normal sized RBCs
Microcytic- Smaller than normal sized RBCs
Macrocytic- Larger than normal sized RBCs
Normochromic
Normal amount of hemoglobin content in the RBC
Hypochromic
Less than normal amount of hemoglobin content in the RBC
Hyperchromic
Higher than normal amount of hemoglobin content in the RBC
Poikilocytes
Abnormal shaped RBCs
Sickle cell anemia
When one amino acid on the beta chain of the hemoglobin molecule is substituted for another.
This abnormal hemoglobin becomes spiky and sharp when oxygen is unloaded or the oxygen content in the blood is below normal.
If an individual carries one copy of the defective gene that causes sickle cell anemia, are they symptomatic?
Generally no, Most individuals need to have two copies of the defective gene in order to display symptoms.
What are the consequences of sickle cell anemia?
When the cells sickle in areas of low oxygen, they can rupture easily and block blood vessels. This interferes with oxygen delivery to those areas and causes extreme pain.
Polycythemia
A disorder characterized by an abnormal increase in the number of red blood cells in the blood. This increase slows blood flow and increases blood viscosity.
A decrease in RBC number that results from a sudden hemorrhage leads to what kind of anemia?
Hemorrhagic anemia
A decrease in RBC number that results from lysis of RBCs due to a bacterial infection leads to what kind of anemia?
Hemolytic anemia
A decrease in RBC number that results from a lack of vitamin leads to what kind of anemia?
Pernicious anemia
A decrease in RBC number that results from destruction of bone marrow by cancer, radiation or certain medications leads to what kind of anemia?
Aplastic anemia
inadequate hemoglobin content in RBCs that results from a lack of iron in the diet or slow/prolonged bleeding leads to what kind of anemia?
Iron-deficiency anemia
Leukopoiesis
Refers to the development/productions of all WBCs
lymphopoiesis
lymphocyte production/development
monopoiesis
monocyte development/production
Diapedesis
the passage of blood cells through the intact walls of the capillaries, typically accompanying inflammation.
amoeboid motion
The flowing movement of the cytoplasm of a phagocyte.
granulocytes
contain lobed nuclei and the granules in their cytoplasm can be stained.
how can neutrophils, eosinophil, and basophils be distinguished by their granules?
neutrophils- contains fine tan/pinkish granules.
eosinophils- larger orange/pinkish granules.
basophils- larger black/purple granules, in the cytoplasm and on the nucleus.
Agranulocytes
lack visible cytoplasmic granules
nuclei are spherical, oval, or kidney shaped
includes lymphocytes (round to oval nucleus) and monocytes (irregular shaped nucleus)
WBCs from most to least abundant
neutrophils, lymphocytes, monocytes, eosinophils, basophils
neutrophil
most numerous WBC.
multilobed nucleus (segmented) or banded.
cytoplasm stains tan/pink and contains fine granules.
function as phagocytes at active sites of infection.
play a role in natural immunity.
numbers increase during infection.
eosinophils
nucleus stains blue-red.
brick red cytoplasmic granules.
function is to kill parasitic worms; play a role in allergy attacks.
play a role in natural immunity.
basophils
rarest of the WBCs.
large histamine-containing granules that stain dark blue to purple.
release histamine (vasodilator) at sites of inflammation.
contain heparin (anticoagulant).
play a role in natural immunity.
lymphocytes
slightly larger than RBCs.
have a large, dark purple nucleus that is round/oval shaped.
can have larger lymphocytes with more abundant cytoplasm.
reside in lymphatic tissues.
play a role in adaptive immune response.
monocytea
largest or the WBCs.
distinctive U or kidney shaped dark purple nucleus.
function as macrophages when they migrate into tissues.
important in fighting chronic infection.
play a role in natural immunity.
Leukocytosis
Abnormally high WBC count.
Normal response to an infection, or potentially more severe disease states.
Leukopenia
Abnormally low white blood cell count.
Commonly caused by certain drugs, such as corticosteroids and anticancer agents.
