Section A

A1: Types of bones, vertebral column and directional references

Long bones: Source of red blood cell production Enables large movements Act as levers to generate force Example: femur, tibia, fibula Short bones: Increase stability, reduce unwanted movements Help body remain upright and blanched Absorb shock Example: tarsals, carpals Flat bone: Protect vital organs Enable muscle attachment for movement Produce blood cells in adults Example: sternum, ribs, pelvis Sesamoid bone: Eases joint movement Resists friction so that movement is not slowed down Example: patella Irregular bone: Provides protection (spinal cord) Allows for movement Example: lumbar vertebrae, thoracic vertebrae, cervical vertebrae

Functions: Cervical: 7 cervical vertebrae. The first two are called axis and atlas and form a pivot joint that allows the head to move, they also attach muscles of the neck. Thoracic: 12 thoracic vertebrae. They are bigger than the cervical and attach the ribs which protect the heart and lungs. They attach the muscles of the back. Lumbar: 5 lumbar vertebrae. They are the biggest of the moveable vertebrae and attach the muscles of the lower back. Sacral: 5 sacral vertebrae that are fused together. It helps form the wall of the pelvis. It also supports the weight of the vertebrae. Coccygeal: 4 coccygeal vertebrae that are fused together. They have no function.

Postural defects:

Natural: Good posture with correct position of the three natural curves When viewing from front (anterior), it should be vertical Occasionally, spine may suffer from disorders which may cause natural curves to change Kyphosis: Excessive outward curve of the thoracic region resulting in a ‘hatchback’ Often caused by poor posture but can be caused by deformities of the vertebrae Scoliosis: Abnormal curve either to the left or to the right (lateral curvature) Most likely to occur in the thoracic region Often found in children but can be found in adults The condition is not thought to be linked to bad posture and the exact reasons for it are unknown although it seems to be inheritable

Directional References: Anterior To the front or in front Posterior To the rear or behind Medial Towards the midline Lateral Away from midline Proximal Near to the root/origin Distal Away from the origin Superior Above Inferior Below

A2: function of skeletal system, process of bone growth

Functions of skeletal system: Mineral store: bones store essential materials such as calcium and phosphorus which are essential for growth. These are released into the blood when required Leverage: bones provide a lever system against which muscle can pull to create movement Weight bearing: bones are strong in order to support the weight of the tissues and muscles. They provide strength to prevent injury Reducing joint friction: synovial joints are an essential part of the skeleton as they prevent bones from rubbing against one another Support: the skeleton allows for the body to maintain shape. It provides a framework for the soft tissue of the body Protection: protects vital organs and tissues for example cranium which protects your brain and the vertebral column which protects your spinal cord Muscle attachment: provides a surface for the muscles to attach to, meaning that the body can move Blood cell production: bone marrow stored in bones produces red and white blood cells. Red blood cells carry oxygen for energy and white blood cells fight infections

Process of bone growth: Ossification is the process in which bones are formed Throughout this process parts of the bone are reabsorbed so that unnecessary calcium is removed via cells called osteoclasts, while new layers of bone tissue are created The cells that bring the calcium to your bones are called osteoblasts and are responsible for creating bone matter Osteoblast activity increases when you exercise so your bones will become stronger the more exercise you do The ends of each long bone contain growing areas called epiphyseal plates and allow long bone to extend Once a bone is fully formed, the head/end of each long bone fuses with the diaphysis shaft to create the epiphyseal line

A3: synovial joints, types of synovial joints, joints used in sport

Synovial joints:

The joint capsule is an outer sleeve that protects and holds the knee together The synovial membrane lines the capsule and secretes synovial fluid (liquid) which lubricates the joint allowing it to move freely The bursa acts as a cushion between the bones and is filled with smooth covering of cartilage at the ends of the bones which stops them rubbing together and provide some shock absorption Ligaments hold the bone together and keep them in place

Types of synovial joints:

Gliding: allows bones to slide over one another. Examples include: the bones in the wrist and foot Pivot: allows twisting and rotation. Examples include: the neck Hinge: only allows flexion and extension. Examples include: elbow and knee Ball and socket: gives the greatest range of movement, flexion, extension, adduction, abduction and rotation. Examples include: the hip and shoulder Condyloid: allows movements in two planes - backwards and forwards and side to side. Examples include: the wrist Saddle: very similar to the condyloid joint but the surfaces are concave and convex. It’s positioned between the carpals and metacarpals

