HSC4555 Dr.Ferdowsi UCF Pathophysiology Final

Total blood volume

75.5 mL/kg in men

66.5 mL/kg in women

ejection fraction

SV/EDV

Blood % of body weight

7%

total blood volume

5/6 L

blood volume composition

55% plasma

45% blood cells

Plasma composition

92% water

7% plasma proteins

blood pH

7.4

plasma proteins in blood

Serum albumin

Serum globulin

Fibrinogen

Regulatory proteins

cellular components of blood

Erythrocytes

Leukocytes

Platelets

other things in blood

Products of tissue metabolism

Nutritive organic materials

Electrolytes

Iron

Products of tissue metabolism in blood

BUN- blood,urine,nitrogen

Nutritive organic materials in blood

amino acids, glucose, cholesterol

electrolytes in blood

fe,na,k,ca

composition of RBCs

most numerous, live for 120 days

4-6 million per cubic mm

rbc Buffer blood

via carbonic anhydrase

what is only found in mature rbc

hemoglobin

hematopoiesis

making rbcs from pluripotent stem cells

made in bone marrow

hematopoietic signs of stress

can release immature cells in emergencies, called reticulocytes

only 1% of blood

hematopoiesis steps

mitotic division

maturation

Erythropoietin

hormone that stimulates erythrocyte production, made in kidneys

Erythropoiesis requirements

Iron

Protein

Minerals

Vitamins

intrinsic factor

needed to absorb vitamin B12

Erythropoiesis regulation

by concentration of hemoglobin in blood

Red Cell Destruction

Methemoglobin is removed by mononuclear phagocytic system

Methemoglobin

oxidized iron 3+, normal heme has iron 2+

reduced by Methemoglobin reductase pathway

Porphyrin is reduced

to bilirubin

bilirubin

pigment released by the liver in bile

Too much bilirubin

jaundice

globin is broken down

into iron and recycled

conjugated bilirubin

excreted in bile

urobilinogen

formed by digestion of bilirubin by intestinal bacteria

How much hemoglobin in blood?

15 g of hemoglobin per 100 mL of blood

In pulmonary capillaries, where PO2 of tissues is high

oxygen binds with hemoglobin

In pulmonary capillaries, where PO2 of tissues is low

oxygen is released from hemoglobin

Oxygen saturation

percentage of hemoglobin bound to oxygen

Oxyhemoglobin dissociation curve

The relationship between the partial pressure of oxygen and hemoglobin saturation

PO2 is high

In the lung

oxygen is loaded onto hemoglobin

PO2 is low

In the tissues

oxygen is unloaded from hemoglobin to tissues

Affinity of hemoglobin for oxygen is affected by

Temperature

Acid-base status

2,3-DPG levels

Carbon dioxide levels

Carbon Dioxide Transport

Carbonic anhydrase in the RBC help to form carbonic acid

Hemoglobin + CO2

Carbaminohemoglobin

Hemoglobin + O2

oxyhemoglobin

Carbonic anhydrase

converts of CO2 and water → HCO3− and H+

called chloride shift

reverse happens in lungs

Haldane Effect

As o2 unloads in lungs causes co2 to load up

if decreased amount of oxygen reaching tissues

results in erythropoietin secretion and production of rbcs

Anemia

Deficit of red blood cells

Low oxygen-carrying capacity results in

hypoxia

Relative anemia

total body size goes up but rbc stays level, eg pregnancy

Absolute anemia

actual decrease in numbers of red cells

causes of absolute anemia

Decreased production

Increased destruction

Polycythemia

Excess of red cells

Increases blood viscosity and volume

General Effects of Anemia

Reduction in oxygen-carrying capacity

(Tissue hypoxia)

Compensatory mechanism to restore tissue oxygenation

increased hr/pulse/blood flow

Increase in 2,3-DPG in erythrocytes

decreased oxygen affinity of hemoglobin in tissues

Increase in erythropoietin activity

Mild anemia

Usually no clinical symptoms

Elderly with cardiovascular, pulmonary disease may have symptoms

Mild to moderate anemia

Fatigue, generalized weakness, and loss of stamina, followed by tachycardia and exertional dyspnea

