ch 20_lecture_presentation

© 2012 Pearson Education, Inc.

20The Cardiovascular System: Blood

PowerPoint® Lecture Presentations prepared bySteven BassettSoutheast Community College Lincoln, Nebraska


Introduction

• The cardiovascular system functions as asystem to transport numerous substancesthroughout the body such as:

• Nutrients• Oxygen and carbon dioxide• Hormones • Ions • Transports metabolic wastes to the kidneys• Transports leukocytes to aid in fighting

infectious agents


Composition of the Blood

• Blood consists of two components• Plasma

• Liquid matrix of blood

• Formed elements: blood cells and cell fragments that are suspended in the plasma, and include:

• Erythrocytes (red blood cells): transport oxygen and carbon dioxide

• Leukocytes (white blood cells): function in the immune system

• Platelets: involved in blood clotting



• Whole blood • Males: 4–6 liters• Females: 4–5 liters• Hypovolemic: low blood volumes• Normovolemic: normal blood volumes• Hypervolemic: excessive blood volumes• pH: 7.35–7.45• Temperature = 100.4°F



• Plasma• Makes up about 55% of the volume of whole

blood• Consists of:

• 92% water• 7% proteins:

• Albumin• Globulins: involved in immune responses• Fibrinogen: involved in clot formation

• 1% other solutes (electrolytes, organic nutrients, organic waste)


Figure 20.1b The Composition of Whole Blood (Part 1 of 2)

Plasma Proteins

Other Solutes

Regulatoryproteins(1%)

Fibrinogen(4%)

Globulins(35%)

Albumins(60%)

Major contributors to osmoticpressure of plasma; transportlipids, steroid hormones

Transport ions, hormones, lipids;immune function

Essential component of clottingsystem; can be converted toinsoluble fibrin

Enzymes, proenzymes,hormones

Electrolytes

Organicnutrients

Organicwastes

Normal extracellular fluid ioncomposition essential for vitalcellular activitiesIons contribute to osmoticpressure of body fluidsMajor plasma electrolytesare Na, K, Ca2, Mg2, Cl,HCO3

, HPO4, SO4

2

Used for ATP production, growth,and maintenance of cells; includelipids (fatty acids, cholesterol,glycerides), carbohydrates(primarily glucose), and aminoacids

Carried to sites of breakdown orexcretion; include urea, uric acid,creatinine, bilirubin, ammoniumions

Components ofplasma

PLASMA COMPOSITION

Plasma proteins

Other solutes

Water

Transports organic andinorganic molecules,formed elements, and heat

7%

1%

92%

Plasma(46–63%)

consists of

Sample ofwhole blood



• Formed elements• Makes up about 45% of whole blood• Platelets (<0.1% of whole blood)• Leukocytes (<0.1% of whole blood)

• Neutrophils (50–70% of the WBCs)• Eosinophils (2–4% of the WBCs)• Basophils (<1% of the WBCs)• Lymphocytes (20–30% of the WBCs)• Monocytes (2–8% of the WBCs)

• Erythrocytes (99.9% of whole blood)


Figure 20.1c The Composition of Whole Blood (Part 1 of 2)

consists of

Sample ofwhole blood

Formed elementsof blood

Formedelements(37–54%)

FORMED ELEMENTS

Platelets

White blood cells

Red blood cells

0.1%

0.1%

99.9%

Platelets

White Blood Cells

Red Blood Cells

Basophils(1%)

Lymphocytes(20–30%)

Monocytes(2–8%)

Neutrophils(50–70%)

Eosinophils(2–4%)


Formed Elements

Red blood cells (RBC) or erythrocytes Most numerous cell Transports oxygen and carbon dioxide Usually degenerate after roughly 120 days in circulation They lack nucleus, mitochondriae and ribosomes. Percentage value of RBC count is called hematocrit.

Elevated hematocrit causes polycythemia. Hemoglobin (Hb)

Give RBCs the ability to transport oxygen and carbon dioxide

Reduced oxygen-carrying capacity of the blood is called anemia.


Figure 20.2a Histology of Red Blood Cells

Blood smear LM 477

When viewed in a standardhistological blood smear, red bloodcells appear as two-dimensionalobjects because they are flattenedagainst the surface of the slide.


Figure 20.2bc Histology of Red Blood Cells

SEM 1838Red blood cells

A scanning electron micrograph of red blood cells reveals their three-dimensional structure quite clearly.

