Ch 4 Hematologic System

blood is made of

liquid plasma

cellular components- erythrocytes leukocytes, thrombocytes suspended in plasma

plasma carries

antibodies and nutrients to tissues and carries wastes away

erythrocytes

RBCs

carry oxygen to tissues and remove carbon dioxide from them

leukocytes or WBCs

participate in inflammatory and immune response

thrombocytes or platelets

along with coagulation factors in plasma are essential to normal blood clotting

plasma consists mainly of

the proteins, albumin, globulin, and fibrinogen held in aqueous suspension

plasma’s osmotic pressure, viscosity, and suspension qualities depend on

its protein content

other components in plasma

glucose

lipids

amino acids

electrolytes

pigments

hormones

oxygen

carbon dioxide

important products of metabolism that circulate in plasma

urea

uric acid

creatinine

lactic acid

RBCs in adults are produced in

bone marrow

in fetus, liver and spleen also participate

erythropoiesis

RBC production process

hemoglobin Hgb

an oxygen-carrying substance

gives RBCs ability to transport oxygen

synthesis of hemoglobin requires

Fe++

RBC production is regulated by

tissues’ demand for oxygen

blood cells’ ability to deliver it

hypoxia in the tissues stimulates

formation and release of erythropoietin, a hormone that activates the bone marrow to produce RBCs

RBC development requries

vitamin B12

folic acid

minerals like copper, cobalt, and iron

iron

found in food

absorbed in duodenum and upper jejunum

meats and some fish and some plants

after absorbed it is transported to bone marrow for hemoglobin synthesis u

unused iron is stored as

ferritin and hemosiderin in reticuloendothelial cells (mostly in liver)

WBCs classification

granular leukocytes - neutrophils, eosinophils, basophils

nongranular leukocytes- monocytes and lymphocytes

most WBCs are produced in

bone marrow

lymphocytes complete maturation

in lymph nodes

normal number of WBCs

5000-10000 per microliter

types of granulocytes

neutrophils

eosinophils

basophils

neutrophils

predominant form of granulocyte

surround and digest invading organisms and other foreign matter by phagocytosis

eosinophils

minor granulocytes

defend against parasites

participate in allergic reactions

fight lung and skin infections

basophils

minor granulocytes

release histamine into blood

participate in delayed allergic reactions

contain heparin an anticoagulant

types of nongranular leukocytes

monocytes

lymphocytes

monocytes

along w neutrophils devour invading organisms via phagocytosis

migrate to tissues where they develop into cells called macrophages that participate in immunity

lymphocytes occur mostly in two forms

B cells

T cells

b cells produce

antibodies

t cells regulate

cell-mediated immunity

platelets

small 2-4 micrometers in diameter

colorless

disk-shaped cytoplasmic cells

split from cells in bone marrow

platelets 3 vital functions to help minimize blood loss

help constrict damaged blood vessels

form hemostatic plugs in injured blood vessels by becoming swollen, spiky, sticky, and secretory

they provide substances that accelerate blood clotting, such as factors III and XIII and platelet factor III

hemostasis

complex process

platelets, plasma, and coagulation factors interact to control bleeding

dyscrasia

abnormal or pathologic condition of blood

bone marrow cells and precursors are vulnerable to changes that affect cell production because

bone marrow cells reproduce rapidly and have a short lifespan

blood disorders may be

primary or secondary

quantitative or qualitative

primary bleeding disorder

occurs bc a problem within blood itself

secondary bleeding disorder results from

a cause other than a defect in blood

qualitative blood disorders stem from

intrinsic cell abnormalities or plasma component dysfunction

quantitative blood disorders result from

increased or decreased cell production or cell destruction

blood disorders may be caused by

trauma

cancer- infiltration of bone marrow

chemotherapy

chronic disease such as cirrhosis

surgery

malnutrition

drugs

toxins

radiation

genetic and congenital defects

sepsis

depressed bone marrow production or increased destruction of mature blood cells can result in

decreased RBCs- anemia

decreased platelets- thrombocytopenia

decreased leukocytes- leukopenia

all three components being decreased- pancytopenia

production of bone marrow components may increase

this results in myeloproliferative disorders like

chronic myeloid leukemia

myelofibrosis

polycythemia vera

essential thrombocytosis

RBC disorders may occur with

a decrease- anemia

an increase- polycythemia

in their production

anemia may result from

decreased RBC production

increased RBC destruction

blood loss

polycythemia may result from

hypoxia

tumors that secrete erythropoietin

kidney disease

genetic defects

an increase in WBC precursors and their accumulation in bone marrow or lymphoid tissue signal

leukemia - cancer of WBCs

cancerous WBC aka blasts

nonfunctioning

harmful-

take over bone marrow, crowding out other vital components, such as RBCs, platelets, and mature healthy WBCs

spill into bloodstream, sometimes infiltrating organs and impairing their function

most common types of WBC deficiencies

neutropenia

lymphocytopenia

WBC deficiencies may result from

inadequate cell production

drug rxns

ionizing radiation

infiltrated bone marrow - cancer

congenital defects

aplastic anemias

folic acid deficiency

hypersplenism

disorders may occur with platelets when they’re

too few- thrombocytopenia

too many- thrombocytosis

dysfunctional- thrombocytopathy

thrombocytopenia may result from

congenital deficiency

exposure to drugs like heparin

cancerous infiltration of bone marrow

abnormal sequestration (blood accumulation and pooling) in spleen

infection

exposure to ionizing radiation

thrombocytosis

occurs as a result of certain diseases such as cancer

thrombocytopathy usually results from

disease- uremia or liver failure

adverse effects of medications like salicylates and nonsteroidal anti-inflammatory drugs NSAIDs

herbs like alfalfa, chamomile, clove, evening primrose oil, garlic, ginger, ginseng, and red clover

blood disorders

acid-base imbalances

anemia

disseminated intravascular coagulation DIC

hemophilia

idiopathic thrombocytopenic purpura ITP

iron deficiency anemia

leukemia

lymphomas

multiple myeloma

thrombocytopenia

acid-base balance is maintained by

buffer systems

lungs

kidneys

they neutralize and eliminate acids rapidly

chemical rxn that is a buffer system occuring in bloodstream at all tiems

CO2 + H20 ←> H2CO2 ←> H+ and HCO3-

kidneys can excrete

H+ or retain HCO3-

acidosis

too much acid in blood

alkalosis

too much base in blood

hypoventilation causes

acidosis

hyperventilation causes

alkalosis

lungs influence acid-base balance by

regulating carbon dioxide PaCO2

kidneys effect acid-base balance by

regulating bicarbonate and acid

disturbances in acid-base balance can be caused by

respiratory dysfunction

metabolic dysfunction

respiratory dysfunction

lungs are cause of problem

retention of too much CO2

elimination of too much CO2

metabolic dysfunction

causes-

renal disorders

gastrointestinal problems (vomiting or diarrhea)

toxin ingestion

drug overdose

uncontrolled diabetes (ketoacidosis)

other metabolic disturbance

4 states of acid-base imbalance

respiratory acidosis

respiratory alkalosis

metabolic acidosis

metabolic alkalosis

because acid-base compensation can take hours to days

medical treatment is often necessary to reverse an acid-base imbalance

signs and symptoms of respiratory acidosis

restlessness

confusion

diaphoresis

bounding pulse

apprehension

somnolence

asterixis (fine or flapping tremor)

coma

headaches

dyspnea and tachypnea

papilledema

depressed reflexes

hypoxemia

tachycardia

hypertension

atrial and ventricular arrhythmias

hypotension with vasodilation