Books on the topic 'Frog muscle physiology'

The pharmacological interventions that constitute general anaesthesia are targeted at producing unconsciousness and an immobile patient even in response to noxious stimuli. Surgical anaesthesia also requires skeletal muscle relaxation, the degree of which depends on the site and nature of the surgical procedure. The anaesthetist therefore needs an advanced level of knowledge and understanding of the function of nerves, synapses, and muscle in order to understand, from first principles, how the drugs they use every day mediate their effects. Nerves and muscle cells are termed excitable cells because the electrical potential across their cell membranes (membrane potential) can be rapidly and profoundly altered because of the presence of specialized ion channels. Some drugs, such as local anaesthetics, act on ion channels involved in nerve conduction while many others act on synaptic transmission, the neurochemical communication between neurons or between a neuron and its effector organ. The neuromuscular junction is a synapse of specific interest to anaesthetists because it is the site of action of neuromuscular blocking drugs. This chapter covers the fundamentals of cellular electrophysiology, structure and function of key ion channels, and the physiology of nerves, synapses, and skeletal muscle.

The chapter begins with a description of the normal findings in healthy sensory and motor nerves. The distribution of nerve fibres by diameter in the sensory nerve and its effect on the recorded action potential is outlined. The method by which velocity and compound muscle action potential are derived from motor stimulation follows. H-reflex studies and F-wave identification are described. A section on the strategies used for nerve conduction study in children and the nerves chosen for examination leads on to a description of the difficulties of deriving normative data in children. Next follows a detailed description of the findings in both sensory and motor nerves in demyelination where a distinction between patchy and homogenous demyelination is possible. An analysis of the nerve findings in axonal degeneration is then presented. The chapter finishes with a discussion of the variability in nerve testing.

This chapter covers two major fields of the blood circulation: ‘distribution’ and ‘exchange’. After a short survey of the types of vessels, which form the circulation system together with the heart, the chapter describes how hydrostatic pressure derived from the heartbeat and vascular resistance determine the volume of blood that is locally delivered per time unit. The vascular resistance depends on the length of the vessel, blood viscosity, and, in particular, on the diameter of the vessel, as formulated in the Poiseuille-Hagen equation. Blood flow can be determined in vivo by different imaging modalities. A summary is provided of how smooth muscle cell contraction is regulated at the cellular level, and how neuronal, humoral, and paracrine factors affect smooth muscle contraction and thereby blood pressure and blood volume distribution among tissues. Subsequently the exchange of solutes and macromolecules over the capillary endothelium and the contribution of its surface layer, the glycocalyx, are discussed. After a description of the Starling equation for capillary exchange, new insights are summarized(in the so-called glycocalyx cleft model) that led to a new view on exchange along the capillary and on the contribution of oncotic pressure. Finally mechanisms are indicated in brief that play a role in keeping the blood volume constant, as a constant volume is a prerequisite for adequate functioning of the circulatory system.

Paediatric Electromyography is a single-author textbook which covers the full range of applications of the techniques of nerve conduction and electromyography (EMG) in children from the neonatal period to the late teenage years. It comprises five sections. Section 1 in its first chapter, gives a detailed introduction to the different skills that are needed to effect successful interventions in paediatric EMG. The emphasis here is that paediatric EMG is not simply adult EMG applied to younger subjects. Its second chapter is an introduction to the basic physiology which is common to any practice of nerve and muscle study. The next three sections (2–4), each comprised of three chapters, are structured anatomically covering in order, nerves, muscles, and neuromuscular junctions. All follow a similar pattern with the first chapter of the section dedicated to the underlying physiology needed for interpretation of the techniques used in the investigation of that particular part of the nervous system. The second chapter gives the pathophysiological associations and the final chapter covers any aspect not covered in the previous two chapters. In section 5 the techniques needed to deal with the more unusual clinical requests, such as investigation of facial palsy, swallowing abnormalities, brachial plexus injuries, and diaphragmatic problems are brought together in a final chapter. The book is concluded with three appendices. Appendix 1 describes protocols devised to cover the differing clinical request sent to any laboratory. Appendix 2 gives a comprehensive database of normative data, often derived from e-norm methodology, and intending to cover every measure recorded. Appendix 3 is an illustrated description of electrode placements for all the common nerve studies.

