section A

Vein

• large lumen

• Has valves

• Thin outer layer

• Diameter of veins increases as you get closer to the heart

Capillaries

• Small lumen

• Wall is a single layer of cells

Arteries

• small lumen

• Thick muscle

• Thick outer layer

• Arteries get smaller as you move away from the heart

Movement of blood in the heart (Start at right atrium)

• right atrium

• Tricuspid valve

• Right ventricle

• Pulmonary artery

• Lungs

• Pulmonary vein

• Left atrium

• Bicuspid valve

• Left ventricle

• Aorta

• Vena cava

Conduction system

• SA node - initiates heart beat and causes atria to contract

• Moves through atria walls

• AV node - helps delay the impulse to allow atria to contract

• Bundle of his - splits into left and right

• Impulse spreads around ventricle walls through network of purkinje fibres which cause both ventricles to contract

• The ventricles then relax and fill up with blood

• cycle is repeated

Cardiac cycle

• both atria fill with blood (diastole)

• Atrial blood pressure rises and causes valves to open and blood passes into ventricles

• Atria contract forcing remaining blood into ventricles

• Both ventricles contract

• Semi lunar valves open

• Blood is forced into aorta and pulmonary arteries

Neural control (receptors)

• baroreceptors - pressure changes

• Propriorecpetors - detect movement

• Chemoreceptors - detect changes in blood acidity

Intrinsic control of HR

• thermoreceptors - detect blood, joint and muscle temperature

Hormonal control of HR

• adrenaline - released due to stress + increases HR

• Noradrenaline - increases transmission speed of nerve impulses

• Acetylcholine - decreases transmission speed of nerve impulses

Parasympathetic nervous system

• bring heart rate down by transmissiting impulses of smaller velocity and magnitude

Sympathetic nervous system

• pases neuron transmissions at a higher rate via conduction system of the heart to increases the frequency and force of contractions

Stroke volume

• amount of blood pumped out by the heart per contraction

Factors affecting stroke volume

• venous return - volume of blood returning to the heat via the veins

• elasticity of cardiac fibres - amount of stretch in cardiac tissue during diastole

• Contractility of cardiac tissue - the greater the contractility of the myocardium, the greater the force of contraction

Venous return

• process of moving blood in the veins to the right side of the heart

Venous return mechanisms

• skeletal pump - pressure is applied to the veins, moving blood back towards the heart

• Pocket valves - allow blood through and prevent back flow

• Atrial suction - chamber walls return to resting position causing a drop in pressure which draws blood from vena cava to atrial walls

• Smooth muscle pump - vasomotor control centre helps squeeze blood through veins

• Respiratory pump - thoracic and abdomen expansion during heightened breathing applies pressure on veins walls

Cardiovascular drift

• progressive decrease in stroke volume together with a progressive rise in heart rate during steady state exercise

When does cardiovascular drift occur

• prolonged periods of exercise (10 mins) and in a warm environment

Why does cardiovascular drift occur

• because when we sweat, a portion of the lost fluid volume comes from blood plasma

• Decrease in blood pressure reduces venous return and stroke volume.

• Heart rate increases to compensate and maintain constant cardiac output

Redistribution of blood

• vasoconstriction - narrowing of blood vessels

• Vasodilation - widening of blood vessels

• Vascular shunt mechanism - redistribution of blood around the body during exercise so muscles receive an increased portion

• Important to - increase supply of oxygen to working muscles for aerobic respiration, to remove waste products, direct more blood to the heart

• Blood flow to the brain has to remain the same to ensure that brain function are maintained

What is coronary heart disease

When coronary arteries get blocked due to fatty deposits (artheroma)

What is angina

• chest pain that occurs when blood supply through coronary arteries to the heart is restricted

Factors that can cause CHD

• high blood pressure

• High cholesterol

• Lack of exercise

• Alcohol

• Smoking

What are low density lipoproteins

• transport cholesterol in blood to tissues (Bad)

What are high density lipoproteins

• transport excess cholesterol in blood to liver where it is broken down (good)

Transportation of O2

• when oxygen diffuses into capillaries from the alveoli, the partial pressure of oxygen is high, so haemoglobin is fully saturated with oxygen

• Partial pressure is lower in muscles because they have used up all of their oxygen and need more so oxygen unbinds from haemoglobin and diffuses into muscle, haemoglobin is not saturated with oxygen

• When oxygen diffuses into the muscle, it combines with myoglobin

A-vo2 diff

Difference between oxygen content of arterial blood arriving at muscles and venous blood leaving muscles

What happens to a-vo2 diff during exercise

• increases as more oxygen is extracted from blood by active muscles needing oxygen

How does an increase in a-vo2 diff have an impact on gas exchange?

