Blood Circulation

Vascular System

circular + closed

Lymphatic System

open ended + linear -> drainage

How do fluids + macromolecules + cells move through the blood + lymphatics?

Exit blood capillaries -> lymphatic capillaries in peripheral tissues -> recirculate back in vascular blood system

How much of the human body is blood?

45-75% -> highest in brain

What is intracellular fluid rich in?

Potassium

Phosphate

Magnesium

Protein

What comprises extracellular fluid?

anything not in a cell -> plasma + interstitial fluid

Why is blood separated?

Each component -> unique function -> separation -> analyzation of each function -> target pt needs

What is whole blood?

plasma + cells -> 8% of body weight (5-5.5L)

What makes up your plasma?

Water

Proteins

Salts

Lipids

Carbs

Gases

What makes up your cells in the blood?

RBC

WBC

Granulocytes

Monocytes

Lymphocytes

Platelets

What is plasma, and how much of the blood does it make up?

Liquid component of blood (55%)

What are thrombocytes?

platelets

What are leukocytes and how much of the blood do they comprise?

WBCs (<1%)

What are erythrocytes and how much of the blood do they comprise?

RBC (45%)

What are stem cells?

Undifferentiated cells that have the potential to become anything + self renew -> earliest types of cells

What is the difference b/w pluripotent and somatic stem cells?

-Pluripotent -> precursor to anything

-Somatic: "adult" -> predetermined function

What is hematopoiesis?

-The process of blood cell formation in the bone marrow

-Stems cells -> differentiated cells

-Tightly regulated + fluctuated on demand

What do lymphoid stem cells make?

immune cells

Lymphoid Stem Cells

NK Progenitor

T-Cell Progenitor (Thymus)

B-Cell Progenitor (Lymph Nodes)

NK Progenitors turn into..

NK Cell -> "Natural killer" -> fight infection + cancer

T-Cell Progenitor (Thymus) turn into..

T Cell -> Immune cell: attack infected cells

B-Cell Progenitors (lymph nodes) turn into...

B Cell -> Plasma Cell: Antibodies -> fight infections

What do myeloid stem cells make?

immune cells + RBC + megakaryocytes (platelets)

Myeloid Stem Cells

Monocyte CFU

Granulocyte CFU

Megakaryocyte CFU

Erythrocyte CFU

Monocyte CFU

-Monoblast -> Monocytes

-Develop into macrophages

Granulocyte CFU

-Eosinophil: parasites + allergic rxns

-Neutrophil: bacterial infections

-Basophil: allergic responses

Megakaryocyte CFU

-Megakaryocyte -> Platelets

-Blood clotting

Erthrocyte CFU

-Reticulocyte -> Erythrocyte

-RBC -> carries O2 to the body

Type of Hematologic Tests

-CBC

-Metabolic Panel -> CMP + BMP

-Lipid Profile

-Serum Protein Electrophoresis

-Immunoglobulin Assays

-Erythrocyte Sedimentation Rate (ESR)

-Bone Marrow Aspiration + Biopsy

Red Cell Disorders

anemias

White Cell Disorders

neoplasia + leukemias

Platelet Disorders

bleeding

Components of Plasma

-90% water

-10% inorganic solutes + plasma proteins + organic substances

Plasma Functions

-Carry cells + transport gases: RBCs

-Aid in body defenses: WBCs

-Prevent blood loss: platelets

Role of Electrolytes

-Control water movement

-Regulate pH

-Regulate BP

7 Essential Electrolytes

Sodium

Potassium

Chloride

Magenisum

Calcium

Phosphate

Bicarbonates

What is intracellular fluid high in?

K+

What is intracellular fluid low in?

Na+, Ca2+, Mg2+

What is extracellular fluid high in?

Na+

What is extracellular fluid low in?

K+, Cl-< HCO3-

What mechanism maintains plasma fluid volume?

Sodium-potassium Pump: 3 Na+ out, 2 K+ in

Electrolytes -> Acid/Base Balance

Acidosis

H+ in -> K+ out -> hyperkalemia

Alkalosis

H+ out -> K+ in -> hypokalemia

What is cholesterol?

