BIOLOGY

• Components of blood


  • RBC (erythrocytes) - Carries O2 from lungs to body
  • WBC (leukocytes) - Fights infections, aids immune system
  • Platelets (thrombocytes) - Helps in blood clotting
• Blood vessels


  • Arteries - Carry blood away from the heart
  • Veins - Carry blood back to the heart
  • Capillaries - Connect arteries and veins
• Heart


  • Muscular organ about the size of a fist, located just behind and slightly left of the breastbone
  • 4 chambers: RA (right atrium), RV (right ventricle), LA (left atrium), LV (left ventricle)
  • RA receives blood from veins and pumps to RV
  • RV receives blood from RA and pumps to lungs
  • LA receives oxygenated blood from lungs and pumps to LV
  • LV strongest chamber that pumps oxygen-rich blood to body
  • Left ventricle's contractions create blood pressure
• Breathing exercise (10 counts)
• Why we breathe


  To move oxygen (needed for cellular respiration) into body tissues and remove carbon dioxide (waste product of cellular respiration) from cells
• Parts of the respiratory system

  • Trachea
  • Bronchi
  • Bronchioles
  • Alveoli
• Respiratory systems allow animals to move oxygen into body tissues and remove carbon dioxide from cells
• Moving air in and out

  1. During inspiration (inhalation), diaphragm and intercostal muscles contract

  2. During exhalation, these muscles relax and diaphragm domes upwards
• Human respiration includes exhalation of carbon dioxide
• When you hold your breath, amount of carbon dioxide in body increases, making blood acidic
• Structures specialized for gas exchange

  • Gills (aquatic animals)
  • Spiracles (terrestrial insects)
  • Lungs (most terrestrial vertebrates)
• Where gas exchange in mammals occurs

  • Alveoli - moist, thin-walled pockets which are the site of gas exchange
  • Slightly oily surfactant prevents alveolar walls from collapsing and sticking together
• Blood flow through the heart
• Vital signs


  • Temperature
  • Pulse rate
  • Respiration rate
  • Blood pressure
• Normal body temperature


  97.8°F to 99.1°F (36.5°C to 37.3°C), average 98.6°F (37°C)
• Normal pulse rate


  60 to 100 beats per minute
• Normal blood pressure


  90/60 mm Hg to 120/80 mm Hg
• Normal respiration rate


  12 to 18 breaths per minute
• During gas exchange, oxygen moves from lungs to bloodstream, and carbon dioxide passes from blood to lungs
• Deoxygenated blood enters right atrium through superior and inferior vena cava
• Vegetarians do not necessarily suffer from iron deficiency anemia
• Lack of vitamin B12, not just iron, can cause anemia in vegetarians
• When you hold your breath, amount of carbon dioxide in body increases
• People with anemia can still exercise and play sports, but should start slowly and listen to their body
• Genes are segments of DNA that contain instructions for making specific proteins or controlling other genes.