Battle of the Sexes: Men Work out More Than Women

Battle of the Sexes: Men Work Out More Than Women

This article from Shape magazine reveals a health disparity between the sexes. According to a study from Preventive Medicine  the average man gets more physical activity than the average woman. To people familiar with gym culture, fitness, or sports in general this is no surprise. However, it does indicate that women would disproportionately suffer negative health consequences due to inactivity. Osteoporosis, heart disease, obesity, and even neurodegenerative diseases are risk factors for inactivity. Oregon State University too a sample of 1,000 men and women According to the data which was not self reported women only got 18 minutes of moderate to intense exercise, while men went to 30 minutes in a session. The data was collected from accelerometers recording total physical activity. It has been recommended that people should get at bare minimum 30 minutes of exercise a day. The problem is women are not getting enough which puts them at higher risk for high blood pressure, high cholesterol, and even depression. One in three women as suffer from metabolic syndrome. What are the possible reasons for this disparity? This question can be answered through sociological and biological factors.

        The text cites “some evidence indicates that women, compared to men, have less confidence in their ability to overcome exercise related barriers.” At first a reader would be perplexed by what that means. To elucidate their is a prejudice and sexism against women who show physical strength, skill,  and power. Simultaneously, women who do seek to improve physical fitness do have a lack of confidence at the beginning of their program. The weaker sex stereotype is still in the consciousness of many and some women are more vulnerable to it. This makes them believe their are certain activities they cannot do, simply because their biology does not allow it. The female body has been regarded as biologically and physically inferior, even though exercise physiology has discredited this notion. The gym and physical activity has been for a longtime thought to be solely a male domain. Gradually, with more women in sports this dated idea has diminished. Yet, sexist stereotypes and traditional gender roles still remain, even in an atmosphere of change. The idea that women can excel at something physical or athletic is considered unladylike. When a strong man shows his skill he is congratulated; when a woman does this she is condemned.

Unfortunately society judges women who are physically strong more harshly than men.  

Muscle and physical fitness are seen as something male only. This effects the way women view exercise throughout their lives. Women may internalize such negative attitudes. While it has been known that weightlifting has more benefits, women may focus on cardio for fear of “getting too big.” With little encouragement and a negative atmosphere women may just stop an exercise regimen all together. There is a segment of  the fitness industry that promotes weight loss for aesthetic purposes rather than health. The impact of body image is powerful, especially is one body type is constantly promoted in various media. If one is surrounded my one image or idea it can distort a person’s thinking. Too many women are attempting to change their bodies to an unattainable or unrealistic body ideal. Extreme cases lead to anorexia or bulimia, which occurs more in women. This is no accident and it is understandable why such a psychological disorder is prevalent. Women who have different body types are either disparaged or ostracized. Women who look different or want to alter their bodies are made into outcasts. If body image pressure is hard on the average woman it is even more intense on the female athlete. While there are sociological barriers, there are some that are biological. Male and female bodies are different, which means there will be a number of outcomes in fitness regimens. Women may have to adjust training to suit their endocrine and musculoskeletal attributes depending on what their goal is. Women on average have less muscular strength and aerobic capacity compared to the average man. Looser joints mean women could be more susceptible to injuries such as ACL tears. This does not mean women cannot handle exercise, it means it should be tailored to prevent injuries and enhance results. Some assume that women cannot gain strength or enhance fitness levels due to sex differences in physiology. Being female does not limit potential,because women can increase their strength and cardiovascular status.

 This will take longer for women to achieve. There are women who get discouraged when results do not happen immediately and quit. Like weight loss regimens, if one is not consistent it will fail. There is a constant inferiority complex that some women might feel that if it is anything physical or sports related, they will fail at. This psychological barrier has to be overcome. Men do not have this problem, because they are not taught to view their bodies as weak. There are differences, but this does not indicate inferiority. Body composition, lung as well as heart size, skeletal and muscle mass just indicate that men have higher physical fitness levels. While women have shown they are capable, that does not mean they have acceptance in the gym space. Traditionally, women were excluded from these areas.

