Which of the following events does not occur during muscle contraction?
The distance between Z-lines increase
Starting with the arrival of an action potential at the nueromuscular junction put the events in order
AP travels down T tubeles, depolarization spreads through the t tubule,calcium released from sarcoplasmic reticulum and myosin binds
When animals die muscles stiffen in rigor mortis because
actin and myosin cannot separate without ATP
How does tropomyosin control muscle contraction
changes in position expose actin-myosin binding sites
Whether a muscle contraction is strong or weak depends on
number of motor nuerons and how fast they are firing
The legs of a cross country skier and long distance runners are more likely to have
more slow twitch fibers
Oxygen can be exchanged in air more easily than in water because
1)oxygen content in air is higher than water
2)oxygen diffuses more slowly in water than in air
3)more energy to move water than air
4)no need to maintain moisture of the respiratory surface with gas exchange
All of the Above
Which of the following statements about myoglobin is false
Myoglobin has lesser for O2 than hemoglobin does
The breathing is generated in the ____ and is influenced by the variation levels of ______ in the blood.
medulla ; CO2 and O2
Systole and Diastole describe the _____and ______, respectively, of the ________in mammals.
contraction; relaxation ; ventricles
A blood pressure represented as 140/100 means that
during ventricular contraction the pressure is at 140 and during ventricular relaxation the pressure is at 100
The timing of the spread of the action potential from atrium to ventricle is controlled by the
The hormone erythropoietin is released by the kidney to stimulate what
the production of red blood cells
When the whole blood is centrifuged it is separated into a liquid component called ______ and a bottom layer of _____
plasma ; cells
As blood enters the capillaries from the arterioles, blood pressure ______ & osmotic potential ______.
decreases ; increases
Organisms that derive both their energy and molecular nutrients from other organisms are called
In the small intestine, the blood and lymph vessels that carry away absorbed nutrients lie in which layer
The gut of a vertebrate is often described as an elongated tube consisting of four layers of different cell types. Which is the correct order of layers from innermost to outermost?
Mucosa, submucosa, circular muscle, longitudinal muscle
Which of the following statements about digestion in the small intestine is false?
Bile molecules have one end that is lipophobic and one end that is hydrophilic
If a person is unable to produce normal levels of cholecystokinin, which of the following will occur after a person eats a fatty meal?
2)stomach will secrete excess acids
3)acid chyme will not be nuetralized in the intestine
4)fat will be emulsified
All of the Above
Marine invertebrates in which the salinity of body fluids changes with the osmotic potential of their environments are known as
Terrestrial organisms must conserve water. The least amount of water is lost with the secretion of which nitrogenous waste product
Which of the following is the proper sequence of the passage of urine from the kidney
Renal pyramid, ureter, bladder, urethra
Valuable molecules like glucose, amino acids, and vitamins are reabsorbed into the blood at which location in the nephron
Proximal convoluted tubule