Vasculogenic Erectile Dysfunction

Kirk A. Keegan , David F. Penson , in Vascular Medicine: A Companion to Braunwald's Heart Disease (Second Edition), 2013

Somatic pathways

Sensory receptors in the penile peel and glans are unique in the homo trunk. 16 They are composed of free nerve endings comprising unmyelinated C fibers and thin myelinated A-delta fibers. These coalesce into the dorsal nerve of the penis, which ultimately forms the pudendal nerve. The pudendal nerve and so enters the S2-S4 nervus roots at the spinal cord. Via spinothalamic and spinoreticular pathways, sensations such as touch on, pain, and temperature are perceived. 17 Interestingly, research by Burnett et al. xviii suggests that the dorsal nerve of the penis carries both autonomic and somatic signals, and therefore contributes to penile sensation, erection, and ejaculation.

Read full affiliate

URL:

https://www.sciencedirect.com/scientific discipline/article/pii/B9781437729306000288

Regulation of the Heartbeat

Achilles J. Pappano PhD , Withrow Gil Wier PhD , in Cardiovascular Physiology (Tenth Edition), 2013

Ventricular Receptor Reflexes Play a Small-scale Role in the Regulation of Heart Charge per unit

Sensory receptors near the endocardial surfaces of the ventricular walls initiate reflexes like to those elicited by the arterial baroreceptors. Excitation of these endocardial receptors diminishes heart rate and peripheral resistance. Other sensory receptors have been identified in the epicardial regions of the ventricles. Ventricular receptors are excited by a multifariousness of mechanical and chemical stimuli, but their physiological functions are not articulate.

Ventricular receptors are suspected of beingness involved in the initiation of vasovagal syncope, which is light-headedness or brief loss of consciousness that may exist triggered by psychological or orthostatic stress. The ventricular receptors are thought to be stimulated past a reduced ventricular filling volume combined with a vigorous ventricular contraction. In a person standing quietly, ventricular filling is diminished because claret tends to pool in the veins in the abdomen and legs, as explained in Chapter 10. Consequently, the reduction in cardiac output and arterial claret pressure leads to a generalized increase in sympathetic neural action via the baroreceptor reflex (see Figure 5-x). The enhanced sympathetic activeness to the heart evokes a vigorous ventricular wrinkle, which thereby stimulates the ventricular receptors. Excitation of the ventricular receptors appears to initiate the autonomic neural changes that evoke vasovagal syncope, namely, a combination of a profound, vagally mediated bradycardia and a generalized arteriolar vasodilation mediated by a diminution in sympathetic neural activity.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780323086974000058

Male Reproduction

Pierre Clément , in Encyclopedia of Reproduction (Second Edition), 2018

Sensory afferents

Sensory receptors stimulated during coitus or masturbation are essentially located in the penile pare, prepuce, and glans. Sensory inputs are conveyed to the upper sacral and lower lumbar segments of the spinal cord via the dorsal nervus of the penis, a sensory branch of the pudendal nerve ( Fig. 2). A relatively sparse sensory innervation of ductus deferens, prostate, and urethra has also been described which reaches the lumbosacral spinal cord via the pudendal nervus. A 2nd afferent pathway is constituted by fibers traveling along the hypogastric nerve and, later passing through the paravertebral lumbosacral sympathetic concatenation, enters the thoracolumbar segments of spinal cord (Fig. 2). Sensory afferents terminate in the medial dorsal horn and the dorsal gray commissure of the spinal cord.

Fig. 2.

Fig. 2. Schematic view of the autonomic and somatic innervation of genitalia. Neural pathways involved in ejaculation are indicated. DNP, dorsal nervus of the penis; DRG, dorsal root ganglia; HN, hypogastric nerve; PN, pelvic nerve; PP, pelvic plexus; PudN, pudendal nerve; SGE, spinal generator of ejaculation.

 Reprinted from Handbook of Clinical Neurology, vol.130, P. Clement and F. Giuliano, Beefcake and physiology of genital organs – men, pp. nineteen–37, 2015, with permission from Elsevier.