Joint Type Bones Moevemnt Elbow Hinge Humerus, ulna, radius Flexion, extension Knee Hinge Tibia, femur flexion , extension Hip Ball and socket Femur, pelvis flexion , extension, adduction, abduction, rotation, circumduction Shoulder Ball and socket Scapula, humerus flexion , extension, adduction, abduction, rotation, circumduction

Joints used in sport:

Pivot in the neck: Header in football Hinge joint at the elbow: Bicep curls/volleyball surf Condyloid joint at the wrist: Handstand in gymnastics Ball and socket in the shoulder: Bowling in cricket Ball and socket in the hip: Kicking a ball in football Saddle joint at the thumb: Throwing darts Gliding joint in the foot: Ice skating

A4, A5 and A6: responses + adaptations of the skeletal system and additional factors

Responses of the skeletal system:

Responses Why? Stimulates uptake of minerals (example, calcium) in the bones. Stimulates production of collagen due to increased stress on the bone. Increasing uptake of minerals which makes the bone denser which means it can cope with weight bearing activities. Collagen increases elasticity of joints and makes your bones stronger.

What happens at a joint during exercise? Increased production of synovial fluid Increased viscosity of synovial fluid Increased pliability of ligaments Adaptations of the skeletal system:

Changes Advantages Increased bone density and strength due to mineral uptake Increased ligament strength Increased thickness of cartilage Bones are less likely to break or fracture Strong ligaments mean that there is reduced risk of dislocation of a joint Thicker cartilage helps to protect the ends of bones from wear to tear

Additional Factors:

Arthritis: condition where inflammation within the synovial joint, causing pain and stiffness. Regular exercise can help prevent arthritis as joints produce more synovial fluid which provides lubrication of the joint Osteoarthritis: this type of arthritis causes the cartilage to thin, which results in the bones rubbing together. Mainly develops in people over the age of 40, although can appear at any age Rheumatoid arthritis: this type of arthritis inflammation of the joints due to a build up of synovial fluid. Although, the inflammation can reduce the joint capsule and is left stretched which makes the joint makes activity difficult Age: the skeletal system is a living tissue that constantly repairs itself so it can provide support and protection. Generally exercise will benefit you. Resistance training should not be done by children as it can damage the epiphyseal plates that are found at the ends of each long bone. Bones will become more brittle and susceptible to breaks as you get older. Resistance training is good for the elderly as it increases the bone density

Section B

B1: types of muscles

Skeletal muscle: Striped/striated in appearance Contracts under conscious control# Therefore a voluntary muscle Connect to bones via tendons Can become fatigued Cardiac muscle: Found in the walls of the heart Does not contract under conscious control Therefore involuntary Works continuously Do not fatigue Smooth muscle: Contracts without conscious control Therefore involuntary muscle Found within the walls of the digestive system Found within blood vessels Help to regulate digestion Help to regulate blood pressure

B2: Major muscles

Functions: Deltoid: abduction at shoulder Bicep: flexion at the elbow Tricep: extension at the elbow Pectoral: horizontal adduction at shoulder Wrist flexors: flexes the hand at the wrist Wrist extensors: extends/straightens the hand at the wrist Wrist supinators: supinates the forearm Wrist pronators: pronates the forearm Abdominals: flexion and rotation of the lumbar vertebrae Obliques: lateral flexion of the wrist Quadriceps: allow extension at the knee Hamstrings allow flexion at the knee Hip flexors: allow flexion at the hip Gluteals: allow extension at the hip Gastrocnemius: plantar flexion Soleus: plantar flexion Tibialis anterior: dorsi flexion Erector spinae: extension of the spine Trapezius: elevates and depresses the scapula Latissimus dorsi: adduction at the shoulder

B3: antagonistic muscle pairs

When a muscle contracts, it pulls on the bone it is attached to. Muscles can only pull. Therefore, if a certain muscle pulls a bone to create movement in one direction, another muscle (pair) has to be able to pull to bring the joint back to its original position.

Origin: stationary end Insertion: end that moves

The muscle that shortens when contracting is the agonist. The muscle that relaxes in opposition to the movement is the antagonist; it is this muscle that is then responsible for the opposing movement.

