Muscular System Anatomy
Unlike smooth muscle and cardiac muscle, skeletal muscle is under voluntary control. You don't want to waste good looks, but more importantly, you don't want to waste time and energy either. Synovial fluid production increases the range of movement available at the joints in the short term. Treatment focuses on decreasing inflammation and avoiding re-injury. Skeletal muscle fibers can be divided into two types based on how they produce and use energy:
You can think of the human body as a biomechanical structure, made up of three systems:
In air -breathing vertebrates like human beings, respiration takes place in the respiratory organs called Lungs. The passage of air into the lungs to supply the body with Oxygen is known as inhalation, and the passage of air out of the lungs to expel carbon dioxide is known as exhalation; this process is collectively called breathing or ventilation. In humans and other mammals, the anatomical features of the respiratory system include trachea, bronchi, bronchioles, lungs, and diaphragm.
Molecules of oxygen and carbon dioxide are passively exchanged, by diffusion, between the gaseous external environment and the blood. This exchange process occurs in the alveoli air sacs in the lungs. Respiration in physiology is defined as the movement of oxygen from the outside environment to the cells within tissues, and the transport of carbon dioxide in the opposite direction.
The physiological definition of respiration differs from the biochemical definition, which refers to cellular respiration , a metabolic process by which an organism obtains energy in the form of ATP by oxidizing nutrients and releasing waste products. Although physiologic respiration is necessary to sustain cellular respiration and thus life in animals, the processes are distinct: In animals with lungs, physiological respiration involves respiratory cycles of inhaled and exhaled breaths.
Inhalation breathing in is usually an active movement. The contraction of the diaphragm muscle cause a pressure variation, which is equal to the pressures caused by elastic, resistive and inertial components of the respiratory system. In contrast, exhalation breathing out is usually a passive process. Breathing in, brings air into the lungs where the process of gas exchange takes place between the air in the alveoli and the blood in the pulmonary capillaries.
The process of breathing does not fill the alveoli with atmospheric air during each inhalation about ml per breath , but the inhaled air is carefully diluted and thoroughly mixed with a large volume of gas about 2. Physiological respiration involves the mechanisms that ensure that the composition of the functional residual capacity is kept constant, and equilibrates with the gases dissolved in the pulmonary capillary blood, and thus throughout the body.
Thus, in precise usage, the words breathing and ventilation are hyponyms, not synonyms, of respiration; but this prescription is not consistently followed, even by most health care providers, because the term respiratory rate RR is a well-established term in health care, even though it would need to be consistently replaced with ventilation rate if the precise usage were to be followed.
Spirometer or Pulmonary Function Testing is an apparatus for measuring the volume of air inspired and expired by the lungs. A spirometer measures ventilation, the movement of air into and out of the lungs. The spirogram will identify two different types of abnormal ventilation patterns, obstructive and restrictive.
There are various types of spirometers which use a number of different methods for measurement pressure transducers, ultrasonic, water gauge. Lung Volumes refer to the volume of air associated with different phases of the respiratory cycle.
Lung volumes are directly measured; lung capacities are inferred from lung volumes. The average total lung capacity of an adult human male is about 6 litres of air. Tidal breathing is normal, resting breathing; the tidal volume is the volume of air that is inhaled or exhaled in only a single such breath.
The average human respiratory rate is breaths per minute at birth, decreasing to breaths per minute in adults. Lungs are the primary organs of respiration in humans and many other animals including a few fish and some snails.
In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the atmosphere and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange.
Respiration is driven by different muscular systems in different species. Mammals, reptiles and birds use their musculoskeletal systems to support and foster breathing. In early tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the primary muscle that drives breathing is the diaphragm. The lungs also provide airflow that makes vocal sounds including human speech possible.
Humans have two lungs, a right lung and a left lung. They are situated within the thoracic cavity of the chest. The right lung is bigger than the left, which shares space in the chest with the heart. The lungs together weigh approximately 1. The lungs are part of the lower respiratory tract that begins at the trachea and branches into the bronchi and bronchioles and which receive air breathed in via the conducting zone.
These divide until air reaches microscopic alveoli, where the process of gas exchange takes place. Together, the lungs contain approximately 2, kilometres 1, mi of airways and to million alveoli. The lungs are enclosed within the pleural sac which allows the inner and outer walls to slide over each other whilst breathing takes place, without much friction.
This sac encloses each lung and also divides each lung into sections called lobes. The right lung has three lobes and the left has two.
The lobes are further divided into bronchopulmonary segments and lobules. The lungs have a unique blood supply, receiving deoxygenated blood sent from the heart for the purposes of receiving oxygen the pulmonary circulation and a separate supply of oxygenated blood the bronchial circulation. The tissue of the lungs can be affected by a number of diseases, including pneumonia and lung cancer.