Read full chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780128012383646056

Neurosensory System

Wanda G. Webb PhD, CCC-SLP , in Neurology for the Spoken language-Language Pathologist (Sixth Edition), 2017

Oral Sensory Receptors

Sensory receptors in the oral region and respiratory system generally are excited by chemical or mechanical stimulation. Taste, of class, is based on chemical stimulation. Mechanicoreceptors reply when stimuli misconstrue them. For instance, the tongue touching the teeth, alveolar ridge, or palate compresses mechanicoreceptors, and the receptors in turn generate electrical impulses to the fibers.

The tongue mucosa and the tongue surface in particular are served by many types of mechanicoreceptors. The endings in these receptors have been divided into diffuse, or gratis, endings and meaty, or organized, endings. Some spoken language experts believe that free endings provide a general sense of touch in sensory control of speech articulation and that organized endings provide sensitive acuity in speech joint. Figure v-vii illustrates the sensory innervation pattern for the tongue. Farther give-and-take of oral sensation and its role in speech communication and swallowing are discussed in Chapter seven.

Read total chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780323100274000051

Proprioception

J.L. Taylor , in Encyclopedia of Neuroscience, 2009

Sensory Receptors Contributing to Proprioception

Sensory receptors in the muscles, joints, and skin are all involved in proprioception. In muscle, the major receptors for proprioception are musculus spindles and Golgi tendon organs. Musculus spindles are complex receptors which lie in parallel with the musculus fibers. They are fluid-filled fusiform (spindle-shaped) capsules of connective tissue with bundles of pocket-size (intrafusal) muscle fibers within them. On the intrafusal fibers are two kinds of sensory nervus endings: the spiral endings of the primary muscle spindle (Ia) afferents and the bloom-spray endings of the secondary muscle spindle (II) afferents. Both classes of muscle spindle endings fire with stretch of the muscle and so requite a point of musculus length. The primary ending has the more dynamic response. It fires a burst at the beginning of a stretch and signals velocity and dispatch as well every bit muscle length. Muscle spindles besides have their ain motor nervus supply to the intrafusal muscle fibers. As contraction of the intrafusal fibers stretches the sensory endings, musculus spindle firing can result from motor output besides as from musculus stretch. Thus, interpretation of muscle spindle signals during agile musculus contractions is circuitous.

Golgi tendon organs are situated at the musculotendinous junction. They consist of several strands of collagen attached to the tendon at one end and to a number (three–25) of muscle fibers at the other end. The strands of collagen are covered past a connective tissue capsule and are innervated past a Ib sensory neuron. Although tendon organs tin fire in response to passive stretch of the whole muscle, they are much more than sensitive to active forces generated by the specific muscle fibers that are attached to them.

In the joints, sensory endings are located in the joint capsule and ligaments. Ruffini endings are slowly adapting afferents which are sensitive to stretch of the joint capsule. They fire most at the ends of articulation range, but a few afferents can fire beyond the midrange of joint movement. Larger tendon-organlike receptors are plant in the ligaments. These also respond to stretch simply have a higher threshold compared to the joint capsule receptors.

In the skin, the receptors most direct associated with proprioception are the slowly adapting blazon Two (SAII) receptors. These fire in response to stretch of the skin in specific directions. They can point changes in joint angle when the skin is stretched over i side of a articulation and compressed on the other side.

Neural signals from all of these sensory receptors are carried via big-bore myelinated sensory neurons with cell bodies in the dorsal root ganglia and projections which enter the spinal string through the dorsal roots. Cutaneous afferents from both the upper and the lower limbs arise straight to the medulla, where they synapse. Muscle afferents from the upper limb follow the same route whereas those from the lower limb have an intermediary synapse in Clarke's cavalcade in the spinal string. From the medulla, proprioceptive signals cross the midline to the contralateral thalamus and from there project to the cortex.

Read full affiliate

URL:

https://www.sciencedirect.com/science/commodity/pii/B9780080450469019070

Sensory Receptors and Mechanotransduction

Andrew South. French , Päivi H. Torkkeli , in Cell Physiology Source Book (Fourth Edition), 2012

Three Sensory Adaptation

Sensory receptors often accept to deal with wide ranges of stimulus amplitudes. Therefore, they need high sensitivity to detect weak stimuli, plus the ability to reduce their sensitivity if the stimulus is strong. In some cases, the maximum sensitivity approaches the limits imposed by physics or chemistry. Human rod photoreceptors and some arthropod photoreceptors can notice single photons arriving in the eye, which is clearly the concrete limit. The human being ear can detect air movements of nearly 0.01   nm, close to the diameter of a hydrogen atom (Hudspeth, 2005). In such cases, the sensory cells must amplify the initial indicate considerably, which at to the lowest degree partly explains the complex morphologies of human rod photoreceptors and the cochlea.

