Kinesiology exam 2
Explain the five major types of static and dynamic muscle actions, and give an example of each.
(Isometric action) is a muscle contraction without motion an example would be holding a dumbbell in a constant/static position rather than actively raising or lowering. (Concentric action) is one in which muscle is able to overcome a load and shortens as it goes through the range of motion; this is usually termed flexion an example would be the flexion of biceps. (Eccentric action) occurs when a muscle cannot develop sufficient tension and is overcome by an external load, and thus it progressively lengthens during movements; this is usually termed extension an example would be the extension of the biceps. (Isokinetic action) the neuromuscular system works at a constant speed during each phase of movement against a preset high resistance, independent of the amount of muscular force generated by the involved muscles an example would be lowering yourself during a sit-up. (Plyometric action) is a sudden eccentric loading and stretching of muscles followed by a strong concentric contraction an example would be skipping.
Exercise in the Heat
- Inability to lose heat >Higher core temperature >Risk of hyperthermia and heat injury - Higher sweat rate >May be as high as 4-5 L/hour >Risk of dehydration
Capillary Supply
-increase number of capillaries supplying each fiber -may be key factor in increase VO2max
Immediate Energy: Phosphagen System characteristics
1.Large amounts energy produced in a short time 2.Fast recovery •Requires sufficient local supply of CP •Small and depleted rapidly •Rest and recovery needed quickly •7-12s @ very high intensity •15-30s @ moderate intensity
Trained athlete
10% deficit
Untrained individuals
20-35% deficit
Distinguish between static and dynamic muscle actions in terms of muscle movement and work done.
A (static) or isometric action is one in which there is no visible change in muscle length, such as when you push against a door frame. The action is against a load that is beyond the capability of the muscles to move, and therefore, no external movement of the load occurs. No work is performed during an isometric muscle action; nonetheless, a relatively high amount of muscle tension is developed and energy is used. An isometric action is not defined by work but by the rate of tension developed and by the duration over which the tension lasts. (Dynamic) The neuromuscular system works dynamically if internal and external forces are unbalanced. Dynamic action involves movement. When the external force is smaller than the internal force generated by the athlete, the latter will be able to resist, and the result will be movement.
energy for the cross bridge binding
ATP molecule breakdown provides
maximal voluntary muscular contraction
Ability to perform _____________ in order to overcome powerful external resistance
Differentiate between absolute and relative strength and give examples of each.
Absolute strength is the maximum amount of force a person can produce in a single effort an example would be someone who can squat 200 pounds is most likely to perform better than someone who can squat 100 pounds. Relative strength is the relationship between maximal strength and body mass an example would be gymnastic movements involving only the client's body weight.
I band
Actin filaments
I band:
Actin filaments
Sliding Filament Theory part 4
Actin filaments move and sarcomere shortens
70% of mans strength
Average woman =
Arteries
Carry blood away from the heart
Veins
Carry blood towards the heart
activity duration and intensity
Contribution of each energy system depends on the _______________
Sliding Filament Theory part 3
Cross bridges move similar to stroking of the oars
At any given level of work, the rate of lactic acid accumulation is decreased in the endurance-trained individual, which means the anaerobic threshold is higher and the individual can work at a higher rate of activity before the accumulation of lactic acid begins. During high-intensity exercise, the rate of lactic acid buildup can be decreased by decreasing the intensity of the activity or by increasing the ability to handle the lactic acid.
Define anaerobic threshold. Is the anaerobic threshold high or low in endurance-trained individuals?
The Krebs cycle is a metabolic process where pyruvate is metabolized, along with other fuel sources such as carbohydrates, protein, and fat. The electron transport chain is the final step in the oxidative system where large amounts of ATP are produced.
Describe two major metabolic pathways of oxidative phosphorylation.
The three systems are designated as aerobic or anaerobic, depending on whether or not oxygen is needed to produce energy. While oxygen is not required by either the phosphagen or glycolytic systems, the oxidative system depends on oxygen to produce energy. The two anaerobic systems can be separated on the basis of whether or not lactic acid is produced during energy production: lactic acid is produced with the glycolytic system, but no lactic acid is produced by the phosphagen system.
