blood 10d

Blood

The Cardiovascular System



A circulating transport system:

–

a pump (the heart)

-

”

cardio

”

–

a conducting system (blood vessels)

-

”

vascular

”

–

a fluid medium (blood)

Blood



Is specialized fluid of connective tissue



Contains cells suspended in a fluid matrix

5 Functions of Blood

1.

Transport of dissolved substances

2.

Regulation of pH and ions

3.

Restriction of fluid losses at injury sites

4.

Defense against toxins and pathogens

5.

Stabilization of body temperature

Figure 19–1a

Whole Blood

Whole Blood



Plasma

:

–

fluid



Formed elements

:

–

all cells and solids

3 General Characteristics

of Blood



38

°

C (100.4

°

F) is normal temperature



High viscosity



Slightly alkaline pH (7.35

–

7.45)

Blood Volume



Blood volume (liters) = 7% of body

weight (kilograms):

–

adult male: 5 to 6 liters

–

adult female: 4 to 5 liters

Plasma



Is similar to, and exchanges fluids with,

interstitial fluid



Is matrix of formed elements

Plasma



Water



Dissolved

plasma proteins



Other solutes

Figure 19–1b

Plasma

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

Differences between

Plasma and IF

1.

Levels of O

2

and CO

2

2.

Dissolved proteins:

–

plasma proteins

do not pass through

capillary walls

3 Classes of Plasma Proteins



Albumins

(60%)



Globulins

(35%)



Fibrinogen

(4%)

Albumins



Transport substances:

–

fatty acids

–

thyroid hormones

–

steroid hormones

Globulins

1.

Antibodies

, also called

immunoglobulins

2.

Transport globulins

(small molecules):

–

hormone

-

binding proteins

–

metalloproteins

–

apolipoproteins (

lipoproteins

)

–

steroid

-

binding proteins

Fibrinogen



Molecules form clots



Produce long, insoluble strands of

fibrin

Other Plasma Proteins



1% of plasma:

–

changing quantities of specialized plasma

proteins

–

enzymes, hormones, and prohormones

Origins of Plasma Proteins



90% made in liver



Antibodies made by plasma cells



Peptide hormones made by endocrine

organs

Serum



Liquid part of a blood sample:

–

in which dissolved fibrinogen has converted to

solid fibrin

About 1/2 the volume of whole blood is

cells and cell products

3 Types of

Formed Elements

1.

Red blood cells

(

RBCs

) or

erythrocytes

:

–

transport oxygen

2.

White blood cells

(

WBCs

) or

leukocytes

:

–

part of the immune system

3.

Platelets

:

–

cell fragments involved in clotting

Red Blood Cells



Red blood cells (RBCs) make up 99.9% of

blood’s formed elements

(5

-

6

million

/

mm³)

Normal Blood Counts



RBC

:

–

male: 4.5

–

6.3 million

–

female: 4.

–

5.5 million



Hematocrit

:

–

male: 4

–

52

–

female: 3

–

47

RBC Structure



Small and highly specialized disc



Thin in middle and thicker at edge

Figure 19–2d

Importance of RBC

Shape and Size

1.

High surface

-

to

-

volume ratio:

–

quickly absorbs and releases oxygen

2.

Discs form stacks:

–

smoothes flow through narrow blood vessels

3.

Discs bend and flex entering small

capillaries:

–

7.8

µ

m RBC passes through 4

µ

m capillary

Lifespan of RBCs



Lack nuclei, mitochondria, and ribosomes



Live about 120 days

Hemoglobin

(Hb)



Protein molecule, transports respiratory

gases



Normal hemoglobin (adult male):

–

14

–

18 g/dl whole blood

Hemoglobin Structure



Complex quaternary structure

Figure 19–3

Hemoglobin Structure



4 globular protein subunits:

–

each with 1 molecule of

heme

–

each heme contains 1 iron ion



Iron ions easily:

–

associate with oxygen (

oxyhemoglobin

)

–

or dissociate from oxygen (

deoxyhemoglobin

)

Fetal Hemoglobin



Strong form of hemoglobin found in

embryos



Takes oxygen from mother’s hemoglobin

Anemia



Hematocrit or hemoglobin levels are below

normal



Is caused by several conditions

Figure 19–4

Recycling RBCs

Recycling RBCs



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

)

