Human Anatomy: Spinal Cord and Vertebrae

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Questions and Answers

Where is the front of the vertebral foramen located?

The side closest to the feet

The side closest to the back of the body

The side closest to the head

The side closest to the front of the body (correct)

What is the reason for the different shapes of vertebrae?

To allow for the different movements of the spine

To protect the spinal cord from damage

To provide different levels of flexibility and strength (correct)

To accommodate the different sizes of the spinal nerves

How many pairs of spinal nerves are in the cervical region?

8 (correct)

What is the approximate length of the spinal cord?

42-45 cm (D) Signup and view all the answers

Which of the following is NOT a part of the central nervous system?

Peripheral nerves (A) Signup and view all the answers

What is the name of the bundle of nerves that extends from the spinal cord into the lower back?

Cauda equina (D) Signup and view all the answers

What is the average length of the vertebral column in a male?

71 cm (C) Signup and view all the answers

What is the function of the spinal cord?

To transmit messages between the brain and the rest of the body (D) Signup and view all the answers

What is the main difference between gray matter and white matter in the spinal cord?

Gray matter is primarily composed of neuron cell bodies, while white matter is composed of myelinated axons. (D) Signup and view all the answers

Which of the following sensory modalities is NOT conveyed by the dorsal column?

Pain (B) Signup and view all the answers

What is the function of the central canal in the spinal cord?

It contains cerebrospinal fluid, which cushions and protects the brain and spinal cord. (D) Signup and view all the answers

What is the name of the tract that carries sensory information from the lower body (legs, abdomen) in the dorsal column?

Fasciculus Gracilis (A) Signup and view all the answers

Where are the enlargements of the spinal cord located?

Cervical and lumbosacral regions. (B) Signup and view all the answers

Why does the butterfly shape of the gray matter change along the length of the spinal cord?

The size of the spinal cord changes, with larger diameters in the cervical and lumbosacral regions. (A) Signup and view all the answers

Which of the following statements BEST describes the somatotopic arrangement of the dorsal column?

Sensory fibers from the upper body are located laterally, while fibers from the lower body are located medially. (D) Signup and view all the answers

Where does the decussation of the first neuron in the dorsal column pathway occur?

Medulla (B) Signup and view all the answers

Which of the following is TRUE about the lateral horn of the spinal cord?

It is primarily involved in the sympathetic nervous system. (B) Signup and view all the answers

What is the order of neurons involved in the dorsal column-medial lemniscus pathway?

1st neuron in dorsal root ganglion, 2nd neuron in dorsal column nuclei, 3rd neuron in thalamus (C) Signup and view all the answers

What is the function of the dorsal column of the spinal cord?

Carry sensory information from the body to the brain. (B) Signup and view all the answers

Which of the following structures is responsible for relaying somatosensory information from the thalamus to the cerebral cortex?

Ventroposterolateral (VPL) nucleus (A) Signup and view all the answers

What is the function of the ventral horn?

Control voluntary muscle movement. (A) Signup and view all the answers

How are additional sensory fibers incorporated into the dorsal column as we ascend the spinal cord?

Fibers enter from the lateral side. (B) Signup and view all the answers

Which term refers to a collection of axons in the central nervous system?

Column (A) Signup and view all the answers

The fasciculus cuneate is responsible for carrying sensory information from which part of the body ?

Arms (C) Signup and view all the answers

What type of sensation is primarily transmitted by the dorsal column?

Proprioception (A) Signup and view all the answers

Which structure decussates at the level of the medulla?

Medial lemniscus (D) Signup and view all the answers

What is the conduction speed of the dorsal column axons?

35 – 70 m/sec (A) Signup and view all the answers

Which of the following statements is true regarding the spinal-thalamic tract?

It carries pain and temperature sensations. (C) Signup and view all the answers

In terms of myelination, how does the spinal-thalamic tract compare to the dorsal column?

It is less myelinated or unmyelinated. (B) Signup and view all the answers

Which type of sensation is NOT associated with the dorsal column?

Temperature (D) Signup and view all the answers

What role does the second neuron play in the dorsal column pathway?

Relays information to the sensory cortex. (D) Signup and view all the answers

Which statement about the dorsal column versus the spinal-thalamic tract is correct?

The dorsal column conveys sensations more rapidly. (C) Signup and view all the answers

What best characterizes the extrapyramidal pathway in relation to movement?

It is crucial for the initiation and modulation of subconscious movements. (A) Signup and view all the answers

What type of movements does the extrapyramidal system primarily regulate?

Postural and skeletal muscle tone. (C) Signup and view all the answers

Which part of the spinal cord is primarily involved in motor function?

Ventral horn. (C) Signup and view all the answers

What is the shape of the gray matter in the spinal cord often described as?

Butterfly-shaped. (A) Signup and view all the answers

What structure in the spinal cord is sometimes referred to as the 'horse's tail'?

Cauda equina. (C) Signup and view all the answers

Which tract is associated with sensory information in the spinal cord?

Spinal-thalamic tract. (A) Signup and view all the answers

In the context of spinal cord anatomy, what does 'dorsal' refer to?

Sensory function. (D) Signup and view all the answers

What division of the spinal cord is primarily responsible for voluntary motor control?

Ventral horn. (B) Signup and view all the answers

Based on the text, what sensory information is primarily conveyed by the spinal-thalamic tract? Choose all that apply.

Temperature (B), Pain (D) Signup and view all the answers

What is the likely destination of a neuron that makes up the spinal-thalamic tract, after synapsing in the thalamus?

Somatosensory cortex (C) Signup and view all the answers

Which of the following is NOT a characteristic of the spinal-thalamic tract according to the text?