The reduction in sensitivity post-obit an increase in stimulus is called adaptation. It may be seen equally a subtract in receptor potential with fourth dimension during a constant stimulus, or as an increase in the strength of stimulus required to produce a constant response. All sensory receptors arrange to some extent, but there is a wide range of adaptation speeds and amounts. At one farthermost are receptors such equally Pacinian corpuscles (Loewenstein and Mendelson, 1965) and spider slit sensilla (French et al., 2002), which burn only i or 2 action potentials with fifty-fifty a strong, continuous stimulus. At the other extreme are Ruffini endings (Malinovsky, 1996), which continue to fire steadily for long periods. The type of adaptation is always advisable to the function of the receptor. Muscle and joint receptors that bespeak limb position would not be useful if they adapted to silence in a few seconds, considering the sense of limb position, or proprioception, would vanish if one did not go on moving. On the other hand, photoreceptors must function under a broad range of light intensities and it is essential that they can adjust their sensitivity to the ambience calorie-free level. The rapid adaptation of Pacinian corpuscles makes them ideally suited for detecting vibration, since a speedily changing stimulus will repeatedly excite the receptor, while a steady stimulus will produce little response.

The mechanisms of accommodation vary widely and may occur at different stages of the process. Some involve components outside the sensory cell, such as the mechanical creep of the musculus in muscle spindles or the movements of screening pigments in insect optics. Others may involve chemical signals within and betwixt cells, as establish in photoreceptors and olfactory receptors. Mechanical adaptation past the sheathing of the Pacinian corpuscle is very well known from the pioneering work of Loewenstein and Mendelson (1965), who described the dramatic reduction in receptor potential adaptation that can be accomplished past removing most of the capsule (Fig. 36.2). Unfortunately, many descriptions stop at this point, leaving the impression that mechanical adaptation dominates Pacinian corpuscle behavior, but Loewenstein and Mendelson showed that, even later on decapsulation, the receptor will simply burn down one or two activeness potentials in response to a prolonged step stimulus (Fig. 36.iiC). They described this equally electric adaptation and it now seems probable that many receptors use voltage- or calcium-activated ion channels in their membranes to produce electrical adaptation by raising the threshold for action potential product. This has been clearly established in several arthropod and vertebrate mechanoreceptors and is likely to occur in other types of receptors that use activeness potentials to encode the sensory point (French and Torkkeli, 1994).

Figure 36.ii. Adaptation in the mammalian Pacinian corpuscle occurs in 2 stages. (A) Stimulating a normal receptor with a mechanical step (1000: bottom) causes chop-chop adapting receptor potential responses at the start and cease of the pace. (B) Removing virtually of the lamellae surrounding the sensory catastrophe (decapsulation) eliminates about of the adaptation to reveal a slowly adapting receptor potential. (C) Suprathreshold stimulation of a decapsulated receptor nonetheless produces only two activeness potentials, showing that there is rapid adaptation in the conversion of receptor potential to action potentials.

 (Redrawn from Loewenstein and Mendelson, 1965.)

Read total affiliate

URL:

https://www.sciencedirect.com/science/article/pii/B9780123877383000366

Control of Ventilation

Joseph Feher , in Quantitative Human Physiology (Second Edition), 2017

Airway and Lung Mechanoreceptors Alter Breathing Patterns

Sensory receptors are institute in a variety of places throughout the respiratory system and are responsible for a wide variety of behaviors. These include the following:

•

Sneezing: Mechanical stimulation of the nasal passage results in the sneeze reflex, consisting of a potent inspiration followed by a rapid expiration with partially closed airways to increase airflow velocity. The reflex clears foreign material from the passages.

•

The diving reflex: Water in the nose elicits a complex series of respiratory and cardiovascular responses including cessation of respiration, closure of the larynx, bronchoconstriction, bradycardia, and vasoconstriction of many vascular beds except those of the brain and heart.

