MUSCLE

WHAT IS MUSCLE?

Muscle is a tissue in the human body that aids in the rotation of joints in order to allow mobility andmovement. There are around 600 muscles in the human body and as much as you may try and prove otherwise your muscles are only capable of a pulling potion, for example pushing a large box is due to muscles on the back of the arm contracting to straighten the arm as you push. They are made up of 75% water! So keep well hydrated as dehydration can lead to elasticity decease which in turn can lead to injuries and tears so always keep a full bottle of water nearby for your workouts. So lets go through the basic structure of muscles and muscle fibres. Attaching every muscle to your bone is a tendon, now the tendon is a collection of tough collagen fibres that is connected directly to the epimysium of the muscle; this is basically the blanket that sheaths the muscle fibres inside and separates the muscle tissue from surrounding tissues. So inside this epimysium are thousands of cylindrical tubes called fascicles, again all Ff these fascicles are somewhat glued together by another membrane called the perimysium. Within these fascicles are thousands more of smaller cylindrical tubes and these tubes are the actual muscle fibres. The structural pattern of these tubes within tube principle allows maximum tension strength and surface area exposure of the muscle fibres to blood and nutrients

WHAT IS THE SARCOMERE?

The sarcomere is the smallest functioning unit of the muscle fibres and the collective action of millions of these in one muscle fibre is what leads to overall contraction.

In the diagram here there are two sub types of filaments within the muscle fibre, these are thick filaments that act like anchors and do not move (Myosin). And thinner filaments that slide in between these thicker filaments to enable contraction (Actin). Basically at rest there is no contraction because the actin protein filaments are actually twisted and the binding site to where the myosin structures grip the filaments cannot be reached. However when you contract your muscles, calcium ions are released into the muscle tissue and this twists the actin filaments whereby the myosin filament grips on and pulls them inwards, shortening the entire muscle and causing contraction, ATP is a small molecule that breaks the bond between the two filaments and the muscle is reset.

HOW DOES MUSCLE

TISSUE VARY?

Muscle tissue comes in three varieties inside the human body. These are skeletal, cardiac and smooth and each are highly adapted for their roles in the body.

Skeletal Muscle – This is the muscle tissue associated with
everything from lifting weights, moving and basic actions like
smiling and its contraction is voluntarily controlled, i.e. you
decide when it moves. Skeletal muscle can be subcategorised
into slow twitch and fast twitch fibres, your slow twitch
muscles appear red due to the high concentrations of oxygen
binding molecules known as myoglobin, therefore the high presence of oxygen means this muscle fatigues slowly. Fast twitch muscle fibres appear white and are highly specialised for much faster contraction but fatigue more quickly than red muscle fibres as they undergo mostly anaerobic respiration (Without oxygen) producing less energy but at the cost of faster contraction.

Cardiac Muscle – Cardiac muscle is unique in that it is only
found in the heart. You will be glad to know this muscle is
extremely slow at fatiguing and relies on a heavy blood and
oxygen supply. With intricate networks of nerves and
interconnecting fibres the cells are separated by intercalated
discs which basically give rise to its contractive abilities, acting like a receptor that sets off a chain of reactions down the line of muscles once
detected by these discs.

Smooth Muscle – The smooth muscle in your body can be found
in arteries and the digestive tract, it is involuntary meaning you
cannot control its contractions. It is a very flat and has a 2d shape
like structure, this gives the muscle cells a large surface area and
elastic properties which are crucial for absorbing maximum
nutrients from the digestive tract and in widening and dilating
arteries in the body to maintain blood pressure. 

  

WHAT IS HYPERTROPHY?

Muscle hypertrophy is the enlargement of muscle tissue through breakdown of the protein filamentswithin the tissue and then sufficient nutritional uptake to increase the size of either the muscle fibresor the sarcoplasmic reticulum. The what? Thesarcoplasmic reticulum can be thought of as like a bag wrapping around all muscle fibres in the tissue with protruding fingerlike structures sticking out into the muscle. These structures are known as T-tubules and this is where the calcium ions travel towards the muscle during contraction. However the sarcoplasmic reticulum is the structure that stores the calcium ions until given the nervous signal to release them. Hypertrophy comes from the Greek meaning ‘excess nutrition’. Muscular hypertrophy can occur in two ways:

Myofibrillar Hypertrophy – This is the physical increase in the size of the muscle fibres, and is achieved by low rep, high weight training. This gives the visible increase in size of the fibres and strength

Sarcoplasmic Hypertrophy – This is the increase in size of the bag like structure discussed before, the sarcoplasmic reticulum. An increase in size is achieved by increased contraction, so higher rep, low weight training. This can also give rise to increased strength without as big a visible increase in size of the muscle, hence explaining why that smaller guy can lift the same as you and not look as big. This is down to more calcium ions being stored and so more secrete into the muscle and more muscle fibres can contract more efficiently and for longer.

WHAT IS ATROPHY?
Muscle Atrophy is the breakdown of muscle tissue due to lack of resistant training and use. Best see if you have ever had a pot or cast on a broken limb, only to find it moving around more loosely after the third or fourth week, will that’s because your muscle tissue is breaking down its protein structures to be used by the body. This can be prevented by a good uptake of protein in the diet and can be quickly regained due to good muscle memory as the blood supply and connections are pre-existent when the muscle was there, it will be built up a lot faster with sufficient blood supply and nutrient supply already in place.

HOW DO I MAXIMIZE MUSCLE GROWTH?

Again being made up of 75% water, keep well hydrated pre, during and post workout, going to the gym takes up 10% of your day maximum, so what yu do in the remaining 90% nutrition wise is what decides how your muscles grow. Sufficient protein intake, now your body synthesises proteins naturally but must obtain essential amino acids from eating meats and nuts etc that the body cannot produce. So keep your protein chicken and eggs close at all times. And finally rest, do not overdo it at the gym, sleep well and always maintain correct form leaving your ego at the door as the last thing you want is injury, form > weight.

Picture sources:
http://food-pictures.feedio.net/anatomy-of-the-skeletal-muscle-human-anatomy-the-brain/human-anatomy-the-brain.anatomyandphysiologyss.com*images*anatomy-of-the-skeletal-muscle-1.jpg/

https://scholar.vt.edu/osp-presentation-tool/viewPresentation.osp?id=7615BCEA5976307243865C69A4D9543B

http://www.vetmed.vt.edu/education/curriculum/vm8054/Labs/Lab10/lab10.htm

http://learninglab.co.uk/headstart/four45.htm

http://www.interactive-biology.com/3373/the-muscular-system-how-we-move-around/

http://www.austincc.edu/rfofi/NursingRvw/PhysText/Muscle.html