Histology of the Central Nervous System

RichTourmaline9881 avatar
RichTourmaline9881
·
·
Download

Start Quiz

Study Flashcards

75 Questions

What is the functional unit in both the CNS and PNS?

Neurons

Which type of neuron comprises the sensory neurons of the retina, the olfactory epithelium, and the inner ear?

Bipolar neurons

What do glial cells specialize in?

Supporting and protecting neurons

Which part of the neuron contains the nucleus and organelles?

Cell body

What is the primary function of pseudounipolar neurons?

Sensory processing

Which cells are responsible for producing myelin in the Central Nervous System (CNS)?

Oligodendrocytes

What is the main function of microglia in the brain?

Protecting from infection and injury

What is the role of ependymal cells within the Central Nervous System (CNS)?

Line the ventricles and produce CSF

What is the function of the meninges in relation to the brain and spinal cord?

Providing mechanical protection

Where is cerebrospinal fluid (CSF) primarily located in the body?

In the ventricles and around the spinal cord

What is the main function of astrocytes in supporting neurons?

Maintaining tight junctions and metabolic support

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

Tightly controlling passage of substances into the CNS

What is the primary function of the choroid plexus in the ventricles?

Producing cerebrospinal fluid (CSF) and removing water from blood

What type of neurons are primarily sensory and located near the Central Nervous System (CNS)?

Pseudounipolar neurons

Which type of cells produce and remove cerebrospinal fluid (CSF) within the ventricles?

Ependymal cells

What is the approximate length of the spinal cord?

45 cm

Where does the spinal cord terminate inferiorly?

Coccyx

What is the shape of the spinal cord in cross-section?

Circular

What stabilizes the entire spinal cord by providing a connection from the conus medullaris to the coccyx?

Fibrous cord

At what level does the spinal cord sometimes terminate inferiorly?

L1 - L2 intervertebral disc

What is the weight of the spinal cord?

30 grams

Where does the spinal cord extend superiorly, forming a continuous structure?

Medulla oblongata

Which artery is known as the largest anterior segmental medullary artery and supplies the lower thoracic and upper lumbar parts of the spinal cord?

Artery of Adamkiewicz

Which veins run along the posterior median sulcus and end in the intervertebral veins?

Posterior spinal veins

Which vessel forms an arterial vasocorona around the spinal cord and supplies the peripheral lateral aspect?

Lateral sacral arteries

Which veins are situated in the pia mater and drain into the internal and external vertebral plexuses?

Ant & Post Internal Vertebral Venous Plexus

Which veins consist of anterior and posterior plexuses that anastomose freely with each other?

Ant & Post External Vertebral Venous Plexus

Which veins drain into dural venous sinuses superiorly and have connections with thoracic, abdominal, and intercostal veins?

Ant & Post Internal Vertebral Venous Plexus

Which vessel arises from the lumbar, iliolumbar, and median & lateral sacral arteries and supplies the conus medullaris?

Arise from lumbar, iliolumbar, and median & lateral sacral a.a.

Which veins are valveless and situated in the pia mater, forming an anastomotic network along the surface of the spinal cord?

Ant & Post Internal Vertebral Venous Plexus

Which veins consist of anterior and posterior plexuses located partly on the post. surfaces of vertebral arches & their processes, and partly between the deep dorsal muscles?

Ant & Post External Vertebral Venous Plexus

Which of the following describes the attachment of spinal nerves to the spinal cord?

Spinal nerves attach to the spinal cord with anterior (motor) roots and posterior (sensory) roots

What is the composition of the white matter that surrounds the grey matter in the spinal cord?

Mainly myelinated fibers with neuroglia & blood vessels

What type of arteries are responsible for the blood supply to the spinal cord?

Longitudinal vessels and segmental (radicular) spinal arteries

What is the anatomical configuration of grey matter in the spinal cord?

Characteristic H or butterfly shape

What is the role of spinal ganglia in relation to the dorsal spinal roots?

Large groups of neurons on the dorsal spinal roots

Where do spinal nerves penetrate the dura to become continuous with peripheral nerves?

Intervertebral foramen

What is the differentiation of the white matter in the spinal cord called?

Anterior, posterior & lateral funiculi (white columns)

Which structure serves to anchor the spinal cord to the end of the dural sac?

Filum terminale

What is the thickest and strongest layer among the connective tissue coverings of the spinal cord?

Dura mater

Which layer forms a spider-web like structure around the spinal cord and separates it from the dura mater?

Arachnoid mater

What is the site for anesthetic injections in the context of spinal cord protection?

Epidural space

Which structure allows the spinal cord to 'float' in the spinal canal and alternate with the points of exit of nerve roots?

Denticulate ligaments

What is the primary function of the central canal in relation to nutrient transport and impact protection?

To transport cerebrospinal fluid (CSF)

Where is the central canal located in relation to its size and shape along the length of the spinal cord?

Posterior third in conus medullaris

What is the approximate weight of the spinal cord?

25 grams

Where does the spinal cord sometimes terminate as low as?

