Fish Part B Flashcards
Advantages of a closed circulatory?
Rapid flow, direction blood, cells contained,
How does closed circulatory system work?
Pumped high pressure, back to heart vessels, blood doesn’t reach tissues, only exit walls
Vertebrae fish heart structure is?
Veins, sinus venous, atria, valves, ventricle, conus, aorta
Fish heart shape characteristics?
Single circulation, 2 chambered heart, 1 atrium, 1 ventricle
What is the sinus venosus?
Thin walls, reservoir, low pressure from veins,
What is passage of blood from heart?
Leaves ventral aorta
Characteristics of external gills?
Highly branched, LSA, thin membranes, easily damaged,
Characteristics of internal gills?
Opercular (ventilate gills), gill arches, filaments, lamellae
What is countercurrent flow?
Blood countercurrents water,
Steps of excretion?
Removal of waste, ammonia,
What are the waste products?
Ammonia (freshwater fish), Urea (less toxic marine fish), Uric acid (insoluble lizards, turtles)
Nephric tubule differences?
Corpuscle (Good size - high h20 output) Corpuscle (Small size - low water output) Corpuscle (Large size - reabsorbtion)
Freshwater fish consists?
Water more dilute than body fluids - moves in
Marine fish consists?
Water more concentrated than body fluids - moves out
What are the main fish glands?
Adrenal, Thyroid, Pancreatic islets, Corpuscles of Stannius, Ultimobranchial, Pineal, Pituitary, Urohypophysis
What does adrenal gland do?
aka Chromaffin cells, near haemopoetic kidney, 20% adrenaline, 80% cortisol,
What does thyroid gland do?
Close to gills, thyroxine, scale formation, osmoregulation
What are the pancreatic islets?
Within liver, pancreas
What do the coruscles of stannius do?
Within kidneys, hypocalcin calcium balance
What are the ultimobranchial glands?
Sacks between oesophagus, Calcitonin calcium levels
What does pineal gland do?
Upper caudal brain, melatonin for photosensory
What does pituitary gland do?
Ventral side, anterior, posterior
What is the urohypophysis?
Swelling in tail, urotensins for reactions