Chronic diseases such as chronic obstructive pulmonary disease and emphysema can be related to smoking or exposure to harmful substances. Diseases such as bronchitis can also affect the respiratory tract.
In embryonic development, the lungs begin to develop as an outpouching of the foregut, a tube which goes on to form the upper part of the digestive system. When the lungs are formed the fetus is held in the fluid-filled amniotic sac and so they do not function to breathe.
Blood is also diverted from the lungs through the ductus arteriosus. At birth however, air begins to pass through the lungs, and the diversionary duct closes, so that the lungs can begin to respire. The lungs only fully develop in early childhood. Idiopathic Pulmonary Fibrosis is a type of chronic Lung Disease characterized by a progressive and irreversible decline in lung function. Symptoms typically include gradual onset of shortness of breath and a dry cough. Other changes may include feeling tired and nail clubbing.
Idiopathic pulmonary fibrosis IPF is a type of lung disease that results in scarring fibrosis of the lungs for an unknown reason.
Over time, the scarring gets worse and it becomes hard to take in a deep breath and the lungs cannot take in enough oxygen. Complications may include pulmonary hypertension, heart failure, pneumonia, or pulmonary embolism. The cause is unknown. Risk factors include a cigarette smoking , certain viral infections, and a family history of the condition.
The underlying mechanism involves scarring of the lungs. Diagnosis requires ruling out other potential causes and may be supported by a CT scan or lung biopsy. It is a type of interstitial lung disease ILD. People often benefit from pulmonary rehabilitation and supplemental oxygen. Certain medications like pirfenidone or nintedanib may slow the progression of the disease. Lung transplantation may also be an option. About 5 million people are affected globally.
The disease newly occurs in about 12 per , people per year. Those in their 60s and 70s are most commonly affected. Males are affected more often than females. Average life expectancy following diagnosis is about four years. Surprising New Role for Lungs: Making Blood Running Improper breathing technique can impair speed and performance. One breath for every two foot strikes taking two steps one left, one right while breathing in and two steps while breathing out 2: Synchronizing the breath to running cadence will keep the organs from putting unnecessary pressure on the diaphragm, which can impede breathing and make running more uncomfortable than it needs to be.
There is also the 3: Aerobics Running Websites for Runners - When starting to run, concentrate solely on form. Keep your hips, spine and neck aligned. Minimize up and down movement. Run in as straight a line as possible. Women Run Faster after taking newly developed supplement combo of minerals and other nutrients in forms of iron, copper and zinc along with two other nutrients — carnitine derived from an amino acid and phosphatidylserine made up of fatty acids and amino acids.
Sprinting is running over a short distance in a limited period of time. It is used in many sports that incorporate running, typically as a way of quickly reaching a target or goal, or avoiding or catching an opponent. Human Physiology dictates that a runner's near-top speed cannot be maintained for more than 30—35 seconds due to the depletion of phosphocreatine stores in muscles, and perhaps secondarily to excessive metabolic acidosis as a result of anaerobic glycolysis.
Foot Speed is the maximum speed at which a human can run. It is affected by many factors, varies greatly throughout the population, and is important in athletics and many sports, such as association football, rugby, American football, track and field, hockey, baseball and basketball. The record was Slumping over is actually better for breathing. Bending over helps your diaphragm the major breathing muscle suck in more air. The bent over position also helps you use your abs to breathe out more forcefully, and may signal your nervous system to relax.
It will also lower your heart rate more quickly than standing up with your hands behind your head. Heavy breathing during running is more of a function of getting the carbon dioxide out. Secondly, delivery of both Oxygen to the muscles and CO2 and other by products to the lungs is the issue.
When you stop running, blood tends to pool in the legs because you no longer have that leg pump to help pump the blood upwards, against gravity, back to the heart. When you stop, the body has the problem of pumping blood against gravity.
The reason you bend over or even lie down after hard exercise is that the body is trying make it where the heart is essentially on the same plane as the rest of the body, so that pumping the blood is easier, and not against gravity. Why do my lungs burn during strenuous exercise?
During high-intensity aerobic activities such as running, cycling, or swimming, you increase the need for oxygen, ventilation and both the rate and the depth of breathing.
As a result many people experience a burning sensation in their lungs and windpipe. A variety of factors affect the degree to which people experience this sensation. If you are new to exercising and are not yet accustomed to the rigors of intense activity, you breathe through your mouth and not just your nose, so the air rushing toward your lungs tends to dry the mucus membranes in your mouth and bronchial passages, resulting in irritation and a burning sensation.
