Chapter 17: Blood
What are the three types of formed elements?
1. erythrocytes 2. leukocytes 3. platelets
Symptoms of aplastic anemia
1. impaired formation of all formed elements 2. defects in blood clotting 3. defects in immunity usually accompanied by other symptoms
Causes of Hemolysis
1. inappropriately matched blood transfusions 2. toxins of certain viral or bacterial infections (streptococcus)
Causes of Aplastic Anemia
1. ionizing radiation 2. drugs, including chemotherapy 3. viruses
What can cause low oxygen concentrations?
1. reduced numbers of red blood cells due to hemorrhage or excessive RBC destruction. 2. insufficient hemoglobin in each RBC (iron deficiency). 3. reduced availability of oxygen, as might occur at high altitudes or during pneumonia.
What is the lifespan of an erythrocyte?
100-120 days
What is the normal value of hemoglobin in adult females?
12-16 grams/100ml
What is the normal value of hemoglobin in adult males?
13-18 grams/100ml
What is the normal value of hemoglobin in infants?
14-20 grams/100ml
What does the protein globin consist of?
2 alpha and 2 beta polypeptide chains, each bound to a ringlike heme group.
What percent of carbon dioxide is transported in the blood?
20%
How much of the blood is made out of formed elements?
45%
How much of the blood volume are erythrocytes?
45%
How much of the blood is made out of plasma?
55%
How much of iron is stored in hemoglobin?
65%
True or False A very large amount of oxygen is dissolved in plasma.
False
True or False Blood supplies carbon dioxide to tissues and removes oxygen.
False
True or False Erythrocytes have mitochondria.
False
True or False Estrogen can enhance EPO production in the kidneys.
False
True or False Red blood cells are able to synthesize new proteins, grow, and divide.
False
True or False The blood does not maintain electrolyte balance of cellular environment.
False
True or False Women tend to have a higher red blood cell count than men.
False
The blood maintains pH balance of cellular environment.
True
True of False Almost all of the oxygen transported by the blood is carried by hemoglobin.
True
True or False Blood is the only fluid tissue in the body.
True
True or False Blood supplies nutrients to tissues and removes waste.
True
True or False Dealing with the cause of blood loss is usually sufficient to allow the body to replace red blood cells through normal erythropoiesis.
True
True or False Erythrocytes can deform to fit through small capillaries.
True
True or False Only leukocytes are complete cells.
True
True or False Testosterone can enhance EPO production in the kidneys.
True
True or False The blood moves heat around the body to maintain temperature.
True
bilirubin
a yellow pigment that is released to the blood and binds to albumin for transport.
What makes up 60% of plasma proteins?
albumin
What is at the center of each heme group?
an iron atom
How do erythrocytes generate ATP?
anaerobically
Anemia
any condition in which the blood has abnormally low oxygen-carrying capacity.
Erythrocytes are shaped like _________ ______.
biconcave discs
Heme degrades into what?
bilirubin
Hemorrhage
blood loss due to injury
carbaminohemoglobin
carbon dioxide bounded to the globin's amino acids rather than to the heme group
platelets
cell fragments that help with blood clotting
What type of tissue is the blood?
connective tissue
deoxyhemoglobin
deoxygenated form of hemoglobin
proerythroblast
develop into early (basophilic) erythroblasts which begin to synthesize ribosomes.
What does a normoblast do?
ejects of most of its organelles, including the nucleus.
Are erythrocytes nucleated or enucleated in mammals?
enucleated
What is a major factor contributing to blood viscosity?
erythrocytes
Hemolysis
erythrocytes lyse prematurely; erythrocytes are abnormally fragile or are destroyed by some chemical or toxin.
Intracellular iron is stored in protein-iron complexes such as
ferritin and hemosiderin
Hemoglobin released into the blood is captured by _________ and is ___________ by __________.
haptoglobin; phagocytized; macrophages
erythropoiesis
hematopoiesis of erythrocytes
All blood cells arise from stem cells called __________.
hemocytoblasts
Erythrocytes are bags of ___________.
hemoglobin
Where does the body store iron?
hemoglobin liver spleen bone marrow
What happens when early erythrocytes develop into late erythrocytes?
hemoglobin synthesis and iron accumulation.
Low RBC Count Anemia
hemorrhage hemolysis aplastic anemia
Types of Anemia
hemorrhage hemolysis aplastic anemia iron deficiency pernicious anemia sickle cell anemia thalassemia
Erythropoietin (EPO)
hormone that stimulates the production of red blood cells
How does urobilinogen leave the body?
in feces as a brown pigment called stercobilin.
Low Hemoglobin Anemia
iron deficiency pernicious anemia
What makes the blood a connective tissue?
it has formed elements that are suspended in a nonliving fluid matrix (plasma).
Fibrinogen
it is involved in the formation of blood clots
What happens to globin after it has been separated from heme?
it is metabolized into amino acids and is released into the circulation.
What happens to the remainder 80% of carbon dioxide?
it is transported as either dissolved carbon dioxide or bicarbonate ion.
Early erythroblasts develop into _____ _________.
late erythroblasts
Where are most of the plasma proteins produced?
liver
Aplastic Anemia
loss of (red) bone marrow; may require bone marrow replacement
What is the main function of albumin?
maintains colloid osmotic pressure (the pressure that keeps water in the bloodstream); blood buffer
Iron is the binding site for what?
molecular oxygen (O2)
What are vitamin B12 and folic acid necessary for?
normal DNA synthesis
Late erythrocytes develop into _________.
normoblasts
oxyhemoglobin
oxygen-bound form of hemoglobin
hemoglobin
oxygen-transporting protein of erythrocytes
What is the nonliving matrix in the blood?
plasma
What do hemocytoblasts differentiate into?
proerythroblasts
What does erythropoietin require?
proteins lipids carbohydrates iron vitamin B12 folic acid
Acute Hemorrhage
rapid blood loss due to trauma.
erythrocytes
red blood cells that transport oxygen and carbon dioxide
where does hematopoiesis occur?
red bone marrow
Normoblasts develop into _________.
reticulocytes (young erythrocytes)
What is used for hemoglobin synthesis?
ribosomes
What happens to bilirubin after it has turned into bile?
secreted into the intestines; the intestines metabolize it into urobilinogen.
What is the main function of the blood?
serves as a transport medium, moving material and energy from place to place within the body.
Abnormal Hemoglobin Anemia
sickle cell anemia thalassemia
Chronic Hemorrhage
slow blood loss due to hemorrhoids or a bleeding ulcer.
What protein helps erythrocytes maintain its shape?
spectrin
hematopoiesis
the formation of blood cells
What happens to the hemoglobin of dying erythrocytes?
the heme and globin are separated; iron is salvaged for reuse.
hematocrit
the measured percentage of erythrocytes in whole blood; it varies with sex and environmental conditions
What is hemoglobin made up of?
the protein globin bound to the red heme pigment.
What is the "red blood cell graveyard"?
the spleen
What happens to dying erythrocytes?
they are engulfed by macrophages, primarily in the spleen.
What happens to old erythrocytes?
they become rigid and fragile; their hemoglobin begins to degenerate.
What happens when the kidney and liver detect low oxygen concentrations?
they increase the production of erytrhopoietin
Renal dialysis patients have too much or too little EPO to support normal erythropoiesis?
too little
What depresses erythropoietin production?
too many erythrocytes or excessive oxygen in the bloodstream.
Circulating iron is loosely bound to what transport protein?
transferrin
What do liver cells to to the bilirubin?
turns it into bile
leukocytes
white blood cells that at in various ways to protect the body
How can acute hemorrhage be treated?
with blood replacement
