Chapter 12 Blood
Blood composition:
Blood, a type of__connective_ tissue, is a complex mixture of what three things? Cells, fluid, and chemicals
functions: What are the functions of blood? Transports substances and maintains a stable environment
Blood Cells:
The blood includes what three types of cells? Red blood cells, white blood cells, platelets
Blood Volume and Composition
A blood ____hematocrit____ is normally _45___% cells and _____55___% plasma.
RBC = erythrocyte:
Red blood cells (erythrocytes) are biconcave disks that contain one-third oxygen-carrying _hemoglobin__ by
volume.
When oxygen combines with hemoglobin bright red__oxyhemoglobin_____ results.
Deoxygenated blood (__deoxyhemoglobin_______________) is darker.
Red blood cells discard their _ nucleus___ during development and so cannot reproduce or produce
proteins.
RBC counts:
What is a typical RBC count for males? 4.6 to 6.2 million/mm3 For females? 4.2 – 5.4 million/mm3
RBC production:
In the embryo and fetus, red blood cell production occurs in the yolk sac, _liver____, and spleen;
after birth, it occurs in the red ___bone marrow_____________ _________________________.
The average life span of a red blood cell is ___120 days_____________________.
Control: The total number of red blood cells remains relatively constant due to a __negative___
feedback mechanism utilizing the hormone _erythropoietin__which is released from the kidneys
and liver in response to the detection of low __oxygen____ levels.
Dietary Factors Affecting Red Blood Cell Production
Vitamins _B12___ and __folic_ acid are needed for DNA synthesis, so they are necessary for the
reproduction of all body cells, especially in hematopoietic tissue.
____iron________ is needed for hemoglobin synthesis.
A deficiency in red blood cells or quantity of hemoglobin results in a disorder called __anemia___.
Destruction of Red Blood Cells
With age, red blood cells become increasingly fragile and are damaged by passing through __capillaries_.
Macrophages in the _liver__ and __spleen___ phagocytize damaged red blood cells.
Hemoglobin from the decomposed red blood cells is converted into ___heme___ and __globin_.
What happens to the heme and iron? Recycled back to be incorporated into new red blood cells
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WBC = leukocyte:
WBC’s are formed from __hemocytoblasts_____ in response to hormones when needed.
Five types of white blood cells are in circulating blood and are distinguished by size, granular appearance of the
cytoplasm, shape of the nucleus, and staining characteristics. Name these five types of leukocytes.
Neutrophils, eosinophils, basophils, monocytes, lymphocytes
What is the basic function of the white blood cells? Protection (by defending against disease)
WBC counts:
Normally a cubic milliliter of blood contains between _5,000___ & __10,000___ white blood cells.
A ___differential_________ white blood cell count can help pinpoint the nature of an illness, indicating
whether it is caused by bacteria or viruses.
This white blood cell count lists the percentages of the types of leukocytes in a blood sample.
_____leukocytosis______ occurs after an infection when excess numbers of leukocytes are present.
_____leukopenia_____ (too few WBC’s) occurs from a variety of conditions, including AIDS.
granulocytes:
Why is this group called granulocytes? Granules are observed in their cytoplasm when stained with certain
stains
neutrophils:
Neutrophils have _red__-staining fine cytoplasmic granules and a _multi-lobed nucleus; they comprise
what percentage of leukocytes? 54 to 62%
What is their function? Phagocytize bacteria, fungi, and some viruses
What does diapedesis mean? Squeezing between cells in blood vessel walls
eosinophils:
Eosinophils have coarse granules that stain deep , a _bi__-lobed nucleus, and make up only ___1 to 3___% of
circulating leukocytes
What are their functions? Moderate allergic reactions, defend against certain parasites
basophils:
Basophils have fewer granules that stain __deep blue__; they account for fewer than 1_% of leukocytes.
Basophils produce chemicals, what are the functions of these chemicals? Increase blood flow to damaged tissues
How do they help fight pathogens? Promote inflammation responses
agranulocytes:
Why are they called agranulocytes? They lack the characteristic cytoplasmic granules
monocytes:
Monocytes are the ___largest____ blood cells, have _oval_-shaped nuclei. What percentage of
circulating leukocytes do they comprise? 3% to 9%
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What is the function of the monocytes? Phagocytize bacteria and cellular debris
lymphocytes:
Lymphocytes are long-lived, have a large, __spherical___ nucleus, and account for ___25 - 33_% of
circulating leukocytes.
