insoluble fiber

(noun)

Insoluble fiber may be metabolically inert and provide bulking or metabolically fermented in the large intestine as a prebiotic fiber.

Related Terms

Examples of insoluble fiber in the following topics:

  • Dietary Fiber

    • Insoluble fiber has bulking action, and it is not fermented.
    • Lignin, a major dietary insoluble fiber source, may alter the fate and metabolism of soluble fibers.
    • Some plants contain significant amounts of both soluble and insoluble fiber.
    • The plum's skin is a source of insoluble fiber while soluble fiber is in the pulp.
    • Table shows the functions and benefits of soluble and insoluble dietary fiber.

  • Overview of Hemostasis

    • Thrombin facilitates the conversion of a soluble plasma protein called fibrinogen into long, insoluble fibers or threads of the protein, fibrin.
    • Fibrin threads wind around the platelet plug at the damaged area of the blood vessel, forming an interlocking network of fibers and a framework for the clot.
    • This net of fibers traps and helps hold platelets, blood cells, and other molecules tight to the site of injury, functioning as the initial clot.

  • Characteristics of Connective Tissue

    • Connective tissue fibers provide support.
    • Three types of fibers are found in connective tissue:
    • Elastic fibers are long, thin fibers that form branching network in the extracellular matrix.
    • Reticular fibers are short, fine collagenous fibers that can branch extensively to form a delicate network.
    • Collagen fibers are the strongest and most abundant of all the connective tissue fibers.

  • Overview of Motor Integration

    • When a motor unit is activated, all of its fibers contract.
    • The number of muscle fibers within each unit can vary.
    • Motor units are generally recruited in order of smallest to largest (from fewest fibers to most fibers) as contraction increases.
    • These small motor units may contain only 10 fibers per motor unit.
    • These muscles may have as many as a thousand fibers in each motor unit.

  • Slow-Twitch and Fast-Twitch Muscle Fibers

    • Most muscles are made up of combinations of these fibers, although the relative number substantially varies.
    • Unlike slow-twitch fibers, fast twitch-fibers rely on anaerobic respiration (glycolysis alone) to produce two molecules of ATP per molecule of glucose.
    • As fast-twitch fibers generally do not require oxygenation, they contain fewer blood vessels and mitochondria than slow-twitch fibers and less myoglobin, resulting in a paler colour.
    • Muscles controlling eye movements contain high numbers of fast-twitch fibers (~85% fast-twitch).
    • Describe the different types of skeletal muscle fibers and their respective functions

  • Classification of Nerves

    • These classifications apply to both sensory and motor fibers.
    • The A group is further subdivided into four types (A-alpha, A-beta, A-delta, and A-gamma fibers) based on the information carried by the fibers and the tissues they innervate.
    • The primary role of B fibers is to transmit autonomic information.
    • C fiber axons are grouped together into what is known as Remak bundles.
    • A-delta and C fibers both contribute to the detection of diverse painful stimuli.

  • Parasympathetic (Craniosacral) Division

    • The motor root carries presynaptic parasympathetic nerve fibers (general visceral efferent fibers) that terminate in the ganglion by synapsing the postsynaptic fibers traveling to target organs.
    • The sympathetic root carries postsynaptic sympathetic fibers (general visceral efferent fibers) that traverse the ganglion without synapsing.
    • The sensory root carries general sensory fibers (general somatic afferent fibers) that also do not synapse in the ganglion.
    • Some ganglia also carry special sensory fibers (special visceral afferent) for taste sensation.
    • Pre- and post-ganglionic fibers and targets are depicted.

  • Preganglionic Neurons

    • In the autonomic nervous system (ANS), nerve fibers that connect the central nervous system to ganglia are known as preganglionic fibers.
    • In the autonomic nervous system (ANS), fibers from the central nervous system to the ganglion are known as preganglionic fibers.
    • Sympathetic preganglionic fibers tend to be shorter than parasympathetic preganglionic fibers because sympathetic ganglia are often closer to the spinal cord while parasympathetic preganglionic fibers tend to project to and synapse with the postganglionic fiber close to the target organ.
    • Another major difference between the two ANS systems is divergence, or the number of postsynaptic fibers a single preganglionic fiber synapses with.
    • Pre- and post-ganglionic fibers and targets are depicted.

  • Structural Elements of Connective Tissue

    • Elastic fibers (or yellow fibers) are bundles of proteins (elastin) found in extracellular matrix of connective tissue and produced by fibroblasts and smooth muscle cells in arteries.
    • These fibers can stretch up to 1.5 times their length and snap back to their original length when relaxed.
    • Elastic fibers include elastin, elaunin, and oxytalan.
    • Reticular fibers or reticulin is a histological term used to describe a type of fiber in connective tissue composed of type III collagen.
    • Reticular fibers crosslink to form a fine meshwork (reticulin).

  • Motor Units

    • The motor unit is the functional unit of muscle contraction and includes the motor nerve fiber and the muscle fibers it innervates.
    • A motor unit consists of the motor neuron and the grouping of muscle fibers innervated by the neuron.
    • The number of muscle fibers within a motor unit varies, and is a function of the muscle's ability for accurate and refined motion.
    • For instance, thigh muscles, responsible for large powerful movements, can have a thousand fibers in each unit, while eye muscles, requiring small precise movements, might only have ten.