Discuss how the three energy systems can be distinguished in terms of both oxygen use and lactic acid production.
The three energy systems coexist and overlap in various combinations depending on the intensity and duration of the activity. It is clear that the phosphagen and glycolytic systems are more important for short-term, high-intensity activities like diving, sprinting, and jumping and throwing events in track and field, whereas the oxidative system is predominant for longer-lasting, less-intensive endurance activities like marathon running and triathlon.
Explain how the three energy systems work together to fuel all our activities.
Muscle movement is controlled by the motor nerve impulses transmitted from the CNS and spinal cord out to the motor unit, which when activated causes the muscle fibers to contract. Whether or not a motor unit actiavtes upon the arrival of an impulse depends upon the so-called all-or-none principal. This principal requires an impulse of a certain magnitude to cause the inneravted fibers to contract. This principle is analogous to flipping a light switch. Once a sufficient amount of pressure is applied, the light turns on or off completely; flipping the switch on harder or faster does not make the light any brighter it is an all-or-none response.
Explain the all-or-none principle of muscle activation.
Energy is liberated for muscular work when the chemical bond between ATP and its phosphate subgroup is broken through hydrolysis( the chemical breakdown of a compound by the addition of water). Muscle cells are able to continually resynthesize ATP by the recombination of ADP with free phosphate. ATP is a renewable resource that can be regenerated provided sufficient chemical energy is supplied via metabolic pathways. This process is called ATP resynthesis.
Explain the hydrolysis and resynthesis of ATP. Why is ATP resynthesis so important?
During the contraction of a muscle, it is the sliding of the thin actin filaments over the thick myosin filaments that causes shortening of the muscle to create movement.
Explain the sliding filament theory.
•Joint Angle •Muscle Cross-Sectional Area •Speed of Movement •Muscle Fibre Type •Age •Sex
Factors Influencing Muscle Action?
joint angle, muscle area, speed of movement, fibre type, age and sex
Factors affecting muscle force ad power include
List the factors that influence muscle action. Provide an example of each.
Factors that can affect force and power output include joint angle, muscle-cross sectional area(larger = more absolute strength), speed of movement(max strength, power max strength, and endurance max strength), muscle fiber type(fast = greater force, speed, fatigue. slow = less force, speed, more endurance), age(lose fast twitch as you age because of muscle atrophy from less activity and less testosterone), and sex(women are 70% as strong as men).
Which major muscle fiber type is further divided into two other fiber types? What are the differences between the two subtypes?
Fast twitch( FT or Type II) and slow twitch (ST or Type 1). FT fibers are more anaerobic, larger, fatigue faster, and have a faster contraction speed than ST fibers. This makes these fibers ideal for actions that are short and require quick bursts of power and energy, such as sprinting or jumping.
greater strength
Greater body mass =
1 repetition maximum (RM)
Highest load lifted in one muscle contraction
During muscle contraction, skeletal muscles shorten, and as a result of the tendinous attachments to bone, function to move the various parts of the skeleton with respect to one another (at joints) to allow changes in the position of one skeletal segment in relation to another.
How do skeletal muscles and tendons work together to cause movement?
The primary fuel source for these activities is the phosphagen system. Under these conditions, creatine phosphate can be broken down to produce phosphate and creatine. The free phosphate then bonds with ADP to reform ATP. Since there is only a small amount of ATP and CP stored within each muscle fiber, and because this system produces energy at a very high rate, this system can provide immediate energy for muscle contractions only in the initial 7 to 12 seconds of high-intensity activity.
Identify the fuel sources of the three energy systems
Phosphagen System
Immediate Energy
•maximal / absolute strength
Inter- and intramuscle coordination, anatomical structure, and muscle elasticity =
Same
Iso =
Static Action
Isometric
90-100 degrees
Joint angle optimal angle
•Maximal strength •Power •Muscular endurance
Linked to the main components of strength:
Oxidative System
Long-term Energy
Relative strength
Maximal strength / Body mass =
medium to high resistance
Maximal strength important when overcoming ___________
length
Metric =
Sliding Filament Theory part 1
Motor nerve activates muscle fibre
static or dynamic, and eccentric, concentric, and isometric
Muscle contraction can be classified as
Sliding Filament Theory
Muscle contraction occurs due to actin sliding over myosin
Briefly discuss the relationship between maximal strength and power.
