2Function of MuscleMuscle tissue is responsible for all body movements. This includes body motion as in walking (Skeletal Muscle) but also organ movement (smooth muscle) such as dilation of blood vessels or heart contraction (Cardiac Muscle).Muscles support the functions of most our systems that keep us alive: ie – respiration, digestion, blood circulation …Heating of body, muscle contractions give off heat and help maintain body temperature. Shivering warms the body when muscles in the skin contract reflexively due to cold.
4Cardiac MuscleFound only in the heart. Able to contract independently of the brain but requires signals from the brain to beat in correct sinus rhythm.
5Anatomy of a Skeletal Muscle Skeletal muscle attaches to bone and moves our skeleton Skeletal muscle is called voluntary muscle as it requires a conscious command from the brain in order to move
6Smooth Muscle tissue is found in the organs and vessels of the body Smooth Muscle tissue is found in the organs and vessels of the body. Smooth muscle is called an involuntary muscle because it requires no conscious signal from the brain to do its function and movements.
7How Many??There are over 600 different muscles in our body. Some are very large for gross motor movement (kicking a ball) and some very tiny fine motor control (blinking).
8Tendon vs Ligament Tendon – attaches muscle to bone Ligament – attaches bone to bone
9Properties of Muscle Fibre Conductivity – can transmit an electrical or neural impulse Contractibility – ability to shorten in length Extensibility – able to extend and become longer over time (flexibility training/stretching) Elasticity – able to be stretched and return to normal length Irritability – ability to respond to a stimulus (nerve impulse)
10Muscle FibersMuscle Fibers are about the diameter of a human hair, they can contract about ½ their length and can lift about 1000 times their weight.Muscle Fibers are malleable. When stimulated by an electrical impulse they contract but need to be pulled back by another force to return to their original length.
11Motor UnitA motor unit consists of the nerve (neuron) and all the fibers connected to it. When a neuron is stimulated all of its fibers will contract completely. This is called the All or None Principal. The number of motor units stimulated the stronger the muscle contraction and vice versa.
12Gross Motor Movements Big muscles with small # of motor units but each motor unit controls larger numbers of muscle fibers
13Fine MotorSmall muscles with lots of motor units to control them but each motor unit controls fewer numbers of muscle fibers.
14Eccentric, Concentric and Isometric Contractions
15Flexibility – muscles will lengthen if stretched regularly over time Flexibility – muscles will lengthen if stretched regularly over time. Better flexibility reduces risk of muscle injuries and can improve your performance in skills
16Muscle StrengthMuscles can adapt to use. Muscle fibres get thicker and stronger if they are exercised regularly over time.
17Micro Tears, Overload, Rest and Recovery Strength Training During weight resistance training we try to overload a muscle. This means work it beyond its normal strengthOverloading results in micro tears in the muscle fibers. Tiny lesions in the fibers open up.During rest and recovery over the next 24 hours the tears heal and make the fiber a bit larger in diameter and as a result strongerOver time repeated training will result in larger fibers and bigger, stronger muscles.
18Muscle ConceptsTransient Hypertrophy – Muscle temporarily get larger during exercise due to increased blood flow. This lasts only for 30 minutes or so after exercise. Does not increase strength.Chronic Hypertrophy – Muscle fibers diameters get bigger as they adapt to repeated exercise training. As fibers get larger the muscle gets bigger and stronger over time.Muscle Atrophy - Muscle fiber diameters get smaller over time as a result of lack of use or training. Results in loss of strength.Hyperplasia – An unproven theory that increases in strength due to exercise actually result in muscle fibers splitting and increasing in number to account for increased strength.Voluntary Muscle – muscles that we consciously control like leg muscles for walkingInvoluntary Muscle – muscles that function without conscious control like our organs – blood vessels, stomach, heart…
19Transient Hypertrophy the muscle increases size from increased blood flow, temporary (30 min) and no strength gain
20Chronic Hypertrophy – muscle gets larger and stronger from training
30Muscle Pairs Agonist and Antagonist Example – Muscles work in pairs to counteract each other’s movement. Example: the bicep is called the agonist (primary mover) and the tricep is the antagonist (returns the arm to its original position.
31Tendons, Origin and Insertion Tendons connect the muscle to bone.Origin is the connection we call an anchor, it does not move during the contractionInsertion is the connection that moves a bone during the contraction.
32Muscle Strain and Tears Symptoms: Pain, Weakness & Function
34Treatment of muscle injury Rest – it takes time for the muscle to repair Ice – helps reduce the swelling and pain Compression – helps hold muscle in line and reduce the pain and swelling Return to action when function is no longer impaired. Returning too soon may result in re injury