Classification of Joints
Structural class of Joint: Function/Movement Example
Fibrous Fixed/Slightly moveable Cranium/Sacrum
Cartiliginous Slightly moveable Vertebrae
Synovial Freely moveable Shoulder/Hip
Divisions of the Skeletion:
There are 2 divisions of the skeleton:
- Appendicular - These are freely moveable joints of the upper and lower limbs and their girdles that join to the axial skeleton. Its function is to provide a framework for muscle attachment and movement.
- Axial - More commonlt, immovable and slightly movable joints that form the long axis of he body including the cranium, spine and ribcage. Its function is to protect, support and carry other body parts
Articular/hyline cartilage - Glassy, smooth cartilage that is quite spongy and covers the ends of the bones at the joints. They prevent friction between the articulating surfaces of the bones at the joint and absorb compression placed on the joint and protect the bone ends from being crushed
Two-layered joint capsule - The outer layer is a tough fibrous layer called the fibrous capsule. The inner layer is the synovial membrane that covers all the internal joint surfaces except for the articular cartilage. They strengthen the joint so that the bones are not pulled apart and they secrete synovial fluid.
Synovial Fluid - A slippery fluid the consistency of egg-whites that is contained within the joint cavity. To reduce friction between the articular cartilages and to nourish the articlar cartliage. To rid the joint of any waste debris.
Ligament - A band of stong fibous tissue that connect bone to bone.
Other common structures specific to the indiviual
Bursae - Flattened fibroud sac lined with synovial membrance containing a thin film of synovial fluid. They prevent friction at sites where ligaments, muscles, tensons or bones might rub together.
Meniscus - A wedge of white fibrocartilage (tough/flexible) that improves the fit between adjacent bone ends. Increases joint stability and reduces wear and tear to joint surfaces.
Pad of fat - A fatty pad located between capsule, bone or muscle. Increases joint stability and reduces friction between joint surfaces.
Types of synovial joints
Ball and Socket - hip and shoulder
Hinge - knee, elbow and ankle
Pivot - radio-ulnar, tibia-fibula and atlas/axis
Condyloid - wrist
Gliding - vertebrae
Saddle - thumb
Anatomical terminology and movement
Anatomical Position - an upright standing position with the head, shoulders, chest, palms of the hands, hips, knees and toes all facing forwards.
Medial - situated in or movement towards the middle of the body
Lateral - situated in or movement towards the outside of the body
Abduction - taking the body part away from the body
Adduction - adding the body part to the body
Flexion - moves in a forwards motion
Extension - moves in a backwards motion
Lateral Felxion - beding the spine from side to side
Pronation - turning the palms outwards
Supination - turning the palms inwards
Circumduction - complete movement in a circle
Rotation - moving in less than circle movements
Plantar Flexion - point the foot to the floor
Dorsi Flexion - point the foot to the ceiling
Wrist - flexion/ extension/ adduction/ abduction/ circumduction
Radio-Ulnar - rotation/ pronation/ supination
Elbow - flexion/ extension
Shoulder - flexion/ extension/ horizontal flexion/ horizontal extension/ abduction/ adduction/ rotation/ circumduction
Spine - flexion/ extension/ lateral flexion/ rotation
Hip - flexion/ extension/ abduction/ adduction/ rotation/ circumduction
Ankle - Dorsiflexion/ plantar flexion
Knee - flexion/ extension
Skeletal muscles attach to and moves the skelenton and is also called voluntary muscles as its under conscious control.
Functions of the skeletal muscle:
Origin - Point of attachment of a muscle relatively fixed during muscular contraction
Insertion - Point of attachment of a muscle that tends to move toward the origin during muscular contraction
Antagonist muscle action - as one muscle shortens to produce movement, another muscle lengthens to allow that movement to take place.
Agonist muscle/ prime mover - the muscle that's directly responsible for the movement at a joint
Antagonist muscle - The muscle that has an action opposite to that of the agonist and helps in the production of a coordinated movement.
Fixator muscle - the muscle that allows the agonist to work effectively by stabilising the origin of the agonist, so that the agonist muscle can pull against the bone without it moveing to achieve an effective contraction.
