Nervous System Functions and Divisions

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Questions and Answers

What is the primary function of the blood-brain barrier (BBB)?

To supply nutrients from the blood

To facilitate nerve signal transmission

To protect the brain from harmful substances (correct)

To enhance blood flow to the brain

Which meningeal layer is described as a delicate impermeable membrane?

Dura Mater

Epidural layer

Pia Mater

Arachnoid Mater (correct)

Which of the following correctly describes the internal carotid and vertebral arteries?

They drain the cerebrospinal fluid.

They return blood from the brain.

They are the primary site for nutrient absorption.

They are responsible for carrying blood to the brain. (correct)

What is a major function of cerebrospinal fluid?

To absorb shock and protect the brain and spinal cord Signup and view all the answers

What structures does the somatic nervous system innervate?

The body wall structures like muscles and skin Signup and view all the answers

Which division of the autonomic nervous system is responsible for the 'fight or flight' response?

Sympathetic division Signup and view all the answers

What is the type of outflow for the sympathetic nervous system?

Thoraco-lumbar outflow Signup and view all the answers

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

Localized responses Signup and view all the answers

Which general function is primarily associated with the parasympathetic nervous system?

Energy conservation Signup and view all the answers

What part of the nervous system does the sympathetic division supply?

Both central and peripheral systems Signup and view all the answers

What is the primary function of the sensory neurons?

To carry impulses from sensory receptors to the CNS Signup and view all the answers

Which cells are responsible for supporting neurons and forming a barrier between blood vessels and neurons in the CNS?

Astrocytes Signup and view all the answers

What are the components of the central nervous system (CNS)?

Brain and spinal cord Signup and view all the answers

What is the main role of interneurons in the nervous system?

To connect sensory and motor neurons Signup and view all the answers

What is the primary function of the motor neurons?

To initiate action in response to stimuli Signup and view all the answers

What is the role of oligodendrocytes in the nervous system?

To form myelin sheath around nerve fibers in the CNS Signup and view all the answers

Which statement accurately describes gray matter in the nervous system?

It is mainly composed of neuronal cell bodies and unmyelinated fibers. Signup and view all the answers

What is the definition of irritability in the context of neurons?

The ability to respond to stimuli Signup and view all the answers

Study Notes

Functions of the Nervous System

The Nervous System is responsible for sensing changes in the internal and external environment, analyzing information received, and initiating actions.
Sensory function is responsible for sensing changes through receptors like pain or pressure.
Integrative function includes analysis of sensory information, storage, and deciding appropriate behaviors.
Motor function allows the body to respond to stimuli through actions.

Divisions of the Nervous System

The Central Nervous System (CNS) consists of the brain and spinal cord.
The Peripheral Nervous System (PNS) connects the CNS to the rest of the body using sensory and motor fibers.
The PNS includes cranial and spinal nerves, muscles, glands, and sensory receptors.

Histology of the Nervous System

Neurons are nerve cells, the functional unit of the nervous system, capable of producing action potentials.
- Structure includes a cell body, dendrites, and an axon.
- Structural Classification is based on the number of processes extending from the cell body.
- Functional Classification divides neurons into sensory, motor, and interneurons.
Neuroglia are support cells of the nervous system.
- Types include astrocytes, microglia, ependymal cells, oligodendrocytes, Schwann cells, and satellite cells, each with specialized functions.

Gray and White Matter

Gray Matter consists of neuron cell bodies, dendrites, and unmyelinated axons.
White Matter consists primarily of myelinated axons, giving it a whitish appearance.

Properties of Neurons

Irritability is the ability of neurons to respond to stimuli.
Conductivity is the ability of neurons to transmit impulses.

Classification of Neurons

Sensory (afferent) neurons conduct impulses from sensory receptors.
Motor (efferent) neurons conduct impulses from the CNS to effectors (muscles and glands).
Interneurons (association neurons) connect sensory and motor neurons within the CNS.

Neuroglia

Astrocytes are star-shaped cells with various important functions like supporting neurons, forming a blood-brain barrier, and controlling the chemical environment of the CNS.
Microglia act as phagocytes, removing debris and defending the CNS.
Ependymal cells line fluid-filled cavities in the brain and spinal cord, aiding in the circulation of cerebrospinal fluid.
Oligodendrocytes produce myelin sheaths around nerve fibers in the CNS.
Schwann cells form myelin sheaths in the PNS.
Satellite cells protect neuron cell bodies in the PNS.

Organization of the Nervous System

The CNS includes the brain and spinal cord.
The PNS includes cranial nerves, spinal nerves, and associated ganglia.

Structures of the CNS

Meninges, protective membranes, surround the brain and spinal cord.
- Dura Mater is the outermost, tough, fibrous layer.
- Arachnoid Mater is a delicate, impermeable middle layer.
- Pia Mater is the innermost, vascular membrane.
Cerebrospinal Fluid (CSF) serves as a shock absorber and transports nutrients and wastes.
Neurons and Neuroglia together make up the functional units of the nervous system.
Axons (nerve fibers) transmit impulses throughout the nervous system.
Gray Matter contains neuron cell bodies and unmyelinated fibers.
White Matter contains myelinated axons, giving it a whitish color.

Blood Supply to the Brain

The brain receives approximately 20% of the total blood supply.
Blood is supplied through internal carotid and vertebral arteries.
Blood returns from the brain through the internal jugular veins.
The blood-brain barrier protects the brain from harmful substances.

Cerebrospinal Fluid (CSF)

Clear fluid that fills the ventricles of the brain and the central canal of the spinal cord.
Shock absorber, protecting the brain and spinal cord.
Transports nutrients and wastes between the blood and nervous tissue.
Formed by filtration from capillaries in the choroid plexuses.
Circulates through the ventricles, central canal, and subarachnoid space.
Absorbed by arachnoid villi.

Peripheral Nervous System

Consists of cranial and spinal nerves and associated ganglia.
Composed of bundles of nerve fibers (axons) that transmit signals throughout the body.

Divisions of the Peripheral Nervous System

Somatic Nervous System controls voluntary movement of skeletal muscle.
Autonomic Nervous System controls involuntary actions of smooth muscle, cardiac muscle, and glands.

Autonomic Nervous System

Sympathetic Nervous System is associated with the "fight or flight" response.
Parasympathetic Nervous System is responsible for "rest and digest" functions, energy conservation, and homeostasis.
The two divisions of the autonomic nervous system often have opposing effects on target organs.

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Description

Explore the intricate functions and divisions of the nervous system. This quiz covers sensory, integrative, and motor functions, along with the roles of the Central and Peripheral Nervous Systems. Test your knowledge on neurons and their crucial functions within the nervous system.