Lab Cns Sheep Brain

Module 07 Lab Worksheet: Central Nervous System- Sheep Brain Dissection

Introduction

This week’s lab will focus on the central nervous system (CNS) and the identification of the anatomical structures that define the CNS.

Objectives

Objectives for this week’s lab include: 1) Demonstrate knowledge and understanding of specimen dissection, 2) Identification of gross anatomy of the sheep brain, and 3) Recognize gross anatomy of the CNS on pictures of human cadaver.

Overview

The CNS consists of the brain and spinal cord. The brain consists of the cerebrum, cerebellum, and brain stem. The cerebrum is divided into left and right hemispheres with frontal, parietal, temporal and occipital lobes within each hemisphere. The brain stem consists of the midbrain, pons, and medulla oblongata. Each region/component of the CNS has a specific function, for example, the occipital lobe allows for the function of vision.

When viewing any aspect of the CNS including the spinal cord, you will notice grey and white sections referred to as grey matter and white matter. The grey matter is technically where the somas (cell bodies) of millions and millions of neurons are collectively found while the white matter is technically where the axons (remember the myelin sheaths) of millions and millions of neurons are collectively found. Basically, the grey matter consists of the somas of neurons that allow for the neural integration (decision making) and the white matter consists of myelinated axons that “transport” neural information from one region of the CNS or PNS to another region of the CNS and/or PNS. Remember, myelin is mainly composed of lipids (fats) giving it a white appearance.

The cerebral cortex of the cerebrum is what many references refer to as “executive suite”, or “higher order” or even “the boss” as it involves the function of our conscious mind. Our ability to remember, communicate, initiate voluntary movement, perceive sensations, and be aware that...