anatomy and physiology 1: chapter 11

________ are the most numerous type of neuron in the CNS. - Bipolar neurons - Unipolar neurons - Interneurons - Motor neurons - Sensory neurons

- Interneurons

Neuron cell bodies in the PNS are clustered together in masses called - peripheral nerves. - nerves. - the spinal cord. - nuclei. - ganglia.

- ganglia.

The ion that triggers the release of acetylcholine into the synaptic cleft is - potassium. - sodium. - magnesium. - calcium. - chloride.

- calcium.

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, 2, 5, 6, 7, 3, 1 - 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

- 4, 6, 7, 1, 2, 3, 5

________ line the brain ventricles and spinal canal. - Oligodendrocytes - Ependymal cells - Satellite cells - Microglia - Astrocytes

- Ependymal cells

Compare presynaptic and postsynaptic cells. (Module 11.2C) - Presynaptic cells are sensory neurons and postsynaptic cells are motor neurons. - Presynaptic cells are usually found in the peripheral nervous system and postsynaptic cells are usually found in the central nervous system. - Presynaptic cells can be a neuron or another type of cell, such as a skeletal muscle fiber or a gland cell and postsynaptic cells are usually neurons. - Presynaptic cells are usually neurons and postsynaptic cells can be a neuron or another type of cell, such as skeletal muscle fiber or a gland cell. - Presynaptic cells are motor neurons and presynaptic cells are sensory neurons.

- Presynaptic cells are usually neurons and postsynaptic cells can be a neuron or another type of cell, such as skeletal muscle fiber or a gland cell.

The neurilemma of axons in the peripheral nervous system is formed by - Schwann cells. - satellite cells. - microglia. - oligodendrocytes. - astrocytes.

- Schwann cells.

Compare the central and peripheral nervous system. (Module 11.1A) - The central nervous system consists of the brain and spinal cord and it integrates, processes, and coordinates sensory data and motor commands. The peripheral nervous system consists of all the nervous tissue outside the central and enteric nervous systems. - The central nervous system consists of all the nervous tissue outside the enteric nervous system. The peripheral nervous system consists of the brain and spinal cord and it integrates, processes, and coordinates sensory data and motor commands. - The central nervous system consists of the brain and it integrates, processes, and coordinates sensory data and motor commands. The peripheral nervous system consists of the spinal cord, and sensory and motor divisions. - The central nervous system consists of the spinal cord and all the nervous tissue outside the enteric nervous system. The peripheral nervous system consists of the brain and it integrates, processes, and coordinates sensory data and motor commands. - The central nervous system consists of the sensory and motor division in the axial region of the body. The peripheral nervous system consists of the sensory and motor division in the appendicular region of the body.

- The central nervous system consists of the brain and spinal cord and it integrates, processes, and coordinates sensory data and motor commands. The peripheral nervous system consists of all the nervous tissue outside the central and enteric nervous systems.

What is the relationship between myelin and the propagation speed of action potentials? (Module 11.11B) - The presence of myelin does not affect the speed of action potentials. - The presence of myelin slows the propagation speed of action potentials. - The presence of myelin speeds up the graded depolarization but does not affect the propagation speed of action potentials. - The presence of myelin blocks the propagation of action potentials. - The presence of myelin increases the propagation speed of action potentials.

- The presence of myelin increases the propagation speed of action potentials.

The all- or- none principle states that - only motor stimuli can activate action potentials. - only sensory stimuli can activate action potentials. - all stimuli will produce identical action potentials. - 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.

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

The glial cells in the central nervous system that form scar tissue after central nervous system injury are the - satellite cells. - ependymal cells. - oligodendrocytes. - astrocytes. - microglia.

- astrocytes.

The ________ nervous system provides involuntary regulation of smooth muscle, cardiac muscle, and glandular activity. - special sensory - automatic - somatic - sensory division of the peripheral - autonomic

- autonomic

The plasma membrane of an axon is called the - axon hillock. - axoplasm. - axokaryon. - axon terminal. - axolemma.

- axolemma.

The axon is connected to the cell body at the - synaptic knobs. - telodendria. - synapse. - collateral branches. - axon hillock.

- axon hillock.

Name the effectors of the ANS. (Module 11.1C) - skeletal muscle only - cardiac muscle, smooth muscle, glands, and adipose tissue - skeletal muscle, cardiac muscle, and smooth muscle - cardiac muscle and smooth muscle - glands and adipose tissue

- cardiac muscle, smooth muscle, glands, and adipose tissue

Name the structural components of a typical neuron. (Module 11.2A) - cell body, flagellum, and synaptic cleft - neurofilaments, neurofibrils, and axolemma - cell body, axon, and dendrites - cell body, cilia, and a basement membrane - neurilemma, neurofibrils, and dendrites

- cell body, axon, and dendrites

The ________ nervous system is composed of the brain and spinal cord. - afferent - central - peripheral - autonomic - efferent

- central

At a(n) ________ synapse, a neurotransmitter is released to stimulate the postsynaptic membrane. - charged - electrical - chemical - ionic - electrochemical

- chemical

Which type of synapse is most common in the nervous system? - radiative - electrical - chemical - mechanical - processing

- chemical

Functions of astrocytes include all of the following except - absorbing excess neurotransmitter. - conducting action potentials. - responding to neural tissue damage. - forming a three-dimensional framework for the CNS. - maintaining the blood-brain barrier.

