Biology Cardiorespiratory System

• Circulatory system


  Consists of the heart and the arteries and veins that convey blood throughout the body
• Blood must always circulate to sustain life
• Blood carries oxygen from the air we breathe to cells throughout the body
• The pumping of the heart drives blood flow through the arteries, capillaries, and veins
• Circulatory system


  • One set of blood vessels circulates blood through the lungs for gas exchange
  • The other vessels fuel the rest of the body
• Pulmonary circulation


  Moves blood between the heart and the lungs, transporting deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide
• Systemic circulation


  Moves blood between the heart and the rest of the body, sending oxygenated blood out to cells and returning deoxygenated blood to the heart
• Pulmonary circulation


  1. Deoxygenated blood exits right ventricle

  2. Passes through pulmonary trunk

  3. Splits into right and left pulmonary arteries

  4. Transports deoxygenated blood to lungs

  5. Carbon dioxide released, oxygen absorbed

  6. Oxygenated blood passes through pulmonary veins to left atrium
• Systemic circulation


  1. Oxygenated blood pumped from left ventricle through aorta

  2. Moves through systemic arteries to arterioles and capillary beds

  3. Oxygen and nutrients released, carbon dioxide and waste absorbed

  4. Deoxygenated blood moves through venules into systemic veins

  5. Flows through inferior and superior vena cava to right atrium
• The heart powers both pulmonary and systemic circulation
• Circulatory system


  Works in tandem with respiratory system
• Pulmonary circulation facilitates external respiration, systemic circulation facilitates internal respiration
• Pulmonary arteries carry deoxygenated blood, pulmonary veins carry oxygenated blood
• Systemic arteries carry oxygenated blood, systemic veins carry deoxygenated blood
• Breathing


  A life process involving the inhalation (inspiration) and exhalation (expiration) of air to provide oxygen to tissues and remove carbon dioxide from the body
• Breathing


  Moving of air in and out of the lungs facilitating gas exchange with the internal environment by taking in oxygen and flushing out carbon dioxide
• Inhalation


  The action of breathing in, occurring through active contraction of muscles such as the diaphragm
• Inhalation is part of the breathing cycle and is autonomic, not needing conscious control
• Inhalation


  1. Contraction of muscles attached to the ribcage causing expansion in the chest cavity

  2. Contraction of the diaphragm resulting in the expansion of the intrapleural space
• Exhalation


  The act of exhaling air taken in, which is passive
• Exhalation


  1. Diaphragm relaxes, moving upwards into the chest cavity

  2. Muscles between the ribs relax, causing the area of the chest cavity to reduce

  3. Carbon dioxide-rich air is expelled out of the lungs and windpipe, ultimately out of the nose
• Trachea


  A cartilaginous tube that connects the pharynx and larynx to the lungs, and allows passage of air. Also known as the 'windpipe,' the trachea is a long membranous tube that is capable of lengthening and widening as air passes through.
• Bronchi


  Extensions of the trachea that carry air from the trachea into the lungs. These main bronchi continue to branch into smaller and smaller bronchi.
• Bronchioles


  Each bronchus is further divided into finer channels known as bronchioles that deliver air to little air sacs called alveoli.
• Nostrils


  For the intake of air.
• Nasal cavity


  Lined with hair and mucus to filter the air from dust and dirt.
• Pharynx


  A passage behind the nasal chamber and serves as the common passageway for both air and food.
• Larynx


  Commonly called the 'voice box' the larynx is involved in breathing, producing sound, and protecting the trachea against food aspiration.
• Epiglottis


  A flap-like structure that covers the glottis and prevents the entry of food into the windpipe.
• Right atrium


  Receives deoxygenated blood from the superior (upper body) and inferior vena cava (lower body)
• Right ventricle


  • Receives deoxygenated blood from the first chamber of the heart passing the Tricupid valve.

  
  

  • Once the deoxygenated blood fills this chamber, it contracts and pumps the blood going to the pulmonary valve to the lungs.

  
  

  • In the lungs, the blood receives the oxygen it needs to nourish the rest of the body. Then, replenished and ready to continue its journey, the blood travels through your pulmonary veins back to another chamber of the heart.
• Blood flow through the heart

  1. Deoxygenated blood enters right atrium

  2. Deoxygenated blood enters right ventricle

  3. Deoxygenated blood pumped to lungs

  4. Oxygenated blood enters left atrium

  5. Oxygenated blood enters left ventricle

  6. Oxygenated blood pumped to body
• Left atrium


  • Receives oxygenated blood from the pulmonary veins which are connected to the lungs
  • Sends blood through the mitral valve and into the left ventricle
• Left ventricle


  • Actively pumps the blood through the aortic valve so it can travel throughout the body
• The main function of the heart is to pump blood throughout the body, supplying oxygen and nutrients to tissues and organs while removing waste products. This function is facilitated by the rhythmic contraction (systole) and relaxation (diastole) of the heart muscle, a process known as the cardiac cycle.
• Right atrium

  Receives deoxygenated blood from the superior (upper body) and inferior vena cava (lower body)
• Right ventricle

  • Receives deoxygenated blood from the first chamber of the heart passing the Tricupid valve
  • Once the deoxygenated blood fills this chamber, it contracts and pumps the blood going to the pulmonary valve to the lungs
• Tricuspid valve

  • Allows the blood to flow from the right atrium to the right ventricle. This prevents blood from flowing backward from the right ventricle to the right atrium.
• Blood flow through the heart

  1. Deoxygenated blood enters right atrium

  2. Deoxygenated blood enters right ventricle

  3. Deoxygenated blood pumped to lungs

  4. Oxygenated blood enters left atrium

  5. Oxygenated blood enters left ventricle

  6. Oxygenated blood pumped to body
• Left atrium

  • Receives oxygenated blood from the pulmonary veins which are connected to the lungs
  • Sends blood through the mitral valve and into the left ventricle