Transcript File - DOCEGG ANATOMY SITE docegg.com

Blood
• Blood (Whole Blood): is classified as connective tissue! It
consists of cells and cell fragments surrounded by a fluid
matrix.
• Formed Elements: cells and cell fragments (platelets) packets
of cytoplasm critical for clotting. The cells are Red Blood Cells
(RBC’s), or erythrocytes, transport carbon dioxide and oxygen.
Less numerous White Blood Cells (WBC’s) or leukocytes, body’s
defense mechanism.
• Plasma: the liquid matrix of dissolved proteins, slightly denser
than water.
• Blood Volume: girls 4 to 5 L, boys 5 to 6 L, and is approximately
8% of the body’s total weight.
• Collection: venipuncture, collection of venous blood from cubital
vein for analysis, most common procedure. Arterial Stick,
sample from the artery for blood gas evaluation.
Blood (cont.)
• Temperature: slightly hotter than body temp. 100.4 F
• Viscosity: 5 x more viscous (stickier) and more cohesive.
• pH: 7.35 – 7.45, venous is slightly lower than arterial.
Function of Blood
• Transportation, Maintenance & Protection
• Transportation of dissolved gases, nutrients, hormones, and
metabolic wastes.
• Regulation of pH and ion composition of interstitial fluids
throughout the body.
• Restriction of fluid loss at injury sites.
• Defense against toxins and pathogens.
• Stabilization of body temperature.
Plasma
• Pale yellow fluid, accounting for a little more than half the blood
volume 55%.
• 92% water, and about 8% dissolved or suspended molecules
• Colloidal Solution; a solution whose particles are resistant to
gravity.
• Plasma proteins: Albumins, globulins and fibrinogens
• Serum: plasma with the clotting factors removed.
• Other Stuff: salts, nutrients, gases, wastes, hormones and
enzymes.
• Albumins: 60% of all plasma proteins, they contribute to the
osmotic pressure of plasma.
• Globulins: 35% plasma proteins, 1) antibodies (immunoglobulins)
attack foreign proteins and pathogens. 2) transport proteins,
carry hormones and compounds that might otherwise be lost in
the kidney.
Plasma
•
Fibrinogens; blood clotting, by forming large insoluble strands
of fibrin.
•
1.
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Composition of Plasma
Water
Plasma Protein
Ions
Nutrients
Gases
Waste products
Enzymes & hormones
91.5%
7.0%
0.9%
0.3%
0.1%
0.1%
0.1%
Formed Elements
•
Highly specialized cells and cell fragments:
1.
2.
Erythrocytes (RBC’s) 95%
Leukocytes (WBC’s) 4%, only formed element with a nucleus
Neutrophils
Basophils
Eosinophils
Lymphocytes
Monocytes
3. Thrombocytes (platelets) 1%
Formed Elements
• Hemopoiesis (matopoiesis): red blood cell production.
• Hemocytoblasts: the stem cells that give rise to various types
of blood cells.
• Types: proerythro, myelo, lympho, mono, and megakaryoblasts
each of these is regulated by a specific growth factor.
• Erythrocytes: most numerous formed elements, 5.2 million per
mm3 in males and about 4.5 million in females. It is a biconcave
disk, this shape increases surface area for gas exchange. It can
bend or fold in the center for easy passage in tight spaces.
They have NO nucleus, and their primary component is a
pigmented protein called Hemoglobin, fills a third of the cell
and gives it, it’s red color.
• Function: transport oxygen from the lungs to the body and
carbon dioxide out.
Formed Elements (cont)
• Hemolysis: rupture of red blood cells and Hgb released into the
plasma.
• Hemoglobin: consists of 4 protein chains and 4 heme groups.
• Globin: protein that is bound to one Heme a red pigmented
molecule with one Fe atom in the middle. Each of you contains
about 4 grams of Fe, 2/3 of which is in the blood.
polycythemia
• An excessive or abnormal increase in the
number of erythrocytes
• may result from bone marrow cancer
• It may also be a normal physiological
(homeostatic) response to living at high altitudes
w / less oxygen available (2^polycythemia).