Antagonistic pairs:

Elbow: bicep + tricep Knee: quadriceps + hamstrings Ankle: tibialis anterior + gastrocnemius Hip: gluteals + hip flexors Shoulder: deltoid + latissimus dorsi

Synergist: muscles that enable the agonist to operate effectively. This muscle works with the agonist to control and direct movement

Fixator: muscles that stop any unwanted movements throughout the body by stabilising a joint. Fixator muscles stabilise the origin.

B4: contractions2 types of muscle contractions: isometric and isotonic.

Isometric contractions:

Muscles are contracting but length does not change. The angle at the joint remains the same. These contractions lead to rapid fatigue and can cause sharp increase in blood pressure Examples: The plank Wall sit A scrum (stationary) Press up hold

Isotonic contractions

2 types of isotonic contractions: concentric and eccentric contractions

Isotonic concentric contractions: This is known as the upwards phase of a movement. The muscle will get shorter/fatter during the contraction. They are often referred to as the positive phase. Examples: Upwards phase of a bicep curl Upwards phase of a press up Upwards phase of a squat

Isotonic eccentric contractions: This is known as the downwards phase of a movement. The muscles will get longer/thinner during the contraction. Often referred to as the negative phase. Eccentric contractions tear more fibres. Examples: Downwards phase of a bicep curl Downwards phase of a press up Downwards phase of a squat Antagonist + agonist

Examples:

Bicep curl: Elbow: concentric upward phase (flexion). Agonist is the bicep Elbow: eccentric downwards phase (extension). Agonist is the bicep.

Press up: Elbow: concentric (extension). Agonist is the tricep Elbow: eccentric (flexion). Agonist is the bicep.

Squat Upwards phase: Hip: extension (gluteals) Knee: extension (quadriceps) Ankle: plantar flexion (gastrocnemius) Squat downwards phase: Hip: flexion (gluteals) Flexion: (quadriceps) Ankle: dorsi flexion (gastrocnemius)

B5: muscle fibres The mix of fibres varies from individual, muscle group to muscle group. To a large extent your fibre mix is inherited. Yet training can influence the efficiency of your fibres

Type 1 fibres: Slow twitch Contract slowly Contract with less force The most resistant to fatigue Suited for longer duration, aerobic activities Have a rich blood supply Contain many mitochondria (site for aerobic respiration) They have a high capacity for aerobic respiration

Type 2a fibres: They are known as fast twitch/ fast oxidative fibres They are able to produce a great force when contracting Resistant to fatigue They fatigue faster than type 1 fibres Use oxygen They are suited to speed, power + strength activities

Type 2b fibres: Known as fast twitch fibres/ fast glycolytic fibres Produce greatest force when contracting Least resistant to fatigue (fatigue fastests) Suited to anaerobic activities Depend upon anaerobic respiration Recruited for high intensity/ short duration activities

None or all law:

In order for a muscle to contract, it must receive a nerve impulse. This impulse must be sufficient to activate the motor neurone. Once activated, all the muscle fibres within the motor unit contract. If the impulse is not strong enough to activate the motor unit, then none of the muscles contract. This is the all or none law of muscle contractions.

B6: Responses of the muscular system

The six responses are: Increased blood supply Increased muscle temperature Increased muscle pliability Lactate Micro tears Delayed onset of muscle soreness

Increased blood supply

When we exercise, there is a greater demand for oxygen/glucose. As it is in the muscles, it’s met with a greater blood supply. Blood vessels will expand to allow more blood to enter the muscle. This is called vasodilation. It ensures the working muscles are both: Supplied with oxygen Waste products are removed (CO2, lactate)

Increased muscle temperature

Muscles require energy from fuels like carbohydrates and fats. The more you exercise, the more energy is needed. As a result, the more heat your muscles will warm up.

Increased muscle pliability

Through increasing temperature we can increase pliability. This also enables us to become more flexible. Pliable muscles are less likely to suffer strains. Pliable muscles will increase ranges of movement at joints. They also reduce the risk of injuries.

Lactate

During high intensity, lactate will build up in the muscle. This is a waste (by) product during anaerobic exercise. This build up results in rapid fatigue. It also impedes muscle contractions.

Micro tears

During resistance training (weights), you place stress on your muscles. This stress results in micro tears swelling in the muscle fibre. Micro tears cause swelling in the muscle which puts pressure on the nerve ending, resulting in pain. Training improvements are made when we rest; allowing repair. After micro tears are repaired, the muscle becomes a little stronger. Protein will support the repair. Most tearing is caused by eccentric contractions.