BLOOD TYPING

Surface Antigens



Are cell surface proteins that identify cells

to immune system



Normal cells are ignored and foreign cells

attacked

Blood Types



Are genetically determined



By presence or absence of RBC surface

antigens

A

,

B

,

Rh

(D)

Figure 19–6a

4 Basic Blood Types

4 Basic Blood Types



A

(surface antigen A)



B

(surface antigen B)



AB

(antigens A and B)



O

(neither A nor B)

Agglutinogens



Antigens on surface of RBCs



Screened by immune system



Plasma antibodies attack (

agglutinate

)

foreign antigens

Blood Plasma Antibodies



Type A:

–

type B antibodies



Type B:

–

type A antibodies



Type O:

–

both A and B antibodies



Type AB:

–

neither A nor B

The

Rh Factor



Also called

D antigen



Either

Rh positive

(Rh

+

) or

Rh negative

(Rh

—

)



Only

sensitized

Rh

—

blood has anti

-

Rh

antibodies

Figure 19–6b

Cross

-

Reaction

Cross

-

Reaction



Also called

transfusion reaction



Plasma antibody meets its specific surface

antigen



Blood will agglutinate and hemolyze



If donor and recipient blood types not

compatible

Blood Type Test



Determines blood type and compatibility

Figure 19–7

Cross

-

Match Test



Performed on donor and recipient blood

for compatibility



Without cross

-

match, type O

—

is universal

donor

White Blood Cells (

WBCs

)



Also called

leukocytes



Do not have hemoglobin



Have nuclei and other organelles

WBC Functions



Defend against pathogens



Remove toxins and wastes



Attack abnormal cells

WBC Movement



Most WBCs in:

–

connective tissue proper

–

lymphatic system organs



Small numbers in blood:

–

6000 to 9000 per microliter

Circulating WBCs

1.

Migrate out of bloodstream

2.

Have amoeboid movement

3.

Attracted to chemical stimuli (

positive

chemotaxis

)

4.

Some are phagocytic:

–

neutrophils, eosinophils, and monocytes

Figure 19–9

Types of WBCs

Macrophage Actions



Engulf large particles and pathogens



Secrete substances that attract immune

system cells and fibroblasts to injured area

Lymphocytes



20

–

30% of circulating WBCs



Are larger than RBCs



Migrate in and out of blood



Mostly in connective tissues and lymphatic

organs

3 Classes of Lymphocytes

1.

T cells

2.

B cells

3.

Natural killer

(NK)

cells

T cells



Cell

-

mediated immunity



Attack foreign cells directly

B cells



Humoral immunity



Differentiate into

plasma cells

(activated B

cells that secrete antibodies).



Synthesize antibodies

Natural Killer Cells

(NK)



Detect and destroy abnormal tissue cells

(cancers)

Platelets



Cell fragments involved in human clotting

system



Nonmammalian vertebrates have

thrombocytes

(nucleated cells)

Platelet Circulation



Circulates for 9

–

12 days



Are removed by spleen



2/3 are reserved for emergencies



150,000 to 500,000 per microliter

3 Functions of Platelets

1.

Release important clotting chemicals

2.

Temporarily patch damaged vessel walls

3.

Actively contract tissue after clot

formation

The Platelet Phase



Begins within 15 seconds after injury

Figure 19–11b

The Coagulation Phase



Begins 30 seconds or more after the injury

Figure 19–12a

The Coagulation Phase



Blood clotting (

coagulation

):

–

Involves a series of steps

–

converts circulating

fibrinogen

into insoluble

fibrin

Blood Clot



Fibrin network



Covers platelet plug



Traps blood cells



Seals off area

Plasma Clotting Factors

Table 19–4

Cascade

Reactions



During coagulation phase



Chain reactions of enzymes and

proenzymes



Form 3

pathways

Bleeding Time



Normally, a small puncture wound stops

bleeding in 1

–

4 minutes

Other Factors



Calcium ions

(Ca

2+

) and

vitamin K

are

both essential to the clotting process

​Blood and diseases :

• -AIDS

• -haemophilia

• -anemia

• -blood tests

• -vaccines (in general or specific)

• -deep vein trombosis

• -embolia

• Prepare 5 slides: Symptoms. Diagnosis, cure, prevention, risks, interesting facts