Components of the Hematologic System - Mercer County Community

14 Pages·2011·1.06 MB·English

Bio217 Unit VI
Components of the
Bio217: Pathophysiology Class Notes
Hematologic System
Professor Linda Falkow
• Main functions

Unit VI: Blood and Cardiovascular System Disorders –Delivery of substances needed for cell
metabolism
–Removal of wastes
Chapter 19: Structure & Function of the Hematologic System
Chapter 20: Alterations of Hematologic Function –Defense against microorganisms and
injury
Chapter 22: Structure & Function of CV & Lymphatic Systems
Chapter 23: Alterations of Cardiovascular Function –Maintain acid-base balance

Components of the Components of the Hematologic System
Hematologic System
• Composition of blood
Composition of blood (~6 quarts) –Cellular components (~45%)
Plasma •Erythrocytes (red blood cells)
55% to 60% of the blood volume –Carry O2 and remove CO2
Organic and inorganic elements –120-day life cycle
•Leukocytes (white blood cells)
Plasma proteins –Defend the body against infection and remove debris
Albumins –Granulocytes (neutrophils, eosinophils, basophils)
Function as carriers and control the plasma oncotic pressure –Agranulocytes (monocytes and lymphocytes)
Globulins
•Platelets
Carrier proteins and immunoglobulins (antibodies)
–Disk-shaped cytoplasmic fragments
Fibrinogen
–Essential for blood clotting

Composition of Whole Blood
Blood Cells
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Evaluation of the
Leukocytes
Hematologic System
• Tests of bone marrow function
–Bone marrow aspiration
–Bone marrow biopsy
–Measurement of bone marrow iron stores
–Differential cell count
• Blood tests
–Large variety of tests
Concept Check
• 1. Which is not a component of plasma?
–A. Colloids C. Glucose • 4. About how many times more RBCs than WBCs
–B. Electrolytes D. Platelets are there in a mm3 of blood?
–A. 15 C. 100
• 2. Which is the most abundant protein in blood? –B. 90 D. 1000
–A. Fibrinogen C. Globulins

–B. Albumins D. Hormones
• 5. Which of the following are agranulocytes?
• 3. The purpose of EPO: –A. Mast cell
–A. Decrease maturation of RBCs –B. Lymphocyte
–B. Detect hypoxia –C. Monocyte
–C. Control RBC production – D. Reticulocyte
–D. Control platelet size
– E. B and C are correct

Alterations of Hematologic Function
Chapter 20 Anemia
• Anemia = reduced number of • Physiologic manifestation
erythrocytes or Hb
–Reduced oxygen-carrying capacity
–Impaired erythrocyte production

–Acute or chronic blood loss
–Increased erythrocyte destruction • Variable symptoms depending on
–Classifications severity and body’s ability to
•Size
compensate
–Identified by terms that end in “-cytic”
–Macrocytic, microcytic, normocytic • Classic anemia symptoms
•Hemoglobin content
–Fatigue, weakness, dyspnea, and pallor
–Identified by terms that end in “-chromic”
–Normochromic and hypochromic

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Bio217 Unit VI
Microcytic-Hypochromic Anemias
Macrocytic-Normochromic Anemias
• Iron deficiency anemia (IDA)
• Pernicious anemia (PA) –Most common type of anemia worldwide
–Due to:
–Caused by a lack of intrinsic factor (IF) (parietal cells in
stomach) • Inadequate dietary intake of iron
–Results in vitamin B deficiency •Pregnancy
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–Loss of appetite, abdominal pain, beefy red tongue •Blood loss (2-4ml/day- ulcer, hiatal hernia, colitis,
(atrophic glossitis), icterus, and splenic enlargement menorrhagia)
•Iron malabsorption (chronic diarrhea, celiac disease)
–PA associated with incr. alcohol intake, hot tea, smoking
–Progression of iron deficiency causes:
–Treatment: Vit. B throughout life
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•Brittle, thin, coarsely ridged, and spoon-shaped nails (koilonychia)
•Red, sore, and painful tongue (glossitis)
Microcytic-Hypochromic Anemias Alterations of Leukocyte Function
• Pathophysiology • Quantitative disorders
–Iron use in body for Hb and storage for future Hb –Increases or decreases in cell numbers
–Iron is recycled and it is important to maintain a –Bone marrow disorders or premature
balance. destruction of cells
–Blood loss  disrupts the balance
–Response to infectious microorganism
–Normal Hb = ~12-18g/dl invasion
–When Hb levels drop to7-8g/dl patients seek

medical attention
• Qualitative disorders
• Treatment
–Disruption of cellular function
–Determine source of blood loss
–Iron replacement therapy
Quantitative Alterations of Leukocytes
Granulocytosis (Neutrophilia)
• Leukocytosis
• Neutrophilia is evident in the first stages of
–Leukocytosis is a normal protective physiologic
an infection or inflammation
response to physiologic stressors