There were only some exercises that were considered acceptable for women. Most were directed at making sure childbirth could be easier. The professional  medical community in the 19th century was not concerned about women’s health, just as long as women could produce children. They though rigorous exercise was bad for the female body and could harm her reproductive capacities. Such falsehoods were promoted by eugenicists and physical educators with the purpose of discouraging women from using their bodies. Although women had been participants in sports since ancient civilization, there has been a constant theme of women being discouraged from the use of their body.  The exercise related barriers are present to this day, even starting at an earlier age. Girls are not taught to throw or  learn other physical skills. If the do receive such instruction, it would only be in physical education. Even in that atmosphere the expectations are lowered. The physical standards for boys and girls in terms of the President’s  Council on Physical Fitness Award differ.

benchmarks_presidential_largeIt makes no sense that the standards are different between the ages of  6 to 13. The reason being is the endocrinological changes from puberty have not occurred. Some standards on the chart are the same, but others are not. Men do not start getting their strength spurt until the age 13, when testosterone production increases. This effects both the muscular and skeletal system giving men more strength. Early on girls seem to be viewed as not capable of playing sports or physical skill. This explains why “you throw like a girl” is used as an insult. There is a subtle sexism that remains in physical education and  is much ore vicious misogyny in sports. Childhood experiences mold what type of person one will be as an adult. If girls at at young age are told they are not capable, they will not attempt try. For both boys and girls their experiences in physical education will influence how they feel about exercise and physical activity. If a PE teacher makes the class unpleasant or dull students will take that negative attitude into adulthood.

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Exercise becomes associated with a chore or a pointless task, when it is essential to your health. The same can be said of children in youth sports. If soccer moms and football dads are too aggressive and pressure their children too much. This will only turn  them away from such activities as adults. They should get from such activities how to work in groups and discover the joy of play.  These exercise related barriers are influenced by environment and culture. Biology may also have influence as well. Boys seem to have more energy and it is harder for them to sit still. Girls seem more sedentary. It is unclear how much is this is cultural or biological. This may explain why to an extent more men gravitate to sports or physical activity. It has been suspected that their is a link between competitiveness and higher testosterone levels. These difference in behavior could be evidence of a human evolutionary past. Men’s desire for physical activity could have been essential in early hunter gatherer societies. Biology is important, but environment has just as great an impact.

       Environment and duties were cited as another reason women had difficulty getting involved in exercise. Childcare was cited as the main duty that women had to do, which effected their exercise pattern. The world has advanced in some ways, but in others it has not. Women are still expected to do all of the child rearing, with minimal help. Life is harder for single mothers who face both stigma and lack of sympathy. There is another problem. Everyone may not have money to afford a gym membership or have access to particular facilities. It should be remembered that conditions vary around the world, even with rapid technological advancement. Women in other nations not only have to deal with childcare, but also financially supporting the family. This is the case in lesser developed nations in which the economy is agriculturally based.Women are to an extent privileged in the West. Daycare services may not be present in certain regions of particular countries.

While there are challenges for the global south nations, the first world nations have another problem. Modern society has caused a new set of health issues. Being overweight  or obese has become more prevalent, seeing as technology has eliminated many manual labor jobs. A majority of occupations or professions do not require much physical activity at all. There are few remaining ones, yet these will gradually disappear when artificial intelligence and robotic automation become more advanced. Combine with a more competitive, fast paced, and regimented workplace severe stress and depression are ubiquitous. The slow paced labor of agricultural and artisan society was eliminated by the industrial revolution. This changed the health of populations , which can be seen today. People are living longer, but the price is that the chances of getting a chronic disease have increased. Abundance is not always a positive development. The surplus in food has made it so that eating out of boredom is a common activity. Unhealthy habits become stress reducers in a society that is too uptight. There are still large numbers of people who smoke and consume alcohol to excess, even when they know the health risks. Rather than just making time for exercise, mentality has to change. Dedication and discipline must be maintained to change habits. If you environment does not encourage will power or self control then  it is more difficult. Time should not be the enemy; we make to for matters that are important to us. This can also be circumvent if a busy schedule gets in a person’s way. Using the stairs or standing can be enough to burn some calories. Short periods of exercise is better than nothing. Doing push ups or sit ups before bed could be useful.

