Blood Flashcards
what is the normal volume of blood in adults
men - 5L
women- 4L
what is the composition of blood
cellular fraction- RBC, WBC, platelets
fluid fraction- plasma
what is a hematocrit
the percentage of RBC in blood
what should the hematocrit for a healthy adult be
~ 40% RBC
~1% WBC
~55% Plasma
what does someone’s level of hemoglobin determine
represent the oxygen carrying capacity of an individual RBC
what are the three general types of blood cells
- red blood cells (RBC)
- white blood cells (WBC)
- platelets
what are the origins of blood cells
develop in red bone marrow from hematopoietic stem cells that divide in response to different growth factors
what are the characteristics of RBC
- are called erythrocytes
- have a biconcave shape
- ~7.5µm
- no nuclei when mature
why do RBCs have a biconcave shape
- increases surface area
- cell membrane is closer to hemoglobin
- movies easier through capillaries
why do RBCs lose their nuclei
- more room for hemoglobin
- can’t divide
- has limited life-span of 120 days
what is RBC count
number of RBCs in 1µL of blood
what is the mechanism of red blood cell production
- erythropoietin secreted by kidney bc low O₂ level.
- stem cells become erythroblast
- erythroblast divide & mature into erythrocytes
- erythrocytes enter blood for ~120 day cycle
what are the dietary factors need for proper RBC production
- B₁₂ & folic acid for DNA synthesis
* Iron for hemoglobin synthesis
why do RBCs have a limited life span
- are damaged as they pass through capillaries
* eventually rupture when passing through liver & spleen
what happens when RBCs finally rupture
hemoglobin broken down by macrophages in the heme and protein components
what happens to the heme components of hemoglobin after its broken down
- iron is reused or stored in liver
* biliverdin is converted into bilirubin
what are the characteristics of WBCs
- called leukocytes
- functions to protect against disease/infections
- develop from hemotopoietic stem cells
- transported by blood to infection site
what are the hormones that stimulate hemotopoietic stem cells to become WBCs
- interleukins
* colony stimulating factors
what are the two groups that categorize WBCs
- granulocytes
* agranulocytes
what are the granulocytes
- neutrophils
- eosinophils
- basophils
what are the agranulocytes
- monocytes
* lymphocytes
what are the characteristics of neutrophils
- aka polymorphonuclear neutrophils
- nuclei has 2-5 lobes
- has purple fine granules
- has 3 granule types: specific, azurophils, tertiary
- 1st to arrive at infection site
- reps 54-62% of WBCs
- function is phagocytosis
what are the characteristics of eosinophils
- has deep red course granules
- has 2 granule types: specific & azurophils
- nuclei has only 2 lobes
- reps 1-3% of WBCs
- functions: fight allergic rxns, parasitic worms, & chronic inflammation
what are the characteristics of basophils
- aka circulating mast cells
- has deep blue course granules
- has 2 granule types: specific & azurophils
- nuclei has only a few lobes
- reps 1-3% of WBCs
- functions: migrate to damaged tissue, bind antibodies, promote increased blood flow
how do basophils promote increased blood flow
by releasing heparin, histamine, or leukotrienes
what are the characteristics of monocytes
- largest blood cell
- no visible granules but has lysosomes
- has single kidney-shaped nuclei
- reps 3-9% of WBCs
- functions: leave blood & become macrophages, serve as antigen-presenting cells, and phagocytize
what are the characteristics of lymphocytes
- has no granules
- smaller than RBCs
- larger nuclei that mostly fills cytoplasm
- reps 25-32% of WBCs
- is functional cell of lymphatic & immune system
what are the three types of lymphocytes
- T cells
- B cells
- Natural killer cells
what are the primary functions of WBCs
to protect against disease/infection by:
•perform phagocytosis
•inflammation
•produce antibodies
what is diapedesis
the movement of WBCs through walls of small blood vessels to circulate to infection site
what is positive chemotaxis
when damaged cells release chemicals that attract WBCs
what are antibodies
proteins that are specific for & bind to foreign materials so that they can be eliminated
what is phagocytosis
process where cells engulf damaged cells or foreign materials
how does histamine promote inflammation
- dilates small blood vessels & cause them to leak
- dilation causes increased blood flow to area
- swelling due to fluid leaking into interstitial space
how does heparin promote inflammation
- prevents blood from clotting
* allows blood flow in area to remain high
what are the characteristics of platelets
- aka thrombocytes
- fragments of larger cells
- stem cells stimulated by thrombopoietin to become megakaryocytes
- megakaryocytes fragment and differentiate in lung to become platelets
what is hematoposis
the formation of the cells found in the CT blood
what is the monophyletic theory
all blood cells arise from a common stem cell called Pluripotential Stem Cell (PPSC)
what are the colony forming units that arise from the pluriopotential stem cell (PPSC)
- multipotential myeloid stem cell
2. multipotential lymphoid stem cell
what are the lineages of the multipotential myeloid stem cell colony forming unit
- erythroid CFU
- granulocyte-monocyte CFU
- eosinophil CFU
- basophil CFU
- megakaryocyte CFU
what are the lineages of the multipotential lymphoid stem cell colony forming unit
- restricted T lymphocyte CFU
2. restricted B lymphocyte CFU
what are the three main plasma proteins found in the blood
- albumin
- globulins
- fibrinogen
what are the characteristics of albumin
- Smallest plasma protein by Size
- Comprise ~ 60% of all plasma proteins
- Synthesized by the Liver
- Aid in keeping water within the blood vessels
what are the characteristics of globulins
- comprise 36% of plasma proteins
- consist of three types
- functions as a carrier for certain hormones
what are the types of globular proteins
- alpha
- beta
- gamma
what are alpha globular proteins
proteins produced in the liver used to transport lipids & vitamins
what are beta globular proteins
proteins produced in the liver used to transport lipids & vitamins
what are gamma globular proteins
a type of antibody formed by B-lymphocytes
what are the characteristics of fibrinogen
- Largest of the plasma proteins by Size
- Comprise ~4% of all the plasma proteins
- Synthesized by the Liver
- Aids in Blood Coagulation
- Precursor to Fibrin
what is fibrin
a major component in the formation of a blood clot
what are the nutrients found in blood plasma
- amino acids
- simple sugars
- lipids
- nucleotides
what is hemostatsis
the stoppage of bleeding
what are the major mechanism of hemostatsis
- Vessel spasm
- Platelet plug formation
- Blood coagulation (clot)
what are the two types of coagulation mechanisms
- intrinsic clotting mechanism
- extrinsic clotting mechanism
how does the extrinsic clotting mechanism work
- damaged tissue releases Tissue Thromboplastin
- Thromboplastin causes platelets to produce & release Prothrombin Activator
- Prothrombin is converted to Thrombin
- Thrombin activates Fibrinogen
- Fibrinogen is converted into Fibrin
- Fibrin produces the clot
how does the intrinsic clotting mechanism work
- blood comes into contact with foreign substance
- this activates Factor XII which activates Prothrombin
- after which process is same as extrinsic
what are ABO blood groups based on
the presence or absence of two types of antigens
what are the types of antigens
- antigen A
- antigen B
- O for none
what are the possible antigen combinations
- Only Antigen A
- Only Antigen B
- Both Antigen A & B
- Neither Antigen A or B
a person with Antigen A is what blood type
-type A
a person with Antigen B is what blood type
-type B
a person with both antigen A & B is what blood type
-type AB
a person with neither antigen A or B is what blood type
-type O
