scholarly journals Anatomy of Cerebellum

2021 ◽  
Author(s):  
Rajasekhar Sajja Srinivasa Siva Naga

The cerebellum receives inputs from spinal cord, cerebrum, brainstem, and sensory systems of the body and controls the motor system of the body. The Cerebellum harmonizes the voluntary motor activities such as maintenance of posture and equilibrium, and coordination of voluntary muscular activity including learning of the motor behaviours. Cerebellum occupies posterior cranial fossa, and it is relatively a small part of the brain. It weighs about one tenth of the total brain. Cerebellar lesions do not cause motor or cognitive impairment. However, they cause slowing of movements, tremors, lack of equilibrium/balance. Complex motor action becomes shaky and faltering.

Author(s):  
Max Fink MD

Electroconvulsive therapy (ECT) is an effective medical treatment for severe and persistent psychiatric disorders. It relieves de pressed mood and thoughts of suicide, as well as mania, acute psychosis, delirium, and stupor. It is usually applied when medications have given limited relief or their side effects are intolerable. Electroconvulsive therapy is similar to a surgical treatment. It requires the specialized skills of a psychiatrist, an anesthesiologist, and nurses. The patient receives a short-acting anesthetic. While the patient is asleep, the physician, following a prescribed procedure, induces an epileptic seizure in the brain. By making sure that the patient’s lungs are filled with oxygen, the physician precludes the gasping and difficult breathing that accompany a spontaneous epileptic fit. By relaxing the patient’s muscles with chemicals and by inserting a mouth guard (not unlike those used in sports), the physician prevents the tongue biting, fractures, and injuries that occasionally occur in epilepsy. The patient is asleep, and so experiences neither the painful effects of the stimulus nor the discomforts of the seizure. The physiological functions of the body, such as breathing, heart rate, blood pressure, blood oxygen concentration, and degree of motor relaxation, are monitored, and anything out of the ordinary is immediately treated. Electroconvulsive therapy relieves symptoms more quickly than do psychotropic drugs. A common course of ECT consists of two or three treatments a week for two to seven weeks. To sustain the recovery, weekly or biweekly continuation treatments, either ECT or medications, are often administered for four to six months. If the illness recurs, ECT is prescribed for longer periods. The duration and course of ECT are similar to those of the psychotropic medicines frequently used for the same conditions. Electroconvulsive therapy has been used safely to treat emotional disorders in patients of all ages, from children to the elderly, in people with debilitating physical illnesses, and in pregnant women. Emotional disorders may be of short or long duration; they may be manifest as a single episode or as a recurring event. Electroconvulsive treatment is an option when the emotional disorder is acute in onset; when changes in mood, thought, and motor activities are pronounced; when the cause is believed to be biochemical or physiological; when the condition is so severe that it interferes with the patient’s daily life; or when other treatments have failed.


2015 ◽  
Vol 61 (3) ◽  
pp. 231-237
Author(s):  
Mohamed Khwanda ◽  
◽  
Yazan Jahjah ◽  

Understanding the complexities of cranial base development, function, and architecture is important for testing hypotheses about many aspects of craniofacial variation and evolution. Architecturally, the cranial base provides the platform upon which the brain grows and around which the face grows. In addition, the cranial base connects the cranium with the rest of the body: it articulates with the vertebral column and the mandible, provides conduits for all the vital neural and circulatory connections between the brain, the face and the neck, houses and connects the sense organs in the skull, and forms the roof of the nasopharynx. The shape of the cranial base is therefore a multifactorial product of numerous phylogenetic, developmental, and functional interactions. Aim. The aim of this research is to perform a morphometric analysis of the skull base to investigate the symmetry between the two hemibases of the cranial fossa with each other in adult patients with normal type of lower jaw rotation using cone beam copmuted tomography CBCT in transversal plane. Materials and methods. In result of radiographic study, 35 Caucasian adult patients with no prior orthodontics treatment were selected (16 males, 19 females) from 16 to 27 years (mean age of 20.02 years: females average age was 20.15 years; males average age was 21.84 years) of age with normal type of lower jaw rotation according to the sum of Björk. Pearson’s Correlation Coefficient was calculated to investigate the symmetry between the two hemibases of the cranial fossa with each other. Results. A difference was found amongst the two genders of the sample subjects in the strength of the correlation between the CBCT angular measurements evaluating the two hemibases of the cranial base symmetry. Conclusion. A difference was found amongst the two genders. This study found no exact symmetry between the samples, but it was in high level for adult females.