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Woman-Doing-a-Sit-Up

Environment can effect health and exercise habits in a population. Increasing exercise can help improve health, but these gains could be lost if pollution and climate change effect the population.  The daily routine of most people seems to involve too much sitting. A sedentary lifestyle causes numerous health issues. For women who on average live longer it can harm the quality of life.

         As we age the body becomes more vulnerable to disease. There can be prevention through exercise and diet. Women have lower bone density. As people age ossification slows and cannot rapidly build bone mass as it used to. Women would be at higher risk for osteoporosis if they are not doing some form of load bearing exercise. Building bone mass is critical to skeletal health. Doing so allows people to be more mobile in old age.  weight training exercise can also maintain muscular strength. Women would lose more considering they have less in terms of body composition. This can also be reversed through physical activity. Maintaining a functioning circulatory system also is essential to health. Heart disease, stroke, and high blood pressure do not only harm the circulatory system, but the entire body. Blocked arteries can effect organs, which need blood.

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It has been hypothesized that being active protects the brain from neurodegenerative disease. Dementia and Alzheimer’s disease  have been increasing in elderly populations. Their causes are not entirely known or understood, but symptoms such as death of neurons and the loss of memory are common. This causes cerebral atrophy and the widening of the brain  ventricles. There is a possible connection that a compromised circulatory system damage could contribute to neurodegenerative  disease.  There have yet to be precise studies, so it remains speculative. Having some physical activity may actually be good for your nervous system than previous thought. Not only that learning and keeping the mind active is just as pivotal. Excess body fat can put strain on the skeleton and possibly a risk for certain cancers. Joints are also put under intense strain from excess weight. Women are more at risk from gaining excess weight due to how food is metabolized in their bodies and the function of estrogen. Estrogen produces higher levels of fat, which means it is more difficult for women to lose weight. Even the slimmest or most muscular woman has a higher fat percentage compared to a man of a similar somatotype.

Body Scan
Body scans of an overweight person and a person of normal weight show how excess weight can negatively effect health. 

Other than the personal risk to  individuals, there is the question remains of healthcare systems. If the population of a nation lives longer and does not have an adequate healthcare system, there will be a crisis. A huge population of sick people means it will be a public health crisis. Another troubling problem is that children are also having weight related health issues as well. Obesity continues to rise in the US and UK. This could be reversed not only with a change in diet and the reduced use of high fructose corn syrup, but simple exercise. It does not have to be intense. Simple walks or jogs could  be effective. High fat and sugar diets are creating health problems in youth as well as adults. Women getting less exercise is a urgent health issue. Women’s health commonly focuses on pregnancy, diseases or conditions of the reproductive system, and differences in how the female body reacts in certain health and medical conditions. There should be more study and expansion to include women’s physical activity. The reason is that the health risk of physical  inactivity  would be too high.

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Battle of the Sexes: Men Work out More Than Women

