circulatory system Flashcards
what is the role of the circulatory system?
- regulates water content of cells
- transports materials around body; nutrients, blood, hormones, waste products
- transports CO2 and waste products from cells to eliminate them
- maintains body temperature
- protects body from infection
components of blood: red blood cells
- contains haemoglobin
- responsible for oxygen transportation produced in red bone marrow
components of blood: white blood cells
- fights infections
- attacks and destroys germ cells
- WBC count increases when body has infection
components of blood: platelets
- blood clotting agents, stops bleeding
- smallest of the blood cells
components of blood: blood plasma
- makes up more than half of blood volume
- 90% water
- transports nutrients, minerals, water, hormones, proteins, waste
what is the heart?
muscular pump that contracts rhythmically, providing force to keep blood circulating throughout body
what structures protect the heart?
sternum and ribs
is it better to have a high or low resting heart rate?
low - more efficient heart, takes fewer beats to get the body what it needs, doesn’t fatigue as easy
what does a low resting heart rate indicate?
good cardiovascular efficiency
heart structure: arteries
- thick muscular walls
- carries blood away from heart at high pressure
- major artery of body is aorta
heart structure: capillaries
- smallest blood vessel
- very thin walls
- nutrients are exchanged
veins
- returns blood to heart
- blood isn’t under much pressure, vein walls aren’t as muscular
- has valves to stop blood running backwards
pulmonary circulation
- flow of blood from heart to lungs and back to heart
- reoxygenates blood
(heart → lungs → heart)
systematic circulation
- flow of blood from heart to body tissue and back to heart
- provides oxygen to working muscles
(heart → body → heart)
what is blood pressure?
circulation of blood controlled by regular heart contractions