Muscle fibres increase in diameter in response to high resistance training, you increase the size by increasing actin and myosin, and maximal strength training can be beneficial to power development. The more internal force an athlete can generate to overcome external resistance, the more movement acceleration increases.
joint angle
Muscle force production depends on
Explain how muscles work in synchrony
Muscles work in the perfect symphony when one muscle contracts(draws together) to move a bone, and the other relaxes, allowing the bone to move
Strength Endurance
Muscular Endurance or
A band:
Myosin filaments
Sliding Filament Theory part 2
Myosin head attaches to actin; cross bride formation
per muscle fibre type
One motor unit per
Nerves
Peripheral nervous system
Relative stregth
Proportion of maximal strength relative to body mass
M line:
Proteins anchoring thick filaments
Z line:
Proteins anchoring thin filaments
Ventricles
Pump blood to the body
Glycolytic System
Short-term Energy
Arterioles
Small vessels that branch from arteries
Venules
Small vessels that branch from veins
lean body mass volume
Strength is determined by
Discuss the differences between strength, power, and endurance sporting activities.
Strength is the ability to maintain shape under the application of force, power is the ability of an athlete to overcome external resistance by developing a high rate of muscular contraction, and endurance is the ability of an athlete to resist fatigue in strength performance of a longer duration.
Explain why muscle cross-section influences the amount of force a muscle can generate.
The more myofibrils there are in a muscle cross-section, the more sarcomere there are, which allows greater force to be generated.
What are the roles of synergists and fixators? Give an example of each.
The muscles surrounding the joint being moved and supporting it in the action are called synergists( complementing the action of a prime mover). Other muscle groups called fixators will steady joints closer to the body's axis so that the desired action can occur. For example, if you want to climb a rope hand over hand, the muscles holding your shoulder girdle tightly to your rib cage are fixators, enabling you to use the muscles acting over the shoulder, elbow, wrist, and finger joints to perform their job and pull you up the rope. An example of a synergist is contracting to complement flexion: deltoid anterior.
Briefly discuss the relationship between maximal strength and muscular endurance.
The number of repetitions that can be done against a high resistance is dependent on maximal strength. The greater a person's maximal strength, the greater the muscular endurance at a particular load.
Blood Volume
The total amount of blood circulating within the body
Cardiac Output
The volume of blood ejected from the left side of the heart in one minute.
Do strength differences exist between men and women? Provide two examples which support your argument.
There are differences but it might not be what you expect because the average woman is 70 percent as strong as a man of the same size. However, differences between the sexes may not be as great as is commonly thought. In fact, in some cases, the differences may not be at all what is typically assumed. Women are able to perform challenging tasks requiring high levels of strength.
What happens to muscular strength as one ages? Why does this occur?
There is a selective loss of fast twitch fibers, mainly fast twitch glycolytic, with aging. As people age, they become less active, which results in muscle atrophy.
Motor nerves:
Transmit information from CNS to skeletal muscles
Sensory nerves:
Transmit information from sensory receptors to CNS
It can produce very large amounts of energy in a really short amount of time and its rate of recovery is relatively rapid. The system can supply energy only until the intramuscular stores of ATP are exhausted, and thereafter, for as long as there is a sufficient local supply of creatine phosphate to resynthesize ATP from ADP. However, the total muscle stores of ATP are very small and are depleted after only a few seconds of high-intensity work. Since the store of creatine phosphate in muscle is also small, it too is depleted rapidly during high-intensity work.
What are the advantages and limitations of the three energy systems?