This condition gets worse in cold weather. And if you are suffering from an acute condition that originates in or affects the lungs or airways, such as bronchitis , emphysema , pneumonia , asthma or strep throat , then any burning sensation you experience when breathing during exercise is apt to be exacerbated.
And if you are a smoker or exercise in an environment heavy in lung irritants , such as an industrial zone, consider removing the source of the physiological distress by moving indoors or quitting smoking. If you have no health issues, with improved conditioning, you will adapt to this and feel less irritation, and the burning sensation will be minimal. Nose Breathing has its own benefits, including increased CO2 saturation in the blood, which creates a more calming effect.
Breathing in through the nose can also help warm the air entering the lungs. The breath should come from the diaphragm the most efficient breathing muscle —not the chest. Breathing deeper, calmer, and more efficiently can also give athletes a psychological edge. Mouth Breathing is breathing through the mouth rather than the nose. Healthy humans may breathe through their nose, their mouth, or both. During rest, breathing through the nose is common for most individuals.
Breathing through both nose and mouth during exercise is also normal, a behavioral adaptation to increase air intake and hence supply more oxygen to the muscles.
Mouth breathing may be called abnormal when an individual breathes through the mouth even during rest. Some sources use the term "mouth breathing habit" but this incorrectly implies that the individual is fully capable of normal nasal breathing, and is breathing through their mouth out of preference.
Chronic mouth breathing in children may have implications on dental and facial growth. It also may cause gingivitis inflamed gums and halitosis bad breath , especially upon waking if mouth breathing occurs during sleeping. Exhale slowly and continuously while pressing the bar, then inhale at the top of the lift or on the return.
Some say you should always exhale on exertion. For example, when you are pushing a bench press off your chest, you exhale on the push and inhale as you bring it slowly to your chest.
You exhale on the pulling up motion and inhale on the way down. How to Breathe in every type Exercise Breathing while Exercising Asthma is a common long term inflammatory disease of the airways of the lungs. Plethysmograph measures the functional residual capacity FRC of the lungs. Functional Residual Capacity is the volume of air present in the lungs at the end of passive expiration. Airway Resistance is the resistance of the respiratory tract to airflow during inspiration and expiration.
Airway resistance can be measured using body plethysmography , which is an instrument for measuring changes in volume within an organ or whole body usually resulting from fluctuations in the amount of blood or air it contains.
Upper Airway Resistance Syndrome is a sleep disorder characterized by airway resistance to breathing during sleep. Spirometer is an apparatus for measuring the volume of air inspired and expired by the Lungs POWERbreathe - How it Works youtube Breathe Strong Faqs Power Lung Humans need Oxygen to live, but oxygen can also hurt us Oxygen Toxicity is a condition resulting from the harmful effects of breathing molecular oxygen O2 at increased partial pressures.
Reactive Oxygen Species are chemically reactive chemical species containing oxygen. Examples include peroxides, superoxide, hydroxyl radical, and singlet oxygen. CO2 Oxidative Stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. Red Blood Cell delivers oxygen O2 to the body tissues—via blood flow through the circulatory system.
Antioxidant is a molecule that inhibits the oxidation of other molecules. Radical is an atom, molecule, or ion that has unpaired valence electrons. Atmosphere Knowledge Empty Nose Syndrome is people who have clear nasal passages experience a range of symptoms, most commonly feelings of nasal obstruction, nasal dryness and crusting, and a sensation of being unable to breathe.
Otorhinolaryngology ear, nose, and throat ENT Shallow Breathing thoracic breathing, or chest breathing is the drawing of minimal breath into the lungs, usually by drawing air into the chest area using the intercostal muscles rather than throughout the lungs via the diaphragm. Shallow breathing can result in or be symptomatic of rapid breathing and hypoventilation. Most people who breathe shallowly do it throughout the day and are almost always unaware of the condition. In upper lobar breathing , clavicular breathing, or clavicle breathing air is drawn predominantly into the chest by the raising of the shoulders and collarbone clavicles , and simultaneous contracting of the abdomen during inhalation.
Maximum amount of air can be drawn this way only for short periods of time, since it requires a lot of effort. When used for prolonged time, this is the most superficial mode of shallow breathing. Don't Sweat the Small Stuff Perspiration also known as sweating or diaphoresis is the production of fluids secreted by the sweat glands in the skin of mammals.
Two types of sweat glands can be found in humans: The eccrine sweat glands are distributed over much of the body. In humans, sweating is primarily a means of thermoregulation , which is achieved by the water-rich secretion of the eccrine glands. Evaporation of sweat from the skin surface has a cooling effect due to evaporative cooling. Hence, in hot weather, or when the individual's muscles heat up due to exertion, more sweat is produced.