The spinal cord and peripheral nerves carry motor and autonomic efferents, as well as sensory afferents connecting the cerebrum with the body. Efferent and afferent fibres form predictable tracts within the spinal cord, forming spinal nerves as they exit the spinal canal. Peripheral nerves are often formed from complicated plexuses of spinal nerves in the cervical, lumbar, and sacral spine. Dermatomes are formed from spinal nerves that innervate specific areas of skin, while myotomes innervate a specific set of muscles. The detailed anatomy of these structures are discussed. Knowledge of the anatomy of these structures is relevant to many clinical situations encountered in the intensive care unit especially with caring for neurological, neurosurgical, orthopaedic, and trauma patients.

This chapter, “Lowly Origins,” examines the evolution of the nervous system and its implications for clinical neurology. Topics include peripheral nerve anatomy, extraocular muscles, and physiologic circuits related to respiration. Human neuroanatomy and neurologic disease carry a record of our vertebrate ancestors, and neurology is more understandable when the clinician is attuned to our ancient neurological circuits. The extraocular muscles are a prime example. Although the extraocular muscles have changed their orientation to the axis of the eye, and although not all of these muscles are as important as they once were, these muscles of the human eye have otherwise changed little from those of the shark. They remain similar in appearance and consistent in innervation. They are the best conserved muscles in all of vertebrate evolution. The development of limbs, loss of gills, assumption of bipedal locomotion, and development of a huge brain has had virtually no effect on them.

The Oxford Textbook of Clinical Neurophysiology provides a comprehensive account from world experts of the modern practice of the specialty. It deals with the full range of techniques giving the underpinning basic science and clinical use. The importance of clinical skills, as well as technical expertise are emphasized. Section I reviews the physiology of nerve, muscle, and cortex, and the digital techniques used to study them. Section II discusses the techniques for nerve conduction, electromyography (EMG), electroencephalography (EEG), magnetoencephalography, evoked potentials, and transcranial magnetic stimulation, including axonal excitability measurement, reflex studies, sleep studies pelvic floor neurophysiology and intracranial EEG. Section III reviews focal and generalized neuropathy, nerve, root, and plexus lesions, neuromuscular junction disorders, muscle disease, paediatric conditions, neurodegenerations, such as amyotrophic lateral sclerosis and EMG-guided botulinum toxin therapy. Section IV reviews generalized and focal epilepsy, status epilepticus, coma, presurgical evaluation for epilepsy, syncope, paediatric conditions, sleep disorders and intraoperative monitoring. This title incudes video content and is written for trainees and trainers in clinical neurophysiology.

This paper focuses on Herder’s contribution to the development of philosophical anthropology by seeing Herder’s philosophy as a response to recent discoveries in medicine and physiology. The major impulse came from Haller’s discovery of the irritability of muscle and sensibility of nerves, which challenged philosophical and theological dogmas about the existence of an immaterial soul and its ability to cause what the mind perceives as voluntary motion. It blurred the traditional division of labor between the physician investigating the body and the philosopher and theologian studying the soul. The chapter will explore how Herder makes creative use of Haller’s concept of irritability as a way of demonstrating a neo-Aristotelian account of the soul as pervading and informing the entire body.

The Oxford Handbook of Medical Sciences is written by biomedical scientists and clinicians to be the definitive guide to the fundamental scientific principles that underpin medicine and the biomedical sciences. It provides a clear and easily digestible account of basic cell physiology, biochemistry, and molecular and medical genetics, followed by chapters integrating the traditional pillars of biomedicine (anatomy, physiology, biochemistry, pathology, and pharmacology) for each of the major systems and processes of the human body: nerve and muscle, musculoskeletal system, respiratory and cardiovascular systems, urinary system, digestive system, endocrine organs, reproductive system, development from fertilization to birth, neuroanatomy and neurophysiology, infection and immunity, and the growth of tissues and organs. Also included are chapters on medicine and society and techniques used in biomedical science research. In its third edition, the Oxford Handbook of Medical Sciences is now fully illustrated in colour, and cross-referenced to the Oxford Handbook of Clinical Medicine, tenth edition, Oxford Handbook of Clinical Specialities, eleventh edition, and Oxford Handbook of Practical Drug Therapy, second edition. Its concise writing style makes it an invaluable source of information for practitioners and students in medicine, biomedical sciences, and the allied health professions.