Skeletal muscle is made up of numerous cylinder-shaped cells called muscle fibers, and each fiber is made up of a number of myofilaments. Each cell (fiber) is surrounded by a connective tissue sheath called the sarcolemma, and a variable number of fibers are enclosed together by a thicker connective tissue sheath to form a bundle of fibers. A large number of individual thread-like fibers known as myofibrils run lengthwise and parallel to one another within a muscle fiber.
What are the structures that make up skeletal muscle?
Endurance-trained individuals are able to remove lactic acid faster from exercising muscles. Faster lactic acid removal will allow people to continue to exercise at higher intensities for longer periods of time. Factors that can lead to an increased rate of lactic acid removal include (a) an increased rate of lactic acid diffusion from active muscle fibers into the circulatory system; (b) an increased muscle blood flow; (c) an increased ability to metabolize lactate in the heart, liver, and nonworking muscle fibers.
What factors can increase the rate of lactic acid removal? Why is this important?
The myosin filaments produce a dark band known as the A band. In the A band region of each sarcomere, two additional bands are present: the H zone that represents the space between the ends of the two sets of thin filaments in each sarcomere and the narrow, dark band in the center of the H zone, known as the M line. The M line is made up of proteins that link together the central region of the thick filaments. The light I band lies between the ends of the A bands of two adjacent sacromeres. It is bisected by the Z line, which anchors the thin filamenets.
What is the A band? What are the two regions of the A band?
During each step of glycolysis, a specific enzyme breaks down the chemical bonds of stored glycogen or blood glucose in the absence of oxygen. The final product in the complex series of breakdowns is termed pyruvic acid, which proceeds in one of two directions. It can be converted into lactic acid if the rate of pyruvic acid production is high or it can be converted to pyruvate and shuffled into the mitochondria, the specialized cellular organelles where the reactions of aerobic metabolism occur
What is the end product of glycolysis, and what happens to this end product?
All energy from the body is derived from the breakdown of three complex nutrients: carbohydrates, fats, and proteins. The end result of the breakdown of these substances is the production of various amounts of the molecule ATP, the body's energy currency.
What is the energy currency of the body, and where does it come from?
brain, spinal cords
What makes up the Central nervous system?
Muscle attached to the skeleton to make it move is known as skeletal muscle. It is also known as voluntary or striated muscle. Skeletal muscle is considered striated because of the alternating light and dark bands that appear when viewed under a light microscope. It's description as voluntary comes from the fact that we can contract skeletal muscle when we want to, voluntarily.
Why is skeletal muscle described as being striated and voluntary?
Muscle Cross-Sectional Area
Women < men More Type 1 / ST fibres (muscle endurance) Less Type 2 / FT fibres (muscle mass and strength)
Lean body mass
Women = men Same strength produced by single muscle fibre
Power
__________ is the ability to overcome resistance with high rate of muscular contraction
Endurance
__________ is the ability to resist muscle fatigue
strength
__________ is the highest load one can lift
Oxidative system
_____________ is the most important as it supports a broad range of activities
Concentric action
a contraction during which the muscle shortens
maximal / absolute strength
active muscle mass =
Endurance training:
anaerobic threshold goes up •Muscle "burn" felt at higher intensity •Faster removal of lactic acid: • muscle blood flow (capillaries, cardiac output) • flow of lactic acid from muscles to blood • metabolism of lactate
life
bio
Nervous system
brain, spinal cord, nerves
Platelets
clot-forming component
Eccentric action
contraction of the same speed over the entire range of motion
Synergist
contracts to complement flexion: deltoid anterior
Prime mover / agonist
contracts to flex shoulder: pectoralis major
Fixator
contracts to steady scapula closer to body: serratus anterior
Prima mover / agonist
contracts: biceps
Muscle force deficit
difference between assisted (e.g., hypnosis) and voluntarily generated maximal force
Plyometric action
fast eccentric muscle action followed by explosive concentric action
Conduction zone
filters, humidifies and adjusts air to body's temperature
Respiratory zone
gas exchange
White blood cells
infection fighting cells
Ventilation
inspiration and expiration
Gluconeogenesis
is a term used to describe glucose synthesis from noncarbohydrate sources such as lactate, protein, and fat.
