Exchange and transport in animals

• Larynx


  Voice box in the throat
• Epiglottis

  A fleshy structure at the back of your throat that stops food or drink from entering the trachea when you swallow
• Intercostal muscles

  Muscles between the ribs that move the ribcage upwards when we inhale
• Pleural fluid

  Fluid held between pleural membranes surrounding the lungs to prevent friction between the lungs and the ribs
• Trachea

  Windpipe, the main airway tube leading from the throat to the bronchi
• Alveoli

  Air sacs in the lungs where gas exchange occurs. Under the microscope, they appear like a bunch of grapes. One is called an alveolus
• Bronchi

  These tubes of the airway branch off the trachea. One goes to each lung
• Diaphragm

  Muscle that contracts at the base of the chest to allow inhalation
• Cartilage

  Provides support for the trachea and bronchi, keeping them open
• Horseshoe-shaped rings

  Flexible rings of cartilage that support the trachea
• Palate

  Separates the nasal cavity and the mouth so you can breathe through your nose even when you're eating
• Pharynx

  The back of the throat, where air and food pass through
• Aerobic respiration

  Respiration that uses oxygen to release energy from glucose.

  Word equation: Glucose + Oxygen → Carbon dioxide + Water + Energy (ATP)

  Symbol equation: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy
• Anaerobic respiration

  Respiration that does not use oxygen, used when oxygen is unavailable.

  Word equation: Glucose → Lactic acid. (in animals)

  Symbol equation: C₆H₁₂O₆ → 2C₃H₆O₃
• Inhalation

  Process of breathing in, an active process that uses energy as muscles contract.
• Exhalation

  Process of breathing out, a passive process as muscles relax
• Respirometer:

  Equipment that allows the rate of respiration to be determined in small organisms by measuring the volume of oxygen used
• Fick's Law

  Fick’s Law describes the factors affecting the rate of diffusion of gases. It states that the rate of diffusion is:

  • Directly proportional to the surface area of the membrane.
  • Directly proportional to the difference in concentration of the gas (the concentration gradient).
  • Inversely proportional to the thickness of the membrane (the distance the gas must travel).

  This can be summarized as:

  • Rate of diffusion ∝ (Surface area × Concentration difference) / Thickness of the membrane.
• Artery

  Blood vessel that transports oxygenated blood to the organs
• Arterial

  Blood vessel that branches off an artery
• Vein

  Blood vessel that carries deoxygenated blood back to the heart.
• Venule

  A very small vein collecting blood from the capillaries.
• Capillary

  Smallest blood vessel, allows exchange of gases and nutrients with body cells
• Aorta

  Biggest artery in the body, takes oxygenated blood from the left ventricle of the heart to the body.
• Vena Cava

  Largest vein that carries deoxygenated blood back to the heart.
• Pulmonary Artery

  Blood vessel that takes deoxygenated blood away from the right ventricle to the lungs.
• Pulmonary Vein

  Blood vessel that takes oxygenated blood from the lungs to the left atrium.
• Atrium

  Chambers of the heart that receive blood from the atria when they contract.
• Ventricle

  Blood passes into this chamber before being pumped out through the aorta.
• Semilunar Valve

  Valve that prevents backflow into ventricles from the aorta and pulmonary artery.
• Atrioventricular Valve

  Valves between the atrium and the ventricle that prevent backflow of blood into atria when they are closed.
• Septum

  Muscle that separates the left and right sides of the heart.
• Cardiac Output

  Volume of blood that leaves the heart per minute
• Stroke Volume

  Volume of blood leaving the left ventricle with each heart contraction.
• Heart Rate

  Number of times the heart contracts per minute (same as pulse).
• Lymphocyte

  Type of white blood cell that produces antibodies.
• Phagocyte

  Type of white blood cell that ingests pathogens.
• Platelet

  Cell fragment in the blood that causes blood to clot, preventing pathogen entry and blood loss.
• Erythrocyte

  Blood cell that transports oxygen, contains haemoglobin.