transport/circulatory system blood heart circulation lymphatics immunity
TRANSCRIPT
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