Types of muscular contraction
- Muscle exerts a force while changing length
- if the muscle is lengthening, it is called an eccentric contraction
- if the muscle is shortening, it is called a concentric contraction
- the muscle is exerting force but there is no change in muscle length
Agonist - shortening (under tension) - concentric contraction
Antagonist - lengthening (under tension) - eccentric contraction
Fixator - no change (but under tension) - isometric contraction
Muscle fibre types
Slow oxidative fibres - red in colour, small, many mitochondria, many capillaries, high myoglobin concentration, low glycogen stores, slow contractile speed, low contractile strength, high fatigue resistance, high aerobic capacity, low anaerobic capacity, found in the gastronemius of a marathon runner, suited to endurance type activities.
Fast oxidative glycolytic fibres - red/pink in colour, intermediate size, many mitochondria, many capillaries, high myoglbin concentration, intermediate glycogen stores, fast contractile speed, intermediate contractile strength, moderatefatigue resistance, moderate aerobic capacity, high anaerobic capacity, found in gastronemius of 1500m runner, suited to activities involving walking, unning and sprinting.
Fast gylcolytic fibres - white in colour, large in size, few mitochondria, few capillaries, low myoglobin concentration, high glycogen stores, fast contractile speed, high contractile strength, low fatigue resistance, low aerobic capacity, hight anaerobic capacity, located in gastonemius of 110m hurdler, suited to speed/power type activities
Fast and slow twitch muscle fibres
Slow twitch: designed for aerobic work, uses O2 to produce a small amount of force, slow speed of contraction, fatigue resistant e.g marathon runner
Fast twitch: designed for anaerobic work, does not require O2 and produces a large amount of force, fast speed of contraction, fatigues quickly, e.g a sprinter or shotputter
Physiological effects of a warm up on skeletal mus
- Increase strength of contraction due to improved elasticity of muscle fibres
- Faster speed of contraction due to increase speed of nerve impulse to muscle
- Faster speed and relaxaion of contraction due to a higher muscle temperature
- Increased speed of strength of contraction due to improved co-ordination between antagonistic pairs, due to a reduction in muscle viscosity
- Increased speed and strength of contraction due to increase in enzyme activity in warmer muscles
- Reduced risk of injury, despite an increase in speed of strength of contraction, due to increase in blood flow and oxygen to muscles.
Linear motion - this is when a body moves in a straight or curved line with akk arts moving in the same distance, direction and speed e.g a tobogganist in a straight line or a shot put in a curved line
Angular motion - This is when a body, or part of a body, moves in a circle, or part circle, around a particular point called the axis of roation e.g the shoulder joint in swimming or the whole body around the high bar in gymnastics
General motion - this is a combination if linear and angular motion
Force - is a push or pull that alers or tends to alter the state of motion of a body. It can:
- cause a body at rest to move
- case a moving body to change direction, accelerate, or decelerate
- change ana object's shape
Without force, there can be no motion
The extend of the resulting motion is dependent upon:
- where the line of application of the force is applied
- the size of the force applied = Newtons 2nd law of motion
- the direction in which the goce is applied = Newton's 2nd law of motion
- the link between motion and forve is explained by newtons laws
Newton's Laws of Motion
First Law of Inertia - 'A body continues in a state of rest or uniform velocity unless acted upn bby an external force'
Second Law of Acceleration - 'When a force acts upon an object, the rate of change of momentum is proportional to the size of the force and teakes place in the direction in which the force acts'
Third Law of Reaction - 'For every action there is an equal and opposite reaction.'
Centre of mass
The centre of mass is the point at which the body in all directions, is balanced or where all the mass could be oconsidered to be concentrated.The centre of gravity is continually changing and can lie within or outside the mass of the body.
