Athena Vale
Muscle is a contractile tissue found in animals that is responsible for movement and the ability to react to external or internal stimuli. The function of muscle tissue is to contract, while nervous tissue is responsible for communication. There are three types of muscles in animal bodies: smooth, skeletal, and cardiac. Muscle fibres differ from species to species and between parts of the same animal. Some animal groups, such as sea sponges, do not have muscles but are still capable of movement.
| Characteristics | Values |
|---|---|
| Presence in animals | Most animals have muscles, but some animal groups, such as sea sponges, do not. |
| Function | Muscles produce movement through contraction. They also generate heat in warm-blooded animals. |
| Types | There are three types of muscles: smooth, skeletal, and cardiac. |
| Control | Some muscles are under conscious control (voluntary), while others are not (involuntary). |
| Structure | Muscles differ in structure, including the presence or absence of striations or bands, the number and location of nuclei, and their location within the body. |
| Energy source | Muscles derive energy from the metabolism of food, converting chemical energy into mechanical energy. |
Explore related products
What You'll Learn
- Muscle contractions are the basis of movement in many, but not all, species
- Muscle cells fuel their actions by converting chemical energy into mechanical energy
- Smooth muscle tissue occurs in the walls of hollow organs such as the intestines, stomach, and urinary bladder
- There are three types of muscle in animal bodies: smooth, skeletal, and cardiac
- Muscle fibres differ from species to species of animal and between parts of the same animal
Muscle contractions are the basis of movement in many, but not all, species
Muscle contractions are the basis of movement for many species. Muscle, a contractile tissue found in animals, produces motion by converting chemical energy in the form of adenosine triphosphate (ATP), derived from the metabolism of food, into mechanical energy. The work done by muscles requires this chemical energy, which is converted to work and heat when muscles shorten while exerting tension and performing mechanical work. Similarly, when muscles lengthen while exerting tension, the chemical energy used, along with the mechanical energy absorbed by the action, is converted to heat. This heat generation is an important function of muscle in warm-blooded animals, as shivering generates heat to warm the body.
Muscles are not the only means of movement in animals, however. Some animal groups, such as sea sponges, lack muscles altogether, having branched off from the evolutionary path before muscle cells evolved. Yet, these animals are still capable of movement, as sponges can contract without muscles. This has led evolutionary biologists to study the contractile sponge epithelium, suggesting that sponge epithelial cells and the muscle cells of other animals may share a common contractile cellular predecessor.
In terms of muscle structure, some muscles are under conscious control and are called voluntary muscles, while others, called involuntary muscles, are not consciously controlled by the organism. For example, skeletal muscles, which are long and cylindrical, attach to bones or skin and control locomotion and any movement that can be consciously controlled. They have a striped or striated appearance due to the regular arrangement of contractile proteins (actin and myosin). On the other hand, involuntary muscles, like those in the heart, pump blood throughout the body and maintain blood pressure.
Even within the category of voluntary muscles, there are different types of skeletal muscle function. White and red muscles are recruited depending on whether an animal needs fast and short or steady and prolonged locomotion. Additionally, some animals have muscle systems that are based on the interaction of longitudinal and circular muscles, like the simple worm-like animal shown in Figure 5. For example, the shell muscle of the abalone Haliotis connects the domed shell to its adhesive foot. When the circular and radial fibres of the muscle contract, the shell is raised from the rock, allowing respiratory water currents to circulate.
The Muscle Shirt: A Guide to This Summer's Essential
You may want to see also
Explore related products
Muscle cells fuel their actions by converting chemical energy into mechanical energy
Muscle cells are contractile tissues found in animals that produce motion. They fuel their actions by converting chemical energy into mechanical energy. This chemical energy is derived from the metabolism of food, which is then converted into adenosine triphosphate (ATP) to be used by the muscles. ATP is essential for both muscle contraction and relaxation.
The process of converting chemical energy into mechanical energy involves muscle cells using the stored chemical energy from the food we eat and converting it into kinetic energy. This energy of motion is similar to the energy produced by an engine, which uses the stored energy of petrol and converts it into heat and kinetic energy. However, muscle cells do not rely solely on the ATP within them, as this would only last for about 3 seconds. Instead, they utilise creatine phosphate, which can be broken down quickly to synthesise more ATP and meet the energy requirements of the muscle.
The synthesis of ATP from creatine phosphate can only sustain muscle activity for about 8-10 seconds. To compensate for this, muscles also store a carbohydrate called glycogen, which can be used to make ATP from glucose. This process is slower, requiring about 12 chemical reactions, but it can provide energy for up to 90 seconds. It is important to note that this process does not require oxygen, which is advantageous as it takes time for the heart and lungs to increase the oxygen supply to the muscles.
The conversion of chemical energy into mechanical energy by muscle cells has significant implications for the entire organism. For example, muscle contractions enable animals to interact with their environment, find food, and react to stimuli. Additionally, the heat generated during this process is crucial for maintaining body temperature in warm-blooded animals. Furthermore, muscle metabolism plays a vital role in sports medicine and kinesthesiology, as it influences the energy requirements of the body during physical activity.
