BIO 123 Exam 2 Quizzes

A student noticed that every time he smelled a certain perfume in the hallway, it reminded him of his mother. This is due largely to the activity of the limbic system.

True

Following running for a long distance, the muscle soreness that occurs the next day is due to chemicals released to repair damaged muscles.

True

Motor neurons of the peripheral nervous system transmit impulses away from the central nervous system.

True

Muscle contraction accounts for over 75% of the heat generated by the body.

True

Muscle soreness several days after exercise is an indication that some sarcomeres were permanently damaged.

True

Muscles produce and resist movement.

True

Reestablishment of the resting potential in a neuron following an action potential requires the activity of the sodium-potassium pump.

True

Slow-twitch fibers contain many mitochondria and are well supplied with blood vessels, and can make ATP as they need it.

True

The absolute refractory period characteristic of neurons is important in ensuring that action potentials travel in only one direction.

True

The somatic division of the peripheral nervous system (PNS) controls skeletal muscles.

True

Axons branch into axon terminals, which have ________ located at the terminal ends.

bulbs

A myogram is a recording of

the activity of muscle cells.

Saltatory conduction is

the process of conduction leaping along myelinated neurons.

Which sequence lists the structures from largest, most inclusive, to smallest?

muscle-fascicle-muscle fiber-myofibril-thick filament

Fast-twitch fibers contain large amounts of myoglobin and predominate in "red" muscle.

False

Muscles constitute 60-70% of our body mass.

False

Neurotransmitters always cause depolarization of the postsynaptic membrane.

False

The "all-or-none principle" states that in a given muscle, all of the cells are contracting simultaneously or none of them is contracting.

False

The functional barrier between blood and the brain is cerebrospinal fluid.

False

The heads of myosin molecules contact the actin filaments when a muscle is relaxed .

False

The repolarization phase of an action potential is dependent on the sodium-potassium pump.

False

The two major subdivisions of the nervous system are the central nervous system and the limbic nervous system.

False

Unlike skeletal muscle, cardiac and smooth muscle do not respond at all to the nervous system, but contract on their own. Differences in the rate of contraction of smooth and cardiac muscle are due to the action of pacemakers in cardiac muscles.

False

The primary energy source used by muscle cells to generate ATP is

Glucose

During a marathon, runners use up ATP and glucose early in the race. Which energy source is generally used next for producing more ATP?

Glycogen

Electrical impulses are transmitted between components of the central nervous system via which one of the following?

Interneurons

Which one of the following activities would fast-twitch fibers be most useful for?

Lifting Weights

Which component of the nervous system is divided into the somatic and autonomic divisions?

Motor

During which one of the following phases of an action potential do the sodium channels close and potassium channels open, releasing potassium from the neuron?

Repolarization

A neuron at rest has a charge difference across its cell membrane, with the interior of the cell negative relative to the exterior. This difference in charge across the plasma membrane is referred to as ________ potential.

Resting

Which one of the following provides the central nervous system with information about the outside environment?

Sensory Division

Which one of the following establishes and maintains the resting potential?

Sodium-potassium Pump

Amyotrophic lateral sclerosis (ALS) is a demyelinating disease that results from nerve damage beginning in the

Spinal Cord

Which one of the following processes is depicted in the figure above?

Synaptic Transmission

Skeletal muscle groups that work together to create the same movement are referred to as

Synergistic

Which one of the following is found within a sarcomere?

The actin and myiosin fibers

Which one of the following statements correctly describes the origin and insertion of a muscle?

The insertion is pulled toward the origin during contraction.

Which one of the following occurs with each cycle of the sodium-potassium pump?

The net effect is removal of one osmotic particle and one positive charge from inside the cell.

Oligodendrocytes are similar to Schwann cells in that they

are a type of neuroglial cell.

Cells that provide direct protection and physical support to neurons are

neuroglial cells.

T, or transverse, tubes in skeletal muscle function to

promote the rapid penetration of the electrical impulse deep into the cell.

The following events are associated with muscle contraction. Which one of the following best describes the order in which these events occur, following the initiation of a contraction by a nerve impulse? 1. T tubules transmit electrical impulses throughout the muscle cell. 2. Myosin contacts actin and pulls it toward the center of the sarcomere. 3. Acetylcholine binds to receptors on the muscle. 4. Troponin-tropomyosin complex shifts to expose myosin binding sites. 5. Calcium is released from the sarcoplasmic reticulum.

3,1,5,4,2

By which one of the following methods is a stronger stimulus coded by neurons differently from a weaker stimulus?

A stronger stimulus results in more action potentials/unit time.

Control of smooth muscle and internal organs is the role of the ________ division of the nervous system.

Autonomic

In order for a muscle contraction to occur, cross-bridges must form between which one of the following structures within a muscle cell?

Actin and Myosin

Which one of the following statements correctly describes activities of muscles?

All muscles shorten when they contract

In the lower leg, the gastrocnemius muscle bends the foot away from the knee, as in pointing one's toes. The tibialis anterior muscle flexes the foot toward the knee. These two muscles are

Antagonistic

Muscle cells produce lactic acid when they have an inadequate supply of

O2

Which one of the following is NOT directly involved in the production of a typical spinal reflex?

Brain

The central nervous system is composed of which of the following?

Brain and Spinal Cord

During synaptic transmission, the influx of ________ causes vesicles in the axon bulb to fuse with the cell membrane, releasing ________.

Ca2+; neurotransmitter

In comparing smooth and cardiac muscle, which one of the following best describes the differences between the two muscle types?

Cardiac muscle requires periods of relaxation, whereas smooth muscle is always in a state of partial contraction.

The region of brain that coordinates antagonistic muscle movements is the

Cerebellum

Once a muscle cell has depleted its small supply of ready-made ATP, what will it use next for energy?

Creatine Phosphate

During periods of stress or increased activity, the parasympathetic division of the autonomic nervous system predominates; during periods of rest, the sympathetic division of the autonomic nervous system predominates.

False

Which one of the following types of neurotransmitter functions as an inhibitory agent, typically suppressing the sensation of pain?

Endorphins

In which one of the following would one expect to find motor units made up of only a few muscle cells?

Eye Muscles

Which one of the following is characteristic of an isotonic muscle contraction but not an isometric muscle contraction?

moves an object or part of the skeleton

When an electrical impulse traveling along a motor neuron arrives at a neuromuscular junction

there is an increase in the secretion of acetylcholine at the neuromuscular junction.

At the end of the contractile period, energy from the breakdown of ATP is used to

transport calcium back into the sarcoplasmic reticulum.