Cardiovascular System

Hemostasis: A series of reactions that stops the bleeding when a blood vessel wall breaks - provides time for the blood vessel to heal itself

  • An injury causes a blood vessel to break

Exposes collagen fibers

Releases proteins

Types of Leukocytes:

Granulocytes -

  • Neutrophils

Most numerous white blood cells (50-70%)

Attracted to sites of inflammation

  • Eosinophils

2-4% of white blood cells

Use enzymes to digest parasitic worms (ex. tapeworms & flukes)

  • Basophils

Rarest white blood cells (less than 1%)

Release histamine

Agranulocytes -

  • Lymphocytes

25% of white blood cells (2nd most numerous white blood cell)

Found in the lymph nodes

  • Monocytes

3-8% of white blood cells

Have a U-shaped nucleus

Largest leukocytes

Become macrophages

Blood Types:

  • 8 Main types of blood

A- (Antigens present: A)

A+ (Antigens present: A & Rh)

B- (Antigens present: B)

B+ (Antigens present: B & Rh)

AB- (Antigens present: A & B)

AB+ (Antigens present: A, B & Rh)

O- (Antigens present: none)

O+ (Antigens present: Rh)

  • 3 antigens/proteins that cause blood type

A antigen

B antigen

Rh factor (causes + blood type)

Components of Blood:

Thrombocytes:

  • < 1% of blood volume

  • Platelets

  • Not true cells - only cell fragments

  • Job: help to clot damaged blood vessels

Leukocytes:

  • < 1% of blood volume

  • True cells

  • Lifespan: 1-3 days

  • Job: defense against diseases

  • 5 main types (from most to least abundant)

Neutrophils, lymphocytes, monocytes, eosinophils, basophils

Plasma:

  • Non-cellular

  • Blood’s liquid matrix

  • 55% of blood volume

  • 90% water

  • 10% Solutes: gases, nutrients, proteins, electrolytes, hormones

Erythrocytes:

  • 45% of blood volume

  • Hematocrit: the % of blood made up by erythrocytes - higher in males

  • Not true cells - lack nuclei & organelles

  • Biconcave discs

  • Lifespan: 120 days

  • Each RBC contains 250 million hemoglobin

  • Hemoglobin: protein that uses iron to bind 4 oxygen

Circulation - Blood Flow Through the Body:

Right Atrium —tricuspid valve-—> Right Ventricle ——pulmonary valve——> Pulmonary Artery ——→ Lungs ———> Pulmonary Vein ——> Left Atrium ——mitral/bicuspid valve——→ Left Ventricle ——-aortic valve——→ Aorta ———> Arteries ———→ Arterioles ———→ Capillaries ———> Venules ————> Veins ————> Vena Cava ————> Right Atrium