Hypomagnesemia is a relatively common electrolyte abnormality that may produce little to no significant clinical manifestations in patients. Commonly used medications such as proton-pump inhibitors and antidepressants can cause magnesium deficiency. The primary cardiac effect of hypomagnesemia is a prolongation of the Q-T interval. It is exposure to other drugs in the perioperative period and physiologic changes caused by anesthesia and surgery that can further alter cardiac electrophysiology and lead to serious ventricular dysrhythmias. Hypermagnesemia is generally iatrogenic from excessive ingestion, renal failure, or therapeutic administration for preeclampsia. Adverse effects of hypermagnesemia include somnolence, muscle weakness, and slowing of cardiac conduction.

The regional anatomy around the DBS lead in the ventral intermediate nucleus of the thalamus (Vim) determines efficacy and adverse effects. Understanding the regional anatomy allows the programmer to adjust the stimulation to provide optimal benefit and the absence of adverse effects. Vim is the target of therapeutic DBS. The ventrocaudal nucleus of the thalamus (Vc) lies posterior to the Vim. Electrical stimulation of Vc can cause treatment-limiting paresthesias. The corticospinal and cortical bulbar tracts in the internal capsule lie lateral and ventral to the Vim. Electrical stimulation of the internal capsule can cause tonic muscle contractions. There are multiple nomenclatures of the subnuclei of the thalamus. Although the term ventrolateral thalamus (VL) is commonly used in the physiology literature, ventral intermediate thalamus (Vim), is used in the DBS literature. Technically, the VL refers to both regions of the thalamus that receive inputs from GPi and cerebellum, whereas Vim refers to the cerebellar-receiving area of the thalamus and is thus a subdivision of the VL and is the target of DBS for tremor-related disorders.

The term ‘polytrauma’ refers to blunt (or crush) trauma that involves multiple body regions or cavities, and compromises physiology to potentially cause dysfunction of uninjured organs. Polytrauma frequently affects muscles resulting in rhabdomyolysis. In daily life, it mostly occurs after motor vehicle accidents, influencing a limited number of patients; after mass disasters, however, thousands of polytrauma victims may present at once with only surgical features or with additional medical complications (crush syndrome). Among the medical complications, acute kidney injury (AKI) deserves special mention, since it is frequent and has a substantial impact on the ultimate outcome.Several factors play a role in the pathogenesis of polytrauma (or crush)-induced AKI: (1) hypoperfusion of the kidneys, (2) myoglobin-induced direct nephrotoxicity, and intratubular obstruction, and also (3) several other mechanisms (i.e. iron and free radical-induced damage, disseminated intravascular coagulation, and ischaemia reperfusion injury). Crush-related AKI is prerenal at the beginning; however, acute tubular necrosis may develop eventually. In patients with crush syndrome, apart from findings of trauma, clinical features may include (but are not limited to) hypotension, oliguria, brownish discoloration of urine, and other symptoms and findings, such as sepsis, acute respiratory distress syndrome, disseminated intravascular coagulation, bleeding, cardiac failure, arrhythmias, electrolyte disturbances, and also psychological trauma.In the biochemical evaluation, life-threatening hyperkalaemia, retention of uraemic toxins, high anion gap metabolic acidosis, elevated serum levels of myoglobin, and muscle enzymes are noted; creatine phosphokinase is very useful for diagnosing rhabdomyolysis.Early fluid administration is vital to prevent crush-related AKI; the rate of initial fluid volume should be 1000 mL/hour. Overall, 3–6 L are administered within a 6-hour period considering environmental, demographic and clinical features, and urinary response to fluids. In disaster circumstances, the preferred fluid formulation is isotonic saline because of its ready availability. Alkaline (bicarbonate-added) hypotonic saline may be more useful, especially in isolated cases not related to disaster, as it may prevent intratubular myoglobin, and uric acid plugs, metabolic acidosis, and also life-threatening hyperkalaemia.In the case of established acute tubular necrosis, dialysis support is life-saving. Although all types of dialysis techniques may be used, intermittent haemodialysis is the preferred modality because of medical and logistic advantages. Close follow-up and appropriate treatment improve mortality rates, which may be as low as 15–20% even in disaster circumstances. Polytrauma victims after mass disasters deserve special mention, because crush syndrome is the second most frequent cause of death after trauma. Chaos, overwhelming number of patients, and logistical drawbacks often result in delayed, and sometimes incorrect treatment. Medical and logistical disaster preparedness is useful to improve the ultimate outcome of disaster victims.