Leukemia
Bone marrow becomes cancerous.
Numerous immature WBC are produced.
Neutropenia
A decrease in the number of neutrophils in circulation.
Neutrophilia
Increase in the number of neutrophils in circulation.
Monocytosis
increase in the number of monocytes in circulation.
Eosinophilia
increase in the number of eosinophils in circulation.
basophilia
increase in the number of basophils in circulation.
megakaryocyte
large platelet precursor cell found in the bone marrow
Megakaryopoiesis
production of megakaryocytes
Thrombocytopenia
decrease in platelets in peripheral blood.
can lead to bleeding because platelets are essential for clotting process.
thrombocytosis
increase in platelets in peripheral blood.
may lead to clotting in the body.
primary hemostasis
blood vessels and platelets work together to form a temporary platelet plug.
secondary hemostasis
activation of the coagulation proteins with the main objective to make fibrin and stabilize the temporary platelet plug.
Fibrinolysis
the gradual digestion and dissolving of the clot following healing.
Hemostasis: Vasoconstriction
Leads to vascular spasms.
Immediate response to blood vessel injury.
Spasms narrow the blood vessel, decreasing blood loss, and aid in the clotting process.
Role of platelets
Surveillance cells that maintain the blood vessel integrity, and the first line of defense when a blood vessel is breached.
Trigger primary hemostasis when exposed to the sub-endothelial membrane/inflammatory proteins at the site of vessel injury.
Metabolically active cells that basically initiate and control hemostasis.
Primary hemostasis: Adhesion
Platelets bind to exposed collagen and the release of vWF from the exposed collagen, links platelets to the collagen.
platelets have receptors that also bind to the vWF to reinforce adhesion process.
What is vWF?
von Willebrand factor
Primary hemostasis: Aggregation
Platelets bind to one another via the platelet receptor GP IIb/IIIa.
Fibrinogen is the bridge that binds to the platelets via the GP IIb receptor in the presence of ionized calcium.
fibrinogen binding is essential for platelet aggregation.
Thromboxane A2
Produced by activated platelets and stimulates the activation of other platelets - recruits others to the site for aggregation.
Coagulation system - secondary
main purpose is to produce fibrin and stabilize the primary platelet plug.
mediated by coagulation proteins via different pathways: intrinsic, extrinsic, common.
Intrinsic pathway
Contact of internal factors to negatively charged surfaces (collagen)
Extrinsic pathway
Activated via external factors due to blood vessel breach - exposure to collagen
common pathway
factors that the intrinsic and extrinsic have in common.
How long does blood take to clot?
3-6 minutes
Thrombus
a clot that develops and persists in an unbroken blood vessel
can be deadly in areas such as the lungs
embolus
A thrombus that breaks away and floats freely in the bloodstream
Can later clog vessels in critical areas such as the brain
Hemophilia
Hereditary bleeding disorder (x-linked)
Normal clotting factors are missing
Minor tissue damage can cause life-threatening prolonged bleeding.
Loss of 15 to 30 % of blood causes what?
pallor and weakness.
Loss of over 30% of blood causes what?
shock, which can be fatal
Transfusion reactions
Lysed red blood cells release hemoglobin into the blood stream
Freed hemoglobin may block kidney tubules, causing kidney failure and death
Fever, nausea, and vomiting can also result.
Blood types are based on the presence of two antigens
Type A and B
Presence of both antigens A and B is called
type AB
presence of antigen A is called
type A
presence of antigen B is called
type B
lack of both antigens A and B is called
type O
Who is the universal recipient?
Type AB
Who is the universal donor?
Type O
how did the Rh blood group get its name?
Named because of the presence or absence of one of eight Rh antigens that was originally defined in Rhesus monkeys
What happens when a mother is Rh- and the child is Rh+
Hemolytic disease of the newborn.
RhoGAM shot can prevent buildup of anti-Rh+ antibodies in mothers blood.
Binds the positive Rh antibodies and prevents them from eliciting an immune response.