Transport/Circulatory System

Blood

Heart

Circulation

Lymphatics

Immunity

Human Circulatory System

Blood

Heart

Arteries

Arterioles

Capillaries

Venules

Veins

Lymph Vessels

Lymph Fluid

Functions of Blood

3 Major Functions of Blood are…1. Transport

2. Regulation

3. Protection

Blood Composition

Blood consists of 2 main parts…1. Plasma (55%)

2. Cells (Red Blood Cells, White Blood Cells, & Platelets) (45%)

Blood Composition

1. Plasma (55%) Amber coloured fluid (92%) Dissolved materials (8%)

a. Nutrients (sugars, amino acids, vitamins)

b. Gases (O2 & CO2)

c. Hormones (Chemical Messengers)

d. Antibodies (infection fighters)

e. Proteins (eg. Prothrombin)

f. Salts (Sodium Chloride, Bicarbonate)

g. Wastes (eg. Urea, Heat)

Blood Composition

2. Cells (45%)a. Red Blood Cells

• Red blood cells (RBC) make up most of the cellular part of blood.

b. White Blood Cells • defenders of the blood circulatory system.

c. Platelets• involved in clotting (initiate clotting process)

RBCs

Red Blood Cells

aka. Erythrocytes (“erythro” meaning red in Greek)

Physical Appearance Small (~ 8 m in diameter) Biconcave Disks

RBCs

• No Nucleus• Very Numerous • 3 – 4 month lifespan• Dead RBCs broken down by liver• New RBCs are produced by bone marrow• Contains hemoglobin (iron rich pigment)

RBCs

Function• Carry O2 and CO2

• O2 + Hemoglobin = Oxyhemoglobin• CO2 + Hemoglobin = Carbaminohemoglobin• Hemoglobin will also carry Carbon monoxide

RBCs

Disorder : Anemia Not enough RBCs in the blood

Symptoms• Fatigue• Listlessness • Increased susceptibility to other diseases

Treatment• Rest • Increased Iron intake

RBCs

Sickle Cell AnemiaCaused by a Mutant

Gene producing defective hemoglobin

Results in RBCs curving like a sickle

Symptoms of anemia due to defective hemoglobin and not enough oxygen being carried to the cells

Sickle Cell Anemia

Abnormal cells tend to form clumps and clog smaller blood vessels causing decrease in circulation…

• Severe pain in abdomen, back, head, and extremities• Enlargement of heart, atrophy in brain cells• Cells die (hemolyze) easily resulting in severe anemia• Victims tend to suffer early death

Evolutionary Benefits• People who have heterozygous state suffer only slight

symptoms, but have a resistance to malaria

WBCs

White Blood Cellsaka. Leukocytes

Function • Defend the body against

foreign invaders

WBCs

• Have a Nucleus• ~1 WBC to every 600

RBCs

Physical Appearance larger than RBCs

(~10 µm) generally round, but

can change shape

WBCs

Disorder : Leukemia• Cancer of blood forming

organs• Increase in WBCs• Decrease in RBCs,

results in Anemia• Immense number of

WBCs do not mature Treatment• Cancer Treatments• Bone marrow transplant

WBCs

White Blood CellsGranular WBCs (Granulocytes)

Non-granular WBCs

(Agranulocytes)i. Neutrophils

ii. Eosinophils

iii. Basophils

i. Lymphocytes

ii. Monocytes

WBCs

Granulocytes• Formed in bone marrow• granules in the cytoplasm• Irregular-shaped nuclei• Short-lived