Anaesthesia induces changes in many organ systems within the body, though clearly none more so than the central nervous system. The physiology of the normal central nervous system is complex and the addition of chronic pathology and polypharmacy creates a significant challenge for the anaesthetist. This chapter demonstrates a common approach for the anaesthetist and specific considerations for a wide range of neurological conditions. Detailed preoperative assessment is essential to gain understanding of the current symptomatology and neurological deficit, including at times restrictions on movement and position. Some conditions may pose challenges relating to communication, capacity, and consent. As part of the consent process, patients may worry that an anaesthetic may aggravate or worsen their neurological disease. There is little evidence to support this understandable concern; however, the risks and benefits must be considered on an individual patient basis. The conduct of anaesthesia may involve a preference for general or regional anaesthesia and requires careful consideration of the pharmacological and physiological impact on the patient and their disease. Interactions between regular medications and anaesthetic drugs are common. Chronically denervated muscle may induce hyperkalaemia after administration of succinylcholine. Other patients may have an altered response to non-depolarizing agents, such as those suffering from myasthenia gravis. The most common neurological condition encountered is epilepsy. This requires consideration of the patient’s antiepileptic drugs, often relating to hepatic enzyme induction or less commonly inhibition and competition for protein binding, and the effect of the anaesthetic technique and drugs on the patient’s seizure risk. Postoperative care may need to take place in a high dependency unit, especially in those with limited preoperative reserve or markers of frailty, and where the gastrointestinal tract has been compromised, alternative routes of drug delivery need to be considered. Overall, patients with chronic neurological conditions require careful assessment and preparation, a considered technique with attention to detail, and often higher levels of care during their immediate postoperative period.

