human body systems

• Respiratory system


  The system that lets us exchange gases (oxygen and carbon dioxide)
• The respiratory system is different from cellular respiration
• Cellular respiration


  The process where cells use oxygen to make ATP and produce carbon dioxide as a byproduct
• Inhalation

  1. Air passes through nasal cavity

  2. Air is warmed, humidified, and filtered

  3. Air passes through pharynx

  4. Air passes through larynx

  5. Air passes through trachea
• Trachea


  • Cylinder tube with rings of cartilage to support and keep it open
• Airflow through lungs

  1. Primary bronchi

  2. Secondary bronchi

  3. Tertiary bronchi

  4. Bronchioles
• Lungs

  • Two lungs, right lung has 3 lobes, left lung has 2 lobes, left lung is smaller
• Airflow through alveoli


  1. Terminal bronchioles

  2. Respiratory bronchioles

  3. Alveolar ducts

  4. Alveolar sacs containing alveoli
• Alveoli


  • Thin-walled cells with large surface area, in direct contact with capillaries
• Respiratory system


  Works closely with circulatory system to deliver oxygen and remove carbon dioxide
• Skeletal system


  • Ribs protect the lungs
• Muscular system


  • Intercostal muscles, diaphragm, abdominal wall muscles involved in respiration
• Involuntary breathing


  Controlled by the nervous system, which uses pH to regulate breathing rate and depth
• Respiratory system is not unique to humans, other organisms like earthworms, fish, and insects have different gas exchange systems
• Understanding the respiratory system helps treat respiratory illnesses and conditions
• Surfactant

  Substance made by type 2 alveolar cells that lowers surface tension in alveoli, preventing collapse
• Premature infants may lack sufficient surfactant, leading to respiratory distress syndrome, which can be treated with artificial surfactant
• Human blood is red and always red although the shade of red can vary based on how much oxygen is in the blood
• Veins and arteries are often drawn in diagrams as blue or red to show whether they have lower or higher concentrations of oxygen, but that's just how it is used in most diagrams. It doesn't mean the blood, or the veins, or arteries are actually that color
• Human blood


  • Maintains a certain pH, temperature, osmotic pressure
  • Transports hormones, nutrients, gases
• Components of human blood

  • Plasma (liquid portion)
  • Red blood cells
  • White blood cells
  • Platelets
• Hemoglobin


  Iron-containing protein in red blood cells that gives blood its red coloring
• Heart anatomy


  • Divided into deoxygenated and oxygenated partitions
  • Congenital heart conditions can result in oxygenated and deoxygenated blood mixing
• Arteries


  Generally carry blood "away" from the heart
• Veins


  Generally carry blood "to" the heart
• Capillaries


  Small blood vessels where oxygen is delivered to organs and tissues and carbon dioxide is picked up
• Blood flow through the heart

  1. Deoxygenated blood enters right atrium

  2. Flows through tricuspid valve to right ventricle

  3. Pumped through pulmonary valve to pulmonary artery

  4. Oxygenated blood returns through pulmonary vein to left atrium

  5. Flows through mitral valve to left ventricle

  6. Pumped through aortic valve to aorta
• Heart needs its own blood supply through coronary arteries to deliver oxygen and glucose
• Atrial septal defect


  Oxygen-rich blood could mix with oxygen-poor blood, causing problems like abnormal heartbeat, stroke, or heart failure
• There continue to be more advancements for treating cardiovascular conditions
• Digestion in mammals is more than just the stomach
• Ingestion


  Taking in of food, eating
• Digestion

  Biomolecule polymers are broken down physically or chemically into their building blocks
• Absorption


  Nutrients are absorbed and delivered to cells
• Elimination


  Waste is removed
• Mechanical digestion


  Physical breaking down of food, e.g. by teeth
• Chemical digestion


  Enzymatic breakdown of biomolecules, e.g. salivary amylase breaking down carbohydrates
• Saliva contains enzymes and buffers to counteract acidity and prevent tooth decay
• The epiglottis blocks the trachea when swallowing food to prevent it from going down the wrong pipe
• Peristalsis in the esophagus helps move food down to the stomach