- conducting action potentials.

An action potential traveling along the entire length of an axon demonstrates ________ propagation. - degraded - saltatory - continuous - graded - relative

- continuous

Opening of sodium channels in the axon membrane causes - depolarization and increased positive charge inside the membrane. - hyperpolarization and increased negative charge inside the membrane. - depolarization and increased negative change inside the membrane. - hyperpolarization and decreased positive charge inside the membrane. - repolarization and increased positive charge inside the membrane.

- depolarization and increased positive charge inside the membrane.

Which of the following is not a function of the nervous system? - direct long-term functions, such as growth - integrate sensory information - control peripheral effectors - coordinate voluntary and involuntary activities - sense the internal and external environments

- direct long-term functions, such as growth

In the peripheral nervous system, Schwann cells participate in the repair of damaged nerves by - producing more satellite cells that fuse to form new axons. - producing new axons. - regenerating cell bodies for the neurons. - forming a cellular cord that directs axonal regrowth. - clearing away cellular debris.

- forming a cellular cord that directs axonal regrowth.

Regions of the CNS where neuron cell bodies dominate constitute the ________ matter. - clear - grey - yellow - white - dark

- grey

Which of the following is not a function of the neuroglia? - support - phagocytosis - maintenance of blood-brain barrier - memory - secretion of cerebrospinal fluid

- memory

After a stroke, what type of glial cell accumulates within the affected brain region? - oligodendrocytes - satellite cells - ependymal cells - Schwann cells - microglia

- microglia

Small, wandering cells that engulf cell debris and pathogens in the CNS are called - satellite cells. - astrocytes. - oligodendrocytes. - microglia. - ependymal cells.

- microglia.

The most abundant class of neuron in the central nervous system is - bipolar. - unipolar. - pseudopolar. - anaxonic. - multipolar.

- multipolar.

The basic functional unit of the nervous system is the - glial cell. - spinal cord. - neuron. - brain. - nerve.

- neuron.

The tiny gaps between adjacent Schwann cells are called - synapses. - gap junctions. - myelinated. - internodes. - nodes.

- nodes.

The myelin sheath that covers many CNS axons is formed by - satellite cells. - astrocytes. - ependymal cells. - oligodendrocytes. - microglia.

- oligodendrocytes.

The separation of plus and negative charges across the membrane creates a ________ difference, or voltage. - concentration - potential - gradient - graded - kinetic

- potential

Which division of the PNS brings information to the CNS? (Module 11.1B) - efferent - sensory - parasympathetic - enteric - motor

- sensory

Which of the following is important in emotional states? - glutamate - noradrenalin - gamma aminobutyric acid - glycine - serotonin

- serotonin

The ________ nervous system controls the skeletal muscles. - somatic - autonomic - sympathetic - afferent - parasympathetic

- somatic

The site of intercellular communication between neurons is the - collateral branch. - synaptic knob. - telodendria. - synapse. - hillock.

- synapse.

The minimum stimulus required to trigger an action potential is known as the - membrane potential. - threshold. - graded potential. - resting potential. - refractory period.

- threshold.

Sensory neurons of the PNS are - anaxonic. - unipolar. - bipolar. - tripolar. - multipolar.

- unipolar.

Neurotransmitter for release is stored in synaptic - knobs. - mitochondria. - telodendria. - vesicles. - neurosomes.

- vesicles.

Regions of the CNS with an abundance of myelinated axons constitute the ________ matter. - dark - clear - grey - yellow - white

- white

Most CNS neurons lack centrioles. This observation explains - the ability of neurons to communicate with each other. - why CNS neurons cannot divide. - the ability of neurons to generate an action potential. - the ability of neurons to produce a resting potential. - why CNS neurons grow such long axons.

- why CNS neurons cannot divide.

The following are the steps involved in transmission at a cholinergic synapse. 1. Chemically gated sodium channels on the postsynaptic membrane are activated. 2. Calcium ions enter the synaptic knob. 3. Acetylcholinesterase hydrolyzes acetylcholine. 4. An action potential depolarizes the synaptic knob at the presynaptic membrane. 5. The synaptic knob reabsorbs choline. 6. Acetylcholine is released from storage vesicles by exocytosis. 7. Acetylcholine binds to receptors on the postsynaptic membrane. 8. Calcium ions are removed from the cytoplasm of the synaptic knob.What is the proper sequence of these events? - 2, 5, 4, 6, 7, 1, 8, 3 - 4, 2, 6, 7, 1, 8, 3, 5 - 6, 4, 2, 7, 1, 8, 3, 5 - 2, 4, 6, 7, 1, 8, 3, 5 - 4, 2, 6, 7, 8, 5, 3, 1

4, 2, 6, 7, 1, 8, 3, 5