Understanding CNS Structure Through Development & A Guide to the Cerebral Cortex

Chapter 7

Gray Matter

Collection of neuronal cell bodies in the CNS, when cut, the neurons appear gray

Cortex

Any collection of neurons that form a thin sheet, usually at the brain’s surface

Ex.) Cerebral cortex (thin sheet of neurons found right under the surface of the cerebrum)

Nucleus

Clearly distinguishable mass of neurons, usually deep in the brain

Substantia

Group of related neurons deep within the brain, but usually with less distinct borders than a nucleus

Locus

Small, well-defined group of cells

Ganglion

Collection of neurons in the PNS

Nerve

Bundle of axons in the PNS, and only one collection of axons in the CNS are called a nerve, the optic nerve

White Matter

Collection of CNS axons, that when cut, appear white

Tract

Collection of CNS axons having a common site of origin and common destination

Bundle

Collection of axons that run together, but do not necessarily have a common origin or destination

Capsule

Collection of axons that connect the cerebrum with the brain stem

Commissure

Any collection of axons that connect one side of the brain with the OTHER side

Lemniscus

Tract that meanders through the brain like a ribbon

Neural Tube

a hollow embryonic structure in a developing fetus that eventually forms the central nervous system, including the brain and spinal cord

Neural Crest

As the neural folds come together, some neural ectoderm is pinched off and comes to lie just lateral to the neural tube. This tissue is called:

Neurulation

The process by which the neural plate becomes the neural tube is called

Differentiation

The process by which structures become more complex and functionally specialized during development

Forebrain

The rostral-most vesicle is called the prosencephalon, the prosencephalon is also called:

Midbrain

Behind the prosencephalon lies another vesicle called the mesencephalon, or:

Hindbrain

Caudal to this is the third primary vesicle, the rhombencephalon, or:

Diencephalon

The central structure that remains after the secondary vesicles have sprouted off is called:

Telencephalon

The telencephalic vesicles together form the:

Olfactory Bulb

Another pair of vesicles sprout off the ventral surfaces of the cerebral hemispheres, giving rise to the: blank, which participate in the sense of smell

Lateral Ventricles

The fluid-filled spaces within the cerebral hemispheres are called the:

Third Ventricle

the space at the center of the diencephalon is called the:

Cerebral Cortex

he walls of the telencephalic vesicles appear swollen due to the proliferation of neurons. These neurons form two different types of gray matter in the telencephalon, (1)

Basal Telencephalon

he walls of the telencephalic vesicles appear swollen due to the proliferation of neurons. These neurons form two different types of gray matter in the telencephalon, (2)

Thalamus

the diencephalon differentiates into two structures: (1) nestled deep inside the forebrain, gets its name from the Greek word for “inner chamber”

Hypothalamus

the diencephalon differentiates into two structures: (2)

Cortical White Matter

contains all the axons that run to and from the neurons in the cerebral cortex. Also continuous with the internal capsule

Corpus Callosum

is continuous with the cortical white matter and forms an axonal bridge that links cortical neurons of the two cerebral hemispheres

Internal Capsule

links the cortex with the brain stem, particularly the thalamus.

Tectum

The dorsal surface of the mesencephalic vesicle becomes a structure called:

Tegmentum

The floor of the midbrain becomes the:

Cerebral Aqueduct

The CSF-filled space in between constricts into a narrow channel called the:

Pons and Medulla Oblongata

The hindbrain differentiates into three important structures: the cerebellum, the *blank*, and the *blank*

Medulla

The combination of the Pons and the Medulla Oblongata is called the:

Fourth Ventricle

The CSF-filled tube becomes the:

Spinal Canal

a bony channel running through the center of the vertebral column that houses and protects the spinal cord

Dorsal Horn

Cut in cross section, the gray matter of the spinal cord (where the neurons are) has the appearance of a butterfly. The upper part of the wings is called the:

Ventral Horn

Cut in cross section, the gray matter of the spinal cord (where the neurons are) has the appearance of a butterfly. The lower part of the wings is called the:

Sulcus

The grooves in the surface of the cerebrum are called:

Gyrus

The bumps of the brain are called:

Temporal Lobe

Under the temporal bone (temple) of the skull is the:

Frontal Lobe

The portion of the cerebrum lying just under the frontal bone of the forehead is called the:

Central Sulcus

Marks the posterior border of the frontal lobe

Parietal Lobe

Caudal to the central sulcus is the:

Occipital Lobe

Caudal to the parietal lobe, at the back of the cerebrum under the occipital bone, lies the:

Hippocampus

Medial to the lateral ventricle is a piece of cortex that is folded onto itself in a peculiar shape. This structure is called the: *blank,* and is only a single cell layer

Olfactory Cortex

Connected to the hippocampus ventrally and laterally is another type of cortex that has only two cell layers. It is called the:

Neocortex

Only found in mammals. The olfactory cortex is separated by a sulcus, called the rhinal fissure, from another more elaborate type of cortex that has many cell layers. This remaining cortex is called the:

Cytoarchitectural Map

a diagram of the brain that divides the cerebral cortex into distinct regions based on the microscopic arrangement, size, shape, and density of its cells

Connectome

a comprehensive map of neural connections in the brain, often described as its biological "wiring diagram"