It twists, it bends, it can cup, it helps suck. The tongue is an essential part of human anatomy. Many of us grew up believing the playful tongue is the strongest muscle in the body.
But, is it really?
There is no straightforward answer to this question. To understand the tongue’s strength and movement, it is necessary to first examine basic muscle anatomy, the muscular system’s relationship to the body, and disorders of the muscular system.
Every movement in the body involves each body system. Without the active cooperation of the nervous, circulatory, endocrine, respiratory, digestive, immune, skeletal, and muscular systems, just to name a few, the body cannot create movement. Every system of the body overlaps and is interdependent.
Without the nervous system, it is impossible to coordinate the muscles of the body or to modulate the dilation of the blood vessels that supply the brain, heart, bones, or muscles with oxygen-rich blood.
Without the circulatory system, other systems, such as the respiratory, digestive, and endocrine systems would not be able to distribute oxygen, nutrients, and hormones to the cells of the body.
The skeletal system and the muscular system, collectively known as the musculoskeletal system, are often treated separately when reviewing anatomy. When reviewing movement, however, it makes sense to think of the muscles and bones working together to negotiate the body’s relation to gravity and space.
The muscular system is made up of muscles, tendons, and nerve endings that orchestrate the precise sequencing and timing of muscle actions. The major muscles of the body are shown in figure 1.
A working muscle is an organ made up of at least four different tissues, as shown in figure 2:
There are three basic types of muscle tissue, as illustrated in figure 3:
The skeletal muscle that we see with the naked eye is made up of bundles of fascicles (illustrated in figure 4) enveloped by a thick connective tissue called the fascia (or deep fascia). The fascia should not be confused with the layers of tissue located within the structure of muscle.
The fascicles consist of bundles of muscle fibers (muscle cells); inside the muscle cells are bundles of myofibrils (myofilaments). The myofibrils are made up of thick and thin twisted strands (filaments) that overlap and lie alongside each other.
Each of these bundles of fascicles, muscle fibers, and myofibrils are wrapped in a layer of connective tissue (epimysium, perimysium, endomysium, and sarcolemma). All of the layers of connective tissue come together—at the ends of the muscles—to create tendons that connect muscles to bones (see figure 5).
Muscles surround joints and wrap around bones in astonishingly sophisticated spiraling layers. The principal functions of the muscular system in the body are as follows.
Skeletal muscles assist in the voluntary actions of every human body part. Active contraction of these muscles transpires at the expense of energy, which creates a force that moves the body part. Muscles can be viewed as the motors of the body, which convert chemical energy, present in food, into mechanical work.
The muscles work collectively as a matrix of potential movement choices. This pattern affects every articulation in the body. Muscles do not function in isolation, and a single muscle never works without support and modulation from other muscles. Each muscle affects every other muscle, whether they are nearby or far away.
When a muscle contracts, molecules create and release bonds between the thick (myosin) and thin (actin) filaments of the sarcomere (a structural unit of a myofibril), as seen in figure 6, to create a sliding action that increases their overlap. This action draws the two ends of the myofibril toward each other. If enough myofibrils shorten, the whole muscle slides shorter.
The human skeleton is composed of bones and the joints that are between them. Skeletal muscles play a significant role in stabilizing the human skeleton. They also help in maintaining proper posture. Muscular and connective tissue provide the joints with stability.
Muscles use a substantial amount of the body’s total energy during an activity such as contraction. Because of this, the body’s metabolic rate is increased, producing a significant amount of heat in the body. This feature of muscles is of particular importance for individuals living in cold climates.
Cardiac muscles are responsible for forcing the blood out of the heart and pumping it throughout the body. The blood is in constant movement with the regular pumping motion of the heart, thereby supplying oxygen and nutrients to every tissue in the body and also removing waste products.
Smooth muscles line the organs of the human digestive system, such as the esophagus, stomach, and intestine. These muscles contract and aid in the digestive system to digest food.
Many ailments can affect muscles. Muscle disorders can cause pain, weakness, or even paralysis (immobility).
Now, on to what you’ve been waiting for—is the tongue the strongest muscle in the body?
The short answer is no.
Just because the tongue doesn’t fatigue (that is if a person doesn’t have any disorders), doesn’t mean it is the strongest.
The question of whether the tongue is the strongest muscle in the body is itself misleading. The soft tongue is not just one muscle; it is a collection of eight separate muscles. There is a lot of redundancy in the muscle architecture of the tongue, which means the activation of different muscle fibers gets the same result.
The tongue also doesn’t win for having the most brute force (i.e., the quadriceps and glutes, which contain a large number of sarcomeres) or for having the most overall work done in the course of a lifetime. By the later measure, the hardest working muscle in the body is the one that is pumping and pumping 24/7 to keep the blood flowing: your heart.
This article is not all inclusive. Please contact us at firstname.lastname@example.org to reach the author and recommend other facts or muscular disorders that interest you!
Written by Sarah Gehrke, MSN, RN and last updated Oct 12, 2017
Last reviewed by Michael A. Tomeo MD on Oct 12, 2017