Chapter 11 Assessment

Place the events occurring at a chemical synapse in the correct order based upon the activity designated in the figure shown.

1.Action potentials arriving at the presynaptic terminal cause voltage-gates CA+2 channels to open 2.Ca=2 diffuses into the cell and causes synaptic vesicles to undergo exocytosis, reeling neurotransmitters molecules 3. neurotransmitter molecules diffuse from the presynaptic terminal across the synaptic cleft 4. neurotransmitter molecules bind receptor sites, causing ligand-gated NA+, channels to open, NA diffuses into the cell or out of the cell, causing a change in membrane potential

Check all of the factors that would increase the speed of an action potential.

-Axons with larger diameters -Increased thickness of myelin sheath -Presence of myelin

Identify the mechanisms by which neuromodulators alter synaptic transmission.

-Changing neurotransmitter receptor numbers -Affecting breakdown of neurotransmitters -Affecting the removal of neurotransmitters

Check all that apply to chemical synapses.

-Chemical synapses are the most numerous type of synapse in the human body. -Chemical synapses are unidirectional (one way).

Check all of the items below that pertain to functions of the nervous system.

-Controlling muscles and glands -Establishing and maintaining mental activity -Integration of information -Maintaining homeostasis -Receives sensory input

Check all of the factors that are necessary for an action potential to occur.

-Depolarization -Graded potentials -Reaching threshold

Select all that apply. Which of following are weaker than a maximal stimulus?

-Submaximal stimuli -Threshold stimuli -subthreshold stimuli

Identify the characteristics of action potentials.

-The strength of the stimulus determines the frequency of the action potentials. -They are all-or-none.

Check all of the components of gray matter in the CNS and PNS.

-cerebral cortex -Ganglia -Nuclei

Identify the two functional subdivisions of the peripheral nervous system.

-motor division -sensory division

Place the following structures in the order that an electrical impulse would travel beginning with the postsynaptic membrane.

1. dendrites 2.soma 3.axon hillock 4. axon 5. presynaptic terminals

place the events in the correct order regarding the production, release, and inactivation of a monoamine neurotransmitter such as norepinephrine, beginning with the production of monoamine.

1. monoamine is produced and stored in synaptic vessivles 2. action potentials open gated Ca+2 channels, leading to release of neurotransmitters 3. neurotransmitters enter the synaptic cleft 4. reuptake of most neurotransmitter from synaptic cleft 5. inactivation of most neurotransmitter by MAO

The division of the peripheral nervous system that transmits electrical impulses from sensory receptors to the CNS is the ______ division, while the ----- division of the peripheral nervous system transmits electrical impulses from the CNS toward muscles and glands.

afferent, efferent

The division of the nervous system that transmits electrical impulses to cardiac muscle, smooth muscle, and glands is the ____ nervous system, while the division that transmits electrical impulses to skeletal muscle is the ____nervous system.

autonomic, somatic

The time when there is complete insensitivity of the plasma membrane to another stimulus

Absolute refractory period

Several excitatory and inhibitory neurons synapse with a single motor neuron cell body

Convergent pathway

A sensory signal can go to both the spinal cord and brain.

Divergent pathway

A spinal interneuron sends signals to both the brain and nearby motor neurons as part of a simple reflex.

Divergent pathway

Depolarization of postsynaptic membrane

EPSP

Membrane becomes more permeable to Na+

EPSP

A membrane potential becomes more negative

IPSP

Hyperpolarization of the postsynaptic membrane

IPSP

The membrane becomes more permeable to Cl- or K+

IPSP

The time when a stronger-than-threshold stimulus is needed to initiate another action potential

Relative refractory period

A positive feedback loop intensifies memory formation in the cerebral cortex.

Reverberating circuit

The repetitive pattern of action potentials among neurons that regulate the respiratory rhythm

Reverberating circuits.

A nerve is a single neuron that transmits impulses.

false

A time when there is a decrease in the sensitivity of the plasma membrane to further stimulation

refractory period

Spontaneous rhythms in the cerebral cortex

reverberating circuit

Action potentials travel fastest on large diameter, myelinated axons.

true

The enzyme acetylcholinesterase, located in the synaptic cleft and on the postsynaptic membrane, breaks ACh down into acetate and choline, thereby stopping the stimulation of a postsynaptic cell. (true/false)

true

True or False: The nervous system and the endocrine system are the major control systems of the body.

true