Animals with few sweat glands, such as dogs, accomplish similar temperature regulation results by panting, which evaporates water from the moist lining of the oral cavity and pharynx. Primates and horses have armpits that sweat like those of humans.
Although sweating is found in a wide variety of mammals, relatively few exceptions include humans and horses produce large amounts of sweat in order to cool down. On average, you lose about one liter approx. There are , , for each sweat glands in your feet, and that can mean a great deal of stinky sweat. Prickly Heat or Heat Rash , happens to adults and children when sweat becomes trapped under the skin.
The rash may appear as blisters or red lumps. Heat rash may cause itchiness or a prickly feeling. Heat rash usually goes away on its own. Use of fans and lightweight clothing can help. When you inhale, you are typically inhaling cooler, less humid air. Your body moistens the surface of your lungs and adds moisture to the air as it passes through your air passageways.
Camel is an even-toed ungulate in the genus Camelus that bears distinctive fatty deposits known as "humps" on its back. The average life expectancy of a camel is 40 to 50 years. A full-grown adult camel stands 1. Bactrian camels weigh to 1, kg to 2, lb and dromedaries to kg to 1, lb.
The widening toes on a camel's hoof provide supplemental grip for varying soil sediments. Camels have a series of physiological adaptations that allow them to withstand long periods of time without any external source of water.
Unlike other mammals, camels' red blood cells are oval rather than circular in shape. This facilitates the flow of red blood cells during dehydration and makes them better at withstanding high osmotic variation without rupturing when drinking large amounts of water: When the camel exhales, water vapor becomes trapped in their nostrils and is reabsorbed into the body as a means to conserve water.
Camels eating green herbage can ingest sufficient moisture in milder conditions to maintain their bodies' hydrated state without the need for drinking. The kidneys and intestines of a camel are very efficient at reabsorbing water.
In general, to compare between camels and the other livestock, camels lose only 1. Why does Saliva increase during strenuous exercise? When exercising you inhale a lot more air at once, this needs to be cleaned before entering your body otherwise you have a risk of infections, therefore, your body produced mucus and saliva to remove the large dust molecules and bacteria.
When you exercise your body takes in a lot more air at a quicker pace, so you produce more mucus to help clean it. It is important that you regularly blow your nose and spit to get rid of the excess and old mucus that is full of bacteria and dust particles from the air.
Swallowing your saliva completely goes against the point of your mucus as the dust and bacteria can then enter your body anyway!
So make sure that you do not swallow your spit and you blow your nose regularly when exercising. Make sure that you also drink fluid during and after exercise to replace the water levels that have gone. Orthostatic Hypotension or head rush, occurs when a person's blood pressure falls when suddenly standing up from a lying or sitting position. Dizziness is an impairment in spatial perception and stability. The sensation of lightheadedness can be short-lived, prolonged, or, rarely, recurring.
In addition to dizziness, the individual may feel as though his or her head is weightless. The individual may also feel as though the room is what causes the "spinning" or moving vertigo associated with lightheadedness.
Most causes of lightheadedness are not serious and either cure themselves quickly or are easily treated. Keeping a sense of balance requires the brain to process a variety of information received from the eyes, the nervous system , and the inner ears.
If the brain is unable to process these signals, such as when the messages are contradictory, or if the sensory systems are improperly functioning, an individual may experience lightheadedness or dizziness. Faint is a sudden loss of consciousness. Pass out from weakness , physical or emotional distress due to a loss of blood supply to the brain. Vertigo is the sensation of spinning or having one's surroundings spin about them. Syncope or fainting, is defined as a short loss of consciousness and muscle strength, characterized by a fast onset, short duration, and spontaneous recovery.
It is due to a decrease in blood flow to the entire brain usually from low blood pressure. Vasovagal Response is a malaise mediated by the vagus nerve. When it leads to fainting. Balance Disorder is a disturbance that causes an individual to feel unsteady, for example when standing or walking. It may be accompanied by feelings of giddiness, or wooziness, or having a sensation of movement, spinning, or floating. Balance is the result of several body systems working together: Degeneration or loss of function in any of these systems can lead to balance deficits.
Human Senses - Immune System Alcohol Effects Alcohol thins the blood which distorts the shape of the inner ear creating a false signal.
The swollen ear parts push on the tiny sensory hairs, deceiving the brain into producing the sense of motion , or spinning. When in the dark the spinning sense is enhanced, since you can no longer rely upon visual cues to counteract the false sense of motion. Vestibular System is the sensory system that provides the leading contribution about the sense of balance and spatial orientation for the purpose of coordinating movement with balance , in your ear is a set of three fluid-filled canals which work like a three-directional spirit level.
