Video Transcript
A sample of tissue is taken from a spinal cord, and the micrograph of the sample is
provided. What type of tissue is being viewed?
This question tells us that the micrograph contains a sample taken from spinal cord
tissue and asks us to identify the type of tissue shown. There are four major types of animal tissue: epithelial, connective, muscular, and
nervous. Our answer will be one of these tissue types, but which one? Well, as you likely already know, the spinal cord is part of the nervous system. More specifically, the brain and spinal cord together make up the central nervous
system. The peripheral nerves and sensory nerves, which branch out from the spinal cord, make
up the peripheral nervous system.
When they receive a stimulus, our peripheral nerves carry signals containing
information about the stimulus to the spinal cord. The spinal cord carries these signals to the brain, where they are processed. The brain then sends signals about how to respond to the stimulus back to the body
through the spinal cord.
Nervous tissues are mostly made of nerve cells called neurons, which are adapted to
receive and transmit electrical signals. Neurons have special parts called dendrites, which receive signals. They also have axons, which are the parts that carry signals away from the cell body
toward the axon terminals, where these signals can be transmitted to other
cells. To support the propagation of these electrical signals, nervous tissue also contains
a wide variety of support cells, called neuroglia.
Looking back at the micrograph, we can actually identify axons, dendrites, and
neuroglia. This, along with our knowledge that the spinal cord is part of the nervous system,
confirms that the type of tissue being viewed is nervous tissue.
