Introduction to the Cardiovascular System

Introduction to the Cardiovascular System

A circulating transport system

A pump (the heart)

A conducting system (blood vessels)

A fluid medium (blood)

Is specialized fluid of connective tissue

Contains cells suspended in a fluid matrix

Functions of Blood

Transport of blood cells and dissolved substances

such as oxygen and carbon dioxide

Regulation of pH and ions

Restriction of fluid losses at injury sites

Defense against toxins and pathogens

Stabilization of body temperature

Physical Characteristics of Blood

Whole Blood Composition

Plasma

Fluid consisting of: ______________________________________________

______________________________________________

______________________________________________

Formed elements:


Three Types of Formed Elements

Red blood cells (RBCs) or erythrocytes

Transport oxygen and carbon dioxide

White blood cells (WBCs) or leukocytes

Protection from toxins and infection

Platelets

Cell fragments involved in clotting


Figure 19–1c The Composition of Formed Elements of Blood


Hemopoiesis

Process of producing formed elements

By myeloid and lymphoid stem cells

Occurs in red bone marrow and lymphatic

tissues


Three General Characteristics of Blood

38°C (100.4°F) is normal temperature

High viscosity:

Slightly alkaline pH:


Blood volume (liters) = 7% of body weight

(kilograms)

Adult Volume:

Normovolemic:

Hypovolemic

Hypervolemic:

Plasma

Makes up 50–60% of blood volume

More than 90% of plasma is water

Extracellular fluids

Interstitial fluid (IF) and plasma

Materials plasma and IF exchange across capillary walls

Water

Ions

Small solutes

Plasma

Plasma Proteins Albumins (60%)

Transport some lipid soluble substances Largely responsible for ability of blood to retain fluid

Globulins (35%) Antibodies, also called immunoglobulins Transport globulins bind to and carry some circulating

molecules

Fibrinogen (4%) Molecules that form clots and produce long, insoluble

strands of fibrin

Plasma

Other Plasma Proteins

1% of plasma

Changing quantities of specialized plasma proteins

Enzymes and hormones

Most are made in liver

Summary of Plasma Composition

Figure 19–1b The Composition of a Typical Sample of Plasma

Red Blood Cells

Red blood cells (RBCs) make up 99.9% of blood’s formed

elements

Transports _______________________

Average about 8 micrometers in diameter

Oxygen and Carbon dioxide

RBC Values

Red blood cell count: the number of RBCs in 1 microliter of

whole blood

Male: 4.5–6.3 million

Female: 4.2–5.5 million

Hematocrit (packed cell volume, PCV): percentage of RBCs in

centrifuged whole blood

Male: 40–54

Female: 37–47

RBC Composition

No nucleus (enucleate) No membranous organelles Hemoglobin

Red, ___ containing molecules Transport oxygen and carbon dioxide

Bind oxygen in the lungs and release it in tissues Bind some carbon dioxide in the tissues and release it in

lungs 280 millions molecules per RBC

iron

Hemoglobin Composition

Protein (globin) part Made of four polypeptides – blue part

Oxygen Binding parts – red parts four iron containing heme groups – iron binds

oxygen

Hemoglobin Values

Normal hemoglobin (adult male)

14–18 g/dL whole blood

Normal hemoglobin (adult female)

12–16 g/dL, whole blood

If values are too low you are ___________.

RBC Formation and Turnover

1% of circulating RBCs wear out per day

About 3 million RBCs per second

Macrophages of liver, spleen, and bone marrow

Monitor RBCs

Engulf RBCs before membranes rupture (hemolyze)

Red Blood Cells

Hemoglobin Conversion and RecyclingPhagocytes break hemoglobin into

components Globin (protein part) to amino acids

Heme to Biliverdin

Iron

Red Blood Cells

Iron Recycling

Iron removed from heme leaving biliverdin

To transport proteins (transferrin)

To storage proteins (ferritin and hemosiderin)

Red Blood Cells

Breakdown of Biliverdin

Biliverdin (green) is converted to bilirubin

(yellow)

Bilirubin is:

Excreted by liver (bile)

Jaundice is caused by bilirubin buildup

Converted by intestinal bacteria to urobilins and

stercobilins

Hemoglobin Recycling

Heme

Globin Amino Acids recycled

Biliverdin

Iron

BilirubinExcreted in urine and Feces

Stored in liver and spleen as ferritin and hemosiderin for later use

Hemoglobin

Red Blood Cell Recycling

Figure 19–5 Recycling of Red Blood Cell Components

Red Blood Cells

RBC Production

Erythropoiesis

Occurs only in myeloid tissue (red bone marrow) in adults

Stem cells mature to become RBCs

Hemocytoblasts

Stem cells in myeloid tissue divide to produce

Myeloid stem cells: become RBCs, and most WBCs

Lymphoid stem cells: become lymphocytes

Red Blood Cell Maturation

Proerythroblasts form from myeloid stem cells become

Erythroblasts __________________________________

Normoblasts lose their nucleus and become reticulocytes

Reticulocytes enter blood to become _______________________________________

Erythrocytes are not able tomake _________________.Why?

