Blood
List the functions of blood
● Delivers oxygen
○ Red blood cells contain hemoglobin which is specialized to deliver oxygen
● Transports metabolic wastes
○ Wastes are released into the bloodstream and carried away
○ Examples of waste products: CO2, ammonia
● Transports hormones
○ Blood is the travel medium of the endocrine system
○ Hormones are released from glands into the bloodstream
● Maintains body temperature
○ Blood is brought closer to the surface to dispacate heat and cool us down and
can be kept near our core to keep us warm
● Maintains body pH
● Maintains fluid volume
○ Water in the blood can be exchanged with cells
● Prevents blood loss
○ Blood clotting
● Prevents infection
○ Phagocytic cells, leukocytes, antibodies, complement proteins → function in
immune system
Describe the composition of whole blood
● Erythrocytes
● Leukocytes
● Plasma
○ Liquid component, background matrix of blood
○ Accounts for 55% of total blood volume
○ 90% water
○ Proteins, primarily albumin which is produced by the liver, float in plasma
○ Globulins function in immunity
○ Plasma can carried dissolved O2 and CO2
● Platelets
Describe the structure, function, and production of erythrocytes
● Erythrocytes = red blood cells
● Start out as living cells but are no longer living in their mature form (lack a nucleus and
organelles)
● Account for 45% of total blood volume
● Function: carrying respiratory gases, primarily oxygen
● Structure
○ Small (compared to WBCs)
, ○ Biconcave
○ Anucleate
○ Contains hemoglobin (protein)
○ Contains antioxidant enzymes (discard free radicals produced by metabolism)
● Erythropoiesis (formation of RBCs)
○ Hemocytoblast → myeloid stem cell
○ Myeloid stem cell → proerythroblast (first committed cell)
○ Proerythroblast → early erythroblast
○ Early erythroblast → late erythroblast
○ Late erythroblast → normoblast
○ Normoblast → loses organelles and nucleus → reticulocyte
■ Accumulation of hemoglobin begins here and pushes out organelles
■ Organelles are recycled to produce new proteins
○ Reticulocyte → mature in bloodstream → erythrocyte
● Regulation of erythropoiesis
○ Erythropoietin
■ Hormone released from the kidneys
■ Monitors blood oxygen levels and releases erythropoietin to stimulate
RBC production when blood oxygen is low
○ Testosterone
■ Stimulates the kidneys to produce erythropoietin
○ Iron
■ Stored in cells as ferritin and hemosiderin
■ Transported as transferrin (circulating in bloodstream)
○ B-vitamins
■ B12 and folic acid
■ Included in prenatal vitamins to promote RBC production to account for
increased blood volume during pregnancy
○ Dietary nutrients
● Erythrocyte longevity
○ Last about 3.5-4 months
○ Old erythrocytes are destroyed by macrophages
■ Cells in the spleen detect abnormal or aging RBCs and send
macrophages to destroy them
○ RBC is recycled
■ Heme is split from globin
■ Iron bound to proteins is stored as ferritin
■ Bilirubin (heme - iron) is produced
● Picked up by the liver and excreted as bile (stored in the
gallbladder) and released in feces
■ Globin is broken down into amino acids
Describe the chemical makeup of hemoglobin
● Globin protein bound to heme pigment
, ● 4 globin units, 2 alpha chains and 2 beta chains
● Heme is the pigment that gives blood its red color
○ Contains an iron core that oxygen can bind to
○ One heme per globin subunit
● 1 hemoglobin can carry 4 oxygens
○ increasing oxygen affinity with each oxygen added
● Oxyhemoglobin: loaded with O2
● Deoxyhemoglobin: O2 has been offloaded
● Carbaminohemoglobin
○ Hemoglobin carrying CO2 → binds to globin proteins, not iron
○ Only 20% of CO2 is carried in this form
■ Majority is carried as bicarbonate is plasma
Define diapedesis
● ability of blood cells to leave circulation (blood vessel → interstitial space/other tissues)
● Only some white blood cells can do this
List the classes, structural characteristics, and functions of leukocytes
● Leukocytes = white blood cells
● Living cells (contain a nucleus and organelles)
● Many different types of leukocytes exists in the blood
● Function: immunity
● Account for less than 1% of total blood volume when combined with platelets
● Only component of blood with DNA
● Positive chemotaxis → attracted to the chemical secretions of other cells, such as those
released by damaged cells
● WBC count increases when we are fighting a bacterial infection
● Types
○ Granulocytes
■ Neutrophils
● Phagocytic
● 50-70% of WBCs
● Multilobe nuclei
● Count increases with inflammation
■ Eosinophil
● 2 lobe nuclei
● 4-6% of WBCs
● Attack parasitic worms by releasing enzymes
■ Basophil
● 0.5-1% of WBCs (rarest)
● Contain histamine which is a vasodilator that functions in
inflammatory response
○ Agranulocytes
■ Lymphocytes
