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Flashcards in Nervous Tissue Deck (53)
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1

The nervous system

A) works with the endocrine system to maintain homeostasis.
B) communicates with the body via action potentials.
C) is responsible for thoughts and behaviors.
D) initiates voluntary movements.
E) All of these are correct. 

2

Each of the following is part of the nervous system EXCEPT the: 

A) brain
B) spinal cord
C) vertebral column
D) neurons
E) neuroglia

3

Which of the following correctly describes a function of the nervous system? 

A) sensory: detect changes in the environment; relays information to the brain and spinal cord.
B) integrative: elicits an appropriate response such as muscle contraction or glandular secretion
C) motor: process and make decisions regarding sensory input; responsible for perception.
D) A and B are correct.
E) A, B and C are correct. 

4

The central nervous system

A) excludes the cranial and spinal nerves, ganglia and sensory receptors.
B) is the source of thoughts and emotions.
C) is the destination of action potentials from motor neurons.
D) A and B are correct.
E) A, B and C are correct. 

5

The peripheral nervous system

A) includes the brain and spinal cord.
B) may be divided into somatic, autonomic and enteric nervous systems.
C) is only involved with unconscious (involuntary) activities.
D) A and B are correct.
E) A, B and C are correct. 

6

The somatic nervous system

A) provides motor signals and conscious control to skeletal muscles.
B) includes sympathetic and parasympathetic divisions.
C) regulates the gastrointestinal tract.
D) is dependent on the autonomic system for control.
E) includes motor neurons to smooth muscles. 

7

Neurons

A) are electrically excitable cells.
B) vary greatly in size.
C) have a perikaryon enriched with the organelles for protein synthesis.
D) A and B are correct.
E) A, B and C are correct. 

8

Which of the following is NOT true? 

A) A dendrite is a nerve fiber that receives impulses from other neurons.
B) Most neurons have many axons and one dendrite.
C) An axon sends an impulse to another neuron or to an effector cell.
D) Slow axonal transport moves axoplasm in only one direction.
E) Fast axonal transport uses microtubules to move materials in two directions.

9

Which of the following is true of a synapse? 

A) The presynaptic neuron carries a nerve impulse away from a synapse.
B) The postsynaptic neuron carries a nerve impulse toward a synapse.
C) A synapse is the site of where two neurons or a neuron and an effector meet.
D) The presynaptic neuron releases chemical messengers called hormones.
E) The synapse of a neuron and a gland is called a neuromuscular junction. 

10

Most of the neurons in the brain and spinal cord are ___ neurons. 

A) anaxonic
B) bipolar
C) Purkinje cells
D) multipolar
E) univocal

11

Neuroglia

A) comprise about one-half of the tissue in the CNS.
B) retain mitotic potential but do not conduct nerve impulses.
C) support and protect neurons.
D) A and B are correct.
E) A, B and C are correct. 

12

Astrocytes:

A) support neurons in the peripheral nervous system.
B) form the blood-brain barrier.
C) regulate growth, migration and interconnection of neurons in the adult brain.
D) form myelin on central nervous system neurons.
E) maintain the blood-cerebrospinal fluid barrier.

13

Which neuroglia cells produce myelin?

A) oligodendrocytes
B) Schwann cells
C) satellite cells
D) A and B are correct.
E) A, B and C are correct. 

14

Gray matter

A) consists of neuron cell bodies, neuroglia and unmyelinated nerve fibers.
B)  is found at the periphery of the spinal cord.
C) may be found in clusters called ganglia in the central nervous system.
D) may be found in clusters called nuclei in the peripheral nervous system.
E) All of the above are correct. 

15

Which of the following statements is correct? 

A) Ion channels in neuron plasma membranes block electron flow across those membranes.
B) Action potentials allow cells to communicate over short distances only.
C) Graded potentials allow cells to communicate over either long or short distances.
D) The electrical current in living cells is the flow of electrons across a plasma membrane.
E) Neurons exhibit differences in electrical voltage across their plasma membranes.

16

When ions move across the plasma membrane,

A) they pass though specific phospholipids that serve as ion channels.
B) they flow up their concentration gradient toward an area of the same charge. 
C) they create a flow of electrical current that can disturb the resting membrane potential.
D) A and B are correct.
E) A, B and C are correct. 

17

Which of the following is NOT true of ion channels?

A) Leakage channels randomly open and close.
B) Leakage channels make the plasma membrane more permeable to Na+ than to K+.
C) There are more K+ leakage channels than Na+ leakage channels.
D) Voltage-gated channels are involved in the generation and conduction of action potentials.
E) Ligand-gated channels are controlled by neurotransmitters, hormones, or specific ions.

18

Which of the following contributes to the maintenance of a resting membrane potential? 

A) equal distribution of ions across the plasma membrane
B) ATPase movement of 2 Na+ into the cell for 3 K+ pushed out of the cell
C) presence of negatively charged proteins and phosphates just outside the plasma membrane
D) lower plasma membrane permeability to Na+ than K+
E) All of the above are correct. 