Stability: is how difficult it is to disturb a body frim a balanced position and is dependent upon 4 principles:
1. Position of athlete's centre of mass 2. Position of athete's line of gravity 3. Athlete's base of support (feet) 4. Mass of athlete
Stability is increased when:
- the centre of mass is within the base of support
- the centre of mass is lower
- there are wider/more bases of suppport
- the line of gravity is shorter and within the base of support
- themass is greater and lower
Relationship between centre of mass and applicatio
The direction of the application of a force in relation to the centre of mass determines whether the motion of a body is linear or angular
Direct force =linear motion
A force whose line of application passes through a bodys centre of mass will cause the resulting motion to be linear
Eccentric force = angular motion
A force whose line of application passes outside the centre of mass of the body causing the resulting motion to be angular (rotation/spin)
Aerobic -is a process taking place in the presence of oxygen.
Anaerobic - is a process taking place in the absence of oxygen.
Heart conduction system
The heart acts as a dual-pump action - two seperate pumps that work simultaneously to pump blood to two different destinations. The right side pumps deoxygenated blood (blood depleted of xygen) towards the lungs and the left side pumps oxygenated (blood saturated with oxygen) towards the rest of the body.
1. The heart is myogenic -controls own electrical impulse - the cardiac impulse
2. Cardiac impulse initiated from SA node (pacemaker) in right atrium
3. Impulse passes through right and left atrium walls to AV node
4. Causing both atria to contract termed 'atrial systole'
5. AV node conducts impulse down through the Bundle of His and down through the septum to the apex of heart
6. Impulse travels up around the ventricle walls via purkinje fibres
7. Causing both ventricles to contract termed 'ventricular systole'
8. Cycle continues, SA node initiates the next cardiac impulse
The cardiac cycle
1.Both atria fill with blood. AV valves closed
2. Atrial blood presure rises above ventricular pressure
3.Rising blood pressure forve AV valves open and blood passively passes into both ventricles. Semilunar valves closed
4. Both Atria contract actively forcing the remaining atrial blood into ventricles
5.semilumar valves remain closed
6.Both ventricle contract increasing ventricular pressure
7.Aortic and pulmonary valves forced open. AV valves closed.
8.Blood forced out into aorta: aorta to body tissues/muscles
9.Diastole of the next cardiac cycle begins. Semilunar valves close preventing backflow of blood from aorta and pulmonary arteries
Resting heart rate
The heart rate represents the number of times the heart ventricles beat in one minute. The everage resting heart rate is 72 beats per minute. The maximal heart rate is 220-age
Bradycardia - is a resting heart rate that is below 60 bpm. It may indicate a high level of aerobic fitness. It may be due to hypertrophy which is an increase in size of the heart muscle wall.
Stroke volume - is the volume of blood ejected by heart ventricles per beat or the difference in the volume of blood before and after each ventricle contraction. The average resting stroke volume is approximately 70ml.
- The end diastolic volume before, is the volume of blood left in the ventricles at the end of the relaxation/filling stage of the cardiac cycle
- The end systolic volume, after, is the volume of blood left in the ventricles at the end of the contraction/emptying stage of the cardiac cycle.
Cardiac Output the volume of blood ejected by heart ventricles in 1 minute
Q = SV x HR (THE AVERAGE: Q =51/m SV=70ml HR=72)
Heart rate responses to exercise
SV = resting(60ml/80ml), submaximal(80/100ml ), maximal(100/120ml) - untrained
resting(80/110ml), submaximal(160/200), maximal(160/200ml) - trained
HR = resting(70/72bpm), submaximal(up to 100/130bpm), Maximal(220-age)
Q = resting(5L/min), Submaximal(up to 10L/min), maximal(20-40L/min)
Submaximal refers to exercise performed at an intensity below an athletes maximal aerobic capacity, or max VO2 - hence it represents aerobic work
SV Response to exercise
Stroke volume respose to exercise: Storke volume increase from values around 60-80ml per beat at rest to maximal values of around 120ml per beat during exercise.
SV increases due to: Increased capacity of heart to fill. Increase in venous return which stretches vetricular walls and increases the filling capacity of the heart and hence the end diastole volume. and increased capacity of heart to empty. A greater EDV provides a greater stretch on the heart walls, which increase the force of ventricular systole. This increases ventricular contractility(the capacity of the heart ventricles to contract), which amost completely empties the blood from the ventricles increasing SV.
