6a. Heart and blood vessels

• What muscle is the heart made from

  Cardiac
• Why does the heart have two pumps rather than one

  Activated enough pressure to send blood to the lungs and the rest of the body
• What is the role of coronary arteries

  Deliver oxygenated blood to the cardiac muscle
• Why does the cardiac muscle need lots of blood

  Production of atp
• Where does blood from the vena cava go

  Right atrium
• Where does blood from pulmonary veins go

  Left atrium
• Where does the pulmonary artery take blood

  To the lungs
• Where does the aorta take blood

  The body
• Does the left side pump oxygenated or deoxygenated blood

  Oxygenated
• What is the function of valves in the heart

  Prevents back flow of blood
• One complete sequence of contraction and relaxation is called the

  Cardiac cycle
• What is atrial systole

  Contraction of atria
• What is diastole

  Heart relaxes and the atria fill with blood
• under what conditions are the semi lunar valves open

  When the pressure is greater in the ventricle than in the arteries
• When are the atrioventricular valves open

  When the pressure in atria is greater than ventricle
• Cardiac muscle is myogenic what does this mean

  Contractions come from the muscle itself
• What is cardiac output and how is it calculated

  Total volume of blood pumped from one ventricle in one minute

  heart rate x stroke volume
• What is stroke volume

  Volume pumped from one ventricle per contraction
• 1 dm3 is equal to

  1000cm3
• What happens to a trained athletes heart

  It will get bigger. Resting stroke volume will be bigger, so resting pulse rate drops, meaning they increase cardiac output
• What does an increase in cardiac output allow

  More glucose and oxygen to be delivered to working muscles
• Where do hepatic veins and arteries go

  Liver
• Where do renal veins and arteries go

  Kidney
• What are the three blood vessels

  Arteries

  veins

  capillaries
• Give features of arteries

  Thick walls. - withstand high pressure

  elastic tissue - stretch and recoil

  layer of endothelium - prevents blood clots
• What are arterioles

  Arteries branch into smaller vessels. They control blood flow to capillaries
• Describe the walls of veins

  Thin and have valves
• How is blood returned to the heart via veins

  Valves - prevent backflow

  contraction of leg muscles pushes blood

  respiratory pump - negative pressure
• Why is rate of blood flow much slower in capillaries

  Much thinner - blood cells in single line
• Why are capillaries good for diffusion

  Very thin walls one cell thick

  pores between cells so highly permeable
• What is CHD

  coronary heart disease
• What happens during CHD

  fatty materials build up and block the blood flow causing heart attack.
• What are the risk factors for CHD

  Genetics

  gender

  age

  smoking

  diet

  high blood pressure