Bones are multifunctional passive organs of movement that supports soft tissue and directly attached muscles. They also protect internal organs and are a reserve of calcium, phosphorus and magnesium. Each bone is covered with periosteum, and the adjacent bone surfaces are covered by articular cartilage. Histologically, the bone is an organ composed of many different tissues. The main component is bone tissue (cortical and spongy) composed of a set of bone cells and intercellular substance (mineral and organic), it also contains fat, hematopoietic (bone marrow) and cartilaginous tissue. Bones are a tissue that even in adult life retains the ability to change shape and structure depending on changes in their mechanical and hormonal environment, as well as self-renewal and repair capabilities. This process is called bone turnover. The basic processes of bone turnover are: • bone modeling (incessantly changes in bone shape during individual growth) following resorption and tissue formation at various locations (e.g. bone marrow formation) to increase mass and skeletal morphology. This process occurs in the bones of growing individuals and stops after reaching puberty • bone remodeling (processes involve in maintaining bone tissue by resorbing and replacing old bone tissue with new tissue in the same place, e.g. repairing micro fractures). It is a process involving the removal and internal remodeling of existing bone and is responsible for maintaining tissue mass and architecture of mature bones. Bone turnover is regulated by two types of transformation: • osteoclastogenesis, i.e. formation of cells responsible for bone resorption • osteoblastogenesis, i.e. formation of cells responsible for bone formation (bone matrix synthesis and mineralization) Bone maturity can be defined as the completion of basic structural development and mineralization leading to maximum mass and optimal mechanical strength. The highest rate of increase in pig bone mass is observed in the first twelve weeks after birth. This period of growth is considered crucial for optimizing the growth of the skeleton of pigs, because the degree of bone mineralization in later life stages (adulthood) depends largely on the amount of bone minerals accumulated in the early stages of their growth. The development of the technique allows to determine the condition of the skeletal system (or individual bones) in living animals by methods used in human medicine, or after their slaughter. For in vivo determination of bone properties, Abstract 10 double energy X-ray absorptiometry or computed tomography scanning techniques are used. Both methods allow the quantification of mineral content and bone mineral density. The most important property from a practical point of view is the bone’s bending strength, which is directly determined by the maximum bending force. The most important factors affecting bone strength are: • age (growth period), • gender and the associated hormonal balance, • genotype and modification of genes responsible for bone growth • chemical composition of the body (protein and fat content, and the proportion between these components), • physical activity and related bone load, • nutritional factors: – protein intake influencing synthesis of organic matrix of bone, – content of minerals in the feed (CA, P, Zn, Ca/P, Mg, Mn, Na, Cl, K, Cu ratio) influencing synthesis of the inorganic matrix of bone, – mineral/protein ratio in the diet (Ca/protein, P/protein, Zn/protein) – feed energy concentration, – energy source (content of saturated fatty acids - SFA, content of polyun saturated fatty acids - PUFA, in particular ALA, EPA, DPA, DHA), – feed additives, in particular: enzymes (e.g. phytase releasing of minerals bounded in phytin complexes), probiotics and prebiotics (e.g. inulin improving the function of the digestive tract by increasing absorption of nutrients), – vitamin content that regulate metabolism and biochemical changes occurring in bone tissue (e.g. vitamin D3, B6, C and K). This study was based on the results of research experiments from available literature, and studies on growing pigs carried out at the Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences. The tests were performed in total on 300 pigs of Duroc, Pietrain, Puławska breeds, line 990 and hybrids (Great White × Duroc, Great White × Landrace), PIC pigs, slaughtered at different body weight during the growth period from 15 to 130 kg. Bones for biomechanical tests were collected after slaughter from each pig. Their length, mass and volume were determined. Based on these measurements, the specific weight (density, g/cm3) was calculated. Then each bone was cut in the middle of the shaft and the outer and inner diameters were measured both horizontally and vertically. Based on these measurements, the following indicators were calculated: • cortical thickness, • cortical surface, • cortical index. Abstract 11 Bone strength was tested by a three-point bending test. The obtained data enabled the determination of: • bending force (the magnitude of the maximum force at which disintegration and disruption of bone structure occurs), • strength (the amount of maximum force needed to break/crack of bone), • stiffness (quotient of the force acting on the bone and the amount of displacement occurring under the influence of this force). Investigation of changes in physical and biomechanical features of bones during growth was performed on pigs of the synthetic 990 line growing from 15 to 130 kg body weight. The animals were slaughtered successively at a body weight of 15, 30, 40, 50, 70, 90, 110 and 130 kg. After slaughter, the following bones were separated from the right half-carcass: humerus, 3rd and 4th metatarsal bone, femur, tibia and fibula as well as 3rd and 4th metatarsal bone. The features of bones were determined using methods described in the methodology. Describing bone growth with the Gompertz equation, it was found that the earliest slowdown of bone growth curve was observed for metacarpal and metatarsal bones. This means that these bones matured the most quickly. The established data also indicate that the rib is the slowest maturing bone. The femur, humerus, tibia and fibula were between