Delayed onset of muscle soreness (DOMs)

DOMs is the pain felt in the muscle 24-48 hours after exercise. DOMs are caused by micro tears. They occur if you are not accustomed to high intensity exercise. Associated with eccentric contractions.

B7: adaptations

The seven adaptations are: Muscular hypertrophy Increased tendon strength Increased number and size of mitochondria Increase in myoglobin stores Increased storage of glycogen Increased storage of fats Increase tolerance of lactate

Muscular hypertrophy

When muscles overload, they will increase in size and strength. They will increase in size because muscle fibres get larger by increasing in protein in the muscle cell. By increase in size, a muscle can contract with greater force.

Increased tendon strength

Tendons are tough bands of fibrous connective tissue designed to withstand tension. Tendons connect muscle to bone. Like your muscles, tendons adapt to regular exercise. When we exercise, our tendons are able to increase in strength and flexibility. This allows muscles to contract and stretch further, while preventing strains. Tendons bind to oxygen and iron and therefore store them.

Increased number and size of mitochondria

When muscles are overloaded, they get bigger (hypertrophy). Within the muscle fibres are tiny structures (mitochondria). Mitochondria is the site for energy production and it is where aerobic respiration takes place. By increasing the size of a muscle and its fibres, there is room for more and larger mitochondria; improving aerobic performance.

Increased myoglobin stores

Myoglobin is a type of haemoglobin. It carries oxygen and is found in the muscle. It carries oxygen through the muscle to the mitochondria. Exercise can increase the amount of myoglobin stored in the muscles. As myoglobin carries oxygen through the muscle to the mitochondria, we can say that the more myoglobin, the more energy (via aerobic respiration).

Increased storage of glycogen

Your body needs a constant and steady supply of glycogen in order to produce energy. Carbohydrates are eaten, broken down into glucose and stored as glycogen. As your body adapts to exercise, you are able to store more glycogen. This allows you to train nat higher intensities for longer durations.

Increased storage of fats

When our glycogen stores become depleted, usually after 90+ mins of continuous aerobic exercise, we begin to burn fats. This process is called beta oxidation. The performer may ‘hit the wall’ when burning fats. This is because a molecule of fat requires 15% more oxygen to break it down; thus, less oxygen attends the working muscles. A trained athlete can use fats as a fuel more effectively.

Increased tolerance of lactate

Anaerobic training stimulates the muscles to become better able to tolerate lactic acid. With endurance training, the capillary network extends to allow greater volumes of blood (oxygen + nutrients) to supply the muscle. The body becomes more efficient at using oxygen and therefore prolonging the build up of lactic acid.

B8: additional factors

2 additional factors: age and cramp

Age

As you get older, your muscle mass decreases. The reduction of muscle mass begins around 50. It is referred to as sarcopenia. Muscle becomes smaller and power and strength decreases.

Cramp

Cramp is an involuntary muscle contraction. You have no control over a tightening muscle fibre - this can be painful. Cramps are often promoted by exercise. The lower legs are most susceptible. They can last for up to 10 minutes. It can be caused by: Dehydration Inadequate blood supply to the muscles (reduces CO2) More frequent in warm environments Already tight muscle groups (lack of flexibility) Loss of electrolytes (salts etc)

Section C

C1: structure of the respiratory system

Three other areas to know: Epiglottis Internal intercostal muscles External intercostal muscles Structure: Nasal cavity: we breathe in air and the hairs filter out dust Pharynx: connects nasal cavity with larynx and it is the pathway for food and air Larynx: known as the voicebox, contains vocal cords and it connects the pharynx with the trachea Trachea: known as the windpipe. It is 12cm long and it is rigid rings of cartilage to prevent collapsing epiglottis : small flap of cartilage, closes over the top of the trachea when you swallow food and prevents food from travelling to your lungs Lungs: the organ that allows oxygen to be drawn into the body. The paired right and left lungs occupy most of the thoracic cavity and extend down to the diaphragm Bronchi: the bronchi branch off the trachea and carry air to the lungs Bronchioles: small airways that extend from the bronchi, they connect the bronchi to small clusters of thin walled air sacs called alveoli. Alveoli: site of gaseous exchange. Oxygen is diffused through the alveoli into the blood capillary. Carbon dioxide is diffused from the blood capillary into the alveoli. Characteristics of the alveoli: Good blood supply Large surface area One cell thick Short diffusion pathway Semi-permeable membrane Small in size, large in amount Diaphragm: a flat muscle, located beneath the lungs. It supports the mechanics of breathing. Drawing in air (oxygen). Breathing out air (carbon dioxide) INSPIRE: contracts and pulls flat EXPIRE: relaxes and rises into a dome shape

Internal intercostal muscles; Lie inside the ribcage. Draw ribs DOWNWARDS and INWARDS. Decreasing the volume of the chest cavity, forcing air out of the lungs when breathing out.

