Nervous System Overview

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Questions and Answers

What is the primary role of the nervous system in relation to the endocrine system?

It controls fewer body systems.

It facilitates internal homeostasis more quickly. (correct)

It integrates sensory information more efficiently.

It has a slower response time.

What is the primary role of the Na+-K+ pump in neurons?

Enhance depolarization speed

Facilitate neurotransmitter release

Maintain action potential duration

Establish resting membrane potential (correct)

Which type of neuron primarily carries sensory information to the central nervous system?

Unipolar neurons (correct)

Bipolar neurons

Multipolar neurons

Interneurons

Which value represents the maximum depolarization stage in a neuron?

+30 mV Signup and view all the answers

Which structure is NOT considered part of the central nervous system?

Peripheral cranial nerves Signup and view all the answers

What is the function of nocioceptors in the nervous system?

Monitor pain and temperature Signup and view all the answers

What is the equilibrium potential value for potassium (K+)?

-90 Signup and view all the answers

In which phase does a neuron become more permeable to K+?

Hyperpolarization Signup and view all the answers

Which statement accurately describes the somatic nervous system?

It carries sensory information from body wall and limbs. Signup and view all the answers

What type of conduction occurs only at the Nodes of Ranvier?

Saltatory conduction Signup and view all the answers

What primarily characterizes mixed nerves within the peripheral nervous system?

They carry both motor commands and sensory information. Signup and view all the answers

How does the permeability of a neuron to Na+ compare to K+ during an action potential?

Neurons are more permeable to K+ Signup and view all the answers

How do efferent neurons primarily function in the nervous system?

They conduct impulses away from the brain. Signup and view all the answers

Which of the following accurately represents a function of interneurons?

Integrate sensory inputs and motor output to the CNS. Signup and view all the answers

Which mechanism allows for rapid signal transmission along neurons?

Saltatory conduction Signup and view all the answers

Which type of sensory receptor is specifically associated with detecting changes in body temperature?

Krause receptors Signup and view all the answers

Which statement about neurotransmitter release is true?

It occurs in the synaptic cleft Signup and view all the answers

What is the primary characteristic of preganglionic neurons in the autonomic nervous system?

They are always cholinergic. Signup and view all the answers

What happens to the distal end of a PNS neuron after an injury?

It dies Signup and view all the answers

Which of the following is characteristic of electrical synapses?

Gap junctions connection Signup and view all the answers

What type of neuron has one dendrite and one axon and is primarily associated with special senses?

Bipolar neurons Signup and view all the answers

Which type of neuroglia is responsible for myelination in the central nervous system?

Oligodendrocytes Signup and view all the answers

What is the primary function of the autonomic nervous system?

Innervate effectors under involuntary control Signup and view all the answers

What characterizes the all-or-none principle in neuronal communication?

Once an action potential is reached, it will always fire. Signup and view all the answers

Which structure contains the cell bodies and is responsible for maintaining the blood-brain barrier?

Astrocytes Signup and view all the answers

What is the role of the Nodes of Ranvier in myelinated axons?

They are sites for action potential transmission. Signup and view all the answers

In which area of the spinal cord would you find gray matter?

Surrounding the central canal Signup and view all the answers

What is the composition of myelin in terms of its substrate?

Lipid and protein Signup and view all the answers

Which type of neuron has multiple dendrites and is typically found in the central nervous system?

Multipolar neurons Signup and view all the answers

What substance is primarily responsible for the darker appearance of gray matter?

Unmyelinated axons and cell bodies Signup and view all the answers

Study Notes

Nervous System Functions

Nervous system and endocrine system work together to maintain homeostasis.
Nervous system is responsible for controlling all body systems, responding quickly to changes in the body.
Endocrine system uses hormones to regulate body functions, which takes longer than nerve impulses.

Organization of the Nervous System

Nervous system includes neurons and neuroglia (support cells).
Nervous structures include the brain, spinal cord, cranial nerves, and spinal nerves.
Accessory structures include ganglia and sensory receptors.

Sensory Information

Sensory receptors detect changes in the internal or external environment.
Sensory neurons (afferent) carry information to the CNS (brain or spinal cord).
Special senses include vision, hearing, taste, smell, and balance.
Somatic senses include touch, temperature, pain, itch, and proprioception.
Sensory receptors are responsible for detecting various stimuli of the body.

Neuroglia

Support cells in the nervous system.
Types of neuroglia include astrocytes, oligodendrocytes, microglia, ependymal cells, Schwann cells, and satellite cells.
Astrocytes maintain the blood-brain barrier and provide structural support.
Oligodendrocytes and Schwann cells myelinate axons in the CNS and PNS respectively.
Microglia are phagocytic cells that remove debris and pathogens.
Ependymal cells line ventricles and the central canal, assisting in cerebrospinal fluid production and circulation.

Myelination

Myelin is a multilayered structure that insulates axons, speeding up nerve impulse conduction.
Myelin is composed of lipids and proteins.
Oligodendrocytes myelinate multiple axons in the CNS, whereas Schwann cells myelinate only one axon in the PNS.
Nodes of Ranvier are gaps between myelinated segments, where action potentials jump.

Gray and White Matter

White matter contains myelinated axons, giving it a white appearance.
Gray matter contains unmyelinated axons, cell bodies, and neuroglia, giving it a darker appearance.
In the brain, gray matter is on the surface and white matter is deeper.
In the spinal cord, white matter is on the surface and gray matter is deeper.

Neuronal Communication

Action potentials follow the all-or-none principle.
Graded potentials can initiate action potentials if they reach threshold.
Resting membrane potential is -70mV.
Depolarization involves Na+ influx, leading to a positive membrane potential.
Repolarization involves K+ efflux, restoring the negative membrane potential.
Hyperpolarization results in a membrane potential more negative than resting potential.
Continuous conduction involves depolarization along the entire axon.
Saltatory conduction involves depolarization only at the nodes of Ranvier, making conduction faster.

Chemical and Electrical Synapses

Chemical synapses involve neurotransmitters released from the presynaptic neuron to the postsynaptic neuron across a synaptic cleft.
Electrical synapses involve direct connections between pre and postsynaptic neurons through gap junctions.

PNS Regeneration

PNS neurons have greater regenerative capabilities than CNS neurons.
Injury to a PNS neuron can cause the distal end to die, but the proximal end can regenerate and establish new connections with effector cells.

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Description

Explore the functions and organization of the nervous system in this quiz. Understand how the nervous and endocrine systems work together to maintain homeostasis and the role of sensory receptors in detecting stimuli. Test your knowledge about the structures and functions of the nervous system.