Lesson 10 - Other Tissues: Muscular and Nervous
Student Performance Objectives
1. List and state the locations of the 3 types of muscular tissue found in the human body.
2. Explain the basic functions of muscular tissue.
3. State the two major characteristics of nervous tissue.
4. List the 4 basic functions of nervous tissue.
A. Other Tissues: to be examined more closely in subsequent lessons.
1. Muscular Tissue - tissue capable of contraction and relaxation that brings about
movement. There are three types of muscular tissue.
a. Skeletal (striated) muscle - generally considered to be under voluntary,
conscious control, although many reflex activities involving these muscles
occur automatically (unconsciously). The tissue is composed of elongated
muscle fibers possessing many nuclei per fiber (multinucleate). This tissue
forms much of the bulk of a human body, composing the muscles that are
attached to and which move the skeleton, generally at the joints. The
contractile filaments within each fiber are arranged in a regular, repeating
pattern which presents the characteristic striated appearance under the light
b. Smooth muscle - involuntary muscle found in the walls of the body's hollow
organs like the stomach and other digestive organs, the urinary bladder and
the blood vessels. Smooth muscle cells are mostly uninucleate; some are
multinucleate. The contractile filaments within this muscle type do not occur
in the regular arrangement that would produce striations so that the muscle,
when viewed under the light microscope, appears non-striated, or smooth.
c. Cardiac - the involuntary muscle tissue composing the heart's myocardium.
Its rhythmic contractions propel the blood through the cardiovascular
system under pressure. Cardiac muscle fibers are striated, are "welded" to
each other through desmosomes (part of intercalated discs), and possess gap
junctions that facilitate electrical signaling from one fiber to the next.
2. Nervous Tissue - tissue possessing the properties of irritability (the ability to be
stimulated and to respond to such stimulation) and conductivity (the ability to transmit
electrochemical signals over long distances along specialized cellular extensions - the
axons and dendrites. Its signals help to regulate and coordinate bodily functions. The
major organized regions of nervous tissue (brain, spinal cord, peripheral nerves, and
sensory receptors) carry out the following functions:
a. Conduct sensory signals (information) from receptors into the central nervous
system (CNS - which consists of the brain and spinal cord working as an
b. Analysis of incoming signals.
c. Store incoming signal patterns as memory.
d. Conduct motor signals from the CNS to muscle and glands.