External intercostal muscles: muscles lie outside the ribcage. Pull the ribs UPWARDS and OUTWARDS. Increasing the volume of the chest cavity and drawing air into the lungs when breathing in.

C2: mechanics of breathing

Breathing or pulmonary ventilation is a process by which air is transported into and out of the lungs. It has 2 phases and requires the thoracic cage to change shape, altering the space/pressure inside.

Concentration gradient

Gases (air) move down a concentration gradient Gases always move from an area of high pressure to low pressure.

Inspiration

The diaphragm contracts and pulls flat, the external intercostal muscles move the ribs up and out. This creates a bigger space and a lower pressure. Air then moves from a high concentration (atmosphere) to a low concentration (lungs)

Expiration

The diaphragm rises into a dome shape and the internal intercostal muscles move the ribs down and in. This creates a smaller space and a higher pressure. Air then moves from a high concentration (atmosphere) to a low concentration (lungs)

Gaseous exchange

When breathing rate and depth increases, the air and oxygen goes through a process called gaseous exchange. Gaseous exchange involves type 1 of gas exchange being exchanged for another. In the lungs, gaseous exchange occurs by diffusion between the alveoli and the blood in the capillaries surrounding their walls.

Movement of CO2

Blood enters the capillaries from the pulmonary artery (major vessel that pumps deoxygenated blood from the heart to the lungs), here, it has lower oxygen concentration and a higher CO2 concentration in the air than in the alveoli. CO2 moves from where it is highly concentrated (blood) to where it is less concentrated (alveoli) then we breathe it out.

Movement of oxygen

Oxygen diffuses into the blood via the surface of the alveoli, through the thin walls of the capillaries and into the bloodstream now oxygenated: it latches onto the haemoglobin. Oxygen moves from where it is highly concentrated (alveoli) to where it is less concentrated (blood).

C3+C4: Lung volumes

The lung volumes are: Tidal volume: volume of air breathed in and out per breath Inspiratory reserve volume: additional volume of air that can be forcibly inhaled after inspiration of normal tidal volume Expiratory reserve volume: additional volume of air that can be forcibly exhaled after expiration of normal tidal volume Residual volume: volume of air that remains the lungs after a maximal expiration Vital capacity (IRV + ERV): maximal amount of air that can be breathed out after breathing in as much as possible Total lung volume: total lung capacity after you inhaled as deeply as you can

In men (litres/min)

In women (litres/min) How does it change during exercise Inspiratory reserve volume 3.0 1.9 Decreases Expiratory reserve volume 1.5 0.7 Decreases Residual volume 1.2 1.1 Stays the same Vital capacity 4.8 3.3

Total lung volume

6.0 4.4

Tidal volume 5.3 5.0 Increases

Neural control of breathing

Inspiration at rest is an active process (diaphragm contracts) white expiration at rest is a passive process (diaphragm relaxes). This process is not possible without neurons in the brain stem. These neurons exist in two areas of our medulla oblongata. Neural control of breathing consist of two areas: Dorsal respiratory group (DRG) Ventral respiratory group (VRG) They are responsible for rhythmic generation; allowing rhythm and continuous breathing

Chemical control of breathing

Another factor that controls breathing is the changing levels of oxygen and carbon dioxide (acidity) in the blood. The sensors that respond to these chemical fluctuations are called chemoreceptors. They are found in the aortic arch and the carotid artery. These chemoreceptors detect changes in blood and carbon dioxide levels as well as changes in the blood acidity. Low concentration of oxygen (O2) High concentration of carbon dioxide (CO2) They send signals to the medulla oblongata to make changes (increase) breathing rate; causing the diaphragm to work harder.