Regulation of RBC Formation (erythropoiesis)

Building red blood cells requires

Amino acids for:

Iron for:

Vitamins B12, B6, and folic acid:

pernicious anemia Low RBC production

Due to unavailability of vitamin B12

Hormonal Control of Erythropoiesis

Erythropoietin (EPO) from Kidneys and liver

Also called erythropoiesis-stimulating hormone

Secreted when oxygen in peripheral tissues is low

(hypoxia)

Due to disease or high altitude

Blood Types

ABO and Rh are most important types

Karl Landsteiner developed classifications for ABO blood types in 1901 Awarded Nobel Prize in medicine in 1930

Landsteiner and Alexander Wiener dicovered Rh type in 1937

Antigens (glycoproteins and glycolipids) called _____________ on surface of RBC’S determine blood types.

These antigens are inherited, thus blood types are inherited

Antibodies (agglutinins) against the antigens may be in the plasma

The following slides will illustrate

agglutinogens

ABO Blood Types

Four ABO Blood Types

A (surface antigen A)

B (surface antigen B)

AB (antigens A and B)

O (neither A nor B)

Blood Type Antibodies

Type A Type B antibodies

Type B Type A antibodies

Type O Both A and B antibodies

Type AB Neither A nor B antibodies

ABO Blood Types Illustrated

ABO Type

Antigen on

RBC’s

Antibodies in Plasma

A A Anti-B

B B Anti-A

AB A&B Neither

O Neither Both

Rh Blood Type

Rh blood type is determined by presence of absence of Rh (D) _____

(_________) on the surface of RBCsIf Rh agglutinogen present, the type is

Rh . If no agglutinogens are present, the type is Rh .

agglutinogen

antigen

+

-

People with Rh- type lack anti-Rh antibodies (agglutinins), but if they receive Rh+ blood, their immune systems will be stimulated to produce them, and they are then _________. Future exposure to Rh+ blood will cause a dangerous blood reaction.

sensitized

Rh Blood Type

Hemolytic Disease of the Newborn (HDN)

Results from Rh incompatibility between ___ mother and her ____child

If Rh+ RBC’s of first born child enter mother’s circulation, mother will be ________, and her plasma will carry anti-Rh agglutinins (antibodies)

Rh- Rh+

sensitized

The first child is not harmed, but the mother’s _________, acquired by exposure to the first child’s blood, easily pass across the placenta where they _________ and destroy the second child’s RBC’s.

How is it prevented?

antibodies

agglutinate

Hemolytic Disease of the Newborn (HDN)

HDN Illustrated

Figure 19–9 Rh Factors and Pregnancy

Hemolytic Disease of Newborn

Figure 19–9 Rh Factors and Pregnancy

The greatest concern with blood types involves _________

Person giving blood is the ______, person getting blood is the ________

If RBCs of a donor are incompatible with the blood of a recipient, antibodies in the plasma of the recipient will bind to the antigens of the donated RBCs.

This reaction will ______ (__________) and destroy (cause hemolysis of) the donated RBCs, resulting in a serious and possibly fatal reaction.

clump agglutinate

Transfusions and Blood Typing

transfusions

donorrecipient

ABO and Rh Donors and Recipients

ABO and Rh Types

Can be donated to types

Can receive from types

A+ A+ and AB+ A+, A-, O+, O-

A- A+, AB+, AB- A-, O-

B+ B+, AB+ B+, B-, O+, O-

B- B+, B-, AB+, AB- B-, O-

AB+ AB+ All ABO and Rh types

AB- AB+, AB- All ABO Rh+ types

O+ All ABO Rh+ types O+, O-

O- All ABO and Rh Types

O-

ABO and Rh Donors and Recipients

Use previous table to answer the following questionsDo you understand why some blood types

are compatible and some are not? What ABO Rh type is the universal donor?

What makes it the universal donor?Why is universal donor important

What is the universal recipient?What makes it the universal recipient?