The Camelita Jeter Story

Carmelita Jeter  is an three time Olympic gold medalist, who holds records in sprinting. She was born in 1979 a resident of California. Her talent was revealed early in her life. Prior to excelling in sprinting events, she was a skilled basketball player. During high school she began to be a track athlete. From there, her skills and talents only grew. Jeter is a graduate of California State University earning her degree in physical education. She remains the school’s most decorated track and field athlete to date. Her professional debut was in 2007 in the World Championships. This competition brought her a great victory in which she won her first medal in the 100m. That same year she won a silver medal in the USA Track and Field Indoor Championships. The year 2008 was a turning point in which she changed her coach and running technique. Jeter stands at 5-4 and a weight of 135 lbs. Her athletic credentials are immense and impressive. Her runs times include 10.64 (100m), 22.20 ( 200m), 10.92 ( 2008 London Grand Pix), and 10.83  (2009 World Championships). Faster than the Flash or Sonic the Hedgehog, she has become the ultimate sprinter. Besides her athletic endeavors she also is involved in philanthropy. She continues to be involved in fund raising for breast cancer research. She was in 2014 the official ambassador for Susan G. koleman ‘s California Circle of Promise Initiative. This program was designed to raise awareness about breast cancer in the African American community. Track and field fans however are more familiar with athletic feats.

      The 2012 Olympics was an event in which Jeter amused audiences. She was the pillar of the 4X100 relay. Carmelita Jeter became the first athlete to win medals in both the 200m and 100m race  at the Olympic Games. These spectacular feats come as no surprise. During the mid-2000s she had been gradually improving. Jeter has successes in the World Championships of 2009 with a record time 10.67. That made her the third fastest woman in history. The 2010 saw Jeter win two gold medals and silver in the World Championships. At this point was clear that her performance could only increase.

That was what made her performance so special. Jamaica produces great runners, but their dominance has been threatened by US talent. Her performance earned her a Jesse Owens Award one of the most prestigious track and field accolades. Jeter has revealed many thoughts and feelings about her career, sports, and live through various interviews. Her views on the student athlete are different from the common perspective. She once said “enjoy college and high school because you don’t get those years back.” Jeter delineates further ” you have plenty of time to become professional.” Too often the student athlete is regimented so they miss out on the simple joys of youth. Carmelita Jeter felt she made a sacrifice at the expense of the care free times of being a young adult. She also emphasized that education is the main goal of being at a university, even if  you are an athlete. If an athletic career does not work out she explained, you need to have a back up plan. Jeter believes that it is best to balance your life, athletic activity, and school work. Jeter revealed that getting to the 2012 Olympics was not a simple task. She admitted “that nobody thought I could make it at my age.” This was around the time she lost her beloved aunt Brenda Washington to breast cancer. This caused her much distress. She was able in her own words turn negative events into positives.

Normally, athletes have a person that inspired them in their career. Jeter said it was her aunt who was her inspiration. Her aunt was not an athlete, but a person that was close and encouraging in her life. The women in her family were her role models. Jeter described her aunt as ” whitley of the family ” ( from the TV show A Different World ). Carmelita Jeter revealed that “the women I look up to are every day women.” However, she does have favorite athletes she likes to see compete. She is a fan of Serena Williams, and Candace Parker. Being a former basketball player she love watching the WNBA. Jeter has much respect for Becky Hammon assistant coach of the Spurs. She is not just an athlete, but also a sports fan. This should be no shock. Carmelita Jeter recalling her childhood stated ” I grew up in a sports household.” She would play basketball with her dad and brother on the weekends. Her beginnings were humble as she revealed ” I didn’t come from a family with a whole lot of money so if we knew we weren’t going to be super smart in the class room we had to be athletic and get scholarships.” Track and field gave Jeter more of a competitive drive and a desire to push herself further. At the 2013 World Championships in Moscow she was able to compete with a torn quadricep. She won a bronze medal in that 100m race.

          Carmelita Jeter during her athletic career followed a particular training and diet regimen to enhance performance. When preparing for competition her diet consists of vegetables and some baked goods. Eating three meals a day with two snacks in between, rest was also important. Jeter claimed that her focus was intense starting her day early and being in bed by 9:00 pm.