Absolute strength
is the maximum amount of force a person can produce in a single effort
oxidative phosphorylation
is used to resynthesize ATP
tendons
it is usually linked to bone by bundles of collagen fibers
less repetitions possible
more force required =
more acceleration
more strength =
Ventilation
movement of air in and out of the lungs
Dynamic Action
muscle contraction with movement
sight
opsis
Red blood cells
oxygen-carrying cells
Apoptosis
programmed cell death
Antagonist
relaxes: triceps
H zone
space between thin filaments
Power
speed-strength =
Skeletal muscle
striated muscle =
strength
the ability to maintain shape under the application of force
Biomechanics of human movement
the assessment of the movement and the sequential pattern of muscle activation acting through joints to move body segments
sarcopenia
the loss of muscle mass, strength, and function that comes with aging
VO2 max
the maximal rate of oxygen that can be consumed to produce energy in the muscle
repetition maximum (RM)
the maximum amount of resistance that can be moved a specified number of times
Plasma
transport fluid
Total body mass
women < men less muscle and more and more adipose tissue
Skeletal Muscles
work together in synchrony to produce a desired movement
Fast twitch muscle fibres
• FT or Type II • Appear white • Fast contraction • Anaerobic • Fatigue fast • Large fibres
Plyometric Action
•A sudden eccentric loading and muscle stretching followed by a strong concentric contraction
Muscle Biopsy
•A tiny piece of muscle is removed and analyzed under a microscope
ATP resynthesis
•ADP + P --------ATP •Energy from breakdown of carbohydrates, protein and fat
Hydrolysis
•ATP --- Adenosine Diphosphate (ADP) + free phosphate (P) •Energy liberated for muscle contraction
O2 extraction
•Ability of tissues to extract O2 •Bohr effect: O2 released from Hb under high CO2 •Affected by mitochondria number and enzyme efficiency
resist fatigue (endurance)
•Ability to ________ in strength performance of longer duration
high rate of muscular contraction
•Ability to overcome external resistance by developing a ___________
Long-Term Energy: Oxidative System
•Aerobic System •Oxidative phosphorylation •Carbohydrate, protein, fat à many ATP •Muscle mitochondria •w enzymes and coenzymes •Most important, broad range of activities •Low and moderate intensities •< anaerobic threshold •Low lactic acid levels •Requirements: 1.Enough muscle mitochondria 2.Sufficient O2 supply 3.Enzymes and intermediate by-products under control
All-or-None Principle
•All muscle fibres that make up a single motor unit will contract maximally if the magnitude is reached
Stroke Volume
•Amount of blood (ml) pumped out of left ventricle per heartbeat •Resting: 70 ml
Cardiac output
•Amount of blood pumped by the heart •Determines O2 volume delivered to tissues
All-or-None Principle
•An impulse of a certain magnitude is required to cause fibres to contract
All-or-None Principle
•An impulse of smaller magnitude will not cause a muscle contraction
Testosterone
•Anabolic hormone •Responsible for muscle growth •Women 20-30% < men
Immediate Energy: Phosphagen System
•Anaerobic Alactic System •Creatine phosphate (CP) •Broken down to P •Combines with ADP •1 ATP •Small amounts of muscle CP and ADP stored •Short duration, very high intensity activities •E.g., shot put, sprint, weightlifting
Short-Term Energy: Glycolytic System
•Anaerobic Lactic System •Glycolysis •Glucose breakdown to 2 ATPs •w enzymes •w/o oxygen 1.High rate: pyruvic acid à lactic acid (anaerobic) 2.Low rate: pyruvic acid à pyruvate (aerobic) •Carbohydrates •Primary source of blood glucose •From pasta, breads, fruits, vegetables, etc
a chemical reaction
•At the endplate electrical current triggers
Oxygen utilization
•At the tissues •Cellular respiration
Tendon
•Attaches muscle belly to bone
Gas exchange
•Between air and blood •Between blood and other tissue
During exercise
•Body heat must be released by additional means •80% of energy released as heat