• If the need for neutrophils increases
• Leukopenia
beyond the supply, immature neutrophils
–Leukopenia is not normal and not beneficial (banded neutrophils) are released into the
–A low white count predisposes a patient to blood
infections
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Granulocytosis (Neutrophilia) Monocytes
• Monocytosis
• This premature release is detected in the
–Poor correlation with disease
manual WBC differential and is termed a shift
–Usually occurs with neutropenia in later stages of
to the left
infections
–Monocytes are needed to phagocytize organisms and
• When the population returns to normal, it is debris
termed a shift to the right
• Monocytopenia
–Very little known about this condition
Lymphocytes Infectious Mononucleosis
• Lymphocytosis
• Acute, self-limiting infection of B-
–Acute viral infections
lymphocytes transmitted by saliva
•Epstein-Barr virus
through personal contact

• Lymphocytopenia
–Immune deficiencies, drug destruction, viral • Commonly caused by the Epstein-Barr
destruction virus (EBV)—85%
–B cells have an EBV receptor site
–Others viral agents resembling IM
• Cytomegalovirus (CMV), hepatitis, influenza, HIV
Infectious Mononucleosis Infectious Mononucleosis
• Symptoms: fever, sore throat, swollen cervical • >50% lymphocytes and at least 10%
lymph nodes, increased lymphocyte count, atypical lymphocytes
and atypical (activated) lymphocytes • Diagnostic test
–Monospot qualitative test for heterophilic
• Serious complications are infrequent (<5%) antibodies
–Splenic rupture is the most common cause of • Treatment: symptomatic
death
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Leukemias
Leukemias
Acute lymphocytic leukemia (ALL)
80% of all childhood leukemias (~81% remission)
• Malignant disorder of the blood and blood- Acute myelogenous leukemia (AML)
forming organs One of most common leukemias in adults
• Excessive accumulation of leukemic cells 1 yr. survival after diagnosis w/ aggressive treatment
• Acute leukemia Chronic myelogenous leukemia (CML)
–Presence of undifferentiated or immature cells, Myeloproliferation in bone marrow, middle aged mostly
usually blast cells
Chronic lymphocytic leukemia (CLL)
• Chronic leukemia
Most benign and slow growing; affects elderly
–Predominant cell is mature but does not
function normally
• Lymphocytic leukemia Pathophysiology
• Myeloid leukemia Immature hematopoietic cells leukemic cells
Leukemic cells multiply  crowding other cell
 abnormal RBCs, WBCs, platelets and decreased numbers
Leukemias Leukemias
• Signs and symptoms of leukemia
–Anemia, bleeding purpura, petechiae, ecchymosis,
thrombosis, hemorrhage, DIC, infection, weight loss,
bone pain, elevated uric acid, and liver, spleen, and
lymph node enlargement
Disorders of Platelets
Disorders of Platelets
• Thrombocytopenia
–Causes
• Thrombocytopenia
• Hypersplenism, autoimmune disease, hypothermia, and viral or bacterial
infections that cause disseminated intravascular coagulation (DIC), HIT
–Platelet count <150,000/mm3
• ITP (Idiopathic thrombocytopenia)
•<50,000/mm3—hemorrhage from minor trauma –I- immune system makes antibodies against platelets
•<15,000/mm3—spontaneous bleeding –T- trapped platelets appear in spleen and liver
•<10,000/mm3—severe bleeding –P- phagocytosis causes thrombocytopenia