Heart rate response to exercise
1. Resting heart rate
3. Rapid increase in heart rate at the start of exercise due to receptors
4. Continued but slower increase in heart rate
5. Aerobic sub-maximal work slight fall/steady plateau in heart rate
6. Maximal anaerobic work: continued rise in heart rate towards maximal values
7. Rapid fall in heart rate
8.Slower fall in heart rate towards resting values
Cardiac Output: response to exercise
Cardiac output, being the product of stroke volume and heart rate increase directly in line with exercise intensity from resting walues of 5L/min up to maximal values of 40L/MIN.
Cardiac control centre
The medulla oblongata in the brain contains the cardiac control centre, which is primarily responsible for regulatin heart rate.
The CCC is controlled by the autonomic nervous system, meaning that it is under involuntary control and consists of sensory and motor nerves from either the sumpathetic or parasympathetic system.
Three main factors affect the activity of the CCC:
- neural control - primary control factor
- hormonal control
- intrinsic control
Control of blood supply
The vascular system controls blood supply. It consists of blood and blood vesseld that transports and directs O2 and CO2 to and from the lungs, heart and body tissues/muscles.
Cardiac output is distributed to the various organs/tissues of the bloodaccording to their need/demand for oxygen.
The blood represents the substance that actually carries/transports the O2 and CO2.
The vast system of blood vesssels represents a system of tubing/plumbing that directs and delivers the flow of blood towards the body tissues/muscles.
Blood vessel Structure
- All vessles have three layers except for single-walled capillaries
- Arteries and arterioles walls have a large muscular middle layer of involuntary smooth muscle to allow them to vasodilate (widen) and vasoconstrict (narrow) to alter their shape/size to regulate blood flow
- Arterioles have a ring of smooth muscle surround the entry to the capillaries that they control the blood flow into. Called pre-capillary sphincters, they can vasodilate and vasoconstrict to alter their shape/size to regulate blood flow
- Capillaries have a very thin, one cell thick layer to allow gaseous exchange to take place
- Larger veins have pocket valces to prevent the back flow of blood and direct blood in one direction back to the heart.
- Venules and veins have a much thinner muscular layer, allowing them to venodilate (widen) and venoconstrict (narrow) to a lesser extent and a thicker outer lauer to help support the bloo that sits within each valve
Regulation/control of the heart:
1. Receptors are sense orfans(proprio, chemo, baraoreceptors) that pick up stimuli/information regarding CO2, O2, pH, blood pressure which is relayed via sensory nerves
2. Sensory nerves transmit information from receptors to the CCC in the medulla oblongate, which stimulates one of two motor nerves, which stimulate SA node
3. Sympathetic accelerator nerves increase heart rate
4. Parasympathetic vagus nerves decrease heart rate
Venous return is deoxygenated blood returning to the heart.
