SCIENCE

• process of taking in oxygen from the environment and delivering it to the cells.

  Respiratory
• pumping action of the heart

  heartbeat
• responsible of carrying and distributing nutrients, gases, hormones, antibodies, and many other important substances that the body needs to live

  network of channels
• Three major parts

  the heart, the blood vessels, and the blood.
• responsible for breathing particularly gas exchange.

  lung
• main stem

  trachea
• large branching stems

  bronchi
• all little stems

  bronchioles.
• little grapes like are air sacs

  alveoli
• long term for nose

  nasal opening towards the nasal cavity
• also known as the throat

  pharynx
• also known as the windpipe

  trachea
• serve as the extension

  bronchi
• tiny sacs inside the lungs

  alveoli
• These receive blood through veins. 


  two atria
• It accepts blood from the lungs.

  left atrium
• It accepts blood from the body.

  right atrium
• chambers force the blood out into the arteries

  two ventricles
• pumps blood towards the lungs.

  right ventricle
• pumps blood towards the body.

  left ventricle
• these prevent the backward flow of the blood.

  valves
• found between the right atrium and right ventricle

  tricuspid valve
• found between the left atrium and left ventricle

  bicuspid valve
• found at the base of the pulmonary artery

  pulmonary valve
• the base of the aorta

  aortic valve
• largest vein. It carries blood towards the heart.

  Vena cava
• conveys blood from the upper extremities towards the heart

  superior vena cava
• conveys blood from the lower extremities towards the heart

  inferior vena cava
• It divides the right and left chambers.

  septum
• The largest artery. It conveys blood from the heart to different parts of the body.

  Aorta
• conveys oxygen-poor blood from the heart to the lungs.

  pulmonary artery
• conveys oxygen-rich blood from the lungs to the heart

  pulmonary vein
• Types of blood circulating in the body

  • Oxygen-rich blood (oxygenated blood)
  • Oxygen-poor blood (deoxygenated blood)
• Journey of deoxygenated blood


  1. Starts at vena cava (superior and inferior)

  2. Enters right atrium

  3. Pumped to right ventricle through tricuspid valve

  4. Pumped out of heart to lungs through pulmonary artery

  5. Prevented from backflowing by semilunar valve
• Gas exchange in the lungs

  1. Blood enters capillaries in lungs

  2. Carbon dioxide replaced by oxygen

  3. Blood now called oxygenated blood
• Journey of oxygenated blood

  1. Goes back to heart through pulmonary vein

  2. Enters left atrium

  3. Pumped to left ventricle through bicuspid valve

  4. Pumped out of heart through aortic valve and into aorta

  5. Distributed throughout body
• 1. main stem
  2. bronchi
  3. bronchioles
  4. alveoli