Chapter 17 - Blood

A+P 2

Cardiovascular System contains

Blood, Blood Vessels, and the Heart

Heart Function

Propels blood and maintains blood pressure

Blood Vessels Function

Distribute blood around the body

Arteries Function

Carry blood away from heart to the capillaries

Veins

Return blood from the capillaries

Cardiovascular System contains

Blood, Blood Vessels, and the Heart

Plasma

Liquid Matrix

55% of the volume of whole blood

High levels of Oxygen and carbon dioxide

plasma proteins cannot cross capillary walls

Formed Element

Cells, and Cell Fragments that are suspended in plasma

45% of the volume of whole blood

Mostly made up of RBCs

Whole Blood

The complete fluid that circulates in the cardiovascular system, consisting of plasma and formed elements such as red blood cells, white blood cells, and platelets.

Average Blood Volume

Males: 5-6 liters

Females 4-5 liters

Properties of Whole Blood

Temperature: 100.4 degrees F

Five times more viscous then water

pH of 7.4 (slightly alkaline)

Hematocrit (PCV) Packed cell volume

is the percentage of formed element in whole blood

~47 for males (androgen)

~42 for females (estrogen)

Plasma Proteins (7%)

The Liver synthesizes these proteins and they makeup most of plasma

Albumins, Globulins, Fibrogen

Albumins

• makeup 60% of plasma proteins

• major contributiors of osmotic pressure from plasma

Globulins

• make up 33% of the proteins in plasma

• contains antibodies (immunoglobulins), plasma globulins, and transport globulins (bind ions, hormones, lipids, and other compounds)

Fibrinogen

• Clotting

• 4% of plasma protein

• Can form large insoluble strands of fibrin (blood clots)

Plasmas other solutes

• Electrolytes

• Organic Nutrients

• Organic Waste

Platelets

Small membrane-bound cell fragments that contain enzymes important for clotting originate from the bone marrow and stay in reservoirs in the spleen

White Blood Cells

Leukocytes: defense mechanism

(Neutrophils, Eosinophils, Basophils, Lymphocytes, and Monocytes)                                                        

Red Blood Cells

Erythrocytes are the most abundant blood cells

Transport oxygen in the blood

Hemopoiesis/Hemoatopoiesis

Formed element develops in red bone marrow

Hemocytoblasts

form from stem cells for RBCs to be produced in the red bone marrow

Lymphoid Stem Cells

Responsible for the production of lymphocytes (immune response)

Some migrate to lymphoid tissues (thymus, spleen, and lymph nodes)

Myeloid Stem Cells

Divide and give to rise to all types of formed elements besides lymphocytes

Hematology

Study of Blood, blood forming tissues, and blood disorders

Dyscrasias

Blood Disorders

Complete Blood Count (CBC)

Determines the RBC count (hematocrit, and platelet count) + WBC count (different types)

Type of Blood Tests

• Hematocrit (Hct) - whole blood

• Hemoglobin Concentration (Hb + Hgb) - concentration of hemoglobin

• Mean Corpuscular Hemoglobin Concentration (MCH) - weight of Hb in one RBC

• Mean Corpus Volume (MCV) - Average volume of one RBC

• RBC Count Number of RBC per microliter

• Reticulocyte Count (Retic. - circulating reticulocytes

Rouleaux

Stack of RBCs

RBC lifespans

~120 days

Hemoglobin

transports oxygen from the lungs to the body's tissues and carries carbon dioxide back to the lungs

two alpha chains and two beta chains

Heme

a nonprotein pigment complex in hemoglobin

holds iron

forms oxyhemoglobin = bright red

Deoxyhemoglobin

hemoglobin molecule whose iron is not bound to the oxygen (burgundy)

Why is pee yellow?

The kidneys excrete some hemoglobin and urobilins

Hematuria

intact RBCs in pee = urinary tract damage

Hemolyze

Macrophages filter RBCs health

ABO blood types

based on the presence or absence of the A and B surface antigens

Hemolytic Disease of the Newborn (HDN)

Mothers’ antibodies in RBCs may cross the placenta and attack the fetal RBCs

more common during secondary pregnancies because of leftover anti-Rh antibodies produced during the first delivery (RhoGAM prevents this)

Granular Leukocytes

Neutrophils, Eosinophils, Basophils

Agranular Leukocytes

Monocytes, Lymphocytes

White Blood Cells

emigrate between organs to reach areas of infection/injury

positive chemotaxis guides them to pathogens, damaged tissue or other WBCs

Hemostasis

Process of stopping bleeding

1. Vascular

2. Platelet

3. Coagulation

Vascular Phase

Endothelial cells contract and release endothelins which stimulate smooth muscle contraction and promote vascular spasms, walls become sticky

Platelet phase

Attachment of platelets to the sticky endothelial surface, the basement membrane, and exposed collagen fibers and each other. (ADP = platelet aggregation and secretion) (PDGF = peptide that promotes vessel repair) Calcium ions are required for the clotting process

Coagulation Phase

Blood Clotting → Pathways → Fibrinogen → Fibrin → Blood Clot → Procoagulants (Proenzymes)

Venipuncture

Essential for diagnosing blood disorders

Nutritional Blood Disorders

Iron deficiency Anemia- Not enough iron

Pernicious Anemia - Vitamin B12 - prevents normal stem cell divisions in bone marrow

Calcium ions and Vitamin K deficiencies

Sickle Cell Disease (SCD)

mutation in the Hb molecule which makes the RBCs sickle shaped (more fragile/carry less o2) can lead to sickle cell anemia (resistant to malaria)

Thalassemias

Abnormal protein subunits in hemoglobin

Hemophila

Bleeding disorder - Abnormal blood clotting activity - varies in severity

Bacteremia/Viremia

Bacteria circulates in blood but doesn’t multiply

Sepsis

Widespread pathogenic infection of body tissue (bacteria multiplies)

Malaria

infects RBCs with Plasmodium, infects liver cells then expands causing fever and chills causes tissue death

Leukemia

Cancers of blood forming tissues, elevated level of WBCs

(DIC) Disseminated Intravascular Coagulation

Bacterial Toxins activate several step in coagulation process that convert fibrinogen to fibrin (uncontrolled bleeding)