BIOL 3070 Lecture Notes - Lecture 11: Partial Pressure, Viscosity, Trachea
Document Summary
Water is denser (1000x) and higher viscosity (50x) than air. More difficult for the animals living in air to move this water through the resp. organs. O2 in fresh water and sea, the o2 in fresh water has a higher concentration. Aquatic animals require a higher ventilation rate. Limited: the skin is not optimal for gas exchange. Slide 4: 1): gill arches: most fish have 4 gill arches covered with bony structures known as operculum. They are vascularized and they are the main attachments for the gill filaments. Slide 5: 2) gill filaments: extension from the gill arch and main anchor point for the lamellae, Slide 6: 3) lamellae (secondary filaments): extending on both sides of the gill filaments and responsible for gas exchange. Slide 7: blood flow within the lamellae is moving in the opposite direction of the water flow to make the exchange between the external medium and to make it more efficient (counter current)
