Nervous Tissue, Spinal Cord, Brain

The ________ division of the peripheral nervous system brings sensory information to the central nervous system.

• afferent

• peripheral

• somatic

• autonomic

  The site of intercellular communication between a neuron and another cell is the

• telodendria.

• synapse.

• collateral.

• hillock.

________ monitor the digestive, respiratory, cardiovascular, urinary, and reproductive systems

• Unipolar neurons

• Internoceptors

• Exteroceptors

• Spinal nerves

The myelin sheath that covers many CNS axons is formed by

• oligodendrocytes.

• microglia.

• satellite cells.

• astrocytes.

At the normal resting membrane potential of a typical neuron, its sodium-potassium exchange pump transports

• 3 intracellular sodium ions for 2 extracellular potassium ions.

• 3 intracellular sodium ions for 1 extracellular potassium ion.

• 2 intracellular sodium ions for 1 extracellular potassium ion.

• 1 intracellular sodium ion for 2 extracellular potassium ions.

Tags

NGSS.HS-LS1-3

The following are the main steps in the generation of an action potential.

 

1. Sodium channels are inactivated.

2. Voltage-gated potassium channels open and potassium moves out of the cell, initiating repolarization.

3. Sodium channels regain their normal properties.

4. A graded depolarization brings an area of an excitable membrane to threshold.

5. A temporary hyperpolarization occurs.

6. Sodium channel activation occurs.

7. Sodium ions enter the cell and depolarization occurs.

 

What is the proper sequence of these events?

• 4, 6, 7, 3, 2, 5, 1

• 4, 6, 7, 1, 2, 3, 5

• 6, 7, 4, 1, 2, 3, 5

• 2, 4, 6, 7, 1, 3, 5

The all-or-none principle states that

• all stimuli great enough to bring the membrane to threshold will produce identical action potentials.

• the greater the magnitude of the stimuli, the greater the magnitude of the action potential.

• only sensory stimuli can activate action potentials.

• all stimuli will produce identical action potentials.

Spinal nerves are

• Sensory and Motor

• Only Sensory

• Only Motor

• Interneuronal

   The spinal cord consists of four regions and ________ pairs of spinal nerves.

• 31

• 25

• 12

• 5

The largest peripheral nerve is the ________ nerve.

• sciatic

• femoral

• phrenic

• obturator