Can the imaginary brains described in Chapter 1 have only representations of perceived patterns, objects, and events? Can hierarchical structures of neurons also represent feelings, beliefs, emotions, and other higher mental states? Creating feelings requires giving emotional perceptions, memories, plans, beliefs, and intentions. How can this be achieved? How are perceived objects and events using their significance for the fate of the conscious system? Do they meet the various needs of the system? In this chapter we show that to achieve this goal, to feel qualia and to create phenomenal awareness, it is necessary to embody the mind. Mental states, such as thoughts and desires, contain intentional content that can be described by referring to something that we expect or believe. Another category are sensory feelings that do not contain intentional content but instead have different qualitative properties like perceptions, impressions, and sensations. The authors indicate four main domains of cooperation between the body and the brain, so that the mind generated in the system has phenomenal consciousness. These domains are 1) The homeostatic system. The body or housing may contain sensors informing the brain about the internal conditions of the body. The signals from these sensors can complement the information coming from the external senses. 2) The motor system. The housing and body, together with the motor system, allow an individual to manipulate objects in the environment and its own body in the environment. The effects of these manipulations can broaden the experience and allow for their evaluation. 3) Participatory analysis. The body or housing can be used to predict, analyze, and plan activities by making calculations through a physical process. 4) The global states of the organism. Internal power supply parameters, information-processing speed, dynamics of operation, and sensitivity thresholds for internal and external sensors can affect performance, the results of evaluation of sensations, and the shape of neural representations. This assumption makes it possible to explain how the imaginary mind can feel subjective impressions, the qualia that are the basis of phenomenal consciousness. The bodily reactions to the sensory stimuli reaching the brain can give value to individual feelings, and emotions. Feeling hardness or smoothness, assessing the attractiveness of smells, judging the importance of sounds, and evaluating the favor of the environment based on images all go beyond the direct response of the senses. The entire brain is involved in the creation of a conscious mind, along with sensory processing, control of movements, memories, predictions, and all other brain structures. This is an emergent phenomenon that is not reflected in any part of the brain's apparatus. In this chapter, the authors explain to what extent we can be aware of our feelings, how far we can understand the world around us and our place in it, how we can consciously direct our thoughts, and how we can focus attention on something.


PEDIATRICS ◽  
1966 ◽  
Vol 38 (5) ◽  
pp. 801-807
Author(s):  
John W. Benton ◽  
Hugo W. Moser ◽  
Philip R. Dodge ◽  
Sheila Carr

Relative nutritional deprivation was produced in groups of 16 to 21 newborn rats who were all nursed by one dam (deprived group) and compared with control litters containing 10 or less animals. Both groups were weaned at 21 days and thereafter allowed an unlimited supply of food. There was diminished somatic growth in all of the deprived group and, at 2 and 3 weeks, the weight of many of the deprived animals was approximately one-half that of the controls. Brain weight, total brain lipids, cholesterol, and phospholipids were reduced to approximately 80% of the control. Brain cerebrosides were affected to a greater extent than the other lipids, being only 50% of the control values. Histological sections showed less myelin. At 6 weeks, following 3 weeks of ad lib. food intake, the body weight, brain weight, and concentrations of the brain lipids of the initially deprived animals were essentially equal to those in the control animals.