London Olympics Athletics WomenJeter said staying hydrated is also critical to her training. Also Carmelita Jeter incorporates weight training into her fitness program. Her schedule goes as follows : in the weight room from 6:30 to 7:45, trains in UCLA, and has cryotherapy. Jeter does this to have her muscles relax from exercise and completes this six hour a day training by 12:30. Jeter also likes doing pilates saying ” that’s why my abs look the way they do.” This training regime produced an impressively powerful body. As she said “when I hopped on the scene I was very fast and very muscular.” She also believed in her own assessment “that it turned people off.” She did not let dated and old fashioned beliefs deter her. To Jeter there is nothing wrong with women being strong. The track and field athlete has embraced the movement of physically strong women saying “I love that women want to strong not just mentally, but physically.” Carmelita Jeter  also clarifies ” it is definitely  inspiring to see the movement to be strong is relating to women and is trickling down to young girls.” Her philosophy is “that is okay to be muscular and it is okay to be buff.” She has started from humble roots to Olympic champion. She certainly will inspire many young women athletes.

        Currently Jeter was set to compete in the 2016 Rio Olympics. Unfortunately, injury pulled her out of the trials. It was clear that if she was not sustain the injury to her quadricep, she would have been excellent. Carmelita Jeter at age 37 is still in great shape. Normally athletes reach there physical fitness peak around this time frame. Jeter has made no indications about whether she will continue to compete or attempt to appear in the 2020 Olympics. The year 2017 she did not run at all instead focusing on mentoring young athletes. It seems that quadriceps issues continue to be a hindrance to her competitive streak. It is too soon to say that she is retiring or done with the sport. If 2016 was the last year fans see her actively compete, she went out with an impressive accomplishments.

The Camelita Jeter Story

Girls’ Participation in Physical Education Why Girls are Disengaged in P.E & School Sport

It is no secret that girls do disengage in P.E. and they are gender based reasons. At this age women are starting to develop issues with their bodies. Girls may not be engaged for reasons of peer pressure and gender role stereotypes. This could have implications on women’s health in the future. If girls have a negative view of physical activity in youth, health habits may not be conducted in adulthood. Health risks such as osteoporosis, heart disease, and diabetes could be problems later in life. To avoid these some level of moderate exercise should be done. There also is the issue about femininity and physical activity that still remains dated. Physical skill and prowess continues to not be viewed as feminine, but gradually these attitudes are changing. This clip from 2011 shows the Ysgol Maesteg school in the UK promoting fitness week. Their intent was to change girls’ attitudes  in regards to P.E. and hopefully participate in sport.

Girls’ Participation in Physical Education Why Girls are Disengaged in P.E & School Sport

A General Introduction To The Muscular System

The muscular system is responsible for movement in collaboration with the nervous system to form impulses for motion. Muscles also contribute to internal functions of the human body which include motion in the intestines and circulatory system. Exercise of this organ system is critical to prevent wasting from age or the possibility of disease. Muscles are placed under the body’s skin sorted in overlapping layers on the skeletal system. All muscle is not the same and be placed into three different types. This includes smooth, skeletal, and cardiac muscle. The human body can contain up to a range of 640 to 650 voluntary muscles. Like other organ systems of the human body, it functions almost like a machine. Various parts and structures perform a role to produce an output.The human body is capable of complex movements due to various organ systems . The muscular system also serves an essential role in athletic performance.

         All muscle is not the same. There are three major muscle tissue types responsible for various functions. The muscles that are the most recognizable are the skeletal muscles. These are connected to bone and produce movement. These muscles can sometimes be referred to as voluntary muscles. Under the microscope they appear striated. Skeletal muscle contains multiple cell nuclei located around the periphery of the cell. Not all skeletal muscle is under voluntary control. The chest wall of the body is automatic to allow for breathing.

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Skeletal Muscle ( microscopic image)

Smooth muscle often referred to as non-voluntary is responsible for actions of the nervous system. An example of this would be the dilating and constriction of arteries or movement in the stomach. These actions require automatic response to assist other organ systems. The smooth muscle cells have spindle like shapes. Narrow at a point to both ends attaching to one nucleus in the cells center.