WBCs

Neutrophils

~65% of WBCs actively phagocytic

engulfs foreign invaders

WBCs

Eosinophils

~ 2-4% of WBCs Destroy foreign proteins Break up blood clots

WBCs

Basophils

~ 0.5% of WBCs Contains Histamine

Initiates swelling

Contains Heparin Anticoagulant

WBCs

Lymphocytes• Makes up 20-25% of

WBCs

Two types

1. B-Cells Forms antibodies

2. T-Cells Memory Storage

WBCs

Monocytes

~3-8% of WBCs Actively phagocytic Macrophages - can eat

up to 100 bacteria at a time

Platelets

Platelets Smaller than RBCs ~3 µm in diameter

Contains

i. Thromboplastin

ii. Serotonin

Platelets

Disorder : Hemophilia• Affects mostly males• Inability to form blood clots

Cause• Genetic• Mutant gene codes for defective protein

Treatment• Injections of missing protein

Blood – “Clotting Cascade”

If a blood vessel is damaged… Platelets are fragile cells, when they hit a part of

damaged wall (torn vessel), they break open. Serotonin (hormone) is released, causing

vasoconstriction Thromboplastin (protein) is released, activating

prothrombin (plasma protein). Prothrombin Thrombin

Blood – “Clotting Cascade”

Thrombin reacts with fibrinogen causing the formation of fibrin (fibers)

Fibrin mesh traps RBCs Mesh + RBCs = Blood

Clot (Thrombus)

“Clotting Cascade” Review

Thromboplastin + Calcium + Prothrombin

Thrombin + Fibrinogen

Fibrin (clot)

Dangers of Blood Clotting

Blood clots prevent the passage of blood Area tissues do not get oxygen If occurs in brain stroke If occurs in heart vessel may have heart

attack A dislodged clot in vessel: embolus

– May get caught in a vessel in a vital organ, causes embolism (coronary, pulmonary)

Blood - What’s Your Type?

Historically, sometimes blood transfusions would keep people alive, other times it wouldn’t. Why?

Karl Landsteiner found that different blood types existed.

Glycoproteins on RBCs determine blood type:• Type A, B, AB, or O• Glycoproteins (A or B) are called antigens• Type O has no glycoproteins• Type AB has both A and B

Blood - Frequencies

O A B AB

NA White 45% 41% 10% 4%

NA Black 47% 28% 20% 5%

Peruvian Indian

100%

Blood – Antigen-Antibody Response

How does the body recognize blood type?

• Body has antibodies for the other antigen (e.g. Type A person will have Anti-B antibodies)

• Antibodies respond to invaders by binding to surface proteins

• With blood, RBC of a different type will agglutinate, or clump.

Blood – Antigen-Antibody Response

Blood Type Blood Contains

Cellular Antigens Plasma Antibodies

O None Anti –A & Anti – B

A A Anti – B

B B Anti - A

AB AB None

Blood - To whom can I donate?

Successful transfusion can occur provided the plasma of the patient and the erythrocytes of the donor are compatible.

For example…

Kevin (Type A) can donate to Michelle (Type A) and Donnie (Type AB)

Blood - To whom can I donate?

A person with what blood type would be considered a Universal Donor?

Type OWhy?A person with what blood type

would be considered a Universal Recipient?

Type AB

Rhesus Factor – The Monkey Factor

A different blood antigen Genetically determined Two types: Rh- and Rh+

~ 83.3% of population are Rh+ (protein present)

~ 16.6% of population are Rh– (protein absent)

Rh- will develop the Rh antibody only when exposed to Rh+ blood

Blood donating: Rh+ can receive from Rh-, but Rh- cannot receive from Rh+

Rhesus Factor – The Monkey Factor

Important for pregnant women:• If there is a tear in the placenta, babies and mom’s blood

cells can enter each other’s blood stream• If mother is Rh- and baby is Rh+, the babies RBC will

stimulate the production of Rh antibodies by the mother• Erythroblastosis fetalis – If the mother’s Rh antibodies

enter the babies blood stream, they will cause agglutination and destruction of babies RBCs, resulting in death of the baby.

Treatment• Immunization of the mother with “Rhogam” or “Wingam”-

medicines that prevent the formation of Rh antibodies (contain Rh anti-antibodies)

Next – The Circulatory System