Download Blood - RuthenbergAP

Blood
Properties of blood
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Viscous
Temp 100.4F
pH range 7.35- 7.45 (alkaline)
5-6 L males; 4-5 L females
8% body weight
Functions of Blood
• Transport (Co2, O2, waste, nutrients,
hormones)
• Maintenance of body temperature, pH,
H2O content cells
• Protection against foreign substances;
antibodies
• Clot formation
Plasma Contents
• Liquid part of blood.
– 91% water ; 9 % solutes
• Proteins
– Albumins: made by liver; viscosity, osmotic
pressure
– Globulins: Transports other molecules
– Fibrinogen: blood clotting
• Ions: involved in osmosis, membrane potentials,
and acid-base balance
• Nutrients: glucose, amino acids, cholesterol,
vitamins
Plasma Contents Cont’d.
• Waste Products:
– Urea, uric acid, creatinine, ammonia salts
– Bilirubin
– Lactic acid
– Gases: oxygen, carbon dioxide, and nitrogen
• Regulatory substances: hormones, enzymes
Formed Elements
RBC
WBC
Platelet
(megakaryocyte)
Hematopoiesis
Hematopoiesis (in bone marrow)
White Blood Cells (WBCs)
• Leukocytes
• Protect body against microorganisms
and remove dead cells and debris
• Movements
– Ameboid: pseudopods
– Diapedesis: cells move through blood
vessels
– Chemotaxis: attraction to and movement
toward foreign materials or damaged cells
White Blood Cells
1% normal blood
Agranular
V.
Granular
Neutrophils
• Lobed nuclei connected
by filaments
• 50-70% WBCs
• Last 1-2 days
• Move into tissues and
phagocytize substances
• Fight normal infections
• bacterial
• PUS!
Eosinophils
• Bi-lobed nucleus;
granules stain red
(“eos” = dawn)
• Enter tissues during
inflammatory
response
• 1-4% WBCs
– Parasitic infections;
Allergic response
Basophils
• Indistinct lobed
nucleus
• Less than 1% WBCs
• Release histamine
(vasodilation) and
heparin
(anticoagulant)
• Inflammatory
response & allergic
reactions
Monocytes
• Kidney shaped or round
nucleus
• 2-8% WBCs
• Become macrophages
• Macrophages found in
tissues (spleen)
• Osteoclasts & Microglia
• Fight chronic infections,
tumors, remove old tissue
• Present antigens to
lymphocytes
Lymphocytes
• Big, round nucleus
• 25-40% WBCs
• B-cells: produced in
Bone marrow
– Produce antibodies
• T-cells: produced in
marrow and migrate
to Thymus to mature
• IMMUNE SYSTEM
Antigen: foreign protein
Antibody: binds to antigen and causes
death or removal by WBC
The Immune System is the Third
Line of Defense Against Infection
Components of the immune system
Lymphocytes
• B Cells
– Produced/ mature in red
marrow; then move to
lymph ts.
– Produce antibodies that
battle bacteria and some
viruses
• T Cells
– Mature in Thymus gland
– Directly contact antigens
– Affect mostly abnormal
body cells (cancerous/
virus infected, transplant
ts.)
Innate Immunity (non-specific) : Immunity an organism is
born with
 Genetically determined
 All antigens attacked equally by neutrophils,
macrophages, basophils, eosinophils
 Skin, saliva, tears, stomach acids, mucus
Acquired Immunity (specific): Immunity that an organism
develops during lifetime after exposure to antigen
 Not
genetically determined
 Based
on immune system recognizing,
remembering, and responding to antigens
 Active
body exposed to antigen (naturally or thru
vaccine) and generates an immune response
 Passive
antibodies (antiserum) introduced to
body; no immune response c=generated; short-lived
Red Blood Cells (RBCs)
• Erythrocytes
• 95% “formed elements”
• Biconcave discs…
WHY?
• Anucleate
• Antigens on surface
determine blood type
Erythropoiesis
• Lifespan= 120 days
• Spleen and liver “clean-up”
– bilirubin
• Takes 4 days to make one RBC; 2.5 million made each
second!
• Reticulocytes: immature RBCs
• Erythropoietin: hormone stimulates RBC production; produced
by kidneys in response to low blood O2 levels
Erythrocyte function: Transport
• Oxygen from lungs to tissues: 98.5%
attached to hemoglobin; 1.5% dissolved
in plasma
• Carbon dioxide from tissues to lungs.
