Cardiovascular system

Cardiovascular disease (CVC)

• Disease of the heart and/or blood vessels

• Most dangerous killer in the developed world

• Few to no signs of illness until it’s too late

Cardiovascular system

• The system that transports nutrients, gases, hormones and other critical molecules throughout the body

• Consists of:

  • Heart

  • Blood vessels

  • Blood

Blood

• A body fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells

• Adult humans have ~5L (11 pints) of blood

  • Separated into 2 parts:

    • Liquid plasma

    • Solid Cellular elements

Plasma 

• Contains:

  • Water

  • Salts

  • Enzymes

  • Antibodies

  • Other proteins

Cellular elements of blood 

• Red blood cell (erythrocytes)

  • Oxygen Transport

• Platelets:

  • Help to form blood clots

• White blood cells (leukocytes)

  • Immune response

Functions of blood

• Transportation: oxygen, nutrients, wastes, carbon dioxide and hormones

• Defense: against invasion by pathogens

• Regulatory functions: body temperature, water-salt balance and body pH

Vascular system

System of arteries, veins, and capillaries through which the blood is pumped

Arteries

• Carry blood away from the heart

  • Coronary arteries: blood vessels that carry oxygenated blood to the heart

• generally smaller than veins, have thicker walls in proportion to their lumen and carry blood under higher pressure than veins.

• Lumen: interior of a tubular structure such as a blood vessel or a portion of the alimentary canal through which blood, chyme, or other substances travel

Veins

• Carry blood towards the heart

• A type of blood vessel that return deoxygenated blood from your organs back to your heart

• generally larger in diameter than arteries, carry more blood volume and have thinner walls in proportion to their lumen

Capillaries

• Allow exchange between the bloodstream and tissue cells

  • Every cell in the body must be close to a capillary

• small blood vessel from 5 to 10 micrometres (μm) in diameter

• Situated between the arteries and veins

• The sites of gas, nutrient, electrolyte and waste exchange between blood and cells

• Oxygen and nutrients filter out of the capillaries into tissues and CO2 and waste diffuses into tissues

• Able to do this due to their very thin walls and slow rate of blood flow

Heart

• The muscular pump that generates force to move blood throughout the body

• About the only muscle in the body that never takes a break

• Varies in size depending on body size and activity levels

  • Adults ~14 cm long and 9cm wide

• Formed of 2 separate pumps (left and right side) and 4 chambers

Chambers of the heart

• 2 Atria: Act as receiving chambers for incoming blood

  • Right Atrium: low oxygenated blood

  • Left Atrium: high oxygen blood

• 2 Ventricles: Act as discharging chambers for outgoing blood

  • Right ventricle: low oxygen blood

  • Left Ventricle: high oxygen blood

    • Much thicker than the right ventricle

Path of blood

1. Heart

2. Arteries

3. Arterioles

4. Capillaries

5. Venules

6. Veins

7. Back to the heart

Path in vertebrates

• Organized into a double circulation system with two distinct circuits of blood flow:

  • Pulmonary Circuit: Carries blood between heart and lungs

  • Systemic Circuit: Carries blood between the heart and the rest of the body

Pulmonary circuit

• Circulates blood between the heart and the lungs

• In the lungs, CO2 diffuses one way (from blood to lungs) while 02 diffuses the other way (from lungs to blood)

• Oxygen rich blood is then returned to the heart

Systemic circuit

• Circulates blood between the heart and the rest of the body

• Delivers O2 and nutrients to the body tissues and organs

• Collects CO2 and other wastes from the body tissues and organs

• Returns to the heart