5 - RESPIRATORY SYSTEM

• What are gills in animals?

  Outfoldings of the body for gas exchange
• What is the function of parapodia in marine worms?

  They function as gills for gas exchange
• Which aquatic animals use gills for respiration?

  Fish, crayfish, and sea stars
• How does ventilation occur in aquatic animals?

  By moving water over their gills
• What is the countercurrent exchange system in fish gills?

  Blood flows opposite to water for diffusion
• Why is blood always less saturated with O2 than water in fish gills?

  It maximizes diffusion of oxygen into blood
• What is the structure and function of fish gills?

  • Gills consist of:
  • Gill arches
  • Gill filaments
  • Lamellae
  • Function:
  • Gas exchange through countercurrent exchange
• What is the role of the operculum in fish?

  It covers and protects the gills
• What is the primary function of the mammalian respiratory system?

  To facilitate gas exchange
• What is the pathway of air inhaled through the mammalian respiratory system?

  Nostrils → pharynx → larynx → trachea → bronchi → bronchioles → alveoli
• How do exhaled air and vocal cords relate?

  Exhaled air passes over vocal cords to create sounds
• What surrounds alveoli for gas exchange?

  Capillaries wrap around alveoli
• How do amphibians ventilate their lungs?

  By positive pressure breathing
• How do mammals ventilate their lungs?

  By negative pressure breathing
• What is tidal volume in respiration?

  Volume of air inhaled with each breath
• What happens during inhalation in mammals?

  Diaphragm contracts, increasing lung volume
• What happens during exhalation in mammals?

  Diaphragm relaxes, decreasing lung volume
• What regulates the rate and depth of breathing in humans?

  The medulla oblongata and pons
• How does the medulla oblongata respond to CO2 levels?

  It adjusts breathing rate and depth
• What role do sensors in the aorta and carotid arteries play?

  They monitor O2 and CO2 concentrations
• What adaptations help organisms with gas exchange?

  • Respiratory pigments bind and transport gases
  • Blood transports large quantities of O2 and CO2
  • Diffusion gradients favor gas exchange in tissues
• What happens to O2 and CO2 in the alveoli?

  O2 diffuses into blood, CO2 into air
• What are respiratory pigments?

  Proteins that transport oxygen in blood
• What is hemocyanin and where is it found?

  Oxygen-binding component in arthropods
• What is hemoglobin's role in oxygen transport?

  It carries four molecules of O2 per molecule
• What is the Bohr shift in hemoglobin function?

  Lower pH decreases hemoglobin's O2 affinity
• What are the methods of carbon dioxide transport in blood?

  • Dissolved in plasma
  • Bound to hemoglobin
  • As bicarbonate ions (HCO3–)
• How do migratory and diving mammals adapt for oxygen consumption?

  They have adaptations for extraordinary feats
• What is the extreme O2 consumption of the pronghorn related to?

  Its ability to run at high speed
• How do Weddell seals store oxygen?

  In muscles using myoglobin proteins
• What is the process of gas exchange in the lungs and body tissues?

  • Inhaled air enters alveoli
  • O2 diffuses into blood
  • CO2 diffuses from blood to alveoli
  • In tissues, O2 diffuses into interstitial fluids
  • CO2 diffuses from tissues into blood
• What is the role of alveolar epithelial cells?

  They facilitate gas exchange in lungs
• What is the function of pulmonary veins?

  To carry oxygen-rich blood from lungs
• What is the function of pulmonary arteries?

  To carry oxygen-poor blood to lungs
• What is the role of systemic arteries?

  To carry oxygen-rich blood to body tissues
• What is the role of systemic veins?

  To carry oxygen-poor blood back to heart
• What is the function of systemic capillaries?

  To facilitate gas exchange in body tissues