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65 terms

Biology Test 2

Which muscle type has gap junctions?
Which muscle type is spindle shaped?
Which of the following events does not occur during muscle contraction?
The distance between Z-lines increase
An individual sarcomere consists of
overlapping actin and myosin
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
Aerobic excercise such as jogging increases
all of the above
bone tissues consist of __cells in a matrix___
osteocytes; collagen and calcium phosphate
Haversian systems consist of
cylindrical tubules that surround a canal of blood vessels
Myofibrils are organized into
Gas exchange in animals always involves
diffusion of internal body fluids and the outside medium
Stages of muiscle contraction in correct order
Breathing also eliminates ______, one of the waste products of the cell metabolism
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
Aquatic animals that lack an internal system for transporting O2
all of the above
The rate of mammals is maximized by
the enormous surface area for gas exchange
Which of the following structures is the site of gas exchange in the lungs
During inhalation what happens to the diaphragm
moves down
Each molecule of hemoglobin carries how many molecules of oxygen
In acidic tissues hemoglobin releases____it does in less acidic environment
more O2 than
Which of the following statements about myoglobin is false
Myoglobin has lesser for O2 than hemoglobin does
Carbonic anhydrase is an enzyme in red blood cells that catalyzes a reaction between CO2 and
Most of the Co2 in blood in transported as ____ and is located mainly in the ______
HCO3 ; plasma
The breathing is generated in the ____ and is influenced by the variation levels of ______ in the blood.
medulla ; CO2 and O2
The blood vessels with the greatest total cross-sectional area are the
In an open circulatory system
there is no distinction between blood and tissue fluid
In the human heart blood is pumped from the left ventricle into the
systematic circuit
In humans which empties into the right atrium
Inferior and Superior vena cava
Which vessels transports oxygenated blood from the lung into the heart
Pulmonary vein
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 specific location of the heart pacemaker is the
sinoatrial node
The timing of the spread of the action potential from atrium to ventricle is controlled by the
atrioventricular node
The most abundant cells in the blood are
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
The function of leukocytes is to
destroy foreign cells or to produce antibodies
A platelet is activated to initiate clotting
when collagen fibers are encountered
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 sweetness that you taste if you keep chewing a piece of bread is due to the enzyme
Pepsinogen is converted into pepsin by
low pH
Which of the following represents the correct direction of formation of the heartbeat
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 structure is not encountered by a food bolus as it is being swallowed?
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
A lipase is an enzyme that breaks down
fat molecules
The major function of the large intestine or colon is
to reabsorb water
If a person is unable to produce normal levels of cholecystokinin, which of the following will occur after a person eats a fatty meal?
1)motility decreased
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
Insulin is released by the pancreas when blood
glucose rises
The effect of antidiuretic hormone is to
increase urine concentration
Marine invertebrates in which the salinity of body fluids changes with the osmotic potential of their environments are known as
Which of the following is not a factor in the movement of water into tissues
Active transport
Which of the following molecules is toxic to cells
Terrestrial organisms must conserve water. The least amount of water is lost with the secretion of which nitrogenous waste product
Uric Acid
The functional unit of the kidney is the
During filtration which of the follwing enters Bowmans capsule from the bloodstream
Plasma proteins
Which structure is found in the inner medulla of the kidney
Loop of Henle
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
Which of the following is a protective mechanism which helps prevent digestion of stomach lining
mucus secretion