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BIOS 3500- Human Physiology
Exam #3--Dr. Linn
50
Physiology
Undergraduate 4
12/09/2011

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Term

T/F

Thin and thick filaments can overlap in the A band

Definition
True
Term

T/F

Oxidative phosphorylation occurs whithin the mitochondria of muscle cells

Definition
True
Term

T/F

The lever system at the elbow joint provides a mechanical advantage meaning that when the biceps muscle contracts to lift an object in the hand, the force needed to develop in the biceps can be considerably less than the actual load that is moved

Definition
False
Term

T/F

The larger a motor unit is in a muscle, the more precisely controlled the gradation of muscle contraction will be

Definition
Fasle
Term

T/F

Ligaments attach muscles to bones

Definition
False
Term

T/F

The parasympathetic nervous system is always inhibitory to the organs it innervates

Definition
False
Term

T/F

Sympathetic innervation to the salivary glands stimulates salivation while parasympathetic innervation to the same glands inhibits saliva release

Definition
False
Term
Actin
Definition
is spherical
Term
Which of the following statements concerning the length-tension relationship of skeletal muscle is incorrect?
Definition
maximum tension can be developed if a resting muscle has been stretched by more than 30% before stimulation
Term
Myosin
Definition
is found in the A band
Term
Which organ is not innervated by the parasympathetic division?
Definition
the majority of blood vessels
Term
Which of the following is not a method of gradation in skeletal muscle contraction?
Definition
stimulating variable portions of each motor unit
Term
A neuromodulator implicated as a neural sleep factor is 
Definition
adenosine
Term
Calcium turns on cross bridges by physically repositioning the troponin-tropomyosin complex to uncover the actin cross-bridge binding sites in 
Definition
Both skeletal and cardiac muscle
Term
Norepinephrine
Definition
binds to adrenergic receptors
Term
The peripheral nervous system
Definition
Both (a) and (b) above
Term
Which is not a normal age related change that occurs in muscles of older individuals?
Definition
a reduction in the blood supply
Term
What would occur if ACh was not removed from the nicotinic receptors on skeletal muscle cells?
Definition
sodium would continue to move into the cell causing excitation
Term
In a muscle fiber undergoing maximal tetanic stimulation, the velocity of shortening _____as the load _________
Definition
decreases, increases
Term
During an isotonic contraction of a muscle in the arm
Definition
the tension in the muscle remains constant
Term
Conscious initiation of muscle contraction is controlled by 
Definition
the cerebral cortex
Term
The smallest unit of contraction within a skeletal muscle is a:
Definition
sarcomere
Term
The origin of a muscle is its
Definition
stationary end of attachment
Term
Which statement is characteristic of sympathetic activity
Definition
the pupils of the eye dilate
Term
Nicotinic receptors
Definition
bind to acetylcholine released from both sympathetic and parasympathetic preganglionic fibers
Term
Cross bridges
Definition
Two of these answers
Term

Indicate which is the proper sequence of events in skeletal muscle contraction:

  1. myosin binds to actin
  2. action potentials is propogated down T-tubule
  3. thin filaments are pulled in toward center of A band
  4. tropomyosin moves to uncover binding site on actin
  5. calcium is released from sarcoplasmic reticulum
  6. calcium binds to troponin
Definition
2,5,6,4,1,3
Term
Fatigue is the failure of a muscle fiber to maintain_____as a result of previous contractile activity
Definition
tension
Term
According to the sliding-filament mechanism of muscle contraction, the
Definition
thin filaments slide inward toward the center of the A band
Term
Intrafusal muscle fibers
Definition
both (b) and (c) above
Term
Which of the following is not a determination of whole muscle tension?
Definition
the proportion of each motor unit that is contracting at any given time
Term
The striated appearance of skeletal muscle is due to the
Definition
regular orderly arrangement of the thick and thin filaments into A and I bands
Term
Which of the following is not a characteristic of skeletal muscle?
Definition
is innervated by afferents from the central nervous system
Term
The first source of ATP used by skeletal muscles comes from:
Definition
creatine phosphate
Term
Slow-wave sleep
Definition
all of these answers
Term
Atropine_____the effect of acetylcholine at _____receptors and ______ _______ receptors
Definition
blocks, muscarinic, does not affect, nicotinic
Term
The T tubules in skeletal muscle
Definition
provide a means of rapidly transmitting the action potential from the surface into the central portions of the muscle fiber
Term
Most readily fatigues
Definition
fast-glycolytic fiber
Term
Is the most powerful fiber
Definition
Fast-glycolytic fibers
Term
Is found predominantly in muscles adapted for low-intensity and long-duration activities
Definition
slow-oxidative fiber
Term
Is found predominantly in muscles designed for endurance
Definition
slow-oxidative fibers
Term
Is found predominantly in muscles designed for sprinting
Definition
fast-oxidative fibers
Term
Can not be transformed into another fiber type by specific training
Definition
slow-oxidative fiber
Term
Produces the most lactic acid
Definition
fast-glycolytic fiber
Term
Causes vasoconstriction in the majority of arterioles throughout the body
Definition
alpha1
Term
Is found in cholinergic neurons
Definition
nicotinic
Term
Causes dilation of bronchioles during sympathetic activity
Definition
beta2
Term
Is found on the dendrites of all postganglionic fibers in the autonomic nervous system
Definition
nicotinic
Term
Causes vasodilation of arterioles in skeletal muscle
Definition
beta2
Term
Is the receptor found in heart muscle
Definition
beta1
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