3B(i) - Cardiovascular & Lymphatic Systems
Functions of blood
- Protection (white blood cells)
- Regulation (body temperature)
Composition of blood
Straw colored liquid that makes up about 55% of blood.
- Transports substances to the cells, and carries away cellular wastes
- Most of the dissolved substances in the blood are plasma proteins (7% - 8%)
o Help balance water flow
Essential to blood clotting
- Formed in red bone marrow
White Blood Cells
Remove wastes, toxins, and damaged or abnormal cells
Warriors in the body’s fight against disease
(Phagocytosis engulfing of the offender)
- 2 groups
o Granulocytes have granules in the cytoplasm containing chemicals that are
used as weapons to destroy invading pathogens, like bacteria.
Neutrophils soldiers of the front line
Eosinophils Defense against parasitic worms & lessen the severity of
Basophils Release histamine which attracts more white blood cells to
the site of infection.
o Agranulocytes lack granules
Monocytes develop into macrophages
Lymphocytes B lymphocytes & T lymphocytes
o B Lymphocytes give rise to plasma cells, which produce antibodies.
o T Lymphocytes body’s defense mechanisms.
Red Blood Cells
Also called erythrocytes
Pick up oxygen in the lungs and transports it to all the cells of the body.
- Packed with hemoglobin, the oxygen-binding pigment. Red Blood Cells Disorders
- Anemia Blood’s ability to carry oxygen is reduced.
o Fatigue, headaches, dizziness, paleness, breathlessness
o Caused by iron-deficiency which leads to inadequate hemoglobin production
White Blood Cells Disorders
- Mono viral disease of the lymphocytes
o Headaches, fever, chills, sore throat
- Leukemia cancer of the white blood cells
ABO blood types
- A, B, AB, or O
- Step 1 Injured cells in the walls of the vessels and platelets release clotting factors.
- Step 2 Clotting factors convert an inactive blood protein to prothrombin activator.
- Step 3 Prothrombin activator convert prothrombin to thrombin.
- Step 4 Thrombin converts fibrinogen to fibrin.
- Step 5 The fibrin network traps red blood cells and platelets, forming a blood clot.
Consists of the heart, and blood vessels
- Heart Artery Arteriole Capillary Venule Vein (Back to heart)
Inner of a blood vessel is called lumen.
Transport blood away from the heart
Body’s main artery is the aorta
- Vasoconstriction blood flow is reduced
- Vasodilation blood flow is increased
- Aneurysm Defect when the artery swells and may burst
- Smallest artery called arterioles
o Control blood pressure
o Gatekeepers to the capillary networks
Connect arterioles and venules
Exchange of material between the blood and the body cells
- Capillary bed capillaries servicing a particular area
- Precapillary sphincter surrounds the capillary where it branches off the arteriole
Smallest vein is called venule
Venules join to form larger veins Veins return the blood back to the heart
3 mechanisms move blood from lower parts of the body towards the heart
1. Valves in veins prevent backflow of blood
2. Contraction of skeletal muscle squeezes veins