– 7% dissolved in plasma
– 23% in combination with hemoglobin
– 70% transported as bicarbonate ions
produced as a result of combination
of H2O and CO2 because of enzyme
carbonic anhydrase found within
RBCs
Hemoglobin
• Hemoglobin (Hgb/ Hb)
– Heme (iron): Fe + Protein (globin)
– Each Hgb carries 4 O2 molecules
(oxyhemoglobin)
– Each RBC carries 250 million Hgb
molecules…
Regulation of blood pH
More H+ causes blood to be more acidic
Fewer H+ causes blood to be less acidic
70% of carbon dioxide (CO2) in blood is dissolved in plasma forming carbonic
acid (H2CO3)
H2CO3 is then dissociated into HCO3- and H+
H2CO3 acts as a hydrogen ion donor (acid)
HCO3- is the hydrogen ion acceptor (base)
HCO3- /CO2 buffer system is extremely important because it can be rapidly
readjusted in alkalosis and acidosis
Acidosis
Too Much CO2 or Too Little HCO3- Will Cause Acidosis
The balance will swing toward a low pH (acidosis) if
1. CO2 is raised  hypoventilation (pneumonia, emphysema)
2. HCO3- lowered  Metabolic conditions such as ketoacidosis caused
by excess fat metabolism (diabetes mellitus) will lower bicarbonate
Symptoms may include:
Confusion
Easy fatigue
Lethargy
Shortness of breath
Sleepiness
Compensation for acidosis:
 Remove CO2: occurs first
because lungs work faster than
kidneys
 Add HCO3-
Alkalosis
Too little CO2 or Too much HCO3 Will Cause Alkalosis
The balance will swing toward a higher pH (alkalosis) if
1. CO2 is lowered (hyperventilation)
2. Bicarbonate is raised (Vomiting reduces stomach acid)
Alkalosis is less common than acidosis
Symptoms may include:
Deep, rapid breathing
Dizziness, agitation;
seizures;
Compensation for alkalosis:
 Add CO2: occurs first
because lungs work faster
than kidneys
 Remove HCO3-
ABO Blood Groups
Rh antigen: another antigen; positive (+) blood has it,
negative (-) does not
Transfusions
• Donor: gives blood
• Recipient: receives blood
• We have antibodies against antigens that
we do not have!
Red Cross Facts
Thrombocytes
• Arise from megakaryocytes; anucleate
• Form platelet plugs (small vessels)
• Form clots (larger wounds)
Hemostasis: “Stop Bleeding”!
1. Vasoconstriction: reduces blood flow
2. Platelet plug formation: platelets attracted to exposed
proteins from damaged tissue, attracted to more
platelets... (Positive feedback!)
3. Coagulation: thrombin (enzyme) activates fibrinogens
(plasma proteins) when tissue is damaged… clotting
factors
4. Dissolution: after epithelial cells rebuild, WBCs destroy
clot
Blood “Thinners”
Heparin inhibits thrombin; isolated from pigs
and cows; must be injected; short-lived
Coumadin: inhibits processing of vitamin K
(needed for liver synthesis of clotting
factors); taken orally
Aspirin: inhibits platelet activation
Coagulation Factors
• Plasma proteins
• 13 clotting factors (+ 4 platelet factors)
• Many made in liver with aid of Vitamin K
Clotting Disorders
• Immune
Thrombocytopenia (ITP)
– autoimmune
• Von Willebrand
– Most common bleeding
disorder
• Hemophilia A: missing
Factor VIII
– 80% Hemophilia
• Hemophilia B: missing
Factor IX
Anemias: usually refers to a condition in
which your blood has a lower than normal number of red
blood cells. This condition also can occur if your red blood
cells don't contain enough hemoglobin
Anemia has three main causes: blood loss, lack of red
blood cell production, or high rates of red blood cell
destruction.
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Iron deficient
Pernicious
Aplastic
Hemolytic
Iron-deficiency anemia
• Lack of iron usually due to blood loss, poor diet, or an
inability to absorb enough iron from foods
• Microcytic RBCs; low hemoglobin values
• Symptoms fatigue, shortness of breath, chest pain,
dizziness, pallor. (Severe iron-deficiency anemia can lead to heart
problems, infections, problems with growth and development in children,
and other complications.)
• People at highest risk for iron-deficiency anemia include
infants and young children, women, and adults who have
internal bleeding.
Hemolytic Anemia: is due to high rates of red blood cell destruction.
When blood cells die, the body's bone marrow makes more blood cells to replace them.
However, in hemolytic anemia, the bone marrow can't make red blood cells fast enough to
meet the body's needs.
Inherited forms:
• Sickle Cell Anemia: a serious, inherited
disease. In this disease, the body makes
abnormal hemoglobin. This causes the red blood
cells to have a sickle, or "C," shape.
– Sickle cells don't last as long as healthy red
blood cells. They usually die after only about
10 to 20 days. The bone marrow can't make
new red blood cells fast enough to replace
the dying ones.
– Sickle cell anemia mainly affects people of
African descent.
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Thalassemias: inherited blood disorders in
which the body doesn't make enough of certain
types of hemoglobin. This causes the body to
make fewer healthy red blood cells than normal.
– most often affect people of Southeast Asian,
Indian, Chinese, Filipino, Mediterranean, or
African origin or descent.
Acquired forms:
Autoimmune hemolytic anemia
(AIHA). In this condition, your
immune system makes antibodies
(proteins) that attack your red blood
cells. Why this happens isn't known.
AIHA accounts for half of all cases of
hemolytic anemia. AIHA may come on
very quickly and become serious. It's
most common in people older than 40.
Rh-Incompatibility: WBC’s of
Rh negative mothers can cause
hemolytic in second child
Aplastic anemia
is a blood disorder in which the body's bone
marrow doesn't make enough new blood cells. This is because the bone marrow's stem cells
are damaged. (Aplastic anemia also is called bone marrow failure.)