What is their function? Involved in immunity responses
platelets = thrombocytes:
Blood platelets are fragments of big cells called ___megakaryocytes_______.
Platelets help repair damaged blood vessels by adhering____ to their broken edges.
Normal counts vary from __130,000___ to __360,000___________ platelets per mm3.
Plasma
Plasma is the clear, straw-colored fluid portion of the blood.
Plasma is mostly ___water_____ but contains a variety of substances.
What are plasma’s functions? Transjport of nutrients and gases, regulates fluid and electrolyte balance, maintains
acid base balance
Plasma proteins: The plasma proteins are the most abundant dissolved substances in the plasma.
Briefly describe the functions of the following plasma proteins.
albumin: maintain the correct osmotic pressure of the plasma
globulin: transport of lipids and fat-soluble vitamins, some are a type of antibody
clotting proteins: play an important role in blood clotting process
hormones: Regulate and control physiological function
Other Plasma Components:
Nutrients and Gases
What are the two most important blood gases? Oxygen and carbon dioxide
The plasma nutrients include amino acids, monosaccharides, nucleotides, and lipids.
Types of lipoproteins include HDL, LDL, VLDL, and chylomicrons.
Nonprotein Nitrogenous Substances generally include amino acids, urea, and uric acid. What are they from?
Plasma electrolytes are absorbed by the intestine or are by-products of cellular metabolism. They include
sodium, potassium, calcium, magnesium, chloride, bicarbonate, phosphate, and sulfate ions.
Hemostasis:
Hemostasis refers to the ___stoppage of bleeding___________________________________
Following injury to a vessel, three steps occur in hemostasis: blood vessel spasm, platelet plug formation,
and blood coagulation
trauma ----> Cutting a blood vessel causes the muscle in its walls to contract in a reflex, or engage in
_vasospasm_______ This reflex lasts only a few minutes, but it lasts long enough to initiate the second and
third steps of hemostasis.
spasm of injured vessel ----> platelet plug ----> Platelets stick to the exposed edges of __damaged__ blood vessels,
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forming a _net___ with spiny processes protruding from their membranes.
on a small vessel.
Platelets release a factor leading to the third step of hemostasis.
A platelet plug is most effective
Coagulation:
Blood coagulation is the most effective means of hemostasis. It is very complex and uses clotting factors.
Damaged tissues release a chemical called tissue __thromboplastin__, which activates the first in a series of
factors leading to the production of _prothrombin__ activator.
This activator converts inactive _prothrombin___ in the plasma into __thrombin_______. This in turn,
catalyzes a reaction that converts soluble _fibrinogen_ into netlike __fibrin_____ causing the blood
cells to catch in the net.
Once a blood clot forms, it promotes still more clotting through __positive__ feedback system.
What happens after the clot forms? Fibroblasts produce fibers throughout the clot
A clot that forms abnormally in a vessel is a ___thrombus_____; if it dislodges, it is an _embolus_____________.
What is hemophilia? Abnormal bleeding because blood fails to clot normally
Blood Groups and Transfusions
After mixed success with transfusions, scientists determined that blood was of different types and only certain
combinations were compatible.
Clumping of red blood cells following transfusion is called __agglutination________________________.
This clumping is due to the interaction of proteins on the surfaces of red blood cells called __antigens__ with
certain proteins called _antibodies___ carried in the plasma.
blood types: A, B, AB, O:
What is an antigen? Special proteins found on the surface of cells
What is an antibody? Special protein in the blood plasm that interact with specific antigen
type A has what type of antigens and antibodies?
Has A type antigens and anti-B antibodies
type B has ….. B-type antigens and anti-A antibodies
type AB has …. Both A-type and B-type antigens and neither type of antibodies
Type O has …. Neither type of antigen but both types of blood antibodies
RH Blood Types
The Rh factor was named after the __rhesus______ monkey.
If the Rh factor surface protein is present on red blood cells, the blood is Rh __positive_______; if not, it
is Rh __negative______.
There are no corresponding antibodies in the plasma unless a person with Rh-negative blood is transfused with Rhpositive blood; the person will then develop antibodies for the Rh factor.
____erythroblastosis fetalis______ develops in Rh-positive fetuses of Rh-negative mothers but can now
be prevented.
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