Exercise in the Cold
•Body less capable to adapt to prolonged cold vs. heat exposure •Hypothermia (significant decreasein body core temperature) •Shivering (involuntary skeletal muscle twitching) increased body's metabolic rate and heat production
Sinus node
•Bundle of nerve fibres that control heart rate •Located inside right atrium wall •Generate a nerve impulse (action potential) •Cause muscle walls to contract •Atria 1st,ventricles 2nd
diffuse into the actin-myosin overlap zone
•Calcium ions are released and
Intramuscle Coordination
•Capacity to activate different motor units simultaneously
Hematocrit
•Concentration of red blood cells •Determines amount of O2 per a volume of blood
Sarcolemma
•Connective tissue sheath •Wraps each muscle fibre
Peripheral Circulatory System
•Consists of blood vessels made up of layers of tissue •Smooth muscle cell layer allow vessels to contact •This regulates blood flow throughout the body
Sarcomeres
•Contractile units •Organized longitudinally in series (end to end)
Muscle fibre
•Cylinder-shaped muscle cell •Contains contractile machinery and organelles for cell respiration
Respiratory system
•Delivers oxygenated air to blood •Removes CO2 from blood •Regulates acid-base balance
Right atrium
•Deoxygenated blood •From body •Via superior/inferior vena cava
Right ventricle
•Deoxygenated blood •To lungs •Via pulmonary artery
Partial pressure of O2 (PO2)
•Determines hemoglobin-oxygen binding •High (e.g., lungs): O2 binds •Low (e.g., muscle): O2 unbinds
Diastolic B
•During heart relaxation (diastole) •Indicates peripheral BP (outside the heart) •Ease with which blood flows from arterioles to capillaries •Normal: 70-80 mm Hg
Systolic BP
•During ventricular contraction (systole) •How hard heart works •Strain against arterial walls during contraction •Normal: 120 mm Hg
Long-Term Energy: Oxidative System characteristics
•Efficient lactic acid removal after intense activity •Liver and Type I oxidative muscles •Efficient breakdown of fuels to produce high ATP yields •Especially fats •Limitations: 1.Adequate O2 supply 2.Slow rate of ATP of production
Motor end plate
•End of a motor neuron •Transmits neural impulses to a muscle fibre
phosphagen, glycolytic, and oxidative
•Energy is produced with 3 energy systems:
Intensity of work
•Estimated by measuring heart rate via carotid or radial pulse •Palpate with middle 2-3 fingers and count # beats per 10 sec x 6
Eccentric Action
•Example: Extension of biceps •Muscle is overcome by a load •Lengthens
Concentric Action
•Example: Flexion of biceps •Muscle overcomes a load •Shortens
Trained athletes
•Exploit a larger number of muscle fibres •Larger muscle mass •More limited in further strength gains
Adenosine Triphosphate (ATP)
•Fuels all biochemical processes •Body's energy currency
•Motor unit
•Group of fibres activated via the same nerve •Basic functional entity of muscular activity
Plyometrics training includes
•Leaping •Bounding •Depth jumping
Endocardium (innermost)
•Lines heart chambers •Allows smooth blood flow
Muscle belly
•Made up of muscle fibre bundles
Long-lasting, low to moderate intensity activities
•Mainly oxidative system •Marathon, triathlon
Short-term, high intensity activities
•Mainly phosphagen and glycolytic system •Jumping, throwing, sprinting
Myofibrils
•Make up muscle fibre •Contain contractile machinery: sarcomeres and myofilaments
Heart contracts in a constant rhythm
•May speed up or slow down •Depending on the body's blood and oxygen need
ATPs
•Muscle work requires energy which is supplied in
Inspiration
•Muscles contract •Cavity and lungs expands •Lung pressure ¯ •Air flows in
Expiration
•Muscles relax •Cavity and lungs shrinks •Lung pressure •Air flows out
is not capable of exciting muscle fibres
•Nerve's electric current (action potential)
Isokinetic Action
•Neuromuscular system works •At a constant speed •During each movement phase •Against a preset high resistance •Independent of muscle force generated •Effective for strengthening muscles uniformly at all angles of motion •Requires specialized equipment
