Spinal Cord and Nerves Overview

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Questions and Answers

What is the primary function of the spinal cord in the nervous system?

To provide a pathway for nerve impulses (correct)

To increase blood flow to the brain

To filter sensory information before reaching the brain

To enhance reflex actions

Where does the spinal cord begin in relation to the brain?

At the top of the lumbar vertebrae

At the foramen magnum, where the medulla oblongata ends (correct)

At the level of the first cervical vertebra

At the base of the skull where the occipital lobe is located

What structure marks the end of the spinal cord?

Cervical enlargement

Conus medullaris (correct)

Lumbosacral enlargement

Cauda equina

Which term refers to the collection of nerves extending from the spinal cord that resembles a horse's tail?

Cauda equina Signup and view all the answers

What are the two main enlargements of the spinal cord called?

Cervical and lumbar-sacral enlargements Signup and view all the answers

What is the function of the filum terminale?

To anchor the spinal cord to the coccyx Signup and view all the answers

How many pairs of spinal nerves exit the spinal cord in total?

31 Signup and view all the answers

What is the main characteristic of the dura mater in relation to the spinal cord?

It contains a space between it and the periosteum. Signup and view all the answers

What is the approximate anatomical landmark where the spinal cord ends?

At the level of the second lumbar vertebra Signup and view all the answers

How is the spinal cord's cross-section described?

Circular but slightly flattened on one side Signup and view all the answers

What are the enlargements of the spinal cord primarily responsible for?

Housing extra nerves for limb innervation Signup and view all the answers

What is the role of the meninges surrounding the spinal cord?

Protect the spinal cord from injury Signup and view all the answers

What role does the spinal cord play in integrating information?

It integrates incoming sensory and outgoing motor information Signup and view all the answers

Which structures does the spinal cord directly connect to?

Both the brain and various body muscles and glands Signup and view all the answers

Where do the nerves from the lumbosacral enlargement exit the vertebral canal?

Via intervertebral foramina Signup and view all the answers

What type of tissue makes up the dura mater?

Dense, irregular connective tissue Signup and view all the answers

What type of neuron is primarily located in the posterior gray horn of the spinal cord?

Interneurons Signup and view all the answers

Where do somatic motor neurons originate in the spinal cord?

Anterior gray horn Signup and view all the answers

What is the role of interneurons in the spinal cord?

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

What is the primary function of the polio virus?

To attack the cell bodies of motor neurons Signup and view all the answers

In which region of the spinal cord do autonomic motor neurons reside?

Lateral gray horn Signup and view all the answers

How does sensory information typically ascend toward the brain from the spinal cord?

Using sensory ascending tracts in white matter Signup and view all the answers

Which disease is also associated with the degeneration of the anterior horn of the spinal cord?

Amyotrophic Lateral Sclerosis Signup and view all the answers

What would happen to sensory information in a reflex arc involving an interneuron?

It would synapse with a somatic motor neuron. Signup and view all the answers

What type of neurons are located in the lateral horn of the spinal cord?

Autonomic neurons Signup and view all the answers

Where do sensory neurons enter the spinal cord?

Dorsal root Signup and view all the answers

Which structure enters the spinal cord via the dorsal roots of the spinal nerves?

Sensory axons Signup and view all the answers

How many pairs of spinal nerves are there in total?

31 pairs Signup and view all the answers

What is the main target of somatic motor neurons exiting the spinal cord?

Skeletal muscle Signup and view all the answers

Which statement is true about cervical spinal nerves?

Each cervical nerve exits above its corresponding vertebra. Signup and view all the answers

What occurs to individuals diagnosed with ALS over time?

Loss of ability to perform basic daily activities Signup and view all the answers

What is the function of somatic motor neurons?

To facilitate voluntary movements Signup and view all the answers

What is the primary function of the cervical plexus?

To innervate the muscles and skin of the head and neck regions Signup and view all the answers

Which spinal nerves contribute to the cervical plexus?

C1 to C4 Signup and view all the answers

Which nerve is associated with the cervical plexus and plays a crucial role in breathing?

Phrenic nerve Signup and view all the answers

What is a key characteristic of peripheral nerves coming from spinal plexuses?

They are combinations of sensory and motor components from various spinal nerve levels Signup and view all the answers

From which spinal level does the phrenic nerve receive contributions?

C5 as well as C1 to C4 Signup and view all the answers

Which plexus is responsible for innervating the diaphragm?

Cervical plexus Signup and view all the answers

What is the most superior plexus in the human body?

Cervical plexus Signup and view all the answers

What is true about the brachial plexus?

It consists of ventral rami from spinal nerves C5 to T1 Signup and view all the answers

What separates the periosteal layer from the dura mater in the spinal cord?

The epidural space Signup and view all the answers

Which layer of the meninges is primarily responsible for supplying blood to the spinal cord?

Pia mater Signup and view all the answers

What is the function of the epidural space in the vertebral canal?

To protect and hold the spinal cord in place Signup and view all the answers

Which statement accurately describes the arachnoid mater?

It contains no blood supply or vessels. Signup and view all the answers

What is the significance of the space between the dura mater and the arachnoid mater?

It acts as a cushion for the spinal cord. Signup and view all the answers

What happens during an epidural anesthesia procedure?

Anesthesia is injected into the epidural space. Signup and view all the answers

What are the extensions of the pia mater that connect it to the dura mater called?

Denticulate ligaments Signup and view all the answers

Which of the following correctly describes the structure of the pia mater?

It tightly adheres to the spinal cord. Signup and view all the answers

Study Notes

Spinal Cord and Spinal Nerves

Spinal cord is a long structure within the central nervous system
It connects the brain to the peripheral nervous system
The spinal cord is surrounded by vertebrae forming the vertebral column
The spinal cord has an anterior (smooth) and posterior (spiny) side
Each vertebra has a vertebral foramen
Stacked vertebrae create the vertebral canal, housing the spinal cord
Spinal cord has cervical, thoracic, lumbar, sacral, and coccygeal regions
Spinal nerves emerge from the spinal cord, and are protected by various coverings
Spinal nerves exit via intervertebral foramina

Spinal Cord Structure

Spinal cord has both white matter and grey matter areas
White matter contains myelinated axons for ascending and descending nerve tracts
Grey matter contains neuron cell bodies, dendrites, and interneurons
Spinal cord has posterior, lateral and anterior horns
Gray commissures connect the right and left sides of the spinal cord
Central canal within the gray commissures contains CSF (cerebrospinal fluid)

Meninges

Spinal cord is surrounded by meninges (connective tissue coverings)
Dura mater is the outermost, thickest layer with a space (epidural space) separating it from bone
Arachnoid mater is a thin, avascular layer beneath the dura mater.
Pia mater is the innermost layer, tightly adhering to the spinal cord
CSF fills the subarachnoid space between the arachnoid and pia mater, acting as a cushion

Spinal Nerves

There are 31 pairs of spinal nerves (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal)
Spinal nerves arise from the spinal cord, each with a ventral and dorsal root
Dorsal root contains sensory neurons; dorsal root ganglion (cell bodies)
Ventral root contains motor neurons

Plexuses

Ventral rami of spinal nerves form plexuses (intermingling nerves)
Four main plexuses: cervical, brachial, lumbar, and sacral (lumbosacral is also stated)
Plexuses redistribute axons to innervate specific muscles and regions
Example: brachial plexus supplies the muscles and skin of the upper limbs.

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Description

This quiz explores the structure and function of the spinal cord and spinal nerves, important components of the central nervous system. It covers aspects such as the regions of the spinal cord, the role of white and grey matter, and the organization of spinal nerves. Test your knowledge on these vital topics!