•

The aspiration reflex: Mechanoreceptors in the epipharynx initiates a series of stiff, cursory inspirations that dislodge materials from the epipharynx into the pharynx where they can exist coughed up or swallowed.

•

The swallowing reflex: Developed humans cannot breathe and eat at the aforementioned fourth dimension. Receptors in the pharynx cause abeyance of respiration, closure of the larynx, and coordinated muscular contractions that motion material from the rima oris into the esophagus.

•

Cough reflexes: Speedily adapting receptors in the airway epithelia answer both to mechanical deformation and chemical irritation. These receptors initiate reflexes that include coughing, fungus secretion, and bronchoconstriction. All of these actions have the common theme of removing the offending irritant. Coughing creates a loftier velocity of airflow that helps eliminate foreign matter. Increasing fungus secretion helps trap the foreign matter. Bronchoconstriction decreases the bore of the airways and therefore increases the velocity of airflow produced past the cough, so that foreign matter can be more easily expelled.

•

The Hering–Breuer inflation reflex: The lower airways contain slowly adapting stretch receptors. Afferent sensory information from these stretch receptors travels over the vagus nervus to the brain stalk where it inhibits inspiration by stimulating the neurons in the PRG. This is the Hering–Breuer aggrandizement reflex. Inflation of the lungs stimulates the stretch receptors, which reflexly inhibit farther inflation.

•

The pulmonary chemoreflex: In addition to stretch receptors, the vagus nervus carries sensory inputs from C fibers, which are unmyelinated nerves with ho-hum conduction velocities on the club of 2.5   m   due south−1. C fibers in the bronchi appear to respond mainly to stretch whereas those fibers almost the capillaries respond to exogenous and endogenous chemicals including capsaicin, the irritant in reddish pepper, histamine, bradykinin, serotonin, and prostaglandins. These chemicals elicit the pulmonary chemoreflex that includes apnea, bradycardia, and hypotension that is immediately followed by rapid, shallow breathing (tachypnea).

Read total affiliate

URL:

https://www.sciencedirect.com/science/commodity/pii/B9780128008836000665

Applying the biopsychosocial model to the management of rheumatic disease

Sarah Ryan RGN PhD MSc BSc FRCN , Alison Carr PhD , in Rheumatology, 2010

PAIN RECEPTORS

Sensory receptors are situated in the tissues of the peel, synovium of joints and arterial walls. These are activated by various stimuli including:

•

mechanical changes: increased synovial fluid in the joint cavity and proliferation of the inflamed synovial tissues causes pain past distension and stretching of the sheathing

•

temperature changes

•

inflammatory changes: the release of prostaglandin, bradykinin, histamine and serotonin.

Peripheral sensory fretfulness transmit signals from the peripheries to the fundamental nervous system enabling stimulus identification. Alpha delta fibres (sparse and myelinated) transmit the sharp hurting of an astute injury and slower C-fibres (unmyelinated) produce the boring aching pain of a more than persistent problem or the burning quality of neuropathic hurting (McCabe 2004).

Sensory nerves deliver data from the peripheries to the dorsal horn where they terminate. This information is so interpreted by transmission cells (T-cells) transmitting information to the local reflex circuits and the brain. When the Alpha delta and C fibres are stimulated T cells are activated resulting in the substantia gelatinosa (SG) being suppressed so that the 'pain gate' opens and messages pass to the brain to exist perceived as pain. When large fibres get activated (Alpha beta) they suppress T cell activity and shut the gate. Alpha beta fibres transmit the sensation of touch. Acupuncture and electrical nerve stimulation piece of work on the same principle and excite large fibre activity. Nervus impulses descending from the brain tin also operate 'the gate'.

Case STUDY 5.i

POSSIBLE Hurting PATHWAYS IN A CASE Written report OF A PATIENT WITH RA (BASED ON AN EXAMPLE BY MCCABE 2004)

Mrs Jones is a 44-year-sometime women diagnosed with RA v years ago. She works as a legal assistant in a busy law business firm. She has had to accept fourth dimension off which is worrying her. Mrs Jones is married with no children. Over the last 3 months she has experienced more early morning stiffness (from 30 minutes to 2 hours) and has pain and inflammation in both wrists and her correct knee. Mrs Jones describes her pain every bit 'burning and tender to touch'. The pain disturbs her sleep and she has difficulty with mobility.