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Smooth Muscle (microscopic image)

Cardiac muscle is the most essential. The responsibility of this tissue is to transmit electric messages fast and in the most efficient manner. Heart muscle is designed to be branched out. The heart needs this type of muscle tissue to ensure it beats correctly. Cardiac muscle can have two or more nuclei at the center of each cell. This demonstrates that organ systems do not work in isolation, but in a coordinated effort.

Cardiac muscle

Muscle cells are the smallest units of the muscular system. Together they form part of the human body mass. Muscle can account for close to 50% of total body mass. This depends on the physical fitness level of the individual and the amount of fat that is also stored in the body. There is a difference in muscle mass between men and women. Men’s muscle fibers are slightly larger in size. Women have higher body fat levels which can range on average 11%, which is higher than men’s range. At the cellular level, there is no difference between male and female muscle.

      Muscles can have a superficial layer and others are deep with in the body. The names of muscles do correspond to their shape. The trapezius obviously takes its name from trapezoid. The muscle that rotates the shoulder blade has that distinct shape. The human body contains many muscles from the face down to the lower body.

Muscle anatomy

Muscular anatomy 2

Each muscle moves are particular part of the body. The muscles of the arm include the deltoid, biceps brachii, triceps, flexor carpi radialis, and barchiordalis. The biceps brachii flexes the forearm at the elbow and can pull the palm upward. The deltoid is capable of moving the away from the body to the front, side. or rear. The triceps have a medial head which covers the forearm at the elbow and can straighten it. There is also a long head of the triceps that allows for straightening of the the forearm. The brachialis brings the forearm to the shoulder. The arm when flexed at the elbow happens due to movement by the brachiordalis. When the hand is flexed at the wrist it is done by the flexor carpi  radialis.

The trunk of the body aids in the movement of the neck and other limbs branching out from the human body. The pectoralis major moves the shoulder blade. The internal intercostal pulls adjacent ribs together while the external intercostal elevates them. The scalenus has to maintain proper assistance in breathing and  the flexing of the neck. The rectus admoninius  flexes the spinal cord, while directing the pelvis forward. The linea  alba separates divides the abdominal muscles .The serratus anterior has to pull shoulder blades away from the spine. Despite its long name the sternocledomastoid only serves the function of tilting and moving parts of the neck.

There are also muscles of the back. It should be noted that while muscles are named in accordance with shape, sometimes names come from the bones they are connected with. The illocostalis runs from the one back muscle to the ribs reaching ilium. The tres major and minor contribute to lifting the arm and stabilizing the shoulder. The infraspinatus allows for rotation of the arm the stabilization of the shoulder joint. The supraspinatus can raise the arm when needed. The rhomboideus major and minor are designed to retract the shoulder blade and return it to a rest position. For the spine to be straightened it require the use of the erector spinae. This muscle is made of three other muscles, which include the spinalis, longissimus, and  illocostalis. The latissimus dorsi rotates arms and pulls shoulders back. It has the largest surface area of any muscle in the human body.  the obliques assist in breathing and abdominal wall stabilization. Internal obliques must focus on pressure inside the abdomen. Obliques both internal and external have the ability to flex and rotate the trunk.

Continuing further there are muscles of the lower body and legs. When humans became bipedal during the course of evolution, this was a major milestone. Humankind is the only primate species that can walk upright. The hamstring consists of three muscles which include the biceps femoris ( rotates the leg ), semitendinosus ( extends thigh, hip and flexes the knee), and semimembranosus (extends thigh, rotates leg and flexes the knee). The hips get stabilization from the quadratus femoris. The muscle also allows for rotation. The gluteus maximus has to straighten the hip by pulling the thighs back in the event of running, walking or jumping. The muscle is not alone in the locomotion process; the soleus has to flex the foot when walking happens. The gastrocnemius which is a calf muscle must contract to flex the ankle and pull the heel up. This is done when standing on a tip-toe position. There is a muscle that also gives the leg thrust when walking called the flexor hallucis longus. The toes and foot itself need control and that function falls on the flexor digitorum longus. The knee also has more assistance with movement with the popliteus. The adductor brevis  rotates thighs in toward the body, while the adductor longus draws into the body. Gracilis also flexes and rotates that leg as needed. There are also muscles in your face which aid in expressions you make. Whether it is a smile or grimace muscle once again work together.