19

Graded potentials 

A) arise when ion movement causes a minor change in the resting membrane potential.
B) usually propagate down the length of an axon.
C) occur when voltage-gated channels open.
D) are most often observed in axons.
E) are usually associated with ion movement through leakage channels.

 

20

Action potentials

A) arise slowly and are observed primarily in dendrites and cell bodies.
B) arise when a stimulus is strong enough to open mechanically-gated ion channels.
C) occur in three phases: latent, graded and polarizing.
D) vary in size depending on the strength of the initial stimulus.
E) allow an impulse to travel over long or short distances. 

21

Place the events involved in generating an action potential in the order in which they occur”

1. K+ moves out of the cell.
2. Na+ activation gates open.
3. Excess K+ leaves cell causing hyperpolarization.
4. Na+ enters cell and voltage becomes less negative.
5. K+ channels close.
6. threshold stimulus arrives.
7. Leakage channels restore resting membrane potential.
8. Na+ inactivation gates close and K+ open.

A) 6, 4, 2, 8, 1, 3, 5, 7
B) 6, 4, 8, 2, 1, 3, 5, 7
C) 6, 2, 4, 8, 1, 3, 5, 7
D) 6, 2, 4, 8, 3, 1, 5, 7
E) 6, 2, 4, 3, 8, 1, 5, 7 

22

Some governments execute convicts using lethal injections that contain high concentrations of  KCl.  At the cellular level, how does the high concentration of KCl kill the convict?

A) The excess K+ disrupts the electrochemical gradient, preventing neurons from depolarizing.
B) The excess K+ disrupts the electrochemical gradient, preventing neurons from repolarizing.
C) The excess K+ enhances generation of action potentials, causing cells to run out of energy.
D) A and B are correct.
E) B and C are correct. 

23

Which of the following is true of nerve impulse conduction? 

A) Saltatory conduction occurs on unmyelinated axons.
B) Continuous conduction occurs on myelinated axons.
C) Saltatory conduction requires more ATP than continuous conduction.
D) Continuous conduction is slower than salutatory conduction.
E) All of these are correct. 

24

Axons classified as A fibers 

A) are myelinated.
B) have large diameters.
C) conduct impulses more rapidly than B or C fibers.
D) A and B are correct.
E) A, B and C are correct. 

25

An instructor helps a student clean up the pieces of a broken beaker. As they search for glass fragments under the lab bench, the instructor inhales sharply and says, “I just found a piece of glass with my knee.”  How could the instructor determine that her knee was in contact with broken glass rather than with the floor?

A) The broken glass generated more frequent action potentials than the pressure of the floor.
B) More action potentials in more neurons were activated by the pressure of the glass.
C) The axons stimulated by the broken glass sent larger action potentials than the other axons.
D) A and B are correct.
E) A, B and C are correct. 

26

Which of the following is NOT true? 

A) No refractory period is associated with graded potentials.
B) Muscle fiber resting membrane potentials are more negative than those of neurons.
C) Neuron action potentials last longer than muscle fiber action potentials.
D) Conduction of action potentials in A fibers is much quicker than that in muscle fibers.
E) Neither B nor C is true. 

27

Electrical synapses 

A) occur when there is direct contact between electrically excitable cells.
B) allow rapid communication between cells.
C) allow synchronization of cellular activities.
D) A and B are correct.
E) A, B and C are correct. 

28

At a chemical synapse, 

A) two cells communicate directly via connexons at gap junctions.
B) action potentials are propagated more quickly than at an electrical synapse.
C) the presynaptic neuron converts an electrical signal into a chemical signal.
D) the postsynaptic neuron converts an electrical signal into a chemical signal.
E) there is a synaptic delay of about 3 seconds as the neurotransmitter crosses the synaptic cleft.

29

Place the events at a chemical synapse in the order in which they occur:

1. action potential arrives at pre-synaptic neuron’s end bulbs; Ca2+ channels to open
2. Ca2+ binds to synaptic vesicles; vesicles fuse with presynaptic neuron’s membrane
3. postsynaptic potential develops
4. neurotransmitter binds to receptors (ligand-gated channels) on postsynaptic membrane
5. neurotransmitter exocytosed; diffuses across synaptic cleft

A) 1, 2, 4, 5, 3
B) 1, 4, 2, 5, 3
C) 1, 2, 5, 4, 3
D) 1, 2, 4, 3, 5
E) 1, 3, 2, 4, 5

30

Which of the following is NOT true? 

A) If a neurotransmitter causes depolarization of the postsynaptic neuron, it is excitatory.
B) If a neurotransmitter causes hyperpolarization of the postsynaptic neuron, it is inhibitory.
C) EPSPs often result from opening cation channels.
D) Information transfer at a chemical synapse is bi-directional.
E) IPSP often result from opening K+ or Cl- channels