Starlings law of the heart:
- SV/Q is dependent on VR
- If VR increases, SV/Q increases
- If VR decreases, SV/Q decreases
- During exercise there is not enough pressure to maintain VR and so SV/Q would decrease
- Insufficient pressure to push blood back towards the heart causes blood pooling in the pocket valves of the veins
- Active cooldown prevents blood pooling after exercise by maintaing muscle and respiratory pumps
Venous Return mechanism's:Five mechanisms: pocket valves, skeletal muscle pump, respiratory pump, smoorth muscle, gravity
Distribution of Q at rest and during exercise
- Only 15 to 20% of resting cardiac output is supplied to the muscles
- The remaining Q (80-85%) supplies the body's organs, kidneys, liver, stomach and intestines
- Increase Q (80-85%) is supplies to the working muscels as intesity increases
- Decreasing percentage of Q is supplied to the body's organs
- Blood supply to the skin during lighter work to reduce body temperatire, but decreases as intesity increases
- The process of redistributing Q is called the vascular shunt mechanism
- Skeletal muscle arterioles and pre-capillary sphincters vasodilate, increasing blood flow to working muscles
- Organs arterioles and pre-capillary sphincters vasoconstrict, decreasing blood flow to organs
Vasomotor control centre
- Located in medulla oblongata
- chemoreceptors and barorecptors stimulate VCC
- VCC stimulates the sympatheric nervous system which controls blood vessel lumen diameter of organs and muscles
- This controls the vascular shunt mechanism
Vascular shunt mechanism
Oragns ----> Increased sympathetic stimulation --->Vasocontriction of arterioles and pre-capillary sphincters ----> Decreased blood flow/Q to capillaries or non-essential organs
Muscles ----> Decreased sympathetic stimulation ---->Vasodilation of pre-capillary sphincters and arterioles ----> Increased blood flow/Q to capillaries or working muscles
O2 and CO2 transport
O2 and CO2 is transported via blood
- 97% transported within the protein haemoglobin, packed with red blood cells, as oxyhaemoglobing
- 3% within blood plasma
- 70% dissolves in water as carbonic acid
- 23% carbaminohaemoglobin (HbO2)
- 7% dissolved in plasma
Effects on the vascular system
- Gradual increas in blood flow/Q due to vascular shunt mechanism via, vasoconstriction of arterioles/pre-capillary sphincters to organs decreasing blood flow to organs OR vasodilation of muscles arterioles/per-capillary sphincters increasing blood flow (O2) to working muschles
- Increased body/muscle temperature increasing transport of enzyme activity required for energy and muscle contraction
- Increase body/muscle temperature which decreases blood viscosity improving blood flow to working muscles, and increases dissociation of O2 from haemoglobin
- Decreases onset of lactic acid due to anerobic work without warm up
- Keeps metabolic activity elevated gradually decreasing HR and respiration
- Maintains respiratory/muscle pumps which prevents blood pooling in veins, maintains venous return. maintains blood flow and blood pressure
- keeps capillaries dilate to flush muscles with O2 blood increasing removal or blood and muscle lactic acid and CO2
There are 3 main respiratory processes;
1. Pulmonary ventilation - the breathing of air in and out of the lungs
2. External respiration - exchange of O2 and CO2 between lungs and blood
3. Internal respiration - exchange of O2 and CO2 between the blood and muscle tissues
Inspiration and Expiration
- 1. Diaphragm contracts- active, external intercoastals contract - active
- 2. Diaphragm flattens/ pushed down, ribs/sternum move up and out
- 3. Thoracic cavity volume increases
- 4. Lung air pressure decreases below atmospheric air (outside)
- 5. Air rushes in
- 1. Diaphragm relaxes - pasibe, External intercoastals relax - passive
- 2. Diaphragm puahed upwards, ribs/sternum move in and down
- 3. Thoracic cavity volume decreases
- 4. Lung air pressure increases above atmoshperic air (outside)
- 5. Air rushes out of lungs
Minute ventilation = tidal volume x frequency
VE = TV x F
= 500 x 15
= 7.51 L/min
Lung volume Definitions
Tidal volume X - Volume of air inhaled/exhaled per breath during rest - 500ml/per breath
Frequency - Number of breaths in one minute - 12-15
=VE Minute Ventilation - Volume of air inspired/expired in one minute - 6-7.5L/min
Inspiratory Reserve Volume - Volume of air that can be forefully inspired after normal TV inspiration - 3100ml
Expiratory reserve volume - Volume of air that can be forvefully exhaled after normal resting TV expiration - 1200ml