So your head knows which direction your head is moving. Endolymph is the fluid contained in the membranous labyrinth of the inner ear. It is also called Scarpa's fluid, after Antonio Scarpa Ampullary Cupula is a structure in the vestibular system, providing the sense of spatial orientation Cochlea Dizzy - Tommy Roe youtube Vestibulo-ocular Reflex is a reflex eye movement that elicits eye movement by stimulating the vestibular system.
This reflex functions to stabilize images on the retinas in yoked vision during head movement by producing eye movements in the direction opposite to head movement, thus preserving the image on the center of the visual field s. For example, when the head moves to the right, the eyes move to the left, and vice versa. Since slight head movement is present all the time, the VOR is very important for stabilizing vision: Image Stabilization are techniques that reduce blurring associated with the motion of a camera or other imaging device during exposure.
Fixation Reflex concerned with attracting the eye on a peripheral object. For example, when a light shines in the periphery, the eyes shift gaze on it. It is controlled by the occipital lobe of the cerebral cortex. The muscles wrapped around the Z-axis of your eyes are there to keep everything level — up to a point.
This reduces the amount of processing power your brain needs to decode the world around you — provided that your head is within about 15 degrees of vertical. Once your head tilts past that point, your eyes stop trying to keep things horizontal, and gives up, untwisting themselves. Spatial Intelligence Body Kinesthetic Intelligence Exercising The Four Basic Exercises Aerobic Exercise is physical exercise of low to high intensity that depends primarily on the aerobic energy-generating process.
Aerobic literally means "relating to, involving, or requiring free oxygen", and refers to the use of oxygen to adequately meet energy demands during exercise via aerobic metabolism. Generally, light-to-moderate intensity activities that are sufficiently supported by aerobic metabolism can be performed for extended periods of time. It utilizes the force of gravity in the form of weighted bars, dumbbells or weight stacks in order to oppose the force generated by muscle through concentric or eccentric contraction.
Weight training uses a variety of specialized equipment to target specific muscle groups and types of movement. Sports where strength training is central are bodybuilding, weightlifting, powerlifting, and strongman, highland games, shot put, discus throw, and javelin throw.
Many other sports use strength training as part of their training regimen, notably; mixed martial arts, American football, wrestling, rugby football, track and field, rowing, lacrosse, basketball, baseball, and hockey. Strength training for other sports and physical activities is becoming increasingly popular. Abdominal Exercise are those that affect the abdominal muscles colloquially known as the stomach muscles or "abs".
Pelvis is either the lower part of the trunk of the human body between the abdomen and the thighs. Yoga Coordination Exercises - Jumping-Rope , tai chi and Dancing helps improve coordination , balance , rhythm , spatial orientation and reaction to visual and auditory stimuli.
Basic Exercises you can do almost anywhere in 15 minutes. You need to train smarter, not harder. Using principles of size, all it takes is 3 exercises, 3 days a week.
Deadlift Do 25 total reps of each exercise, using a weight you can lift 4 to 6 times before your speed slows down or your form changes. Rest about 60 seconds between sets. Dumbbell single-arm shoulder press 2. Dumbbell single-arm row 3. Dumbbell lunge or stepup Do 40 total reps of each exercise with each arm or each leg, using a weight you can lift 10 to 12 times before your speed slows down or your form changes.
Do all the reps of each exercise before resting. Rest 45 seconds between sets. Barbell bent-over row 2. F; Balady, G; Blair, S. Executive summary of a Cochrane Collaboration systematic review". Journal of Cachexia, Sarcopenia and Muscle. Diagnosis, assessment, and treatment". Current Opinion in Behavioral Sciences. Aerobic physical exercise PE activates the release of neurotrophic factors and promotes angiogenesis, thereby facilitating neurogenesis and synaptogenesis, which in turn improve memory and cognitive functions.
Exercise limits the alteration in dopaminergic neurons in the substantia nigra and contributes to optimal functioning of the basal ganglia involved in motor commands and control by adaptive mechanisms involving dopamine and glutamate neurotransmission. The benefits of regular exercise, physical fitness and sports participation on cardiovascular and brain health are undeniable Exercise also enhances psychological health, reduces age-related loss of brain volume, improves cognition, reduces the risk of developing dementia, and impedes neurodegeneration.
Aerobic physical exercise produces numerous health benefits in the brain. Regular engagement in physical exercise enhances cognitive functioning, increases brain neurotrophic proteins, such as brain-derived neurotrophic factor BDNF , and prevents cognitive diseases [76—78]. Recent findings highlight a role for aerobic exercise in modulating chromatin remodelers [21, 79—82]. These results were the first to demonstrate that acute and relatively short aerobic exercise modulates epigenetic modifications.