List the functions of blood
● Delivers oxygen
○ Red blood cells contain hemoglobin which is specialized to deliver oxygen
● Transports metabolic wastes
○ Wastes are released into the bloodstream and carried away
○ Examples of waste products: CO2, ammonia
● Transports hormones
○ Blood is the travel medium of the endocrine system
○ Hormones are released from glands into the bloodstream
● Maintains body temperature
○ Blood is brought closer to the surface to dispacate heat and cool us down and
can be kept near our core to keep us warm
● Maintains body pH
● Maintains fluid volume
○ Water in the blood can be exchanged with cells
● Prevents blood loss
○ Blood clotting
● Prevents infection
○ Phagocytic cells, leukocytes, antibodies, complement proteins → function in
immune system
Describe the composition of whole blood
● Erythrocytes
● Leukocytes
● Plasma
○ Liquid component, background matrix of blood
○ Accounts for 55% of total blood volume
○ 90% water
○ Proteins, primarily albumin which is produced by the liver, float in plasma
○ Globulins function in immunity
○ Plasma can carried dissolved O2 and CO2
● Platelets
Describe the structure, function, and production of erythrocytes
● Erythrocytes = red blood cells
● Start out as living cells but are no longer living in their mature form (lack a nucleus and
organelles)
● Account for 45% of total blood volume
● Function: carrying respiratory gases, primarily oxygen
● Structure
○ Small (compared to WBCs)
, ○ Biconcave
○ Anucleate
○ Contains hemoglobin (protein)
○ Contains antioxidant enzymes (discard free radicals produced by metabolism)
● Erythropoiesis (formation of RBCs)
○ Hemocytoblast → myeloid stem cell
○ Myeloid stem cell → proerythroblast (first committed cell)
○ Proerythroblast → early erythroblast
○ Early erythroblast → late erythroblast
○ Late erythroblast → normoblast
○ Normoblast → loses organelles and nucleus → reticulocyte
■ Accumulation of hemoglobin begins here and pushes out organelles
■ Organelles are recycled to produce new proteins
○ Reticulocyte → mature in bloodstream → erythrocyte
● Regulation of erythropoiesis
○ Erythropoietin
■ Hormone released from the kidneys
■ Monitors blood oxygen levels and releases erythropoietin to stimulate
RBC production when blood oxygen is low
○ Testosterone
■ Stimulates the kidneys to produce erythropoietin
○ Iron
■ Stored in cells as ferritin and hemosiderin
■ Transported as transferrin (circulating in bloodstream)
○ B-vitamins
■ B12 and folic acid
■ Included in prenatal vitamins to promote RBC production to account for
increased blood volume during pregnancy
○ Dietary nutrients
● Erythrocyte longevity
○ Last about 3.5-4 months
○ Old erythrocytes are destroyed by macrophages
■ Cells in the spleen detect abnormal or aging RBCs and send
macrophages to destroy them
○ RBC is recycled
■ Heme is split from globin
■ Iron bound to proteins is stored as ferritin
■ Bilirubin (heme - iron) is produced
● Picked up by the liver and excreted as bile (stored in the
gallbladder) and released in feces
■ Globin is broken down into amino acids
Describe the chemical makeup of hemoglobin
● Globin protein bound to heme pigment
, ● 4 globin units, 2 alpha chains and 2 beta chains
● Heme is the pigment that gives blood its red color
○ Contains an iron core that oxygen can bind to
○ One heme per globin subunit
● 1 hemoglobin can carry 4 oxygens
○ increasing oxygen affinity with each oxygen added
● Oxyhemoglobin: loaded with O2
● Deoxyhemoglobin: O2 has been offloaded
● Carbaminohemoglobin
○ Hemoglobin carrying CO2 → binds to globin proteins, not iron
○ Only 20% of CO2 is carried in this form
■ Majority is carried as bicarbonate is plasma
Define diapedesis
● ability of blood cells to leave circulation (blood vessel → interstitial space/other tissues)
● Only some white blood cells can do this
List the classes, structural characteristics, and functions of leukocytes
● Leukocytes = white blood cells
● Living cells (contain a nucleus and organelles)
● Many different types of leukocytes exists in the blood
● Function: immunity
● Account for less than 1% of total blood volume when combined with platelets
● Only component of blood with DNA
● Positive chemotaxis → attracted to the chemical secretions of other cells, such as those
released by damaged cells
● WBC count increases when we are fighting a bacterial infection
● Types
○ Granulocytes
■ Neutrophils
● Phagocytic
● 50-70% of WBCs
● Multilobe nuclei
● Count increases with inflammation
■ Eosinophil
● 2 lobe nuclei
● 4-6% of WBCs
● Attack parasitic worms by releasing enzymes
■ Basophil
● 0.5-1% of WBCs (rarest)
● Contain histamine which is a vasodilator that functions in
inflammatory response
○ Agranulocytes
■ Lymphocytes
