Transportation & Circulatory System Biology 30S

Human Circulatory System Blood Heart Arteries Arterioles Capillaries Venules Veins Lymph Vessels Lymph Fluids

Functions of Blood 3 Major Functions of Blood are… Transport Regulation Protection What is Blood: https://www.youtube.com/watch?v=CRh_dAzXuoU

Blood Composition Blood consists of 2 main parts… Plasma (55%) Cells (Red Blood Cells, White Blood Cells, & Platelets) (45%)

Blood Composition Plasma (55%) Function: contains and carries dissolved material Composed of: Amber coloured fluid (92%) Dissolved materials (8%) Dissolved Materials  Antibodies (Infection Fighters)  Nutrients (Sugar, Amino Acid, Vitamin)  Proteins (Prothrombin)  Gases (O2 & Co2) Salts (Sodium Chloride, Bicarbonate)  Hormones (Chemical Messengers  Waste (Urea & Heat)

Blood Composition 2. Cells (45%) Red Blood Cells Red blood cells (RBC) make up most of the cellular part of blood. White Blood Cells defenders of the blood circulatory system. 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 Anemia Caused 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 Cells aka. 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

Types of WBCs WBCs Non-granular WBCs (Agranulocytes) Granular WBCs (Granulocytes) Non-granular WBCs (Agranulocytes) Neutrophils Eosinophils Basophils Lymphocytes Monocytes

WBCs: Granulocytes Granulocytes Formed in bone marrow Granules in the cytoplasm Irregular-shaped nuclei Short-lived

WBCs: Granulocytes Neutrophils ~65% of WBCs actively phagocytic engulfs foreign invaders

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

WBCs: Granulocytes Basophils ~ 0.05% of WBCs Contains Histamine Initiates swelling Contains Heparin Anticoagulant

WBCs: Agranulocytes Agranulocytes Produced in lymph tissues Have no granules Have round nuclei Are longer lived than granulocytes There are 2 kinds of agranulocytes: Monocytes Lymphocytes

WBCs Lymphocytes Makes up 20-25% of WBCs Two types B-Cells Forms antibodies T-Cells Memory Storage

WBCs Monocytes ~3-8% of WBCs Actively phagocytic Macrophages - can eat up to 100 bacteria at a time

Blood Cells

(Lymphocyte) (Lymphocyte)

Platelets Smaller than RBCs ~3-7 µm in diameter Contains Thromboplastin 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” Thromboplastin (platelet) + Calcium (plasma) Prothrombin Thrombin Fibrinogen Fibrin (clot)

“Clotting Cascade”

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)

Stem Cells: Where do all these blood cells come from? Stem cells form all other blood cells in the body & are found within the bone marrow within your body