• Causes increased blood viscosity,
• flow sluggishly in the body and impairs
circulation. •
Anemia types
• Hemorrhagic – sudden hemorrhage
• Hemolytic - Lysis of RBCs due to bacterial infections
• Pernicious - Lack of vitB12 (Usually due to lack of
intrinsic factor required for absorption of the vitamin.
Intrinsic factor is formed by stomach mucosa cells.)
• Aplastic - Depression/destruction of bone marrow by
cancer, radiation, or certain medications
• Iron-deficiency - diet or slow/prolonged bleeding (heavy
menstrual flow or bleeding ulcer), which depletes iron
reserves needed to make hemoglobin; RBCs are small
and pale because they lack hemoglobin. –
• Sickle-cell anemia - Genetic defect leads to abnormal
hemoglobin, which becomes sharp and sickle shaped
under conditions of increased oxygen use by body;
occurs mainly in people of African descent
WBC’s
• Leukocytes
• less numerous than red blood cells, 1 percent of total
blood volume
• body defense against disease.
• 4000 to 11,000 WBCs per cubic millimeter,
• only complete cells in blood;(nuclei and organelles)
• protective, hitler was here . #NAZI4LYFE my defends
the body against damage by bacteria, viruses,
parasites, and tumors
• diapedesis - able to slip into and out of the blood
vessels
• chemotaxis - WBCs locate tissue damage/Infection by
responding to chemicals that diffuse from the
damaged cells.
• Leukocytosis - total WBC count above 11,000 cells/mm3
• the body speeds up their production due to disease
• indicates that a bacterial or viral infection is stewing in the
body.
• leukopenia - is an abnormally low WBC count.
• caused by certain drugs, - corticosteroids and anticancer
agents.
• Leukocytosis is a normal and desirable re-sponse to infectious
threats to the body. By contrast, the excessive production of
abnormal WBCs that occurs in infectious mononucleosis and
leukemia is distinctly pathological. In
• leukemia "white blood," the bone marrow becomes cancerous,
and huge numbers of immature WBCs incapable of protective
functions.
• Consequently, the body becomes the easy prey of diseasecausing bacteria
WBCs are classified into two major groups
• Granulocytes are granule-containing WBCs.
They have lobed nuclei, which typically consist
of several rounded nuclear areas connected by
thin strands of nuclear material. The granules in
their cytoplasm stain specifically with Wright's
stain.
• The granulocytes include the neutrophils ,
eosinophils, and basophils.
• agranulocytes, lack visible cytoplasmic
granules. Their nuclei are closer to the normal
spherical, oval, or kidney-shaped.
• The agranulocytes include lymphocytes and
monocytes
Hematopoiesis - Blood cell formation occurs in red bone marrow,
the myeloid tissue in the flat bones of skull, pelvis, ribs, sternum
• All the formed elements arise from
one type of stem cell, the
hemocytoblast.
• The developmental process from
hemocytoblast to mature RBC
takes 3 to 5 days.
• RBCs become rigid and fragment,
or fall apart in 100 to 120 days.
• erythropoietin - controls rate of
erythrocyte production (hormone)
• colony stimulating factors
(CSFs) and interleukins - not only
prompt red bone marrow to turn
out leukocytes, but also enhance
the ability of mature leukocytes to
protect the body.
• Thrombopoietin - accelerates the
production of platelets (hormone)
hemostasis (hem = blood; stasis = standing still),
or stoppage of blood flow
• This response, which is
fast and localized,
involves many
substances normally
present in plasma, as
well as some that are
released by platelets and
injured tissue cells.
• Hemostasis involves
three phases, which
occur in rapid sequence:
• vascular spasms,
• platelet plug formation,
• coagulation, or clotting.