The transient epigenetic modifications observed due to chronic running training have also been associated with improved learning and stress-coping strategies, epigenetic changes and increased c-Fos-positive neurons Nonetheless, these studies demonstrate the existence of epigenetic changes after acute and chronic exercise and show they are associated with improved cognitive function and elevated markers of neurotrophic factors and neuronal activity BDNF and c-Fos.
The aerobic exercise training-induced changes to miRNA profile in the brain seem to be intensity-dependent . These few studies provide a basis for further exploration into potential miRNAs involved in brain and neuronal development and recovery via aerobic exercise. Retrieved 9 December A range of validated platforms assessed CF across three domains: In studies of executive function, five found a significant ES in favour of higher PA, ranging from small to large.
Although three of four studies in the memory domain reported a significant benefit of higher PA, there was only one significant ES, which favoured low PA. Only one study examining processing speed had a significant ES, favouring higher PA. A limited body of evidence supports a positive effect of PA on CF in young to middle-aged adults.
Further research into this relationship at this age stage is warranted. Significant positive effects of PA on cognitive function were found in 12 of the 14 included manuscripts, the relationship being most consistent for executive function, intermediate for memory and weak for processing speed. A meta-analysis including the evaluation of control group response". Exercise has established efficacy as an antidepressant in people with depression.
Exercise significantly improved physical and psychological domains and overall QoL. The lack of improvement among control groups reinforces the role of exercise as a treatment for depression with benefits to QoL. Research investigating the effects of exercise on older adults has primarily focused on brain structural and functional changes with relation to cognitive improvement.
In particular, several cross-sectional and intervention studies have shown a positive association between physical activity and cognition in older persons  and an inverse correlation with cognitive decline and dementia . Older adults enrolled in a 6-month aerobic fitness intervention increased brain volume in both gray matter anterior cingulate cortex, supplementary motor area, posterior middle frontal gyrus, and left superior temporal lobe and white matter anterior third of corpus callosum .
In addition, Colcombe and colleagues showed that older adults with higher cardiovascular fitness levels are better at activating attentional resources, including decreased activation of the anterior cingulated cortex. One of the possible mechanisms by which physical activity may benefit cognition is that physical activity maintains brain plasticity, increases brain volume, stimulates neurogenesis and synaptogenesis, and increases neurotrophic factors in different areas of the brain, possibly providing reserve against later cognitive decline and dementia [89, 90].
A large collection of research in humans has shown that a single bout of exercise alters behavior at the level of affective state and cognitive functioning in several key ways.
In terms of affective state, acute exercise decreases negative affect, increases positive affect, and decreases the psychological and physiological response to acute stress . These effects have been reported to persist for up to 24 hours after exercise cessation [28, 29, 53]. In terms of cognitive functioning, acute exercise primarily enhances executive functions dependent on the prefrontal cortex including attention, working memory, problem solving, cognitive flexibility, verbal fluency, decision making, and inhibitory control .
These positive changes have been demonstrated to occur with very low to very high exercise intensities , with effects lasting for up to two hours after the end of the exercise bout Fig. Moreover, many of these neuropsychological assessments measure several aspects of behavior including both accuracy of performance and speed of processing.
McMorris and Hale performed a meta-analysis examining the effects of acute exercise on both accuracy and speed of processing, revealing that speed significantly improved post-exercise, with minimal or no effect on accuracy . These authors concluded that increasing task difficulty or complexity may help to augment the effect of acute exercise on accuracy. Arq Bras Endocrinol Metabol in Portuguese. Interestingly, some symptoms of OT are related to beta-endorphin beta-end effects.
Some of its effects, such as analgesia, increasing lactate tolerance, and exercise-induced euphoria, are important for training. The runner's high describes a euphoric state resulting from long-distance running. Scand J Med Sci Sports. This systematic review and meta-analysis found that physical activity reduced depressive symptoms among people with a psychiatric illness.
The current meta-analysis differs from previous studies, as it included participants with depressive symptoms with a variety of psychiatric diagnoses except dysthymia and eating disorders. This review provides strong evidence for the antidepressant effect of physical activity; however, the optimal exercise modality, volume, and intensity remain to be determined.
Conclusion Few interventions exist whereby patients can hope to achieve improvements in both psychiatric symptoms and physical health simultaneously without significant risks of adverse effects.
Physical activity offers substantial promise for improving outcomes for people living with mental illness, and the inclusion of physical activity and exercise programs within treatment facilities is warranted given the results of this review.
Consistent evidence indicates that exercise improves cognition and mood, with preliminary evidence suggesting that brain-derived neurotrophic factor BDNF may mediate these effects. The aim of the current meta-analysis was to provide an estimate of the strength of the association between exercise and increased BDNF levels in humans across multiple exercise paradigms.
