Chapter 11: Nervous System

Which of the following is NOT one of the basic functions of the nervous system? ANSWER: A. Decode sensory information from the environment. B. Release hormones into the bloodstream to communicate with other cells in the body. C. Generate direct, electrical signals. D. Integrate sensory input for decision making.

As you start working out, you notice that your heart rate and breathing rate start to increase. Which division of your nervous system is generating this response? Be as specific as possible. ANSWER: A. the somatic nervous system B. the afferent division of the nervous system C. the parasympathetic division of the autonomic nervous system D. the sympathetic division of the autonomic nervous system

Which of the following types of glial cells monitors the health of neurons, and can transform into a special type of macrophage to protect endangered neurons? ANSWER: A. microglia B. ependymal cells C. astrocytes D. oligodendrocytes

Ependymal cells line many open cavities in the central nervous system (CNS). Ependymal cells have cilia on the side of the cell that face these openings. What is the most likely function of these ciliated cells? ANSWER: A. create myelin sheaths for CNS cells B. movement and circulation of cerebrospinal fluid C. act as macrophage cells to destroy microorganisms or neuronal debris D. exchange of nutrients between the circulatory system and neurons

Which of the following peripheral nervous system (PNS) neuroglia form the myelin sheaths around larger nerve fibers in the PNS? ANSWER: A. astrocytes B. oligodendrocytes C. Schwann cells D. satellite cells

Many neurons have many short, branching extensions called dendrites. What is the benefit of these structures for a neuron? ANSWER: A. There is a large amount of space for myelin to form and make electrical conduction more efficient. B. There is a large surface area to send signals to other cells. C. There is a large area for production of chemicals used to signal other neurons. D. The dendrites provide a large surface area for connections from other neurons.

Bundles of neurons in the central nervous system are called tracts. ANSWER: A. True B. False

Which of the following is true of axons? ANSWER: A. Axons use chemically gated ion channels to generate graded potentials. B. A neuron can have only one axon, but the axon may have occasional branches along its length. C. Smaller (thinner) axons are more likely to bear myelin sheaths than larger (thicker) axons. D. Neurons can have multiple axons but only one dendrite

What is the basic condition when a neuron is described as polarized? ANSWER: A. There is a separation of positive and negative charges across a membrane. B. There are large, protein anions inside the neuron. C. Na+ is found outside of the neuron. D. Na+ is found outside of the neuron and K+ is found inside of the cell.

Na+ leaks through neuron membranes faster than K+ because of the properties of the non-gated leak channels. ANSWER: A. True B. False

Which of the following statements is correct regarding the polarization of a neuronal membrane and the formation of a resting membrane potential? ANSWER: A. As Na+ leaks across the membrane, that establishes a negative charge inside the membrane. B. As sodium leaks into the cell, the inside of the cell becomes more negative. C. A resting potential can be generated without the energy as an input. D. Sodium/Potassium pumps maintain concentration gradients; sodium and potassium move down their concentration gradients through leakage channels.

Which criterion is used to functionally classify neurons? ANSWER: A. the number of processes extending from the cell body neuron B. the direction in which the nerve impulse travels relative to the central nervous system C. whether the nerve fibers are myelinated or unmyelinated D. whether the neurons are found within the CNS or the PNS

Which of the following does NOT describe conditions that occur during an action potential? ANSWER: A. After initial depolarization, K+ now has both an electrical and a chemical gradient drawing it out of the cell. B. Na+ enters the cell through voltage-gated channels, causing a reversal of the resting membrane potential. C. Na+ is used to repolarize the membrane. D. The Na+/K+ pump reestablishes resting concentration gradients.

You discover that a new chemical compound interacts with K+ voltage-dependent channels. What would be the effect on a neuron if the chemical came into contact with the axonal membrane? ANSWER: A. The cell would die. B. The cell would be unable to depolarize. C. The cell would be unable to generate a resting potential. D. The neuron would be unable to repolarize.

