Comparison of Red and White Muscle Fibres

1. Explain how the cerebellum controls muscular movements in the body. For this you may want to discuss the sensorimotor system, but you do not need to. Write 2 -3 paragraphs outlining your understanding. Include examples of specific muscles if you can

The cerebellum is an organ that is located behind the brain’s stem top part and is primarily defined by two halves.  As an organ, the cerebellum is accountable for coordinating smooth movement of the skeletal muscles as well as the attainment of equilibrium. How so? The primary role of the organ is to rely on information delivered by the sensory neurons, then subsequently compare the positioning of skeleton-muscular contraction, to the external environmental anticipation and finally command the skeletal muscles through the transmission of information via the neurons, in a bid to nurture coordinated movement.

For instance, when playing football, the sensory neurons send the information to the cerebellum about what the body is doing. When the ball approaches you, the sensory neurons compare the positioning of the muscles to outside events. Once internalized the cerebellum sends a physical command to the gastrocnemius (calf) muscle via the sensory nerves to strike the incoming ball upon contact, resulting in coordinated movement.

2. Explain how a specific voluntary movement is 'learned' by the body. You may choose to write about any movement which you have knowledge of or you may want to use eye movement as an example. Write 300 words approximately.

One of the primary functions associated with the brain is the inherent ability to direct the body in a positive manner that initiates purposeful and healthy interaction with the environment. It is a fact that as a result of evolution, man’s brain has enabled him to interact with the environment in numerous sophisticated ways, one example being voluntary responses. By definition, voluntary responses refer to actions that are consciously initiated by the brain and remain under the brains influence until culmination. A practical example would be walking.

When focusing on walking as the primary example of a voluntary response, the brain usually sends out motor impulses as a technique to control movement. Additionally, the motor signals initiated are often reliant on thought and involving stimulus, as an approach to invoke responses. Information is generally compiled and stored under the brain with the intention of recording the given action as a routine behavior, Hence when in demand, the brain invokes the internal receptors to release the collected information through the sympathetic and parasympathetic nerve impulses nurturing the emergence of the voluntary movement.  

3. Explain how the body perceives speed. Write up to 2 paragraphs on this

Sight as one of the five sense relies on the ability of the nervous system to decrypt the depth of the information according to space and time equalities. When breaking down speed depending on the degree of motion, the brain utilizes a sheet of sensory receptors that are located in the retina. Once the raw data is acquired the brain relies on computations as a platform to calculate speed and direction of the moving objects.

Interestingly, the brain relies on monocular vision (from a single eye) to detect nearby speed, while given that the alternate offers poor depth perception, the brain relies on binocular vision to assess an object’s speed from a distant.  When processing the information about an object’s speed, velocity, and direction, the nervous system transports information perceived in the retina to the visual cortex and subsequent somatosensory cortex. The final information once decrypted is sent to the Brodmann's area and, middle temporal area when the objects motion, speed, and direction are interpreted.

4. Explain the operation of tendons, during a specific movement (selected by you) of a limb.

Tendons when defined represent strong flexible and fibrous body tissues that usually join together the muscle of a specific region to the associated bone. When focusing on the movement of tendons, the particular body tissues are always determined to follow the movement of the original muscle.  For instance, when lifting up weight the biceps brachii muscle through concentric contraction decrease in length while the extensor carpi radiallis and brachioradialis muscles remains stationary, an aspect that triggers the tendons to move towards the original biceps brachii muscles that contracted.

5. Compare the function of motor with sensory fibres in nerves supplying muscles

Motor fibers predominantly make up the skeletal muscles while sensory fibers make up 40% nerve’s composition to the muscle cell. From a functional point of view; the motor fibers are responsible for transporting signals from the spinal cord structure, to the receiving effectors located adjacent to muscles all in a bid to produce locomotion effects. Sensory nerves, on the other hand, are responsible for transmitting sensory information from the muscles to the centralized nervous system based on the assessment of immediate environmental triggers.

6. Compare differences in the structural characteristics of red and white muscle fibres

The muscles within one’s body can be separated into two major categories namely; red and white muscles. Interestingly, the two muscles when compared to a structural point of view have three primary differences. First, from an appearance point of view, the red muscles are rich in capillaries with red hemoglobin and myoglobin, hence appear to be reddened. Contrastingly, the white muscle fibers lack myoglobin. Secondly, red blood cells are rich in Mitochondria, while white muscles generally have fewer Mitochondria. Finally, red muscles are thin in structure, while white muscles are thick. 