Moderators of this effect were also examined. Effect size analysis supports the role of exercise as a strategy for enhancing BDNF activity in humans.
This omission is relevant, given the evidence that aerobic-based physical activity generates structural changes in the brain, such as neurogenesis, angiogenesis, increased hippocampal volume, and connectivity 12, In children, a positive relationship between aerobic fitness, hippocampal volume, and memory has been found 12, Mental health outcomes included reduced depression and increased self-esteem, although no change was found in anxiety levels This systematic review of the literature found that [aerobic physical activity APA ] is positively associated with cognition, academic achievement, behavior, and psychosocial functioning outcomes.
Importantly, Shephard also showed that curriculum time reassigned to APA still results in a measurable, albeit small, improvement in academic performance The actual aerobic-based activity does not appear to be a major factor; interventions used many different types of APA and found similar associations.
In positive association studies, intensity of the aerobic activity was moderate to vigorous. The amount of time spent in APA varied significantly between studies; however, even as little as 45 minutes per week appeared to have a benefit.
Considered overall, the studies included in the present review showed a strong effectiveness of exercise combined with antidepressants. Conclusions This is the first review to have focused on exercise as an add-on strategy in the treatment of MDD. Our findings corroborate some previous observations that were based on few studies and which were difficult to generalize. Moreover, we hypothesize that the main role of exercise on treatment-resistant depression is in inducing neurogenesis by increasing BDNF expression, as was demonstrated by several recent studies.
A Clinical Review and Management Guideline". Keeping in mind that exercise shows no medication side effects such as withdrawal symptoms 20 , weight gain, dry mouth or insomnia 21 , but shows potential health benefits such as weight reduction, it is highly recommended to use exercise as an adjunctive treatment for depression New findings confirm that exercise can be recommended as a first-line treatment for mild to moderate depression; as an adjunct to medications 23 ; as an alternative to cognitive behavioral therapy 11 ; and in preventing depression in clinical as well as healthy populations 24— Although recent findings have shown that exercise can decrease depressive symptoms, there are still many questions and limitations to wider application of exercise in depression.
For instance, there are deficiencies in methodological planning such as uncontrolled nonrandomized trials, small sample sizes, inadequate allocation concealment, lack of intention-to-treat analyses, non-blinded outcome assessments, and inclusion of subjects without clinical diagnosis that limit the interpretability of research outcomes The effects of physical exercise on cognition and behavior in children and adults with ADHD: The present review summarises the impact of exercise interventions 1—10 weeks in duration with at least two sessions each week on parameters related to ADHD in 7-to year-old children.
We may conclude that all different types of exercise here yoga, active games with and without the involvement of balls, walking and athletic training attenuate the characteristic symptoms of ADHD and improve social behaviour, motor skills, strength and neuropsychological parameters without any undesirable side effects.
Available reports do not reveal which type, intensity, duration and frequency of exercise is most effective in this respect and future research focusing on this question with randomised and controlled long-term interventions is warranted. Lay summary — Exercise may improve thinking ability and memory 27 December In patients with MCI, exercise training 6 months is likely to improve cognitive measures and cognitive training may improve cognitive measures.
Clinicians should recommend regular exercise Level B. Exercise generally had a positive effect on rate of cognitive decline in AD. A meta-analysis found that exercise interventions have a positive effect on global cognitive function, 0. Cognitive decline in AD is attributable at least in part to the buildup of amyloid and tau proteins, which promote neuronal dysfunction and death Hardy and Selkoe, ; Karran et al.
Evidence in transgenic mouse models of AD, in which the mice have artificially elevated amyloid load, suggests that exercise programs are able to improve cognitive function Adlard et al.
Adlard and colleagues also determined that the improvement in cognitive performance occurred in conjunction with a reduced amyloid load. Research that includes direct indices of change in such biomarkers will help to determine the mechanisms by which exercise may act on cognition in AD. Am J Occup Ther. All studies included people with AD who completed an exercise program consisting of aerobic, strength, or balance training or any combination of the three.
The length of the exercise programs varied from 12 weeks to 12 months. Six studies involving participants tested the effect of exercise on ADL performance These positive effects were apparent with programs ranging in length from 12 wk Santana-Sosa et al.
Furthermore, the positive effects of a 3-mo intervention lasted 24 mo Teri et al. No adverse effects of exercise on ADL performance were noted. The study with the largest effect size implemented a walking and aerobic program of only 30 min four times a week Venturelli et al.
Cochrane Database Syst Rev. A systematic review and meta-analysis of longitudinal studies". Longitudinal observational studies show an association between higher levels of physical activity and a reduced risk of cognitive decline and dementia. A case can be made for a causal interpretation. Future research should use objective measures of physical activity, adjust for the full range of confounders and have adequate follow-up length.
