Sci

• Respiratory and circulatory systems


  • They are interconnected biological systems that maintain the flow of blood and oxygen within the body
• Respiration


  The transportation of oxygen from the surrounding air to every cell and tissue of the human body
• Breathing process


  1. Inhalation

  2. Exhalation
• Breathing is a function that can be performed consciously as well as unconsciously because the diaphragm is controlled by both the voluntary and autonomic nervous systems</b>
• The heart is connected to the autonomic system only, so although you can speed up your heart rate during exercise, you cannot immediately slow it down
• Respiratory system


  • It is a set of organs responsible for absorbing oxygen into the body and for discarding carbon dioxide
• Parts of the respiratory system

  1. Air enters through nose or mouth

  2. Moves through nasal cavity, pharynx, epiglottis, larynx

  3. Travels through trachea, bronchi, bronchioles

  4. Reaches alveoli in lungs
• Lungs


  • They are a pair of spongy bags where oxygen, carbon dioxide, and other gases interchange
  • They are divided into lobes, with alveoli located at the tip of the bronchioles
  • The alveoli transport oxygen into the bloodstream and release carbon dioxide
• The right lung is bigger but shorter than the left, to accommodate the liver below it
• The left lung is slightly smaller than the right, to give space to the heart behind it
• There are approximately 300 to 500 million alveoli in the human lungs
• Breathing


  1. Diaphragm moves down, ribs move out during inhalation

  2. Diaphragm moves back, ribs move inwards during exhalation
• Exercising is done in various ways, such as sports, dancing, cardio, and yoga
• Bronchiole


  Bronchioles are small airways in the lungs
• Alveoli


  Alveoli are tiny air sacs located at the end of bronchioles where gas exchange occurs
• Gas exchange during breathing

  1. Oxygen is delivered to alveoli

  2. Carbon dioxide is removed from alveoli
• Oxygen and carbon dioxide exchange occurs in the alveoli
• The trachea is the main airway in the lungs for air entering and leaving the lungs
• Cilia help move mucus and particles out of the airways
• The respiratory system is responsible for breathing and keeping the lungs clean and healthy
• Lungs


  • The right lung is bigger but shorter than the left lung
  • The lungs are surrounded by a thin membrane called the pleura
• The pharynx connects the nasal cavity to the esophagus
• The epiglottis prevents food from entering the larynx during swallowing
• The larynx, also called the voice box, contains the vocal cords and allows air to pass through while preventing food from entering