Author(s):  
M.P. Sutunkova ◽  
B.A. Katsnelson ◽  
L.I. Privalova ◽  
S.N. Solovjeva ◽  
V.B. Gurvich ◽  
...  

We conducted a comparative assessment of the nickel oxide nanoparticles toxicity (NiO) of two sizes (11 and 25 nm) according to a number of indicators of the body state after repeated intraperitoneal injections of these particles suspensions. At equal mass doses, NiO nanoparticles have been found to cause various manifestations of systemic subchronic toxicity with a particularly pronounced effect on liver, kidney function, the body’s antioxidant system, lipid metabolism, white and red blood, redox metabolism, spleen damage, and some disorders of nervous activity allegedly related to the possibility of nickel penetration into the brain from the blood. The relationship between the diameter and toxicity of particles is ambiguous, which may be due to differences in toxicokinetics, which is controlled by both physiological mechanisms and direct penetration of nanoparticles through biological barriers and, finally, unequal solubility.


Parasitology ◽  
1941 ◽  
Vol 33 (4) ◽  
pp. 373-389 ◽  
Author(s):  
Gwendolen Rees

1. The structure of the proboscides of the larva of Dibothriorhynchus grossum (Rud.) is described. Each proboscis is provided with four sets of extrinsic muscles, and there is an anterior dorso-ventral muscle mass connected to all four proboscides.2. The musculature of the body and scolex is described.3. The nervous system consists of a brain, two lateral nerve cords, two outer and inner anterior nerves on each side, twenty-five pairs of bothridial nerves to each bothridium, four longitudinal bothridial nerves connecting these latter before their entry into the bothridia, four proboscis nerves arising from the brain, and a series of lateral nerves supplying the lateral regions of the body.4. The so-called ganglia contain no nerve cells, these are present only in the posterior median commissure which is therefore the nerve centre.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zakaria Djebbara ◽  
Lars Brorson Fich ◽  
Klaus Gramann

AbstractAction is a medium of collecting sensory information about the environment, which in turn is shaped by architectural affordances. Affordances characterize the fit between the physical structure of the body and capacities for movement and interaction with the environment, thus relying on sensorimotor processes associated with exploring the surroundings. Central to sensorimotor brain dynamics, the attentional mechanisms directing the gating function of sensory signals share neuronal resources with motor-related processes necessary to inferring the external causes of sensory signals. Such a predictive coding approach suggests that sensorimotor dynamics are sensitive to architectural affordances that support or suppress specific kinds of actions for an individual. However, how architectural affordances relate to the attentional mechanisms underlying the gating function for sensory signals remains unknown. Here we demonstrate that event-related desynchronization of alpha-band oscillations in parieto-occipital and medio-temporal regions covary with the architectural affordances. Source-level time–frequency analysis of data recorded in a motor-priming Mobile Brain/Body Imaging experiment revealed strong event-related desynchronization of the alpha band to originate from the posterior cingulate complex, the parahippocampal region as well as the occipital cortex. Our results firstly contribute to the understanding of how the brain resolves architectural affordances relevant to behaviour. Second, our results indicate that the alpha-band originating from the occipital cortex and parahippocampal region covaries with the architectural affordances before participants interact with the environment, whereas during the interaction, the posterior cingulate cortex and motor areas dynamically reflect the affordable behaviour. We conclude that the sensorimotor dynamics reflect behaviour-relevant features in the designed environment.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Conor McQuaid ◽  
Molly Brady ◽  
Rashid Deane