It carries information primarily about fine touch and vibration. (A) Signup and view all the answers

Based on the text, what is the significance of the axial twist hypothesis?

It helps explain the presence of decussation in the nervous system. (B) Signup and view all the answers

What is the likely meaning of the term 'proprioception' as used in the text?

The sense of body position and movement. (C) Signup and view all the answers

Based on the text, why are ascending axons more vulnerable to damage as you move higher up the spinal cord?

Ascending axons have longer pathways, increasing the risk of damage. (B) Signup and view all the answers

How is the name of a sensory tract determined, according to the text?

By the origin and destination of the tract. (D) Signup and view all the answers

What is the primary purpose of the decussation of axons in the spinal-thalamic tract?

To ensure that sensory information reaches the correct side of the brain. (D) Signup and view all the answers

Study Notes

Quiz Information

A 12-minute quiz will be given in two weeks.
The quiz will cover all five lectures.

Central Nervous System

The central nervous system contains the cerebrum, diencephalon, brain stem, cerebellum, and spinal cord.
The cerebrum is composed of cerebral hemispheres.
The brain stem includes the midbrain, pons, and medulla.
The cerebellum is located at the back of the brain.
The spinal cord transmits messages between the brain and the rest of the body.

Spinal Cord

The spinal cord is a long, thin, tubular bundle that extends from the base of the brain down the back.
It transmits messages between the brain and the rest of the body.
The spinal cord is protected by bones, discs, ligaments, and muscles.
The spine is made of bones called vertebrae.
The vertebrae provide flexibility of motion, while maintaining strength and stability.

Spinal Cord Vertebrae

Vertebrae have different shapes
Different shapes allow for a range of motion
Different shapes provide strength and stability

Spinal Cord and Vertebral Foramen

The spinal cord is located in the vertebral foramen.
Vertebrae are stacked on top of each other, creating a space for the spinal nerves to enter and exit.

Spinal Cord Segments

There are 31 spinal segments in the spinal cord.
Each segment gives rise to a pair of spinal nerves.
The cervical region contains 8 pairs of nerves.
The thoracic region contains 12 pairs of nerves.
The lumbar region contains 5 pairs of nerves.
The sacral region contains 5 pairs of nerves.
The coccygeal region contains 1 pair of nerves.

Spinal Cord and Cauda Equina

The spinal cord tapers at the lumbar region to become the conus medullaris.
Spinal nerves arising from the conus medullaris and below continue down the vertebral column as the cauda equina.
The cauda equina resembles a horse's tail, hence the name.

Development of Spinal Cord

In the fetus, the spinal cord and vertebral column are the same length until the third month.
Spinal nerves pass through the neural foramina as the embryo grows, and the spinal cord lengthens.
The spinal cord gradually recedes from below, as vertebral column growth is faster.

Human Brain Growth

The human brain grows much less than other parts of the body after birth.
As a result, the brain is proportionally smaller in adults compared to children.

Cauda Equina

The cauda equina is the collection of spinal nerve roots that extend from the conus medullaris.
The cauda equina resembles a horse's tail, hence the name.
The spinal cord ends approximately at the level of L1 or L2.

Spinal Cord Organization and Function

The spinal cord is organized into a butterfly shape.
The grey matter is in the center, and white matter surrounds it.
The cervical and lumbosacral regions of the spinal cord are enlarged.
The enlargements contain more grey matter where motor neurons and sensory neurons reside, and allows for greater control of muscle movement and sensory input from limbs.

Spinal Cord and Grey and White Matter Organization

There are areas of grey matter (collection of neuron cell bodies)
There are areas of white matter (collection of bundles of myelinated nerve fibers/axons)
The shape of grey matter is often described as a butterfly or an 'H' shape
The grey matter is centrally located in the spinal cord, surrounded by white matter.

Sympathetic and Parasympathetic Nervous System

The sympathetic nervous system controls "fight or flight" responses.
The parasympathetic nervous system controls "rest and digest" functions.
The sympathetic nervous system originates in the thoracic and lumbar regions of the spinal cord.
The parasympathetic nervous system originates in the cranial and sacral regions of the spinal cord.

Spinal Cord White Matter Tracts

The ascending tracts carry sensory information up to the brain.
The descending tracts carry motor commands from the brain.
White matter is organized into tracts (bundles of axons) with a common origin and destination.
Different tracts are designated to sensory or motor functions in the spinal cord
Several types of sensory tracts and motor tracts exist, carrying specific types of information to and from the brain
The dorsal column is more recent in terms of evolutionarily, than the spinal-thalamic tract, because it has more myelination
The amount of white matter in the cervical and lumbosacral regions of the spinal cord is different from the thoracic region. This is due to the need for higher density of fibres and neurons in the control of the limbs.
The spinal-thalamic tract conveys sensory information about pain, temperature, and crude touch to the brain.
The dorsal/posterior column carries sensory information about fine touch, pressure, vibration, and proprioception to the brain.
The spinocerebellar tract carries proprioceptive information to the cerebellum.

Spinal Cord and Reflexes

Spinal reflexes do not require input from the brain.
Spinal reflexes involve sensory neuron, interneurons, and motor neurons
The brain can send orders down the spinal cord but it not needed for spinal reflexes.
Some reflexes involve direct connections between the dorsal and ventral horns.

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Description

Explore the intricate structures of the spinal cord and vertebrae in this quiz. Covering key concepts such as the location of the vertebral foramen, spinal nerve pairs, and characteristics of gray and white matter, it’s perfect for anatomy enthusiasts. Test your knowledge and understanding of the central nervous system’s functions and anatomy.