Moderate to severe anemia

Orthostatic/generalized hypotension, vasoconstriction

pallor

transient murmurs

Intermittent claudication (leg cramps)

Tinnitus

Aplastic Anemia

Stem cell disorder,

reduction of hematopoietic tissue,

fatty marrow replacement, and

pancytopenia (low RBC, WBC, and platelets)

pancytopenia

(low RBC, WBC, and platelets)

Aplastic Anemia cause

chemical/radiation damage to bone marrow

Aplastic Anemia symptoms

Insidious onset of symptoms

Thrombocytopenia (prone to bleeding)

Neutropenia (prone to infections)

aplastic anemia diagnosed by

bone marrow biopsy

Disease of the young (15 to 25) or old

aplastic anemia treatment

bone marrow transplant, stop further exposure to toxic causes

aplastic anemia prognosis

fatal unless successful transplant

Anemia of Chronic Renal Failure

Failure of the renal endocrine function impairs erythropoietin production and bone marrow compensation.

Decreased RBC count

Anemia of Chronic Renal Failure treatment

dialysis and administration of erythropoietin

high survival rate with therapy

Pernicious anemia

caused by lack of intrinsic factor leading to vitamin B12 deficiency

megaloblasts

large, immature red blood cells

produced by Disruption in DNA synthesis of blast cells

Low folate levels associated with

neural tube deficits

Clinical manifestations of anemia

Low RBC, WBC, and platelet counts with increased MCV

Peripheral nerve degeneration

Treatment of megaloblastic anemia

determine if vitamin B12, folate, or a combined deficiency is the cause

then treat cause

prognosis of megaloblastic anemia

good prognosis, slow healing of nerve damage

Iron Deficiency Anemia

Most common nutritional deficiency in the world

Insufficient iron for hemoglobin synthesis

Iron Deficiency Anemia symptoms

Pica

Koilonychias (spoon-shaped nails)

Blue sclerae

Iron Deficiency Anemia treatments

oral iron supplements

inherited anemic disorders

Thalassemia

Sickle Cell Anemia

Hereditary Spherocytosis

G6PD Deficiency

Thalassemia

Increased RBC destruction (hemolysis)

Associated with mutant genes

Thalassemia treatment

Blood transfusions

Splenectomy

Chelation therapy

Bone marrow transplantation

Sickle Cell Anemia

a genetic disorder that causes abnormal hemoglobin, resulting in some red blood cells assuming an abnormal sickle shape

Sickle Cell Anemia Treatment

stem cell transplant (no cure)

sickle cell prognosis

if no transplant death

G6PD deficiency

Genetic disorder resulting in RBC membrane destruction

primarily in males

G6PD deficiency treatment

avoiding infection

Polycythemia

Excess RBCs

Increased blood viscosity, hypertension

Polycythemia Vera (Primary Polycythemia)

Neoplastic transformation of bone marrow stem cells

polycythemia vera treatment

phlebotomy, chemoradtherapy

polycythemia vera prognosis

poor unless managed

Secondary Polycythemia

Caused by chronic hypoxemia with resultant increase in erythropoietin

Increased RBC production

Secondary Polycythemia treatment

Identify and manage underlying cause of hypoxemia;

phlebotomy may be used to decrease cardiovascular workload

Relative Polycythemia

Caused by dehydration with spurious increase in RBC production

Elevated hematocrit, hemoglobin, and RBC count

Relative polycythemia treatment

Recognize and manage underlying cause

Fluid administration with management of long-term conditions

Determinants of Systemic Blood Pressure

Pressure differences between the left and right sides of the heart produce systemic movement of blood

Arterial blood pressure is produced by

left ventricular contraction pumping blood into aorta

Cardiac output (CO) =

SV (stroke volume)×HR (heart rate)

Systemic Vascular Resistance (SVR)

afterload

afterload is determined by

Radius of arteries

Degree of vessel compliance

End-diastolic volume

preload

preload

Amount of blood returned to the heart

blood pressure (BP)=

CO(cardiac output) ×SVR(Systemic Vascular Resistance)

Arterial Blood Pressure measured by

Pulse pressure=Systolic − diastolic

systole

Contraction of the heart