6.2

• Ventricle


  thick walled muscular pump that builds up enough pressure to send the blood out from the heart with force.

  
• Atria


  each side of heart has collection chamber for blood that is moving slowly in from veins. Contracts to force any remaining blood into Ventricle.

  
• Pulmonary Circuit


  From right side of heart, pumps along route to lung

  
• Systemic Circuit


  from left side of heart, pumps blood around body

  
• Semilunar Valve


  pulmonary (r) and aortic (l) valve, between ventricle and arteries

  
• Atrioventricular valve


  tricuspid (r) and mitral (l) valve, between atrium and ventricle. Are open.

  
• Lup-dup sound


  closing valve (ex. atrioventricular valves)
• Arteriole


  Smallest artery which leads to capillary bed

  
• Contraction of Ventricle


  Causes closure of atrioventricular valve to prevent backflow to right atrium, dramatic increase in blood pressure inside right ventricle which opens right valve and allows blood into pulmonary artery. Due to increase in blood pressure blood leaves through pulmonary artery.
• Myogenic Initiation


  Cardiac muscle spontaneously contracts and relaces without nervous system control.
• Sinoatrial valve


  a mass of tissue inside walls of right atrium which acts as pacemaker for the heart: sends electrical signal to the heart to contract both atria every 0.8 seconds
• Atrioventricular node


  recieves signal from the SA node, waits approximately 0.1 seconds, and sends another electrical signal to the much more muscular ventricles and results in their contraction.
• Fluctuation in CO2 Levels

  If you exercise, there is increased demand for oxygen due to cell respiration and you need to get rid of CO2 so medulla senses increased level and signal is sent to cranial nerve. When heart rate stabilizes, the medulla sends a signal through the vagus nerve to decrease heart rate.
• Plasma


  Liquid portion of blood
• Erythrocytes


  red blood cell (carry oxygen and CO2)

  
• Leucocytes


  white blood cells (phagocytes and lymphocytes)

  
• Platelets


  cell fragments (assist in clotting)

  
• arteries


  Carry blood away from heart.Thick walled.No exchanges.No internal valves.Internal pressure high.High oxygen content.

  
• capillaries


  Smallest blood vessels.wall is 1 cell thick.All exchanges occur.No internal valves.Internal pressure low.

  
• veins


  Thin walled.No exchanges.Have internal valves to stop blood from passing backwards.Internal pressure low.Low oxygen content.

  
• transported by blood

  nutrients: glucose, amino acids, etc.oxygen: reactant needed for aerobic respirationcarbon dioxide: waste product of aerobic respirationhormones: transported from gland to target cellsantibodies: protein molecules involved in immunityurea: nitrogenous waste (filtered from kidneys)heat: skin arterioles (can change diameter in order to gain or lose heat; causes skin to turn red)
• Heart Circulation