Chapter 19- Blood Flashcards
Major components of blood
Plasma- extracellular matrix
Formed elements- cells and cell fragments in plasma
Formed elements in blood
Erythrocytes- red blood cells
Leukocytes- white blood cells
Platelets- tiny cellular fragments
Hematocrit
Percentage of blood that is composed of erythrocytes
Functions of blood
Exchanging gases Distributing solutes Immune functions Maintaining body temp Sealing damaged blood vessels- clotting Preserving acid-base homeostasis Stabilizing blood pressure
Plasma
Pale yellow liquid composed primarily of water. Determines viscosity of blood
Top layer of blood when centrifuged
55% of total blood volume
Plasma proteins
Made by the liver and too big to dissolve in the water portion so form a colloid
Albumin
Immune proteins
Transport proteins
Clotting proteins
Albumin
Synthesized only the liver
Large protein responsible for the pressure that draws water into the blood via osmosis (gradients)
Antibodies (immune proteins)
g-Globulins
Plasma proteins of the immune system.
Produced by leukocytes
Transport proteins
Bind to fats and steroids which are hydrophobic you help them move safely through blood without binding to each other and and forming clumps
a and B-globulins
Lipoproteins
Clotting proteins
Combine with platelets to form blood clots to stop bleeding from injured blood vessels
Buffycoat
Middle layer of centrifuged blood consisting of leukocytes and platelets
Only 1% of total blood volume
Erythrocytes
Red blood cells
Bottom layer of centrifuged blood
44% of total blood volume
Exchanging gases function
Erythrocytes Carey oxygen from the lungs to other tissues and carry CO2 back to the lungs
Distributing solutes function
Plasma transports nutrients, hormones and wastes
Performing immune functions
Leukocytes and proteins use blood as transport system to any tissue in the body
Maintaining body temperature function
Blood carries heat away from actively metabolizing tissues
Sealing damaged vessels by forming blood clots function
Platelets form cloys when vessels are damaged to prevent excess blood loss
Preserving acid-base homeostasis
Blood composition controls the body’s buffer systems
Stabilizing blood pressure
Blood volume determines blood pressure and is vital to keeping it at a constant level
Erythrocyte structure
Biconcave disc; flattened, donut shape
Increases surface area of the cell
Their structure enables them to transport O2 and CO2
Mature RBCs are anucleate-no nucleus and barely any other organelles
Hemoglobin
Large, oxygen binding protein consisting of 4 polypeptide subunits: two alpha chains and two beta chains
Releases O2 into regions where O2 concentration is low
Heme group
Each heme group contains one iron ion with a polypeptide making it able to bind to oxygen
Oxyhemoglobin
Red colored molecule that forms in the lungs when the iron ion in a heme group is exposed to high concentration of oxygen
Carbaminohemoglobin
Hemoglobin binds to CO2 in tissues where O2 levels are low
Accounts for 23% of CO2 transportation in blood
Life span of an erythrocyte
100-120 days
Hematopoiesis
takes place in red bone marrow
Formed elements are produced by hematopoietic stem cells (HSCs)
Erythropoiesis
Specific process that produces erythrocytes from HSCs
5-7 day process
Erythrocyte colony forming units (CFUs)
HSCs differentiate into progenitor cells that have committed to forming only one single cell type
Proerythroblasts
Blast cell of a hematocytoblast stem cell that develops into an erythrocyte
Erythrocyte CFUs differentiate into proerythroblasts when erythropoietin is secreted by the kidneys
Erythroblasts
Immature erythrocyte, containing a nucleus
Rapidly synthesize Hb and other proteins
Reticulocyte
Immature red blood cell that has no nucleus
Enter blood stream after rejecting remaining organelles
Erythropoietin
Hormone secreted by the kidneys that speeds up RBC production and reduces the amount of time it takes for them to mature
Leukocytes
White blood cells that perform immune functions. Divided into two basic categories:
Granulocytes
Agranulocytes
Granulocytes
Distinguished by the unusual shape of their nuclei and the different colors they take on when staid with various dyes like methylene blue and acidic eosin dye
Include: neutrophils, eosinophils, basophils
Agranulocytes
WBCs lacking visible granules
Include: lymphocytes, monocytes
What are Neutrophils and what is their percentage in the blood?
Most common leukocyte
When stained will be lilac in color. Nucleus is usually 3-5 lobes
Involved in chemotaxis
Directly kill bacterial cells, enhance inflammation
50-70%
What are Eosinophils and what is their percentage in the blood?
Nucleus is “bilobed” and cell will spear red when dyed.
They respond to infection by parasitic worms and allergic reactions
2-4%
What are Basophils and what is their percentage in the blood?
Least common leukocyte. S-shapes nucleus and will appear dark purple
Their function is to mediate inflammation
1%
What are Lymphocytes and what is their percentage rate in the blood?
Second most common leukocyte. Have large round nucleus and a thin, light blue rim of cytoplasm. Activated by antigens
B lymphocytes- produce antibodies that bind to and remove antigens from tissues
T lymphocytes- do not produce antibodies. Directly destroy abnormal cells like cancer
20-30%
What are Monocytes and what is their percentage in the blood?
Largest leukocyte. Large U-shapes nucleus surrounded by light blue or purple cytoplasm
Only stay in blood briefly before entering tissues where some mature into macrophages
2-8%
Leukopoiesis
Process in the bone marrow that uses HSCs to form new leukocytes
HSCs divide and split into two cell lines: myeloid cell line, lymphoid cell line
Myeloid cell line
Produces most of the firmed elements including RBCs and platelets
Lymphoid cell line
Produces lymphocytes
B lymphocytes remain in blood while they grow
T lymphocytes move to the thymus
What do platelets lack?
Nuclei and other organelles
Megacaryocytes
Developed from megacaryoblasts that go through multiple rounds of mitosis but never divides so it results in a very large cell with multiple copies of DNA
Lifespan of platelets
7-10 days
Hemostasis
Series of 5 distinct events that form a a clot that plugs broken blood vessels. Primary function is to limit significant blood loss
Blood groups
Genetically predetermined carbohydrate chains
What is differential count of WBCs?
The percentage of each WBC type present in your blood
Order of blood cells from largest to smallest percentage in the blood
Neutrophils (50-70%) Lymphocytes (20-30%) Monocytes (2-8%) Eosinophils (2-4%) Basophils (1%)