the values of these features for the metatarsal, metacarpal and rib bones. The rate of increase in bone mass and length differed significantly between the examined bones, but in all cases it was lower (coefficient b <1) than the growth rate of the whole body of the animal. The fastest growth rate was estimated for the rib mass (coefficient b = 0.93). Among the long bones, the humerus (coefficient b = 0.81) was characterized by the fastest rate of weight gain, however femur the smallest (coefficient b = 0.71). The lowest rate of bone mass increase was observed in the foot bones, with the metacarpal bones having a slightly higher value of coefficient b than the metatarsal bones (0.67 vs 0.62). The third bone had a lower growth rate than the fourth bone, regardless of whether they were metatarsal or metacarpal. The value of the bending force increased as the animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. The rate of change in the value of this indicator increased at a similar rate as the body weight changes of the animals in the case of the fibula and the fourth metacarpal bone (b value = 0.98), and more slowly in the case of the metatarsal bone, the third metacarpal bone, and the tibia bone (values of the b ratio 0.81–0.85), and the slowest femur, humerus and rib (value of b = 0.60–0.66). Bone stiffness increased as animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. Abstract 12 The rate of change in the value of this indicator changed at a faster rate than the increase in weight of pigs in the case of metacarpal and metatarsal bones (coefficient b = 1.01–1.22), slightly slower in the case of fibula (coefficient b = 0.92), definitely slower in the case of the tibia (b = 0.73), ribs (b = 0.66), femur (b = 0.59) and humerus (b = 0.50). Bone strength increased as animals grew. Regardless of the growth point tested, bone strength was as follows femur > tibia > humerus > 4 metacarpal> 3 metacarpal> 3 metatarsal > 4 metatarsal > rib> fibula. The rate of increase in strength of all examined bones was greater than the rate of weight gain of pigs (value of the coefficient b = 2.04–3.26). As the animals grew, the bone density increased. However, the growth rate of this indicator for the majority of bones was slower than the rate of weight gain (the value of the coefficient b ranged from 0.37 – humerus to 0.84 – fibula). The exception was the rib, whose density increased at a similar pace increasing the body weight of animals (value of the coefficient b = 0.97). The study on the influence of the breed and the feeding intensity on bone characteristics (physical and biomechanical) was performed on pigs of the breeds Duroc, Pietrain, and synthetic 990 during a growth period of 15 to 70 kg body weight. Animals were fed ad libitum or dosed system. After slaughter at a body weight of 70 kg, three bones were taken from the right half-carcass: femur, three metatarsal, and three metacarpal and subjected to the determinations described in the methodology. The weight of bones of animals fed aa libitum was significantly lower than in pigs fed restrictively All bones of Duroc breed were significantly heavier and longer than Pietrain and 990 pig bones. The average values of bending force for the examined bones took the following order: III metatarsal bone (63.5 kg) <III metacarpal bone (77.9 kg) <femur (271.5 kg). The feeding system and breed of pigs had no significant effect on the value of this indicator. The average values of the bones strength took the following order: III metatarsal bone (92.6 kg) <III metacarpal (107.2 kg) <femur (353.1 kg). Feeding intensity and breed of animals had no significant effect on the value of this feature of the bones tested. The average bone density took the following order: femur (1.23 g/cm3) <III metatarsal bone (1.26 g/cm3) <III metacarpal bone (1.34 g / cm3). The density of bones of animals fed aa libitum was higher (P<0.01) than in animals fed with a dosing system. The density of examined bones within the breeds took the following order: Pietrain race> line 990> Duroc race. The differences between the “extreme” breeds were: 7.2% (III metatarsal bone), 8.3% (III metacarpal bone), 8.4% (femur). Abstract 13 The average bone stiffness took the following order: III metatarsal bone (35.1 kg/mm) <III metacarpus (41.5 kg/mm) <femur (60.5 kg/mm). This indicator did not differ between the groups of pigs fed at different intensity, except for the metacarpal bone, which was more stiffer in pigs fed aa libitum (P<0.05). The femur of animals fed ad libitum showed a tendency (P<0.09) to be more stiffer and a force of 4.5 kg required for its displacement by 1 mm. Breed differences in stiffness were found for the femur (P <0.05) and III metacarpal bone (P <0.05). For femur, the highest value of this indicator was found in Pietrain pigs (64.5 kg/mm), lower in pigs of 990 line (61.6 kg/mm) and the lowest in Duroc pigs (55.3 kg/mm). In turn, the 3rd metacarpal bone of Duroc and Pietrain pigs had similar stiffness (39.0 and 40.0 kg/mm respectively) and was smaller than that of line 990 pigs (45.4 kg/mm). The thickness of the cortical bone layer took the following order: III metatarsal bone (2.25 mm) <III metacarpal bone (2.41 mm) <femur (5.12 mm). The feeding system did not affect this indicator. Breed differences (P <0.05) for this trait were found only for the femur bone: Duroc (5.42 mm)> line 990 (5.13 mm)> Pietrain (4.81 mm). The cross sectional area of the examined bones was arranged in the following order: III metatarsal bone (84 mm2) <III metacarpal bone (90 mm2) <femur (286 mm2). The feeding system had no effect on the value of this bone trait, with the exception of the femur, which in animals fed the dosing system was 4.7% higher (P<0.05) than in pigs fed ad libitum. Breed differences (P<0.01) in the coross sectional area were found only in femur and III metatarsal bone. The value of this indicator was the highest in Duroc pigs, lower in 990 animals and the lowest in Pietrain pigs. The cortical index of individual bones was in the following order: III metatarsal bone (31.86) <III metacarpal bone (33.86) <femur (44.75). However, its value did not significantly depend on the intensity of feeding or the breed of pigs.