Peripheral mechanisms

The inflammatory process (demonstrated by swelling, pain and stiffness) has generated peripheral sensitization. Reporting called-for pain indicates activation of the C fibres or changes in the dorsal horn resulting in central sensitization. Problems with mobility may be due to changes in human knee intra-articular force per unit area.

Key mechanisms

Generalised tenderness indicates a lowering of the Alpha beta fibre threshold and may have been induced by the duration of symptoms. Changes in proprioception due to knee swelling may create a mismatch in the motor and sensory systems. This mechanism has been proposed as an explanation for the perception of stiffness in RA (Haigh et al 2003). Other factors that may influence Mrs Jones' pain are her lack of sleep and work concerns.

Read total affiliate

URL:

https://world wide web.sciencedirect.com/science/article/pii/B978044306934500005X

Review of Pertinent Anatomy and Physiology

Sandy Fritz MS, NCTMB , ... Glenn G. Hymel EdD, LMT , in Clinical Massage in the Healthcare Setting, 2008

JOINT Construction AND FUNCTION

Joints are innervated past the articular nerves, which are branches of the peripheral nervous system. Branches of these fretfulness also supply the muscles decision-making the joint. This is important in understanding how muscles tin cause joint dysfunction and how joint dysfunction can cause musculus problems.

Many sensory receptors surround the joint. The four types of joint receptors are located in the articulation sheathing, ligaments, periosteum, and articular fat pads.

•

Type 1 receptors are located in the superficial layers of the superficial joint capsule. These are mechanoreceptors that provide information virtually the static and dynamic position of the articulation.

•

Type 2 receptors are located in the deep layers of the fibrous joint sheathing. They are dynamic mechanoreceptors that provide information most acceleration and deceleration motility.

•

Type 3 receptors are located in the intrinsic and extrinsic joint ligaments. These are dynamic mechanoreceptors that monitor the direction of motion and accept a reflex result on muscle tone to provide deceleration.

•

Type four receptors are located in joint capsules, ligaments, and the periosteum. They are pain receptors.

These receptors send data to the CNS on the functional status of the joint and its surrounding soft tissue. The reflex control of the muscles surrounding the joint is called the arthrokinematic reflex. The CNS creates contraction or relaxation of the muscles to protect the joint. The arthrokinematic reflex coordinates agonists, antagonists, and synergists effectually the joint and in other jointed areas for large movements and fine muscular command.

Proper function of these reflex mechanisms is extremely important in posture, coordination, and balance; direction and speed of move; position of the joint and torso; and pain in the joint. With irritation of the hurting receptors and mechanoreceptors, the joint flexors typically are facilitated (i.e., they become curt, tight, and hypertonic) and the joint extensors are inhibited (i.e., they go weak, long, and taut).

Irritation of the joint receptors can as well atomic number 82 to abnormalities in posture, muscle coordination, and control of movement, balance, and awareness of body position. This is a major concern for patients. Cess and treatment of gait patterns and firing patterns through the use of massage and muscle energy methods can back up normal reflex functions.

evolve 6-23

See the Evolve website for more detailed information about joint structure and role.

Irritation and injury to the articulation capsule can create musculus contractions designed to protect the joint; this muscle response is chosen guarding.

evolve 6-24

For more data on guarding, see the Evolve website.

Fibrosis, or thickening of the outer layer of the joint capsule, is caused by astute inflammation, irritation or inflammation caused by imbalanced stresses on the joint, and/or immobilization. A tight, fibrotic joint capsule results in compression of certain areas of the cartilage and degeneration of the articulation surfaces. The capsule and supporting ligaments may also be overstretched considering of injury or excessive stretching during activities such as dancing and gymnastics. If immobilization causes a loss of adequate motion, the fibrous layer of the joint capsule atrophies, resulting in joint instability.

The synovial membrane can also be injured or go dysfunctional every bit a result of immobilization, acute trauma to the joint, or cumulative stress from chronic irritation acquired by imbalanced forces on the articulation. Joint swelling occurs during inflammation. The swelling typically causes aberrant function of the muscle decision-making the joint. During immobilization, the synovial fluid thickens with disuse, and the corporeality of synovial fluid secreted decreases. This leads to the development of adhesions between the capsule and the articular cartilage, tendon sheaths, and bursae, which contributes to stiffness and articulation degeneration.