7. Summarize events occurring during muscular contraction, at a microscopic level

At a microscopic level, muscle contraction commences with the sending and receiving of the trigger signal from the motor neuron to the specific muscle fiber.  Once the neurotransmitter breaks down the message, the membrane of fiber depolarizes, enabling positively charged ions to enter. The triggered action potential spreads to the rest of the membrane depolarizing gradually, into the T-tubes. Subsequently, the trigger action leads to the release of Calcium ions which initiate contraction, an aspect that is sustained by ATP. The constant presence of Calcium ions in the sarcoplasm binds with troponin keeping the unshielded atom-binding sides open for ATP to deliver cross-bridge cycling. The cumulative result is pulling if actin strands by myosin, an element that continues to shorten the muscle’s anatomical unit.

8. Select three muscles throughout the body. Explain in 2-3 sentences the physical effects of a major injury to each.

The spraining of extrinsic muscles primarily in the foot may emerge as a result of enhancement in extreme supports. The key result of spraining is intense pain and swelling.

The anterior thigh muscles particularly quadriceps femoris can be injured in a road accident setting. Common results include bruises and contusions which manifest when blood vessels under the skin rupture, leaking into the muscle and causing a black-blue color change.

Thirdly, the anterior arm muscles and particularly biceps brachii injury in a bump or fall event may lead to escalating pain. The pain emerges as a result of pulled muscle strain, such as the hamstring. 

9. Compare the energy pathways of skeletal and smooth muscles cells (no more than 1/2 page)

Skeletal muscles are usually associated with voluntary movement of the body organs. From a comparison perspective, the energy pathways of skeletal muscles are the largest of the two. Additionally, they are periodically defined by a presence of T tubules. Given that the muscles do require enormous energy for action, they do store calcium within the sarcolemma SR.  Smooth muscles, on the other hand, occur in hollow organs such as the uterus, intestines, urinary bladder, and stomach among others. Smooth muscles rely on Calcium ions to generate energy. Their pathways are generally smaller than the skeletal muscles, and often they do lack T-tubules. Finally, the lack of calcium storing sarcolemma SR.  

10. Describe the action of muscle filaments when contracting (1/2 page)

When breaking down the process of contraction under sliding filament theory, it is essential first to understand the units of muscles. Muscles are made up of long fibers, which are defined by subsequently long myofibrils. When broken down the myofibrils are split to sacrometers which represent a muscle’s smallest functional unit. Muscles are generally made up of two filaments namely actin which is the thin filament, and myosin which is the thick filament. During the contract, both of the filaments overlap each other. As the contractions get intense, the filaments slide further over each other nurturing a bigger overlap which resultantly shortens the muscle’s length. It is crucial to note that an impulse nurtures contraction by incoming at the neuromuscular junction and subsequently, spreading the impulse via the T tubules.

11. Consider your current physical condition, diet and lifestyle (and family history if you know of any). Create a table that shows how specific aspects of each contribute, either positively or negatively to your risk of developing a cardiovascular disease. You should have between 5 and 10 specific risk factors in your table

Specific Risk

Positive or Negative Impact

Smoking

Negative – Chemicals in cigarettes force heart to pump harder and damage arteries, escalating probability of cardiovascular diseases. 

Physical inactivity

Negative-inactivity escalates blood pressure, excessive weight circumference, and deter weight control, elements that catalyze cardiovascular diseases.

Obesity

Negative-obesity nurtures high blood pressure, and diabetes as well as high body fats, conditions that cultivate cardiovascular complications.

High blood pressure

Negative- harms arteries, catalyzing the probability of heart attack.

Excessive Drinking

Negative- excessive intake of alcohol damages the heart muscle and causes irregular breathing.

12. Congestive heart disease results in the ventricular cavities becoming enlarged. Explain as best you can what you think the consequences of right ventricle enlargement might be in no more than one paragraph

When the right ventricle is enlarged, it is forced to utilize more force so that it can pump blood to the lungs, the long-term impact of this aspect is that it can lead to the wearing down of the heart over an extended period. Additionally, the process nurtures the increase in blood pressure within the heart. The disastrous impact of this is that it becomes complicated for the heart to conduct electrical impulses that are essential for the heart to pump. Cumulatively, the process leads to serious health complications.