• more oxygen is take in and so more co2 is removed

How does a trained performed increase a-vo2 difference

• adaptations of mitochondria

• Increased myoglobin

• Improved muscle capillarisation

Bohr shift

• during exercise, curve shifts to the right because when muscles are respiring aerobically they require more oxygen

• The dissociation of oxygen from haemoglobin in blood capillaries to muscle tissue occurs more willingly

• Saturation of blood with oxygen at a given partial pressure of oxygen is lower becase more oxygen is being released

Oxyhaemoglobin dissociation

• first molecule of oxygen combines with haemoglobin and slightly distorts it. Joining at first is quite slow

• After haemoglobin has changed shape, it becomes easier for 2nd and 3rd to join

• It flattens off at top because 4th o2 is slightly more difficult

What is inspiratory reserve volume

• volume of air that can be forcibly inspired after a normal breath

Residual volume

• volume of air that remains in the lungs after maximal expiration

Minute ventilation

• volume of air breathed in or out per minute

Tidal volume

• volume of air breathed in or out per breath

Expiratory reserve volume

• volume of air that can be forcibly expired after a normal breath

How does tidal volume change during exercise

Increase

How does inspiratory and expiratory reserve volume change during exercise

Decreases

How does residual volume change during exercise

Stays the same

How does minute ventilation change during exercise

Increases

Process of inspiration

• external intercostal muscles contract

• Diaphragm contracts And flattens

• Pulls ribcage up and out

• Thoracic cavity volume increases

• Decreasing pressure inside thoracic cavity

• Oxygen is drawn in down the pressure gradient

Process of expiration

• intercostal muscles relax

• Ribcage moves downwards

• Diaphragm relaxes and returns to dome shape

• Decreasing volume of thoracic cavity

• Increasing pressure

• Oxygen moves out of lungs down pressure gradient

Regulation of breathing - chemical

• Increase in co2 levels

• Increase in acidity

• Detected by chemoreceptors

Regulation of breathing - hormonal

• adrenaline transported in blood and released due to exercise

• Brain sends impuse to renal glands which respond and pump adrenaline into blood in anticipation

Regulation of breathing - neural

• nervous centre

• Messages sent to medulla

• Messages sent to respiratory muscles via sympathetic nervous system

• Movement of muscles and joints is detected by proprioreceptors

Structure of alveoli

• one cell thick - short diffusion pathway

• Extensive capillary network - good blood supply

• Large surface area - greater uptake of oxygen

Pathway of gas exchange

• nose

• Mouth

• Pharynx

• Larynx

• Trachea

• Bronchi

• Bronchioles

• Alveoli

Factors affecting rate of gas exchange

• thickness of membrane

• Distance through membrane

• Surface area

Characteristics of type 1 muscle fibres

• slow contraction speed

• Lower intensity exercise

• Low force produced

• High aerobic capacity

• High mitochondrial density

Characteristics of type 2a - fast oxidative muscle fibres

• fatigues quite quickly

• Produce energy anaerobically

• Large motor neurone size

• High force produced

• Fast contraction speed

Characteristics of type 2b muscle fibres - fast glycolytic

• fatigue very quickly

• High explosive events

• Large motor neurone size

• High force produced

• Low mitochondrial density

• Low myoglobin density

• High anaerobic capacity

• Fast contraction speed

what is a motor unit 

made up of a motor neurone (which are nerve cells that transmits brain instructions to muscle fibres) and muscle fibres 

the all or none law

• either all of the muscle fibres contract or none of them contract

• a motor unit cannot partially contract

• minimum stimulation of stimulation called the threshold is required to start a contraction

wave summation

the repeated activation of a motor neurone, stimulating muscle fibres resulting in a stronger force of contraction.

calcium is released each time a nerve impulse reaches the muscle cell

the greater the frequency of the stimuli, the greater the tension developed by the muscles.

tetanic contraction 

forceful, sustained, smooth contraction

spatial summation

recruitment of additional and bigger motor units within a muscle to develop more force, occurs when impulses are received at different places

PNF stand for

proprioreceptive neuromusclar facilitation - increases the range of movement

what are muscle spindles and what are their roles in PNF

• sensitive proprioceptors, they lie between muscle fibres

• provide info to CNS about how far and fast a muscle is being stretched

• CNS sends impulse back to muscle, impulse tells muscle to contract, which triggers stretch reflex

• prevents over stretching and reduces risk of injury

what are Golgi tendons and what is their role in PNF

• found between the muscle and the tendon

• they detected levels of tension in the muscles 

• when muscles contract isometrically, they detect the increase in muscle tension