Intervertebral disc between L5 & S1

How long is the spinal cord approximately?

40 - 45 cm

What is the shape of the spinal cord in cross-section?

Circular

What structure connects the conus medullaris to the back of the coccyx?

Filum terminale

Which part of the spinal cord is continuous with the medulla oblongata?

Superior part

What stabilizes the entire spinal cord by providing a connection from the conus medullaris to the coccyx?

Coccygeal ligament

What structure is a long, thin tissue that extends from the conus medullaris to the coccyx?

Filum terminale

What is the largest and thickest of the three layers surrounding and protecting the spinal cord?

Dura mater

What is the potential space located between the outermost layer of the spinal meninges and the walls of the vertebral canal?

Epidural space

Which double folds of pia mater allow the spinal cord to 'float' in the spinal canal and alternate with the points of exit of nerve roots?

Denticulate ligaments

Which type of neurons are primarily found in the dorsal spinal roots?

Sensory neurons

What is the continuous structure filled with cerebrospinal fluid (CSF) that extends throughout the length of the spinal cord?

Central canal

What is the main role of the segmental (radicular) spinal arteries in the spinal cord?

To anastomose with the anterior spinal artery

Which fissure divides the spinal cord into right and left halves, and is a deep longitudinal fissure?

Anterior median fissure

What is the configuration of grey matter in the spinal cord?

H-shaped

What is a shallow furrow that runs along the posterior aspect of the spinal cord?

Posterior median sulcus

What is the composition of the white matter that surrounds the central core of grey matter in the spinal cord?

Mainly myelinated fibers with neuroglia

What is the source of blood supply for the longitudinal vessels that descend on the surface of the spinal cord?

Vertebral arteries

Where are the spinal nerves united as ventral and dorsal roots, attached to the sides of the spinal cord?

Intervertebral foramen

What is significant about the amount of grey matter present at any given level in relation to muscle innervation?

It is inversely proportional to muscle innervation

Which artery is responsible for forming an arterial vasocorona around the spinal cord and supplying the peripheral lateral aspect?

Lumbar artery

Where does the Artery of Adamkiewicz arise from?

Intercostal arteries

Which veins are valveless and situated in the pia mater, forming an anastomotic network along the surface of the spinal cord?

Radicular (or segmental medullary) veins

Which veins run behind the nerve roots and end in the intervertebral veins?

Lateral segmental (radicular) veins

Which venous plexus consists of anterior and posterior plexuses that anastomose freely with each other?

External vertebral venous plexus

Where do ascending branches from lumbar, iliolumbar, and median & lateral sacral arteries supply the conus medullaris?

Sacral region

Which veins empty into dural venous sinuses superiorly and have connections with thoracic, abdominal, and intercostal veins?

Internal vertebral venous plexus

What is the major supply territory of the Artery of Adamkiewicz?

Lower thoracic & upper lumbar parts of spinal cord

What is another name for the Artery of Adamkiewicz?

All of the above

Study Notes

  • Pseudounipolar neurons are primarily sensory neurons near the Central Nervous System (CNS).

  • Brain and spinal cord are covered by three protective membranes called meninges.

  • The brain and spinal cord are made up of gray matter and white matter.

  • Gray matter (pia mater) is a thin layer with abundant nerve fibers, glia, and blood vessels.

  • White matter (dura mater and arachnoid layer) is a protective layer made of fibrous tissue and collagen.

  • Cerebrospinal fluid (CSF) fills the brain ventricles and spinal cord, providing mechanical and immunological protection.

  • Lumbar puncture is a medical procedure to collect CSF for diagnostic testing.

  • Astrocytes are the largest neuroglial cells, helping neurons by maintaining tight junctions and metabolic support.

  • Oligodendrocytes produce myelin, and one cell myelinates many axons.

  • Microglia are phagocytic cells, protecting the brain from infection and injury.

  • Ependymal cells line the ventricles and produce CSF.

  • Blood-brain barrier (BBB) is a functional barrier that tightly controls the passage of substances into the CNS.

  • Choroid plexus in the ventricles produces CSF and removes water from blood.

  • The cerebrum consists of white matter and gray matter, with the cortex being highly convoluted.

  • The cerebral cortex contains various neuronal and glial cells, including Betz's pyramidal cells, capillaries, oligodendrocytes, astrocytes, and microglia.

  • The cerebellum's white matter forms a branched tree-like structure.

  • The Purkinje layer is an intermediate layer in the cerebellum with large Purkinje cells and tree-like dendritic arborizations.

  • The spinal cord consists of several structures, including the conus medullaris, cauda equina, filum terminale, and spinal meninges.

  • The conus medullaris is a medullary cone located at the end of the spinal cord, while the cauda equina is a collection of nerve roots that continue beyond the termination of the spinal cord.

  • The filum terminale is a long, thin tissue that extends from the conus medullaris to the coccyx and serves to anchor the spinal cord to the end of the dural sac.

  • The spinal cord is surrounded and protected by three connective tissue coverings: the dura mater, arachnoid mater, and pia mater.

