Nervous System Lab 1

The Central Nervous System

In this lab you will learn about structures of the central nervous system.

Begin by clicking on the following:

Central Nervous System Anterior View

Here you will see the brain and spinal cord.

The superficial portion of the brain is called the cerebrum. The cerebrum is divided into lobes. There are a number of folds on the cerebrum known as gyri. These are separated by grooves called sulci. Deep grooves are called fissures.

Identify the following structures:

    Frontal Lobes Right and Left

    Temporal Lobes Right and Left

    Pons

    Spinal Cord

Next rotate the image to 90 degrees to the right.

Underneath the cerebrum lies the cerebellum.

Identify the following structures:

    Parietal lobe right

    Temporal lobe right

    Occipital lobe right

    Cerebellum right

    Vermis of cerebellum

Notice that the frontal lobe is separated from the parietal lobe by a sulcus known as the central sulcus. The lateral fissure separates the temporal lobe from the frontal and parietal lobes.

Dissect away the following structures:

    Frontal lobe right

    Parietal lobe right

    Temporal lobe right

    Occipital lobe right

    Optic radiation right

    Corticospinal (and pyramidal) tract and corticobulbar tract right

    Claustrum right

    Putamen right

    Globus pallidus external segment right

    Globus pallidus internal segment right

    Caudate nucleus right

Locate the cerebral spinal fluid of the lateral ventricle right. This is part of the system of fluid-filled chambers in the brain called ventricles. There are 4 ventricles including right and left lateral ventricles, a 3rd and 4th ventricle. The ventricles contain a clear fluid called cerebral spinal fluid. What you see is the space in the right cerebral hemisphere that contains the fluid. This is called the right lateral ventricle.

Now dissect this structure away (cerebral spinal fluid of lateral ventricle right).

Locate the reticular nucleus of the thalamus right. This is part of a portion of the brain called the thalamus. One of the primary functions of the thalamus is to relay sensory information to the cerebrum.

Dissect away the following:

    Reticular nucleus of the thalamus right

    Ventral nuclei of the thalamus right

    Lateral posterior nucleus of the dorsal nucleus of the thalamus right

    Anterior nuclei of the thalamus right

    Fornix right

    Medial nucleus of the thalamus right

You should now be able to locate the cerebral spinal fluid of the 3rd ventricle. The 3rd ventricle is a space near the thalamus.

Locate the following:

    Splenium of corpus callosum

    Trunk of corpus callosum

    Genu of corpus callosum

The corpus callosum is a bridge of white matter that connects the 2 cerebral hemispheres.

Click on the following to reorient the brain:

Lateral view of brain and spinal cord

Locate the hypothalamus. Notice the hypothalamus is anterior and inferior to the thalamus.

Locate the adenohypophysis and neurohypophysis. These are both parts of the pituitary gland. The adenohypophysis is the anterior pituitary and the neurohypophysis is the posterior pituitary. Notice how close the pituitary gland is to the hypothalamus. Both are closely connected and function to regulate and secrete hormones in the endocrine system.

Spinal Cord

Reorient the dissection by clicking on the following:

Anterior spinal cord with spinal nerves

Here you see the spinal cord with the spinal nerves. Locate the following:

    Cervical nerve C1 Left

    Cervical nerve C3 Left

    Intercostal Nerve T4 Right

    Lumbar Nerve L2 Left

This is a sampling of the spinal nerves that exit the spinal cord. They are named for where they exit the cord at the vertebral levels. The spinal cord is a pathway that sends information in the form of nerve impulses to and from the brain. The information enters and exits the cord via the spinal nerves.

Locate the phrenic nerve right. This nerve exits the spinal cord at C3, C4, and C5 and supplies the diaphragm. If there is a spinal cord injury above these levels, the person will need assistance in breathing such as a ventilator.

Use the diagrams in your textbook to study the remaining central nervous system structures including the spinal cord structures.

This concludes this lab.