Opening K+ or Cl- channels in a postsynaptic membrane would produce an inhibitory postsynaptic potential (IPSP). ANSWER: A. True B. False

Which of the following is a factor that determines the rate of impulse propagation, or conduction velocity, along an axon? ANSWER: A. length of the axon B. degree of myelination of the axon C. the number of axon collaterals extending from a truncated axon D. whether the axon is located in the central nervous system or in the peripheral nervous system

In a lab you are conducting tests with various chemicals and neurotransmitter receptors. You notice that exposed frog muscle cells depolarize when you add the chemical nicotine to the acetylcholine (ACh) receptors. What does this tell us about the relationship between neurotransmitters and their receptors? ANSWER: A. The response generated by a receptor is very broad in nature. B. The effect of a neurotransmitter is based on the properties of the receptor more than the neurotransmitter. C. Neurotransmitter receptors only bind specifically with their neurotransmitter. D. The effect of a neurotransmitter is based on the properties of the neurotransmitter more than the receptor.

Which of the following does NOT describe the process of summation? ANSWER: A. One EPSP fails to bring the cell to threshold. B. One EPSP and one IPSP cancel each other out. C. Two EPSPs occur close enough in time to bring the cell to threshold. D. Two EPSPs are generated at the same time by two separate synapses, bringing the cell to threshold.

Which of the following circuit types is involved in the control of rhythmic activities such as the sleep-wake cycle, breathing, and certain motor activities (such as arm swinging when walking)? ANSWER: A. reverberating circuits B. diverging circuits C. converging circuits D. parallel after-discharge circuits

In the brain, vision originates in the rods and cones in the retina. Separate regions of the brain decode basic information, like color, shapes, intensity of light, and there are other regions that decode information like position in space, and awareness of patterns. As you use your visual system, all of these regions are working simultaneously. This simultaneous awareness of all regions working at the same time is due to which processing pattern listed below? ANSWER: A. oscillative processing B. parallel processing C. serial processing D. reflexive processing

master controlling and communicating system of the body

communicates by means of chemical messengers (hormones) secreted into the blood

employs electrical and chemical means to send messages from cell to cell

cells communicate within the nervous system via

information gathered by sensory receptors about internal and external changes

processing and interpretation of sensory input

activation of effector organs (muscles and glands) produces a response

what are the functions of the nervous system

what are the divisions of the nervous system

the brain and spinal cord of the dorsal body cavity are apart of what division of the nervous system

division of the nervous system that is known as the integration and control center

the portion of the nervous system outside the CNS; communication lines between the CNS and the rest of the body

division of the nervous system that consists mainly of nerves that extend from the brain and spinal cord

name the two functional divisions of the peripheral nervous system

conducts impulses from skin, skeletal muscles, and joints to CNS

conducts impulses from visceral organs to CNS

transmits impulses from CNS to effector organs (muscles and glands)

the two divisions of the motor division of the PNS

motor division of the PNS; conducts impulses from CNS to skeletal muscle; voluntary nervous system

visceral motor nerve fibers; regulates smooth muscle, cardiac muscle, and glands; involuntary nervous system

name the two functional divisions of the autonomic nervous system that work in opposition to each other

somatic and visceral sensory nerve fibers; conducts impulses from receptors to the CNS

motor nerve fibers; conducts impulses from the CNS to effectors (muscles and glands)

functional division of autonomic nervous system that mobilizes body systems during activity

functional division of autonomic nervous system that conserves energy and promotes house-keeping functions during rest

small cells that surround and wrap delicate neurons

excitable cells that transmit electrical signals

most abundant, highly branched glial cells found in CNS; cling to neurons, synaptic endings, and capillaries; support and brace neurons; control chemical environment around neurons

small, ovoid cells with thorny processes touch and monitory neurons; migrate toward injured neurons; monitor the health of other neurons; can transform to phagocytize microorganisms and neuronal debris; known as the defensive cells in the CNS

cells that line cerebrospinal fluid-filled cavities of the brain and spinal column; form permeable barrier between cerebrospinal fluid and tissue fluid bathing CNS cells; range in share from squamous to columnar; may be ciliated

branched cells that have processes that form myelin sheaths around CNS nerve fibers

armlike processes that extend from body

bundles of neuron processes in CNS

bundles of neuron processes in PNS

what are the two types of neuron processes

short, tapering, diffusely branched processes; receptive (input) region of neuron; convey incoming messages toward cell body as graded potentials (short distance signals)

conducting region of neuron; generates nerve impulses

protects and electrically insulates axon; increases speed of nerve impulse transmission

surround neuron cell bodies in the PNS; function similar to astrocytes of CNS

surround all peripheral nerve fibers and form myelin sheaths in thicker nerve fibers; similar function as oligodendrocytes

structural units of the nervous system; large, highly specialized cells that conduct impulses