causing excitation of the sarcolemma
•Neurotransmitter (acetylcholine) is released and diffuses across the neuromuscular junction
Reticulocytes
•New RBCs with more hemoglobin •Produced in bone marrow •Tightly controlled with a hormone erythropoietin (EPO)
Capillarization
•Number of capillaries in tissue •Affects the ability of cardiovascular system to place RBCs close to the working tissues
Muscle Fibre Bundle
•Numerous muscle fibres wrapped by a thick connective tissue
Movement of air gases in and out lungs
•O2 •CO2 •Nitrogen
Atrioventricular valves
•Open when atria contract to direct blood flow into ventricles 1.Tricuspid valve: right atrium ----- right ventricle 2.Bicuspid / mitral valve: left atrium ----- left ventricle •Close when atria relax to prevent backflow
Semilunar valves
•Open when ventricles contract to direct blood flow into arteries 1.Pulmonary valve: right ventricle ---- pulmonary artery 2.Aortic valve: left ventricle ---- aorta •Close when ventricles relax to prevent backflow
Valves
•Open with blood flowing towards heart •Close with blood flowing away from heart
Long-Term Energy: Oxidative System
•Oxygen transport •Lungs ------ circulation ------- muscle • ATP need = O2 delivery (linear): • ventilation • O2 blood uptake • O2 muscle uptake •Maximal aerobic power (VO2max) •Maximal rate of O2 that can be consumed Additional energy produced anaerobicaly
•Left atrium
•Oxygenated blood •From lungs •Via pulmonary vein
Left ventricle
•Oxygenated blood •To body •Via aorta
Biological adaptation
•Performance improvements through strength training •Reflected in increased strength
Pericardium
•Protective sac •Loosely surrounds heart
Hemoglobin
•Protein and iron molecule inside RBCs that binds to up to four O2
Atria
•Pump blood into ventricles
Heart
•Pumps blood through the human body
Arterial-venous oxygen difference (a-v O2
•Rest: 4-5 ml O2 /decilitres blood •Exercise: 15 ml O2 /decilitres blood
Heart rate
•Rhythmical contraction of the heart walls (beats per minute, bpm) •Resting: 40-70 bpm •Maximum: 220 - age (years)
Slow twitch muscle fibres
•ST or Type I •Appear red •Slow contraction •Aerobic •Fatigue resistant •Small fibres
Optimal joint angle
•Sarcomeres at optimal distance •Optimal number of cross bridges •Maximal force developed
Small joint angle
•Sarcomeres too close together •Cross bridges interfere •Smaller force developed
Large joint angle
•Sarcomeres too far apart •Fewer cross bridges •Smaller force developed
Plyometric Action
•Sets off the Golgi tendon organ reflex •Protects muscle overstretching •Causes concentric contraction
Cardiovascular system
•Supplies muscles and organs with O2 •Removes metabolic by-products from tissues •Critical for performance
Short-Term Energy: Glycolytic System characteristics
•Supports high intensity activities •Lactic acid = painful and fatiguing by-product •Converts to lactate and hydrogen ions •Hydrogen ions cause muscle "burn" and diminish contraction Lactate metabolised in heart, liver, and muscles
Intermuscle Coordination
•The capacity to activate different muscles to produce a movement
Myocardium (middle)
•Thick and muscular •Pumps blood
Epicardium (outer)
•Thin •Protection
Myofilaments
•Thin filaments with actin proteins •Thick filaments with myosin proteins
Capillaries
•Tiny vessels that branch from arterioles •Composed only of endothelial cells •O2, nutrient, by-products exchange
expose the active sites on the actin molecule to the myosin
•Troponin and tropomyosin change shape and position and
•Blood flow against gravity
•Valves close to prevent back flow •Venous smooth muscle cells contract •Skeletal muscles contract
Isometric
•contraction in which there is No visible change in muscle length •Load > muscle force •No work, high tension and energy •Defined by: •Rate of tension •Duration
Trainable factors
•fibre diameter, intra- and inter-muscle coordination, nerve impulse frequency, muscle and tendon elasticity, energy stores, capillary density