Ideally, randomised controlled trials will be conducted. On the whole the results do, however, lend support to the notion of a causal relationship between physical activity, cognitive decline and dementia, according to the established criteria for causal inference. Role in Drug Addiction and Novel Treatments". There is accelerating evidence that physical exercise is a useful treatment for preventing and reducing drug addiction In some individuals, exercise has its own rewarding effects, and a behavioral economic interaction may occur, such that physical and social rewards of exercise can substitute for the rewarding effects of drug abuse.
The value of this form of treatment for drug addiction in laboratory animals and humans is that exercise, if it can substitute for the rewarding effects of drugs, could be self-maintained over an extended period of time. Work to date in [laboratory animals and humans] regarding exercise as a treatment for drug addiction supports this hypothesis.
However, a RTC study was recently reported by Rawson et al. Animal and human research on physical exercise as a treatment for stimulant addiction indicates that this is one of the most promising treatments on the horizon. Muscle fibers are in turn composed of myofibrils. The myofibrils are composed of actin and myosin filaments, repeated in units called sarcomeres , which are the basic functional units of the muscle fiber.
The sarcomere is responsible for the striated appearance of skeletal muscle, and forms the basic machinery necessary for muscle contraction. Connective tissue is present in all muscles as fascia. Enclosing each muscle is a layer of connective tissue known as the epimysium ; enclosing each fascicle is a layer called the perimysium , and enclosing each muscle fiber is a layer of connective tissue called the endomysium.
Muscle fibres are the individual contractile units within muscle. A single muscle such as the biceps brachii contains many muscle fibres. Another group of cells, the myosatellite cells are found between the basement membrane and the sarcolemma of muscle fibers.
Individual muscle fibers are formed during development from the fusion of several undifferentiated immature cells known as myoblasts into long, cylindrical, multi-nucleated cells. Differentiation into this state is primarily completed before birth with the cells continuing to grow in size thereafter. Skeletal muscle exhibits a distinctive banding pattern when viewed under the microscope due to the arrangement of cytoskeletal elements in the cytoplasm of the muscle fibers.
The principal cytoplasmic proteins are myosin and actin also known as "thick" and "thin" filaments, respectively which are arranged in a repeating unit called a sarcomere. The interaction of myosin and actin is responsible for muscle contraction.
Every single organelle and macromolecule of a muscle fiber is arranged to ensure form meets function. The cell membrane is called the sarcolemma with the cytoplasm known as the sarcoplasm. In the sarcoplasm are the myofibrils.
The myofibrils are long protein bundles about 1 micrometer in diameter each containing myofilaments. Pressed against the inside of the sarcolemma are the unusual flattened myonuclei. Between the myofibrils are the mitochondria. While the muscle fiber does not have a smooth endoplasmic cisternae, it contains a sarcoplasmic reticulum. The sarcoplasmic reticulum surrounds the myofibrils and holds a reserve of the calcium ions needed to cause a muscle contraction. Periodically, it has dilated end sacs known as terminal cisternae.
These cross the muscle fiber from one side to the other. In between two terminal cisternae is a tubular infolding called a transverse tubule T tubule. T tubules are the pathways for action potentials to signal the sarcoplasmic reticulum to release calcium, causing a muscle contraction.
Together, two terminal cisternae and a transverse tubule form a triad. Muscle architecture refers to the arrangement of muscle fibers relative to the axis of force generation of the muscle. This axis is a hypothetical line from the muscle's origin to insertion. For some longitudinal muscles, such as the biceps brachii , this is a relatively simple concept. For others, such as the rectus femoris or deltoid muscle , it becomes more complicated. While the muscle fibers of a fascicle lie parallel to one another, the fascicles themselves can vary in their relationship to one another and to their tendons.
The fascicles of longitudinally arranged, parallel, or fusiform muscles run parallel to the axis of force generation, thus these muscles on a whole function similarly to a single, large muscle fiber. For instance, fusiform refers to a longitudinal architecture with a widened muscle belly biceps , while parallel may refer to a more ribon-shaped longitudinal architecture rectus abdominis.
A less common example would be a circular muscle such as the orbicularis oculi , in which the fibers are longitudinally arranged, but create a circle from origin to insertion.
The fibers in unipennate muscles are all oriented at the same but non-zero angle relative to the axis of force generation. However, because of this angle, more fibers can be packed into the same muscle volume, increasing the Physiological cross-sectional area PCSA. This effect is known as fiber packing, and—in terms of force generation—it more than overcomes the efficiency loss of the off-axis orientation.