Symptoms irregular heartbeats called arrhythmias, an enlarged heart, heart
failure, infections, and bleeding. Severe aplastic anemia can even cause death.
Acquired aplastic anemia: most common, sometimes temporary. In many people
the cause is unknown. Some research suggests that stem cell damage may occur because
the body's immune system attacks its own cells by mistake.
Inherited aplastic anemia (rare): Certain inherited conditions can damage the stem cells
Causes:
• Toxins, such as pesticides, arsenic, and benzene.
• Radiation and chemotherapy (treatments for cancer).
• Infectious diseases, such as hepatitis, Epstein-Barr virus, cytomegalovirus,
parvovirus, HIV.
• Autoimmune disorders, such as lupus and rheumatoid arthritis.
• Pregnancy. (Aplastic anemia that occurs during pregnancy often goes away after
delivery.)
• Sometimes, cancer from another part of the body can spread to the bone and
cause aplastic anemia.
Erythrocytosis
an excess of erythrocytes, (RBCs)
Polycythemia
• Hematocrit over 48% (women) or 52% (men)
• The extra red blood cells make your blood
thicker than normal leading poor circulation
and possible to heart attack and stroke
• Symptoms headaches, dizziness, itching,
and vision problems, such as blurred or
double vision, angina (chest pain), and heart
failure
• Causes of Primary polycythemia: DNA
mutation causes excess RBC production;
• Causes of Secondary polycythemia: living at
high altitudes as a response to lower oxygen
levels; hypoxic diseases, radiation exposure
Normal blood
Polycythemia vera
Hemochromatosis:
iron builds up in body
Excess iron can is toxic to organs and causes organ failure. Iron especially builds
up in the
• liver (enlarged liver, liver failure, liver cancer, or cirrhosis )
• heart (irregular heartbeats called arrhythmias and heart failure)
• pancreas (diabetes)
Primary hemochromatosis: recessive genetic disorder; one of the most
common genetic diseases in the United States; most common in Caucasians of
Northern European descent; less common in African Americans, Hispanics,
Asians, and American Indians; more common in men than in women; older
people are more likely to develop the disease than younger people.
Secondary hemochromatosis : can be caused by thalassemias, other
anemias, chronic alcoholism
** Certain factors can affect the severity of the disease. For example, a high
intake of vitamin C can make hemochromatosis worse. This is because vitamin C
helps your body absorb iron from food**
Leukocytosis is an increased number of leukocytes
A high white blood cell count usually indicates:
• An increased production of white blood cells to fight an infection
• A reaction to a drug that enhances white blood cell production
• A disease of bone marrow, causing abnormally high production of white blood
cells
• An immune system disorder that increases white blood cell production
Specific causes of high white blood cell count include:
• Leukemia
* Measles
• Myelofibrosis
* Other bacterial infections
• Other viral infections
* Polycythemia vera
• Rheumatoid arthritis
* Smoking
• Tuberculosis
* Whooping cough
• Stress
* Tissue damage, such as from
burn
• Allergy, especially severe allergic reactions
• Drugs, such as corticosteroids and epinephrine
Leukopenia – low wbc count
Causes:
• Viral infections that temporarily disrupt bone marrow function
• Congenital disorders characterized by diminished bone marrow function
• Cancer or other diseases that damage bone marrow
• Autoimmune disorders that destroy white blood cells or bone marrow cells
• Overwhelming infections that use up white blood cells faster than they can be produced
• Drugs that destroy white blood cells or damage bone marrow
Specific causes of low white blood cell count include:
• Aplastic anemia
* Leukemia
• Lupus-autoimmune disorders
* Other congenital disorders
• Parasitic diseases
* Radiation therapy
• Rheumatoid arthritis
* Vitamin deficiencies
• Certain medications, such as antibiotics and diuretics
* Chemotherapy
• HIV/AIDS/
* Hypersplenism
• Hyperthyroidism (overactive thyroid)Infectious diseases
• Kostmann's syndrome, a congenital disorder involving low neutrophil production
Leukemia
• Bone marrow produces a high number of abnormal WBCs
• Chronic: progresses slowly Vs. Acute: progresses quickly
• Type of leukemia depends on what type bone marrow cell affected
(myeloid: early granular WBC or lymphoid: early lymphocyte)
– Some types are more common in children or adults
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Symptoms Weakness, Fatigue, Anemia, Frequent infections or fever,
Weight loss and/or loss of appetite, Increased bruising or bleeding from
wounds, Bone pain or joint pains caused by the spread of malignant cells to
the surface of the bone or into the joint from the marrow cavity, Enlarged
lymph nodes, liver and/or spleen
• Treatment includes chemotherapy, radiation, medication GOAL=
remission
Chronic lymphocytic
leukemia (CLL): mostly
adults
Chronic myeloid leukemia
(CML): mostly adults
Acute lymphocytic
(lymphoblastic) leukemia (ALL):
most common in childrem
Acute myeloid leukemia (AML):
both adults and children