Abstract Background SARS-CoV-2, a coronavirus (CoV), is known to cause acute respiratory distress syndrome, and a number of non-respiratory complications, particularly in older male patients with prior health conditions, such as obesity, diabetes and hypertension. These prior health conditions are associated with vascular dysfunction, and the CoV disease 2019 (COVID-19) complications include multiorgan failure and neurological problems. While the main route of entry into the body is inhalation, this virus has been found in many tissues, including the choroid plexus and meningeal vessels, and in neurons and CSF. Main body We reviewed SARS-CoV-2/COVID-19, ACE2 distribution and beneficial effects, the CNS vascular barriers, possible mechanisms by which the virus enters the brain, outlined prior health conditions (obesity, hypertension and diabetes), neurological COVID-19 manifestation and the aging cerebrovascualture. The overall aim is to provide the general reader with a breadth of information on this type of virus and the wide distribution of its main receptor so as to better understand the significance of neurological complications, uniqueness of the brain, and the pre-existing medical conditions that affect brain. The main issue is that there is no sound evidence for large flux of SARS-CoV-2 into brain, at present, compared to its invasion of the inhalation pathways. Conclusions While SARS-CoV-2 is detected in brains from severely infected patients, it is unclear on how it gets there. There is no sound evidence of SARS-CoV-2 flux into brain to significantly contribute to the overall outcomes once the respiratory system is invaded by the virus. The consensus, based on the normal route of infection and presence of SARS-CoV-2 in severely infected patients, is that the olfactory mucosa is a possible route into brain. Studies are needed to demonstrate flux of SARS-CoV-2 into brain, and its replication in the parenchyma to demonstrate neuroinvasion. It is possible that the neurological manifestations of COVID-19 are a consequence of mainly cardio-respiratory distress and multiorgan failure. Understanding potential SARS-CoV-2 neuroinvasion pathways could help to better define the non-respiratory neurological manifestation of COVID-19.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Martin L. Pall

Abstract Millimeter wave (MM-wave) electromagnetic fields (EMFs) are predicted to not produce penetrating effects in the body. The electric but not magnetic part of MM-EMFs are almost completely absorbed within the outer 1 mm of the body. Rodents are reported to have penetrating MM-wave impacts on the brain, the myocardium, liver, kidney and bone marrow. MM-waves produce electromagnetic sensitivity-like changes in rodent, frog and skate tissues. In humans, MM-waves have penetrating effects including impacts on the brain, producing EEG changes and other neurological/neuropsychiatric changes, increases in apparent electromagnetic hypersensitivity and produce changes on ulcers and cardiac activity. This review focuses on several issues required to understand penetrating effects of MM-waves and microwaves: 1. Electronically generated EMFs are coherent, producing much higher electrical and magnetic forces then do natural incoherent EMFs. 2. The fixed relationship between electrical and magnetic fields found in EMFs in a vacuum or highly permeable medium such as air, predicted by Maxwell’s equations, breaks down in other materials. Specifically, MM-wave electrical fields are almost completely absorbed in the outer 1 mm of the body due to the high dielectric constant of biological aqueous phases. However, the magnetic fields are very highly penetrating. 3. Time-varying magnetic fields have central roles in producing highly penetrating effects. The primary mechanism of EMF action is voltage-gated calcium channel (VGCC) activation with the EMFs acting via their forces on the voltage sensor, rather than by depolarization of the plasma membrane. Two distinct mechanisms, an indirect and a direct mechanism, are consistent with and predicted by the physics, to explain penetrating MM-wave VGCC activation via the voltage sensor. Time-varying coherent magnetic fields, as predicted by the Maxwell–Faraday version of Faraday’s law of induction, can put forces on ions dissolved in aqueous phases deep within the body, regenerating coherent electric fields which activate the VGCC voltage sensor. In addition, time-varying magnetic fields can directly put forces on the 20 charges in the VGCC voltage sensor. There are three very important findings here which are rarely recognized in the EMF scientific literature: coherence of electronically generated EMFs; the key role of time-varying magnetic fields in generating highly penetrating effects; the key role of both modulating and pure EMF pulses in greatly increasing very short term high level time-variation of magnetic and electric fields. It is probable that genuine safety guidelines must keep nanosecond timescale-variation of coherent electric and magnetic fields below some maximum level in order to produce genuine safety. These findings have important implications with regard to 5G radiation.


Sign in / Sign up

Export Citation Format

Share Document