Blood Typing

To assure blood type compatibilities Blood type must be typed or Blood must be cross-matched (check page 664)

Supplies for blood typing: Sample of blood to be typed Three separate bottles of sera containing Anti-A,

Anti-B and Anti-Rh (D) antibodies Slide with three spaces marked A, B and Rh Three toothpicks to stir the the samples

Blood Typing

Procedure for blood typing Put drops of blood (all the same) in the A, B and Rh

spaces Put drops of each serum in respective bloods

Anti-A serum in A space Anti-B serum in B space Anti-Rh (D) serum in Rh space

Mix each sample, being careful not to contaminate, and observe sample for any changes in appearance

What does it mean if sample clumps? What does it mean if sample does not clump?

Determining ABO and Rh Types

Figure 19–8 Blood Type Testing

Blood Type Cross Reactions

Figure 19–7b Blood Types and Cross-Reactions

Percentage of Blood Types

Notice how percentages vary in different populations Notice that Native South Americans are all type O+

White Blood Cells

Also called leukocytes

Have nuclei and other organelles

WBC functions

Defend against pathogens

Remove toxins and wastes

Attack abnormal cells

White Blood Cells

WBC Circulation and Movement

Most WBCs in

Connective tissue proper

Lymphoid system organs

Small numbers in blood

5000 to 10,000 per microliter

White Blood Cells

WBC Circulation and Movement

Characteristics of circulating WBCs

Can migrate out of bloodstream

Have amoeboid movement

Attracted to chemical stimuli (positive chemotaxis)

Some are phagocytic:

What does phagocytic mean?

Types of WBCs

Granulocytes Granules in cytoplasm

Neutrophils

Eosinophils

Basophils

Types of WBCs

Agranulocytes No granules in cytoplasm

Monocytes

Lymphocyte

Facts About White Blood Cells

Neutrophils

Also called polymorphonuclear leukocytes

50–70% of circulating WBCs

Pale cytoplasm granules with

Lysosomal enzymes

Bactericides (hydrogen peroxide and superoxide)


Neutrophil Actions Very active, first to attack bacteria

Phagocytes - engulf pathogens and digest

pathogens

Defensins (peptides from lysosomes) attack

pathogen membranes and destroy them

Form pus


Eosinophils 2–4% of circulating WBCsCounteract inflammationAttack large parasitesAre sensitive to allergens


Basophils

Are less than 1% of circulating WBCs

Are small

Help cause inflammation by accumulating in

damaged tissue and releasing histamine

Release heparin to prevent blood clotting


Monocytes


Are large and spherical

Enter peripheral tissues and become

macrophages

Engulf large particles and pathogens


Lymphocytes


Are larger than RBCs

Migrate in and out of blood

Mostly in connective tissues and lymphoid organs

Are part of the body’s specific defense (immune)

system

White Blood Cells

The Differential Count and Changes in WBC Profiles

Percentage range for different WBCs

Detects changes in WBC populations during:

Infections, inflammation, and allergic reactions

Will learn differential for WBCs in lab

WBC Disorders

Leukopenia

Abnormally low WBC count

Leukocytosis

Abnormally high WBC count

Leukemia

Cancer of WBC forming tissues

Results in extremely high WBC count and other symptoms

WBC Production - Leukopoiesis

All blood cells originate from hemocytoblasts

They produce myeloid stem cells and lymphoid stem cells

Myeloid Stem Cells

Differentiate into progenitor cells, which produce all WBCs

except lymphocytes

Lymphoid Stem Cells

Produce lymphocytes

Leukopoiesis -WBC Formation

Granulocytes and Monocytes develop in red bone marrow from myeloid stem cells Myeloid stem cells become myeloblasts and

monoblasts Myeloblasts become granular WBC’s Monoblasts become monocytes

Lymphocytes develop from lymphoid stem cells of the bone marrow and lymph tissues Lymphoid stem cells become lymphoblast Lymphoblasts become lymphocytes

Leukopoiesis Diagram

Myeloblasts

Neutrophils, eosinophils and basophils

Monocytes

Lymphoblasts

Lymphocytes

Myeloid Stem Cells Lymphoid Stem Cells

Monoblasts

Platelets

Cell fragments involved in human clotting system

Nonmammalian vertebrates have thrombocytes (nucleated

cells)

Circulate for 9–12 days

Are removed by spleen

2/3 are reserved for emergencies

Platelets

Platelet Counts

150,000 to 500,000 per microliter

Thrombocytopenia

Abnormally low platelet count

Thrombocytosis

Abnormally high platelet count

Platelets

Three Functions of Platelets:

1. Release important clotting chemicals

2. Temporarily patch damaged vessel walls

3. Actively contract tissue after clot formation

Platelets

Platelet Production

Also called thrombocytopoiesis

Occurs in bone marrow

Megakaryocytes

Giant cells in bone marrow

Manufacture platelets from cytoplasm

Platelet Formation (thrombocytopoiesis)

Myeloid Stem Cells

Megakaryoblasts

Megakaryocytes

Platelets (thrombocytes)

fragmentation

Hemostasis

Hemostasis is the cessation of bleeding

Consists of three phases

Vascular phase

Platelet phase

Coagulation phase

Hemostasis Stages

Vascular Phase Muscles in cut

vessels constricts Blood loss is

immediately reduced

Clotting factors concentrate faster

Hemostasis Stages

Platelet Phase Platelet adhesion

Platelet release reaction

Platelet aggregation

Coagulation Phase - Clot Formation

Clot consists of a gel of _____ and trapped formed elements

Clot closes cut vessel

Clotting process called __________

fibrin

coagulation

Coagulation Phase - Clot Formation

Three Coagulation Pathways

Extrinsic pathway

Begins in the vessel wall

Outside bloodstream

Intrinsic pathway

Begins with circulating proenzymes

Within bloodstream

Common pathway

Where intrinsic and extrinsic pathways converge

Ends with formation of clot

Basic Steps in Clotting

Clotting is a cascade of chemical reactions as follows: When vessels are cut or damaged, several

clotting factors from the extrinsic and intrinsic pathways interact to form the enzyme _____________

In common pathway prothrombinase catalyzes the conversion of the plasma protein ___________ to _________

In turn, above chemical acts as an enzyme to convert __________ to ____

prothrombinase

prothrombin thrombin

Fibrinogen fibrin

Basic Coagulation Diagram

Several clotting factors released from damaged tissues, vessel wall and platelets

Prothrombinase

Ca2+

Prothrombin Thrombin

Fibrinogen Fibrin (clot)Thrombin

Ca2+ CommonPathway

Extrinsic andIntrinsic Pathways

*More Complete Coagulation Diagram

Figure 19–13a The Coagulation Phase of Hemostasis

Check Table 19-4, page 676 for list of Clotting Factors

Electron Micrograph of Coagulation

Figure 19–13b The Coagulation Phase of Hemostasis

Calcium (Ca2+) and Vitamin __ needed to form four of the clotting factors

Within 30 minutes platelets begin to _____ the clot by pulling edges of cut vessel together

Clots may form within closed vessels

K

retract

More Fact About Clotting

Intravascular Clot

Intravascular clot – clot within closed vessel Damaged vessel lining or slowing of blood flow Platelets aggregate and release clotting factors Resulting clot called a ________ Moving piece of the clot is an _______ Clot moves downstream and blocks smaller vessel

________ May cut off blood supply to organ

thrombus

embolus

embolism

Clot Dissolution (Dissolving)

As repair of a cut or damaged vessel proceeds, a series of enzyme catalyzed reactions called _________ slowly dissolves the clot

An enzyme called ____________________ catalyzes the conversion of inactive enzyme ___________ to active enzyme plasmin

Plasmin catalyzes the dissolving of clot

fibrinolysis

tissue plasminogen activator

plasminogen

Clot Dissolving Diagram

Plasminogen PlasminTissue plasminogen activator

*Anticoagulants

Chemicals that decrease or prevent blood clotting are called ___________

Heparin is administered medically and it occurs naturally in our bodies. It works by decreasing thrombin production

Coumadin (warfarin) is effective as a long-term anticoagulant. It is an antagonist of vitamin K.

EDTA and CPD are used in blood banks to keep the donated blood from clotting. They both work by tying-up and removing calcium.

anticoagulants

Clinical Terms

Polycythemia High RBC count

Anemia Low RBC count (hematocrit) or low hemoglobin

Hemophilia Bleeder’s disease, inherited from mom to son

Leukophilia (leukocytosis) High WBC count

Clinical Terms

Leukopenia Low WBC count

Thrombocytopenia Low platelet count

Sickle cell disease Inheritance of faulty hemoglobin causing

RBC’s to sickle. Mostly in people of African and Mediterranean ancestry

Clinical Terms

Hemoglobinuria Hemoglobin breakdown products in urine due

to excess hemolysis in bloodstream

Hematuria Whole red blood cells in urine due to kidney or

tissue damage

Jaundice Yellowing of eyes and skin due to buildup

of excess bilirubin

Introduction to the Cardiovascular System

Documents

ability of blood

blood male

blood volumemore

carbon dioxidebind oxygen

erythrocytestransport

moleculestransport oxygen

plasmamaterials plasma

carbon dioxideregulation