Vital Capacity - maximal volume of air that can be expired after maximal inspiration: VC=TV+IRV+ERV - 4800ml
Residual volume - Volume of air remaining in the lungs after a forced expiration - 1200ml
Total lung capacity - maximal volume of air contained in the lungs after a maximal inspiration: TLC = TV+ IRV + ERV +RV - 6000ml
Gaseous exchange is the exchange of CO2 and O2 by the process of diffusion
Diffusion is the movement of a gas from asn area of high pressure to an area of low pressure
Partial pressure is the pressure a gas exerts within a mixture of gases
Myoglobin is the red pigment in muscles that stores and transports O2 to the mitochondria in muscles
- If blood is oxygenated - it has a high PP of O2 and a low PP of CO2
- if blood is deoxygenated - it has a low PP of O2 and a high PP of CO2
Where - Alveolar-capillary membrane between alveoli air and blood in alveolar capillaries
Movement - O2 in alveoli diffuse to blood; CO2 in blood diffuses to alveoli
Why - PP of O2 in alveoli higher tham the PP of O2 in the blood so O2 diffuses into the blood
Why - PP of CO2 in the blood is higher than the PP pf CO2 in the alveoli so CO2 diffuses into the alveoli
Where - Tissue- capillary membrane between the blood in the capillaries and the tissue (muscle) cell walls
Movement - O2 in blood diffuses into tissue; CO2 in tusses diffuses into blood
Why - PP of O2 in blood is higher than the PP of O2 in the tissue so O2 diffuses into the myoglobin within the tissues
Why - PP of CO2 in the tissue is higher than the PP of CO2 in the blood so CO2 diffuses into the capillary blood
Respiratory response to exercise
Mechanics of breathing:
Addition muscles cause the increase in rate/depth of breating during exercise:
Inspiration: 1 Diaphragm contracts, external intercostals contract, Sternocleidomastoid contracts, scalenes contract, pectoralis minor contracts, 2. Diaphragm flattens with more force increased lifting of ribs and sternum. 3. Increased thoracic cavity volume. 4. Lower air pressure in lungs. 5. More air rushes into lungs
Expiration: 1. Diaphragm relaxes, external intercostals relax, internal intercoastals contract(active) rectusabdominus/obliques contract(active). 2. Diaphragm pushed up harder with more force, Ribs/sternum pulled in and down. 3. Greater decrease in thoracic cavity volume. 4. High air pressure in lungs. 5. More air pushed out of the lungs
Lung volume/capacity changes during exercise
Tidal volume X- 500ml per breathe (rest), Increases up to 3-4 litres(exercise)
Frequency - 12-15(rest), increase: 40 - 60(exercise)
=VE minute ventilation - 6-7.5L/min(rest), Increase: values up to 120L/min in smaller individuals and up to 180+L/min in larger aerobic trained athletes(exercise)
Inspiratory Reserve Volume -3100ml(rest), Decreases(exercise)
Expiratory reserve volume - 1200ml(rest), slightly decreases (exercise)
Vital Capcity - 4800ml(rest), Slight decrease(exercise)
Residual volume - 1200ml(rest), slight increase(exercise)
Total lung capacity - 6000ml(rest), slight decrease(exercise)
Ventilation response to light, moderate and heavy
1. Anticipatory rise prior to exercise
2. Rapid rise in VE due to neural stimulation
3. Slower increase/plateau due to receptor stimulation of RCC
4. Continued but slower increase in HR
5. Rapid decrease in VE
6. Slower decrease towards resting VE values
During exercise 4 factors shift the dissociation curve to the right, or simply increase the dissociate of O2 for Hb in the blood capillaries to the muscle tissue, increasing the supply of O2 tothe working muscles.
1. Increase in PP of CO2 increasing O2 diffusion gradient
2. Decrease in PP of O2 within muscle increasing O2 diffusion gradient
3. INcrease in blood and muscle temperature
Bohr effect - increase in acidity(lower pH)
Control of breathing
- The respiratory control centre (RCC) is located in the medulla oblongata of the brain and regulates breathing
- RCC controls breathing via the respiratory muscles
- The respiratory muscles are under involuntary neural control from the inspiratory and expiratory centres, which stimulate the respiratory muscles at rest and during exercise
Effects of altitude on the respiratory system
Exposure to high altitude has a significant effect upon performance. At high altitude (above 1500m) the PP of O2 decreases and had a series of knock-on effects, which decrease the efficiency of the respiratory process.
- Decrease in O2 and Hb association
- reduction in the diffusion gradient
- Decreased pO2 in alveoli
- Long term effects
- Water loss
- Increase the onset of muscular fatigue
- Causes a reduction in O2 available to muscles
- Resulting in decrease O2 transport in the blood