The muscles of the face can be either attached to bone or connective tissues known as aponeuroses. The presence of this fibrous and sheet structured tissue means that facial muscles are connected to one another. The muscles of the head and neck interact to produce facial expressions, which can vary depending on emotional state. The facial muscles are controlled by a nerve known as cranial VII. If damage is inflicted on this nerve facial mobility would be lost, making it difficult to communicate. The structures such as the occipitofrontalis raise the eye brows and zygomaticus major pulls the corner of the mouth up and out. The sternohyoid depresses the larynx, while the platysma  lowers the mandible and covers the mouth. The muscles of the face and neck are critical for speech and even a function as simple as chewing. Facial muscles can fill the role as sphincters ( such as the orbicularis oculi  that allows your eyes to close). The function of sphincter is to open and close a particular orifice. Besides basic functions of eating, talking, or drinking the head must be balanced on the body. The average adult head weights about 5kg ( 11 lbs). Muscles of the neck , back and shoulders must act as a stabilizing force. They are active in a constant fashion tensing and contracting based on particular movements.

The rectus capitis posterior( minor and major) ,  oblique (inferior and superior) , levator scapulae, semispinalis captis and splenius captis are needed for balance of the head on the body. When moving the face and the neck it is hard to image such labor has to be put in to make a simple action possible. Chewing requires the force of the masseter muscle. Without it the mouth could not close the mandible when eating. This is only a general delineation of the structure of the muscular system. While the estimate of skeletal muscles is placed at 650, more could be classified as such. This depends on if a muscle is classified individually or part of a much larger skeletal muscle.

         Skeletal muscle tends to be the majority of the muscular system, when compared to cardiac and smooth muscle. Skeletal muscles have extra classification based on their unique shape. The two bellied parallel muscle contains two separate muscles separated by an intersection of sinew. Three headed parallel muscle is designed to attached to three different places. The quadrate muscle forma a flat four sided shape, which acts more like protective covering.  The straight muscles run parallel converging at a tendon point. Orbiculars are muscles that function like  sphincters and triangular muscles form a fan shape. The reason for this is to allow for the maximum force of contraction. These muscle also have a common site of attachment. Two headed parallel muscle splits at a point nearest to the body. Flat muscles serve mostly as a covering. The abdominal wall would be considered a flat muscle. Fusiform muscles have fibers that are positioned parallel to each other in the middle then meet to form a tendon at one or two ends. These muscles are responsible for moving the fingers, specifically the flexor pollicus longus. The last type of skeletal muscle is the pennate muscles. They contain strong muscle fibers, but fatigue quickly. They have a feather like appearance.

      The physiology of the muscular system is just as impressive as its numerous structures. The skeletal muscle is connected to tendons, which means they can only pull when contracting. During this process they shorten. Muscle in a controlled setting can achieve a threshold stimuli and can respond to the next stimulus without relaxing completely. Tetanus happens when full sustained contraction is achieved. The tetanic contraction happens when muscles are actively used. Even when there is no active motion muscles still exhibit tone. Muscle tone refers to fibers still contracting while at rest. if this did not happen during rest the body could collapse around the neck, trunk, and legs.

Muscle tone is the key to maintaining good posture. The muscle fibers are packed into bundles. The muscle fiber cell has various components. There is a plasma membrane known as the sarcolemma, which forms a transverse system. The T tubules move down into the cell making contact with the sarcoplasmic reticulum. There are storage sites present for calcium. The sarcoplasmic reticulum is home to thousands of myofibrilis which are contractile muscle fiber tissue. The myofibril has sarcomeres which are contractile units. The myofibrils are cylinder shaped and can be as long as the muscle fiber. On the tissue itself are striations, which are formed by the sarcomeres. When in a state of rest dark lines known as Z lines. What should be understood is that the muscle fiber functions on different protein filaments. Actin filaments slide past myosin, which induces contraction. Myosin pulls the actin through cross bridges including split ATP. The process can be described as the sliding filament model.