Massage Application

With a fibrotic articulation sheathing, massage is used to innovate mechanical forces into the tissue to increase pliability. The fibrotic sheathing is treated with manual pressure on the capsule itself. The massage strokes are oriented in all directions, addressing the irregular alignment of the collagen. Active and passive movement and stretching are used to reduce intraarticular adhesions.

A sheathing that is likewise loose needs exercise rehabilitation to help lay downward new collagen fibers and proprioception exercises to help restore neurologic function. Appropriate friction massage tin stimulate an acute inflammatory response that stimulates collagen formation.

An acute, bloated joint capsule is treated with gentle, rhythmic compression and decompression of the articulation and lymphatic drainage to pump the excess fluid out of the sheathing. Hurting-costless, passive range of motion is also used in the flexion-extension pattern to deed as a mechanical pump. If the joint has too little fluid, passive and active movements assist stimulate the synovial membrane, increasing the production and movement of synovial fluid and thereby supporting lubrication and nutrition.

evolve 6-25

See the Evolve website for more detailed information on massage application with regard to joint motion.

Synovial joints generate compression and decompression through movement, intermittent contraction of the muscles, and twisting and untwisting of the articulation capsule. Massage awarding that includes passive joint movement introduces pinch and decompression and supports joint health.

Cartilage damage is mutual. An arthritic joint is a articulation with degeneration of the cartilage. Damage to articular cartilage may be caused past astute trauma or cumulative stress. These stresses ofttimes are the consequence of imbalances in the muscles surrounding the articulation, a tight joint capsule, or a loose joint sheathing. A tight capsule creates a high-contact area of the cartilage and decreased lubrication. A loose capsule allows inappropriate joint laxity and rubbing. Dysfunction of the muscles that move the joint create excessive pressure on the cartilage. The cartilage degenerates, beginning with damage to the collagen fibers and depletion of the ground substance.

Recent studies show that cartilage cells can create new cartilage. The joint must be moved to stimulate the synthesis of chondrocytes and the secretion of synovial fluid. Compression followed by decompression of the joint capsule pumps synovial fluid into and out of the cartilage, rehydrating it. In addition to appropriate practice, massage and musculus energy methods back up joint health through the use of techniques such as contract, relax, reciprocal inhibition, pulsed muscle, or a combination of these methods. Both active and passive movement of the articulation, also as compression and decompression, promote fluid substitution.

Read total chapter

URL:

https://www.sciencedirect.com/science/article/pii/B9780323039963500131

The System of Locomotion: The Distributive Regulation of Limb Mechanics by Spinal Circuits During Locomotion

T. Richard Nichols , Thomas J. Burkholder , in Systems Medicine, 2021

Peripheral Sensory Systems

Two sensory receptors closely associated with feedback control of movement are the muscle spindle and the Golgi tendon organ. These structures reside in the muscle and the junction between musculus and tendon, respectively, and discharge in response to deformation, providing neural signals that depend on the kinematics and kinetics of movement. They are generally considered to encode the essential mechanical variables of length, velocity, and forcefulness.

Musculus spindles contain modest, specialized muscle fibers that are associated with two types of receptors, primary, and secondary. These specialized muscle fibers produce negligible forces and mainly influence the signaling properties of the receptors. The primary receptor senses kinematic variables, including length of fascicles of the ability-producing muscle cells and a fractional power of velocity (Houk et al., 1981a). These receptors provide monosynaptic excitation of the parent musculus and synergistic muscles, pathways that constitute a major component of the stretch reflex. Secondary receptors detect mainly changes in the lengths of muscle fascicles. Their primal connections are more widely distributed than primaries with functions that are less well understood (Matthews, 1972). The specialized muscle fibers also receive motor input from the spinal cord that can modulate the sensitivity and background firing rate of both receptors (Matthews, 1972).

Golgi tendon organs are located at the junction between muscle and tendon. Because these receptors are connected in series with musculus fascicles, they detect muscular forces (Houk and Henneman, 1967). The feedback from tendon organs is distributed more widely than feedback from the primary receptors of muscle spindles, as will be discussed in more detail below.

Read full chapter

URL:

https://www.sciencedirect.com/science/commodity/pii/B9780128012383113893