Circulatory System

Introduction to the Circulatory System

• Also called the vascular system

• Function: Transports oxygen, water, food, and protects against infection

• Removes waste materials from the body

• Oxygen is necessary, otherwise one will die within minutes.

​Vascular Systems

• There are two vascular systems:

  • Blood Vascular System

    • Circulates blood throughout the body

  • Lymph Vascular System

    • Runs parallel to blood veins

• The scientific study of these systems is called angiology.

​Parts of the Circulatory Systems: The Heart

• Hollow, musclar organ

  • The size of a fist

  • Weighs about 9 oz

• Pumps blood through rhythmic contractions

• Chambers:

  • Atria - receives blood

  • Ventricles - pumps blood out

Blood Vessles - Capillaries

• Smallest blood vessels

• Deliver oxygen and nutrients to cells

• Receive nourishment and remove waste products

Blood Vessles - Veins

• Thin-walled

  • Contain valves to prevent backflow

• Carry oxygen-poor blood back to the heart

• Found near the surface of the body

• Run parallel to arteries

  • Have the same name

    • Eg: Brachial (artery/vein)

Arteries of the Hand & Arm: Main

• Femoral Artery & Vein:

  • Supplies blood to the leg

• Great Saphenous Vein: Front and inner side of the leg

• Small Saphenous Vein: Back of the leg

Arteries of the Hand & Arm

• Cephalic and Basilic: Forearm veins

  • Cephalic: located on the Radial side of the forearm

  • Basilic: located on the ulnar side of the forearm

• Radial and Ulnar: located on respective sides

• Dorsal Metacarpal and Digital Veins: Found in the hand

  • Dorsal metacarpal: veins on the back of the hand

  • Digital: runs alongside each finger

Arteries of the Hand & Arm

• Subclavian: Supplies blood to the hand

• Axillary: Located under the shoulder

• Brachial: Supplies the upper arm

• Ulnar & Radial: Main arteries for arm/hand

  • Ulnar: located on the little finger side of the forearm

  • Radial: located on the thumb side of the forarm

The Blood - Composition

• Comprised of 70% plasma

  • Plasma is made up of water, nutrients, and waste

• Solid part of blood

  • Corpuscles & Platelets

• 1/20 of blood supply circulates in the skin

• Bright red = oxygenated

• Dark red = lacks oxygen

Types of Blood Cells

• Red Corpuscles - blood cells:

  • Also called erythrocytes

    • carry oxygen away from the lungs, carry carbon dioxide back to the lungs for breathing out

Types of Blood Cells - continued

• White Blood Cells:

  • Also called leukocytes

    • Protect the body from disease; fighting harmful bacteria

• Platelets

  • Also called thromocytes

    • Aid in clotting of blood to seal injured vessels

    • Smaller than red blood cells

The Blood - Functions

• Carry oxygen and food to cells

• Carry away carbon dioxide and waste

• Equalize the body temperature

• Provide clotting mechanisms to heal wounds

• Carry internal secretions (hormones) to maintain chemical activity within the body.

Lymphatic System

• Parallels venous system

• Lymphatics (lymph vessels) carry blood supply to parts of the body not reached by blood

  • Lymphocytes aid in fighting infection

• Lymph colorless watery fluid derived from plasma containing white blood cells - aka - tissue fluid.

  • Carries away waste

    • Bathes tissues in nutrients taking

Circulation Types

• Pulmonary Circulation

  • Deoxygenated blood (from heart) to the lungs to become purified - oxygenated back to heart

• Systemic Circulation:

  • Oxygen-rich blood (from heart) to the entire body back to the heart

Blood Vessles - Arteries

• Tick-walled, Muscular vessles

• Carry oxygen-rich blood away from the heart to capillaries and other parts

• Main artery: Aorta