–Symptoms:
•Nosebleed, oral bleeding
•Purpura
•Petechiae

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Disorders of Platelets Disorders of Platelets
• Immune thrombocytopenic purpura • Immune thrombocytopenic purpura
(ITP)
(ITP)
–IgG antibody that targets platelet
–Manifestations
glycoproteins
–Antibody-coated platelets are sequestered •Petechiae and purpura, progressing to major
and removed from the circulation hemorrhage
–The acute form of ITP that often develops
after a viral infection is one of the most
common childhood bleeding disorders
Disseminated Intravascular
Coagulation (DIC)
• Complex, acquired disorder in which clotting and
hemorrhage simultaneously occur Structure and Function of the Cardiovascular
• DIC is the result of increased protease activity in the and Lymphatic Systems
blood caused by unregulated release of thrombin w/
subsequent fibrin formation and accelerated
Chapter 22
fibrinolysis
• Endothelial damage is the primary initiator of DIC

Circulatory System
The Heart Wall

Pulmonary circuit Systemic circuit
(right heart) (left heart)

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The Chambers of the Heart The Valves of the Heart

LA

RA LV

RV
Blood Flow Blood Flow and Cardiac Cycle
• Cardiac cycle
• Diastole
• Systole
• Phases of the cardiac cycle
The Coronary Vessels
Blood Flow and Cardiac Cycle
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Conduction System of the Heart Cardiac Output
Systemic Circulation Structure of Blood Vessels
• Arteries • Lumen
• Arterioles • Tunica intima
• Capillaries • Tunica media
• Venules • Tunica externa (adventitia)
• Veins
Endothelium Structure of Blood Vessels
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Structure of Blood Vessels Concept Check
• 1. Oxygenated blood flows through:
A. SVC
B. Pulmonary veins
C. Pulmonary arteries
D. Coronary veins
2. In the normal cardiac cycle which of the
following occurs? (more than one is correct)
A. RA and RV contract together
B. The 2 atria contract together, while the 2 ventricles relax
C. The 2 ventricle contract together , while the 2 atria relax.
D. Both the ventricles and the atria contract simultaneously to increase
cardiac output.
• 3. The normal heartbeat is initiated by:
– A. Coronary sinus C. SA node
– B. AV bundle D. AV node

• 4. Which does not significantly affect HR:
– A. SNS nerves C. AV valves
B. PSN nerves D. ACh
Alterations of CV Function

5. Which is the correct sequence of the pulmonary circuit?
a. Pulm. Veins • Chapter 23
b. Pulm. Arteries
c. Lungs
d. RV
e. LA
Diseases of the Veins Diseases of Veins
Deep venous thrombosis (DVT)
◦ Obstruction of venous flow leading to increased
venous pressure
◦ Factors
Poor circulation Venous stasis (immobile, age, CHF)
Venous endothelial damage (drugs, trauma)
Hypercoagulable states (inherited states, BCP)
Venous stasis ulcer
Venous thrombi are more common than arterial due
to low pressure in veins
Venous thrombi
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Diseases of the Arteries and Veins Primary Hypertension
• Hypertension (HT)
– – consistent elevation of BP
– Systolic > 140 mmHg; Diastolic > 90 mmHg

–Primary HT
•aka essential or idiopathic HT
•Genetic and environmental factors
•Affects 92% to 95% of individuals with hypertension

–Secondary HT
•Caused by a systemic disease that raises PR or CO
Understanding HT HT
• 1. Kidneys  renin into blood
• Complications
• 2. Renin converts angiotensin to angiotensin I
–- can occur late in the disease
• (in liver)
–- can attack any organ
• 3. Angiotensin I  Angiotensin II (in lungs) –- CAD, angina, MI, arrhythmias, sudden death
–Angiotensin II - potent VC

• 4. Angiotensin II  constriction in arterioles and secretion
of aldosterone Location, location, location
Symptoms depend on location of vessel damage
• 5. Aldosterone  Na+ and H0 retention
2 – brain – stroke, TIAs
• 6. Retained Na+ and HO  incr. blood vol.
2 – retina – blindness
• 7. VC  increased PR
– heart – MI
• 8. Incr. blood vol. and PR  HT – kidneys – proteinuria, edema  renal failure
Treatment for Hypertension Diseases of the Arteries and Veins
• Arteriosclerosis
–Chronic disease of the arterial system
•Abnormal thickening and hardening of
vessel walls

•Smooth muscle cells and collagen fibers
migrate to the tunica intima

•Results in narrowing of lumen
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