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Adenosine Triphosphate  (ATP)

The sarcomeres shortens causing the actin filaments to slide past the myosin filaments. The I band will shorten and the H zone disappears. This is how muscle contractions behaves. Like two people doing a short of tug of war, this shows how the filaments move. Besides ATP, myoglobin stores oxygen and phosphocreatine helps with energy needs. Phosphocreatine does not directly get involved in muscle contraction, but has the ability to anaerobically regenerate ATP.  This helps supply enough energy for muscular contraction. Once the phosphocreatine is depleted the mitochondria can produce enough ATP for muscular contraction to proceed. Another method for supplying energy is fermentation. This does not require oxygen, but can happen during strenuous exercise. ATP can only be supplied for a short period. Lactate then amasses and there will be fatigue. Lactate may not cause muscles to ache, but rather act as a protective measure to prevent harm to the muscle.

This explains why at some point when exercising intensely muscles will fatigue. Breathing patterns even change during long term intense exercise. The oxygen debt has to be restored. This means cells must return to their original energy state. The intake of oxygen must complete the metabolic process for lactate. The lactate must be transported to the liver, where it will be broken down into carbon dioxide and water ( 20% ) . There will be ATP gained from respiration, in which 80% of the lactate will be converted into glucose. People who consistently train ( athletes for example ) the number of mitochondria increases which decreases reliance on fermentation. As a result ATP is produced more efficiently and there is less of both lactate and oxygen debt.

        While there is very little difference in structure and function of the muscular system between the sexes, there is one aspect that effects athletic performance. Men have more type II muscle fibers. Fast twitch muscle fibers generate more power, but fatigue at a faster rate. They are not oxygen dependent. Women have more type I muscle fibers which are more resistant to fatigue and can contract for longer periods. The slow twitch fibers get their energy for contraction  from the break down fat from blood, muscle cells, and adipose tissue. This explains why women have more of these muscle fibers, because estrogen means women will have higher body fat percentages. Fat breakdown needs only oxygen and some glycogen . Fast twitch requires phosphocreatine and glycogen reserves in the muscle itself. Glucose remains stored in the blood and glycogen in the liver. Sex is not the only factor in muscle fiber composition. It can be based on either genetics or physical fitness training. Marathon runners would have more type I muscle fibers, compared to the type II weightlifters. The difference in physical strength is not just due to the size of the muscle fiber, but endocrinology. Men produce higher levels of testosterone which allows for a greater amount of muscular hypertrophy. This explains why a man and a woman who do the exact same training regimen, it is more likely the man will have more absolute strength.

It is not just the difference in size of the muscles or endocrinology. The difference in absolute strength comes also from the nervous system. Men’s nervous system signals faster when muscle contraction is occurring. The common misconception is that women would not benefit from weight lifting because they have smaller muscles. Women’s muscles still can experience hypertrophy. The difference appears to be mostly in quantity, rather than quality of the muscular structure. Then one must considered starting point. If men have lower body fat levels and more muscle mass to begin with their total strength would be higher. Women would gain more relative to their size, seeing as their natural strength levels are lower. People with mesomorphic body types will have a natural advantage when engaging in a train regimen. The female body is capable of developing strength. The muscular system is almost like a multilayered puppet with tendons and muscles working in collaboration. This organ system is pivotal to athletic performance and overall health.

 References

Mader, Sylvia. Biology. New York : McGraw-Hill, 2007.

Parker, Steve. The Human Body Book. New York: DK Publishing, 2013.

Brewer, Sarah. The Human Body: A Visual Guide to Anatomy. London: Quercus, 2012.

 

A General Introduction To The Muscular System