BIO 123 Unit 2: The Nervous System: Integration and Control

When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron,

ion channels in the plasma membrane of the receiving neuron open

Cells in nerve tissues that support and protect neurons are ____ cells

neuroglial

Cells that provide direct protection and physical support to neurons are

neuroglial cells

A molecule that carries information across a synaptic cleft is a

neurotransmitter

An impulse relayed along a myelinated axon "jumps" from ___ to _____

node of Ranvier...node of Ranvier

The transmission of a nerve impulse first triggers the ______

opening of voltage-gated sodium channels and the diffusion of sodium ions into the neuron

A stimulus has opened the voltage-gated sodium channels in an area of a neuron's plasma membrane. As a result, _____ rushes into the neuron and diffuses to adjacent areas; this in turn results in the ____ in the adjacent areas.

sodium... opening of voltage-gates sodium channels

Excitatory neurotransmitters encourage the generation of new electrical impulses by

stimulating depolarization of postsynaptic neurons

Which of the causes the releases of neurotransmitter molecules?

an action potential reaching the end of the axon

During a brain surgery, the surgeon passes an instrument through the dura matter. Which of the following does he pass through next?

arachnoid

Shifting the membrane potential of a neuron from negative to positive, due to inward movement of sodium ions, is referred to as ____.

depolarization

Peripheral Nervous System (PNS)

everything else

During an action potential

the inside of the neuron becomes positively charges relative to the outside

Saltatory conduction is

the process of induction leaping along myelinated neurons

If a signal from a sending neuron makes the receiving neuron more negative inside,

the receiving neuron is less likely to generate an action potential

Autonomic Division

Carries output from the CNS to smooth muscle, cardiac muscle, glandular epithelial tissue, all of which are unconsciously controlled. Thus, the autonomic division is responsible for controlling basic body function over which you exert no conscious control such as breathing, heart rate, digestive system function etc.

Somatic Division

Carries output from the CNS to the skeletal muscle, triggering contraction and relaxation. This is the only part of the nervous system over which you exert and conscious control

The central nervous system is enclosed by membranes of meninges called the

dura matter, pia matter and arachnoid

During periods of stress or increased activity, the parasympathetic division of the autonomic nervous system predominates

false

The two major subdivision of the nervous system are the central nervous system and the limbic nervous system

false

The three main anatomical division of the bran are the

forebrain, midbrain, hindbrain

Electrical impulses are transmitted between components of the central nervous system via

interneurons

During depolarization of a neuron,

sodium channels close and potassium rushed out of the cell to temporarily re-establish the membrane potential

The small space between the sending neuron and the receiving neuron is the

synaptic cleft

The space between an axon of one neuron and the dendrite of another neuron is call a(n) ______

synaptic cleft

What part of a neuron relays signals from one neuron to another neuron or to an effector?

synaptic terminal

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

At rest, which of these plays a role in establishing the charge differential across a neuron's plasma membrane

the sodium-potassium pump moving sodium ions out of the neuron and potassium ions into the neuron

Insufficient production of acetylcholine in the synapses of the brain, abnormal angels neurons, and large deposits of beta amyloid are problems associated with

Alzheimer's disease

Oligodendrocytes are similar to Schwann cells in that they

are a type of neuroglial cell

An action potential moves along a(n) ______

axon

Twelve pair of ___ nerves carry nerve impulses from the brain to glands, muscles, head, neck, and the abdominal and thoracic cavities.

cranial

A nerve impulse moves toward a neuron's cell body along

dendrites

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

repolarization

Sodium-potassium pumps

restore the distribution of ions inside and outside an neuron's membrane following an action potential

Neurons store neurotransmitter molecules in vesicles located within ______.

synaptic terminals

The central nervous system is composed of

the brain and spinal cord

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

true

What type of cell makes up the myelin sheath of motor neuron?

Schwann cells

A neuron's nucleus is located in its

cell body

When calcium ions enter the synaptic terminal,

they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron

Motor neurons

transit impulses away from the central nervous system

Sensory neurons

transit impulses toward the central nervous system

Interneurons

transmit impulses within the central nervous system

Which of the following is a characteristic of the autonomic nervous system?

Axons of postganglionic neurons synapse with the target organ

Motor Branch

Carries output from the CNS to tissues, organs, and organ systems

Sensory Branch

Receives information from receptors monitoring both your internal and external environment and relays it to the CNS

What causes an action potential to be conducted along a neuron's axon?

The change in charge difference across the membrane spreads from open sodium channels, causing sodium channels farther along the axon to open

Central Nervous System (CNS)

Your brain and spinal cord, the CNS is responsible for integration and processing of all incoming sensory information, as well as generating responses

A nerve impulse move away from a neuron's cell body along

axons

Which of the following events associated with the transmission of an impulse across a synapse occurs last?

chemically gated channels for sodium open

The left and right sides of the cerebrum are interconnected by the

corpus callosum

This type of neurotransmitter functions as inhibitory agent, typically suppressing the sensation of pain

endorphins

Axons insulated by a(n) ____ are able to conduct impulses faster than those not so insulated

myelin sheath

Which of the following events is the first to occur during an action potential?

sodium channels opens

When a neuron is at its resting potential

there are more potassium ions inside the neuron that outside

A neuron has a resting potential of about ____ millivolts

-70

Nervous system basic functional characteristics

1. The nervous system is constantly receiving info from receptors that monitor both the internal and external environment 2. The nervous system, particularly the brain and spinal cord, integrate this information into what is essentially a picture of your body's current status. 3. Based upon this status, the nervous system can regulate the function of organ systems that initiate conscious thoughts, responses, and emotions. 4. Speed. The nervous functions extremely quickly. Info can be received, integrated, and response generated within milliseconds.