  • The dura mater is the thickest and strongest of the three layers, serving as a durable protective covering for the spinal cord. It is continuous with the cranial dura mater at the cranial end and joins the filum terminale at the caudal end.

  • The arachnoid mater is a thin, transparent layer that forms a spider-web like structure around the spinal cord. It carries blood vessels and separates the spinal cord from the dura mater.

  • The pia mater is the innermost layer of the spinal meninges, which adheres closely to the surface of the spinal cord. It terminates at the inferior limit of the spinal cord and contains the central canal, which is filled with cerebrospinal fluid (CSF) and extends throughout the length of the cord.

  • The epidural space is a potential space located between the outermost layer of the spinal meninges (dura mater) and the walls of the vertebral canal. It contains loose connective and adipose tissue and serves as a site for anesthetic injections.

  • The denticulate ligaments are double folds of pia mater that extend from the lateral aspects of the cord, penetrate the arachnoid, and attach to the inner surface of the dura. They allow the cord to "float" in the spinal canal and alternate with the points of exit of nerve roots.

  • The central canal, also known as the ependymal canal, is a continuous structure filled with CSF that extends throughout the length of the spinal cord. It helps transport nutrients to the cord and protects it by cushioning against impact.

  • The spinal cord contains several fissures and sulci that divide it into right and left halves. The anterior median fissure is a deep longitudinal fissure, while the posterior median sulcus is a shallow furrow. The spinal cord is joined by a commissural band of tissue that contains the central canal.

  • The posteriorolateral sulcus is a sulcus that runs laterally from the posterior median sulcus on each side of the spinal cord.

  • The size and shape of the central canal varies along the length of the spinal cord, with it being situated nearer the anterior aspect at the cervical and thoracic segments and in the center at the lumbar segments. In the conus medullaris, it is located in the posterior third and is lined by ciliated, columnar epithelium.

  • The central canal, also known as the terminal ventricle or the ampulla caudalis, is a structure located at the transition from the tip of the conus medullaris to the origin of the filum terminale. It is a fusiform, widest part of the central canal that is visible in newborns and up to 5 years of age, but regresses during the first weeks after birth.

  • The spinal cord contains several fissures and sulci that divide it into right and left halves. The anterior median fissure is a deep longitudinal fissure, while the posterior median sulcus is a shallow furrow. The spinal cord is joined by a commissural band of tissue which contains the central canal. The posteriorolateral sulcus is a sulcus that runs laterally from the posterior median sulcus on each side of the spinal cord.

  • The Spinal Cord: Gross Anatomy

  • 31 pairs of spinal nerves attached

  • Dorsal roots enter the spinal cord in the cervical and upper thoracic segments only

  • Spinal nerves attach to the spinal cord with anterior (motor) roots and posterior (sensory) roots

  • Each root is attached by series of rootlets, each posterior nerve root has a posterior root ganglion (dorsal root ganglion)

  • Spinal nerves are united as ventral and dorsal roots, attached to the sides of the spinal cord

  • Spinal ganglia are large groups of neurones on the dorsal spinal roots

  • Spinal nerves penetrate the dura at the intervertebral foramen, and the sleeve of dura becomes continuous with the epineurium of the peripheral nerves

  • The Spinal Cord: Gross Anatomy & Internal Structure

  • Spinal cord has a central core of grey matter surrounded by an outer covering of white matter

  • Grey matter is configured in a characteristic H or butterfly shape

  • Amount of grey matter present at any given level is related to amount of muscle innervated at that level

  • Spinal cord is differentiated into ventral & dorsal columns, or horns

  • White matter surrounds the central core of grey matter, composed mainly of myelinated fibres with neuroglia & blood vessels

  • White matter is divided into anterior, posterior & lateral funiculi (white columns)

  • Rostral regions of the spinal cord have more white matter due to accumulated ascending fibers and fewer descending fibers

  • Grey matter and white matter are continuous across the midline through the grey and white commissure

  • Cervical sections are wide and flat with large ventral horn enlargements, while sacral sections have almost no white matter

  • The Spinal Cord: Gross Anatomy & Blood Supply

  • Blood supply comes from 2 sources: longitudinal vessels and segmental (radicular) spinal arteries

  • Longitudinal vessels arise superior to the cervical portion of the cord and descend on its surface

  • Ant. spinal artery: a single artery from vertebral arteries, runs parallel to the anterior median fissure

  • Post. spinal arteries: paired arteries that originate from the terminal branch of each vertebral artery and descend along the posterolateral sulcus

  • Segmental (radicular) spinal arteries: branches of the vertebral arteries that enter the spinal cord via the intervertebral foramina and anastomose with the anterior spinal artery.

Test your knowledge of the histology of the central nervous system with this quiz. Explore topics such as nerve cells, glial cells, brain anatomy, spinal cord, peripheral nervous system, and the distribution of myelin.

Make Your Own Quizzes and Flashcards

Convert your notes into interactive study material.

More Quizzes Like This

Use Quizgecko on...
Browser
Browser