Adductors: Muscles or Tendons? Understanding the Anatomy of Movement
You may want to see also
Explore related products
Smooth muscle tissue occurs in the walls of hollow organs such as the intestines, stomach, and urinary bladder
Smooth muscle tissue is a type of tissue found in the walls of hollow organs, such as the intestines, stomach, and urinary bladder. It is also found in the walls of passageways, including arteries, veins, and the respiratory tract. Smooth muscle is an involuntary muscle, meaning it is not under conscious control. Instead, it is regulated by the nervous system, which uses it to control many of the body's subsystems. For example, smooth muscle helps regulate blood pressure and tissue oxygenation by contracting and relaxing the walls of blood vessels.
In the digestive system, smooth muscle plays a crucial role in digestion and nutrient collection. It helps move food along the intestines through peristalsis and facilitates the transport of chyme through wavelike contractions of the intestinal tube. Smooth muscle is also important in the urinary system, where it aids in the removal of toxins and the maintenance of electrolyte balance.
The unique properties of smooth muscle are essential for the bladder's function. The bladder relies almost exclusively on smooth muscle to maintain contractile tone and facilitate the passage of urine. Damage to smooth muscle regulation in the bladder can lead to loss of tone and subsequent neurological issues. Smooth muscle is also found in the eye, where it plays a role in adjusting the size of the pupil and the shape of the lens.
Smooth muscle differs from skeletal muscle in several ways. Unlike skeletal muscle, smooth muscle does not have striations and has only one nucleus per cell. It contracts slower than skeletal muscle but is stronger and requires less energy. Smooth muscle cells are also tapered at both ends and have a fusiform shape. Additionally, smooth muscle can be categorised into single-unit and multi-unit types based on their functionality.
The Visceral Muscle: A Vital Force Within Us
You may want to see also
Explore related products
There are three types of muscle in animal bodies: smooth, skeletal, and cardiac
Muscle is a soft tissue and is the most plentiful tissue in many animals. It is found in almost all animals, except for some that branched off from the evolutionary path before muscle cells evolved, such as sea sponges. Muscle contractions are the basis of movement in many species.
Skeletal muscle tissue forms skeletal muscles, which attach to bones or skin and control locomotion and any movement that can be consciously controlled. They are long and cylindrical in appearance and have a striped or striated appearance due to the regular arrangement of contractile proteins (actin and myosin). Skeletal muscle is also called voluntary muscle and has multiple nuclei present in a single cell.
Cardiac muscle tissue is only found in the heart, and cardiac contractions pump blood throughout the body and maintain blood pressure. Like skeletal muscle, cardiac muscle is striated, but it cannot be consciously controlled and is called involuntary muscle. It has one nucleus per cell, is branched, and is distinguished by the presence of intercalated discs.
Different types of skeletal muscles are described as white and red muscle, which are recruited depending on whether fast and short or steady and prolonged locomotion is needed by the animal.
Heart Muscle Bundles: What Are They?
You may want to see also
Explore related products
Muscle fibres differ from species to species of animal and between parts of the same animal
Muscles also differ in their speed of action, including the rates at which they develop force and shorten. The maximum rates of shortening vary between species and between muscle fibres in a single animal. For example, two muscles in the limbs of mice have maximum shortening speeds (at 37 °C) of 24 and 13 lengths per second. The adenosine triphosphate (ATP) that muscles use as their immediate energy source may be produced either by oxidative reactions or by anaerobic processes that do not require oxygen. Vertebrates and crabs use the anaerobic process of glycolysis for short bursts of vigorous activity, such as sprinting.
Different skeletal muscles in animals are described as white and red muscle. These different types of skeletal muscles are recruited depending on whether fast and short or steady and prolonged locomotion is needed by the animal. Most fishes show an obvious distinction between the main bulk of white swimming muscle and a narrow strip of red muscle along the side of the body. Slow swimming is powered by the red (oxidative) muscle, while bursts of fast swimming are powered by the white (glycolytic) muscle. Red and white muscles are also easy to distinguish in the domestic chicken, in which the pale meat of the breast consists mainly of white fibres and the dark meat of the legs consists of red fibres.
Skeletal muscle tissue forms skeletal muscles, which attach to bones or skin and control locomotion and any movement that can be consciously controlled. Skeletal muscles are long and cylindrical in appearance and have a striped or striated appearance due to the regular arrangement of contractile proteins (actin and myosin). Actin is a globular contractile protein that interacts with myosin for muscle contraction. Smooth muscle tissue occurs in the walls of hollow organs such as the intestines, stomach, and urinary bladder, and around passages such as the respiratory tract and blood vessels.
Measuring Muscle: A Comprehensive Guide to Tracking Growth
You may want to see also
Frequently asked questions
No, not all animals have muscles. While muscle contractions are the basis of movement in many species, some animal groups, such as sea sponges, do not have muscles as they branched off from the evolutionary path before muscle cells evolved.
There are three types of muscles in animal bodies: smooth, skeletal, and cardiac. Smooth muscle cells have no striations and are not under voluntary control. Skeletal muscle cells are long, striated, and under voluntary control. Cardiac muscle cells are striated, found only in the heart, and are not under voluntary control.
Muscles are contractile tissues that produce motion. They fuel their action by converting chemical energy in the form of adenosine triphosphate (ATP), derived from the metabolism of food, into mechanical energy.