A waxy, fat like substance -> derived from diet

What transports cholesterol?

lipoproteins

Cholesterol Functions

-Hormone molecule precursor

-Vit D synthesis importance

-Cell membrane component

-Bile salt -> digest fat soluble vitamins (A, D, E, K)

How are carbs used in the body?

broken down from food -> glucose -> primary energy source for cells

How is glucose regulated?

pancreas secretions

Hydrostatic Pressure

Pressure exerted by a fluid against a vessel wall

Oncotic Pressure

Pressure made by a protein conc (albumin) -> makes a conc gradient -> pulls water into vessels

Why is balancing HP + OP so important?

imbalances -> swelling

% of Albumin in plasma proteins

60%

Where is albumin synthesized?

liver

Albumin Functions

-OP: Keeps fluid in -> prevents swelling

-Transports fatty acids, Ca2+, drugs, hormones, bilirubin

-Counteracts free radicals as an antioxidant+ maintains pH balance

% of Globulin in plasma proteins

35%

What do alpha globulins transport?

-Haptoglobin

-Copper (via ceruloplasmin)

-Steroids

-Hormones

What do beta globulins encompass?

-Transferrin

-complement proteins (immune support)

-lipoproteins

What do gamma globulins do?

antibodies

% of fibrinogen in plasma proteins

5%

What secretes fibrinogen and why?

liver -> acute phase reactant

What does fibrinogen do?

Creates a "mesh" -> catches blood -> converted to fibrin -> clotting process

When is whole plasma used?

Massive bleeds + liver disease

When are clotting factors used?

Specific deficiencies

When is albumin used?

Burns + hemorrhagic shock

When is plasmapheresis used?

Temp + autoimmune diseases

When is platelet-rich plasma used?

Promote healing + dec inflammation from injury

How do thrombocytes work?

Platelets form a plug -> coagulation cascade initiation -> establish a clot with fibrin

Not enough platelets leads to

bleeding + bruising

Too many platelets lead to

blood clots

Normal Platelet Count

90,000-140,000

How does aspirin prevent blood clots?

Aspirin -> COX-1 inhibition -> prevents blood clots -> dec MI + stroke risk

Types of Leukocytes

granulocytes and agranulocytes

Types of Agranulocytes

-B+T Lymphocytes -> 100-300 days

-Monocytes -> months-years

Types of Granulocytes

ACUTE (3-4 days)

-Neutrophils

-Eosinophils

-Basophils

CBC + Differential shows what?

total WBC + % of each

Normal CBC

4,500-11,000

Leukocytosis

11,000+

Leukopenia

<4,000

Leukopenia vs Neutropenia

-Leuko: dec in WBC total

-Neutro: drop in neutrophils

-both inc infection risk

RBC lifespan

120 daysW

What do RBC do?

transport O2

If RBCs are altered, what can that lead to?

specific blood disorders

Why is the spleen considered the "graveyard of RBCs?"

Destroys abnormally shaped + hemolyzed RBCs

What causes splenomegaly?

Inc RBC breakdown -> enlarged spleen

Hematocrit

percentage of blood volume occupied by red blood cells

Normal Hematocrit %

M: 45-52%

F: 37-48% (menstrual blood loss)

What is erythropoiesis?

Specific series of steps in the bone marrow -> mature RBCs

Erythropoiesis Steps

1. Hypoxia -> kidneys release erythropoietin

2. Erythropoietin -> bone marrow synthesizes RBCs

What does adequate synthesis of RBC depend on?

*iron, Vit B12, proteins, folic acid

What are reticulocytes?

immature RBC (1%)

Why are reticulocytes released?

rapid bleeding -> can't meet demand

Why can't reticulocytes be used during genetic testing?

DNA is expelled

What do inc #s of reticulocytes signify?

accelerated destruction/ loss of RBCs -> anemia

Hemoglobin

-Globin portion: alpha + beta

-Heme Portion: iron

How much of O2 is bound to Hgb?

98% -> loosely + reversibly

How is Hgb broken down?

Porphyrin -> biliverdin -> bilirubin

What can inc RBC breakdown lead to?

hyperbilirubinemia -> skin + eye sclera stained yellow -> "jaundice"

How is O2 transported in the body?

Hgb binds to O2 in lungs -> carried to tissues for cellular use

CO2 Transport

carried back to the lungs as a waste product -> dissolved as plasma or bound to Hgb as carbaminohemoglobin

Gas Exchange at Tissues

-As O2 is released from Hgb -> CO2 binds more easily to Hgb in tissues

-Ensures efficient gas exchange b/w O2 + CO2

What does the oxygen-hemoglobin dissociation curve show?

how readily Hgb binds to release O2 -> direct relationship b/w partial pressure + % Hgb saturation