0.45–1.16 m 2.31–2.85 m

7.2–8.4 m

A sectional view of a red blood cell


Figure 20.3 The Structure of Hemoglobin

Hemoglobinmolecule

Heme

Heme

chain 1

chain 1

chain 2

chain 2


Formed Elements

• The blood type is determined at the cellular level by presence or absence of specific antigen on the RBC plasma membrane.– Based on the presence or absence of Ag A and Ag B,

there are blood type A, B, AB and O.– Based on the presence or absence of Ag D or Rh

antigen the blood group can be positive or negative.– O is universal blood donor.– AB is universal blood recipient.


Formed Elements

• Blood Types (continued)• People with type A blood have the b

agglutinin in their plasma.• People with type B blood have the a

agglutinin in their plasma.• People with type AB blood have neither

agglutinin a nor agglutinin b in their plasma• People with type O blood have both agglutinin

a and agglutinin b in their plasma.


Figure 20.4 Blood Typing

Type A Type B Type AB Type O

Type A blood has RBCs withsurface antigen A only.

Type B blood has RBCs withsurface antigen B only.

Surface antigen A

Surface antigen B

If you have Type A blood, your plasma contains anti-Bantibodies, which will attackType B surface antigens.

If you have Type B blood, your plasma contains anti-Aantibodies.

Type AB individuals do nothave anti-A or anti-Bantibodies.

Type AB blood has RBCswith both A and B surfaceantigens.

Type O blood has RBCslacking both A and B surfaceantigens.

An individual with Type Oblood has plasma containingboth anti-A and anti-Bantibodies.

Your blood type is a classification determined by the presence or absence of specific surface antigensin RBC plasma membranes. There are four blood types based on the A and B surface antigens.


Figure 20.4 Blood Typing

The plasma contains antibodies that will react with foreign surface antigens in a processcalled agglutination. The cells may also break apart, an event known as hemolysis.

RBC

Surface antigens Opposing antibodies Agglutination (clumping) Hemolysis


Formed Elements

White blood cells (WBC) or leukocytes Defend body against pathogens and remove

toxins, wastes, and abnormal or damaged cells Two classes:

Granular leukocytes Neutrophils Eosinophils (acidophils)/orange Basophils

Agranular leukocytes Monocytes Lymphocytes

Show chemotaxis (the attraction to specific chemicals) and diapedesis (the ability to move through vessel walls)


Figure 20.5 Histology of White Blood Cells

Neutrophil

RBCRBC RBC

LM 1500 LM 1500 LM 1500Eosinophil Basophil Monocyte

RBC

LM 1500 LM 1500

RBC

Lymphocyte


Table 20.3 A Review of the Formed Elements of the Blood


Formed Elements

Platelets Not cells; they are membrane-enclosed packets of cytoplasm Released into blood by megakaryocytes, enormous cells in the

bone marrow Circulate for 10 —12 days before being removed by phagocytes;

continually replaced Functions

Transport chemicals important for clotting Temporarily patch the walls of damaged blood vessels Causing contraction after a clot has formed to reduce the size

of the break in the vessel wall Hemostasis is obtained by going through the following stages in

order: Vasoconstriction Platelet aggregation Clot formation


Figure 20.6 Histology of Megakaryocytes and Platelet Formation

Nutrient artery

Venoussinuses

Red bonemarrow

Developing erythrocytesand granulocytes

Adipocyte

Bone marrow section LM 673

Platelets

MegakaryocyteRed blood

cell


Hemopoiesis

The process of blood cell formationAll blood cells are produced in the bone marrow. Stem cells or pluripotential stem cells (PPSC) divide to form all of the blood cells.

Give rise to myeloid stem cells and lymphoid stem cells

Original blood cells form in developing blood vessels.

Spleen and liver contribute in fetal blood cell development

Red bone marrow takes over in postnatal life


Figure 20.8 The Origins and Differentiation of Formed Elements

Red bone marrow

Myeloid Stem Cells

Progenitor Cells

PluripotentialStem Cells

Red Blood Cells(RBCs)

Blast Cells

Myelocytes

Band Cells

White Blood Cells (WBCs)

Proerythroblast

Erythroblast stages

Reticulocyte

Ejection ofnucleus

Erythrocyte

Megakaryocyte

Platelets

Myeloblast

Basophil Eosinophil Neutrophil

Granulocytes Agranulocytes

Monoblast Lymphoblast

Promonocyte Prolymphocyte

Monocyte Lymphocyte

Lymphoid Stem Cells

ch 20_lecture_presentation

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blood plasma

blood clotting

blood males

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low blood volumes normovolemic

excessive blood volumes

erythrocytes red blood