Undesirable Clotting
• thrombus - A clot that develops and persists in
an unbroken blood vessel (coronary
thrombosis),
• embolus - a thrombus breaks away from the
vessel wall and floats freely in the bloodstream
• Undesirable clotting may be caused by anything
that roughens the endothelium of a blood
vessel and encourages clinging of platelets,
such as severe burns, physical blows, or an
accumulation of fatty material.
• Slowly flowing blood, or blood pooling, is
another risk factor, especially in immobilized
patients.
Bleeding Disorders
• Thrombocytopenia - insufficient number of circulating
platelets. Even normal movements cause
spontaneous bleeding from small blood vessels.
• It can arise from any condition that suppresses
myeloid tissue, such as bone marrow cancer, radiation, or certain drugs.
• vitamin K is needed by the liver cells to produce
clotting factors.
• in hepatitis and cirrhosis, only whole blood
transfusions are helpful.
• hemophilia - several different hereditary bleeding
disorders that result from a lack of any of the factors
needed for clotting.
• hemophiliacs are given a transfusion of fresh plasma
or injections of the purified clotting factor they lack.
• or genetically engineered clotting factors.
Blood
groups
and
transfusions
Losses of 15 to 30 percent lead to pallor and weakness.
•
• Losses of over 30 percent cause severe shock, which can be fatal.
• treated blood can be stored (refrigerated at 4°C) for about 35 days until
needed
• Human Blood Groups
• The plasma membranes of RBCs, like those of all body cells, bear
genetically determined proteins (antigens), which identify each person as
unique.
• An antigen is a substance that the body recognizes as foreign and
stimulates the immune system to release antibodies against it.
• Most antigens are foreign proteins, that are part of viruses or bacteria
• each of us tolerates our own cellular (self) antigens,
• one person's RBC proteins will be recognized as foreign if transfused into
another
• The "recognizers" are antibodies present in the plasma that attach to RBCs
bearing surface antigens different from those on the blood recipient's RBCs.
• Binding of the antibodies causes the RBCs to clump, called agglutination*
• There are over 30 common RBC antigens in humans, allowing each
person's blood cells to be classified into different blood groups. However, it
is the antigens of the ABO and Rh blood groups that cause the most
vigorous transfusion reactions
•
•
The Rh blood groups are so named because one of the eight Rh antigens (agglutinogen D) was originally
identified in Rhesus monkeys. Later the same antigen was discovered in human beings. Most Americans are
Rh+ (Rh positive), meaning that their RBCs carry the Rh antigen. Unlike the antibodies of the ABO system,
anti-Rh antibodies are not automatically formed and present in the blood of Rh~ (Rh negative) individuals.
However, if an Rh" person receives mismatched blood (that is, Rh+), shortly after the transfusion his or her
immune system becomes sensitized and begins producing antibodies (anti-Rh+ antibodies) against the
foreign blood type. Hemolysis (rupture of RBCs) does not occur with the first transfusion because it takes time
for the body to react and start making antibodies. But the second time and every time thereafter, a typical
transfusion reaction occurs in which the patient's antibodies attack and rupture the donor's RBCs.
An important Rh-related problem occurs in pregnant Rh~ women who are carrying Rh+ babies. The first such
pregnancy usually results in thedelivery of a healthy baby. Buc because the mother is sensitized by Rh+
antigens that have passed through the placenta into her bloodstream, she will form ;mti-Rh+ antibodies
unless treated with RhoGAM shortly after giving birth. RhoGAM is an immune serum that prevents this
sensiti/ation and her subsequent immune response. If she is not treated and becomes pregnant again with an
Rh+ baby, her antibodies will cross through the placenta and destroy the baby's RBCs. producing a condition
known as beinolytic disease of the newborn. The baby is anemic and becomes hypoxic. Brain damage and
even death may result unless fetal transfusions are clone before birth to provide more RBCs for oxygen
transport.