Download Unit 3 Notes – Part 1

Unit 3 Notes – Part 1
Homeostasis
•
Maintaining a ________________________________________
Thermoregulation
• ____________________________________________________________________.
• Negative feedback loop – _______________________________________________ and responding to
internal conditions.
• Ex. Room temperature, air conditioning turns on if it gets too hot, furnace turns on if it
gets too cold.
Body Temp
• Normal human body temperature is 37 C ___________________
• When the temperature changes the ____________________________________________________________
of the blood passing through it.
• If temperature is too high or low, the __________________________________________________________
____________________________________________________________________________________________________.
• Ex. Shivering, perspiration, dilation or constriction of blood vessels.
Homeostatic Mechanism
• System(s) in body that _________________________________________________________________.
Question (circle the correct answer)
The human body maintains a constant internal temperature of 98.6 F. Which changes occur
when the hypothalamus detects a temperature of 100.1 F?
a. Muscle tissue shivers and skin capillaries dilate
b. Perspiration increases and skin capillaries dilate
c. Muscle tissue shivers and skin capillaries constrict
d. Perspiration increases and skin capillaries constrict.
Osmoregulation
• ____________________________________________________________________________.
• Organisms that live in _________________________ environments are always in a state of
___________________________.
(solution has less solutes dissolved in then in the cell)
• Ex. Freshwater fish ______________________________________________ to eliminate excess water.
Osmoregulation
• Organisms in saltwater are _____________________ to their environment.
• They must find ways to retain the solutes they need and eliminate the excess sodium
and chloride ions in seawater.
• Marine fish have ____________________________________________________________________________.
Osmoregulation
• Land animals – __________________________________________.
• Their urine is much ___________________________________________ than their blood, containing a
high ratio of solutes to water. Ex. NaCl in blood is 5:1
•
Allows them to ___________________________________________ while conserving water.
Kidneys
• The kidneys ______________________________________________________________________________.
• The kidneys control how concentrated urine is.
• The ______________________________________________________________ that produce a feeling of
dryness. –thirst
• Blood vessels of the ____________________________________________________________________ in the
body.
• ______________________________________________________________________.
Water loss
• Land animals lose water through ________________________, _________________________, and
__________________________.
Paramecium
• Single-cell protist (eukaryote)
• Has a ________________________________ that pumps water out of the cell.
• What kind of environment do parameciums have?____________________________
Gas Exchange
• The levels of dissolved _________________________________________________________________________
to allow respiration to take place.
• Ex. Fish perform gas exchange through gills
Water _________________________________________ in the gills, which contain a ___________________________
___________________ and a lower concentration of oxygen than the surrounding water.
The differences causes carbon dioxide to move into the water and oxygen to move into the
bloodstream, through passive transport. (______________________)
Gas Exchange
• In mammals occurs in _______________________________________.
• Capillaries – tiny blood vessels, surround each of the microscopic air sacs in the lungs
called alveoli.
• Blood flowing to the alveoli contains _____________________________________________________.
• So carbon dioxide crosses through blood cell membrane into the air in the lungs.
• _______________________________________________________________________________________________.
Regulation of Blood Glucose
• Glucose – is the macromolecule, __________________.
• Monomer – _____________________________
• Human body requires a blood
Glucose level of around 90 mg/100mL.
If it falls too low or rises too high, homeostatic mechanisms bring it back into range.
• The ________________________________________________________________________________.
• When glucose is too high the pancreas releases the hormone insulin.
• _________________ causes the cells of the muscles, liver, and other tissues to allow more
glucose to cross the plasma membrane
Blood Sugar Levels
• The ______________________________________________________________________________.
• Glycogen is how animals store carbohydrates.
• When blood glucose is low, the ________________________ another hormone, ________________.
• Glucagon causes the liver to break down stored glycogen and release the glucose into
the bloodstream.
Question
After skipping a meal and exercising, a body’s blood glucose falls to 85 mg/100mL. What
changes will occur in the body?