• they send inhibitory signals to the brain which allows antagonist muscle to relax and lengthen - known as autogenic inhibition

3 types of joints

• fixed (fibrous)

• slightly moveable (cartilaginous)

• synovial (freely moveable)

sagittal plane

• side to side divison

• forwards and backwards movements

• flexion and extension

• backwards/fowards somersault

frontal plane 

• divides body front to back

• side to side movements

• abduction and adduction 

• cartwheel 

transverse plane

• divides body top to bottom

• rotation, turning movements

• spinning in skating

transverse axis

• passes horizontally through centre

• sagittal plane

sagittal axis

• passes horizontally front to back 

• frontal plane

longitudinal axis

• passes vertically from top to bottom

• transverse plane

concentric contraction

• fibres contract to shorten muscle length

• during upward phases of movements

eccentric contraction 

• fibres contract to lengthen muscle length

• lowering, weight bearing, stopping movements 

isometric contraction

• takes place when muscle is contracting but there is no movement occurring

glycolysis

• takes place in sarcoplasm

• breakdown of glucose into pyruvic acid via phosphofructokinase

• produces 2 molecules of ATP

• pyruvic acid turns into acetyl coenzyme A

kreb cycle 

• takes place in mitochondria 

• acetyl coenzyme A combine with oxaloacetate forming citric acid

• citric acid undergoes oxidative carboxylation 

• 2 ATP is formed with H+ ions which are carried into the electron transport chain

electron transport chain

• takes place in cristae of mitochondria

• 32-34 ATP produced

anaerobic glycolytic system

• duration of system relies on performer

• resynthesises ATP

• last between 8-10seconds - 3 minutes

• limited energy production

ATP - PC system 

• only provides energy for 8-10 seconds 

• can only replenish itself during low intensity exercise when oxygen is present

• ATPase breaks down ATP bond

• create kinase detects high levels of ADP

• creatine kinase breaks phosphocreatine bond releasing energy

advantages of ATP - PC system

• provides an immediate source of energy

• useful in events such as 100m or powerlifting

disadvantages of ATP - PC system

• limited amount of PC stores in body

• can take up to 2 minutes to completely replenish PC stores

phases of plyometric training (stretch shortening cycle)

• aims to develop power, activates and develops fast twitch fibres

• muscles generate more force if they have been previously stretched, stretch of muscle before contraction is known as the stretch shortening cycle

• eccentric phase - pre loading phase (muscles lengthen under tension)

• amortisation phase - time between eccentric and concentric phase (short as possible)

• concentric phase - muscle contraction (increases force of contraction)

altitude training

• over 2500m above sea level

• partial pressure of oxygen is lower than at sea level

• body produces EPO

• increased number of RBC

• increased number of haemoglobin

• increased oxygen carrying capacity

• increased lactic acid buffering

• benefits last for up to 14 days

negatives of altitude training

• altitude sickness

• loss of fitness due to acclimatisation

• benefits lost shortly after arriving back at sea level

• psychological problems linked to travel/being away from home

HIIT training

• short duration

• anaerobic

• short recovery

• increased anaerobic capacity

• increased fat burning

• reduced body fat

SAQ training

• zig zag runs

• foot ladders

• increased muscular power

• improved spatial awareness

• improved motor skills 

• improved reaction time

factors affecting vo2 max

• increased haemoglobin, increased stroke volume, greater heart rate range

• sedentary lifestyle, smoking, poor diet, poor fitness

• aerobic interval training, continuous

• genetics

• age - vo2 max decreases as age increases, body becomes less efficient

• body composition

lactate threshold

the point at which lactic acid starts to accumulate in the blood

OBLA

accumulation of lactate in the blood

relationship between vo2 max and lactate threshold 

the higher the vo2 max, the more delay in lactic acid build up so lactate threshold increases

factors affecting rate of OBLA

• intensity of exercise

• fitness of performer

• vo2 max of performer

• muscle fibre type (slow twitch fibres delay OBLA)

lactate sampling and RER

• taking blood samples

• ensures training is at correct intensity

• enables coach to monitor improvements

• her provided ratio of co2 to o2

• tests if performer is working aerobically or not

• RER more than 1 means anaerobic respiration

EPOC - slow component 

• when using oxygen, lactic acid is converted into pyruvic acid 

• oxidised into co2 and water 

• some lactic acid is transported in blood to liver and converted to glycogen

EPOC - fast component

• faster and deeper breathing after exercise

• recovery in 2-3 minutes

• takes 3-4 oxygen

• resythesises ATP and PC stores

• resynthesises myoglobin stores