The Circulatory System Flashcards
Function of the circulatory system
- Circulate blood to body
- Transport O2, water and nutrients to cells in the blood
- Transport CO2, and wastes away from the cells
- Maintain body temperature
- White blood cells fight infection
Vasodilate / vasoconstrict
Arteries open up ( vasodilate ) and constrict ( vasoconstrict) to allow more or less blood to reach certain areas of the body
Systemic circulation
Carries blood from the heart to all parts of the body (except lungs) and back again
Left side of heart pumps oxygenated blood to rest of body via aorta
Pulmonary circulation
Carries blood from heart to lungs and back again
Arteries function
Carries blood away from the heart
Blood is pushed through the arteries caused by contractions of the heart
Flow or surge of blood through the arteries with each heart beat can be felt near the surface of the skin - this is referred to as the pulse
Arteries structure
- oxygenated
- Increasing high blood pressure
- no valves
- thick, muscular
Veins function
Carry blood towards the heart
Valves which allow the return of blood to the heart, but prevent the back flow of blood
Veins structure
- Thick valves
- low blood pressure
Capillaries - function
Tiny blood vessels which reach every cell of the body
Allow the passing of oxygen to tissues and removal of carbon dioxide
Functions of blood
- Transport of nutrients and waste products
- Regulation of body’s temperature
- Protection of the body
→ white blood cells
Plasma (55%)
Clear yellow fluid, 90% is water
Plasma carries blood cells
Provides cells with antibodies, proteins, glucose, salts, fats
Red blood cells (RBC’S) (45%)
Responsible for carrying O2 to cells & removal of CO2
→ from cells of muscles and organs
White blood cells ( WBC’s) (<1%)
Responsible for moving to sites of infection where they destroy bacteria & other disease causing organisms
Platelets (very small percentage)
Produced in bone marrow-cause blood clot when vessel damaged - prevent excess bleeding
Functions of the respiratory system
- Deliver oxygen front the atmosphere to the lungs
- Provide method of gaseous exchange within the lungs
- Creates speech
- Facilitate sense of smell
- Expels heat