TAMS, Dr. Jag, Biology, Ch. 49
Terms
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- What is homeostasis?
- The dynamic constancy of internal environment.
- Describe a negative feedback loop.
- Sensors measure a condition and relay the information to an integrating center which sends a message to effectors once the condition deviates from a set point. Effectors tend to correct the deviation.
- What monitors glucose levels in the blood? How do they respond to an increase?
- The islets of Langerhan? They secrete insulin.
- What are antagonistic effectors? What are positive feedback loops?
- Effectors where one and only one is active at all times. Loops that cause even further deviation from the set point. Very unstable.
- What is osmolality? What is osmotic pressure? What are osmoconformers? Osmoregulators?
- Moles of solute per kg of water. The tendency of a solution to take in water by osmosis. Animals that have similar molality to the environment. Animals that maintain a different molality than what their environment is.
- What are the osmoregulatory/excretory cells in flatworms? in insects? in vertebrates?
- Flame cells. Malpighian tubules. Kidneys.
- What are two osmotic problems for freshwater fish? How are these problems solved?
- Water tends to enter the body and solutes tend to leave. Fresh water fish don't drink water, reabsorb nutrients from nephrons, and actively transport ions.
- What problem existed for marine fish? How was it solved by bony fish? Cartilaginous fish?
- Water tended to leave the body. Bony marine fish drink sea water. Cartilaginous fish maintain high blood urea concentration.
- What are the different forms of nitrogenous wastes?
- Ammonia, which can be converted into urea (mammals...)or uric acid (reptiles, birds...) which is converted by most mammals into allantoin.
- What are the repeating units of kidneys?
- Nephrons.
- What is the structure of nephrons?
- They have an afferent arteriole that leads to a glomerulus. The Bowman's capsule envelopes the glomerlus and descends into the prosimal convoluted tubule. It goes through the loop of Henle into a distal convoluted tubule that leads to a collecting duct. Peritubulur capillaries around the tubules reabsorb necessary nutrients.
- Describe the human kidney.
- The kidney is divided into a renal cortex and renal medulla. A renal pelvis collects urine into the ureter which leaves each kidney to a urinary bladder.
- How is reabsorption take place in the proximal convoluted tubules?
- It carries out active transport and secondary active transport.
- Who are you going to vote for MHA president?
- Robert Fromm.