C5+C6: responses and adaptations

The responses of the respiratory system are: Increased breathing rate Increases tidal volume

Increased breathing rate

Exercise increases the rate and depth of breathing. Muscles need more oxygen, stimulating an increase in rate, carbon dioxide production stimulates an increase in rate. After several minutes of aerobic exercise, the breathing rate continues to rise. Breathing rate has a direct correlation with exercise intensity. If intensity continues to increase, so does the breathing rate. When exercise intensity remains constant, breathing rate levels off. Anticipatory rise: Breathing rate will also rise prior to exercise and is known as the anticipatory rise. It's the mind’s response to the body’s need to prepare for exercise. This is due to the release of adrenaline to the heart. It triggers an increase in breathing rate and hear rate.

Increased tidal volume

The volume is the ‘volume of air breathed in and out per breath’. During exercise, it increases. This enables more air to pass into the lungs. As the demand for oxygen increases during exercise, tidal volume becomes deeper and more frequent to compensate

Minute ventilation

Minute ventilation = breathing rate x tidal volume Breathing rate (12 breaths at rest/30 during exercise) Tidal volume (increases during exercise) Minute ventilation as a result can be up to 15 times greater than at resting levels; due to an increase in tidal volume and breathing rate.

C7: additional factors

The two additional factors: Asthma Effects of altitude

Asthma

A common condition where the airways of the respiratory system can become restricted, making it harder for air to enter the body. The result: coughing, wheezing and shortness of breath. During normal breathing, bands of muscle that surround the airway are relaxed and air moves freely. Asthma causes the bands of muscles surrounding the airway to tighten and contract. Asthma will have a negative effect on sport performance as it restricts oxygen delivery to working muscles. However, regular exercise will strengthen your respiratory system and help prevent asthma. An inhaler helps to relax the bands of muscles surrounding the airways, supporting the movement of air/ gas through the system.

Altitude

Many athletes choose to train at altitude (300m above sea level) due to lower air pressure and the oxygen particles are further apart This creates two effects: Short term effects Long term effects

Short term effects

Less oxygen in the atmosphere; oxygen supply to alveoli is less Reduces diffusion gradient of oxygen Less oxygen combining with haemoglobin; so less O2 in the body Reduction in air pressure causes an increase in breathing rate Performance at altitude decreases; fatigue sets in sooners

Long term effects

Effects seen when returning to sea level Increased EPO (erythropoietin; stimulates red blood cell production) Increased red blood cells; greater oxygen carrying capacity Can work aerobically at higher intensities without fatigue Improves recovery time after exercise

Negative effects of altitude Due to hypoxia (body temperature being deprived of oxygen) Altitude sickness, headaches and dizziness Financially unsustainable Time away from family

D1: structure of the cardiovascular system

The heart is a muscle and acts as a pump. It is located underneath the sternum. The outside of the heart is surrounded by a twin layered sac, known as the pericardial fluid. The pericardial fluid is important to prevent friction.

3 layers of the heart:

Epicardium (outer layer) Myocardium (string middle layer, forming most of the heart walls) Endocardium (inner layer)

The septum

This is a solid wall of muscle. It separates the right side from the left side and the ventricles from the atrium (bottom to top). As a result, it keeps the oxygenated and deoxygenated blood separate

The right atrium: this chamber supplies deoxygenated blood at lower pressure and moves blood down to the right ventricle The right ventricle: this chambers supplies deoxygenated blood at lower pressure and moves blood to the lungs (pulmonary artery) The left atrium: this chamber supplies oxygenated blood at higher pressure and moved blood down to the left ventricle The left ventricle: this chamber supplies oxygenated blood at a high pressure and moves blood to the body (aorta)

1- inferior vena cava 2- superior vena cava 3- right atrium 4- tricuspid valve 5- right ventricle 6- pulmonary valve 7- pulmonary artery 8- pulmonary artery 9- pulmonary vein 10- left atrium 11- bicuspid valve 12- left ventricle 13- aortic valve 14/15- aorta

The atriums: Upper chambers of the heart Receive blood returning to your heart Returning from the body or lungs Right receives deoxygenated blood from the vena cava Left receives oxygenated blood from left and right pulmonary veins

The ventricles: Pumping chambers of the heart Thicker walls than atria They pump blood at high pressures Pump blood against force of gravity The left ventricle is most muscular Right ventricle pumps to lungs (pulmonary circulation) Left ventricle pumps to body (systemic circulation)

Tricuspid valve: 1 of the 4 valves Situated between right atrium and right ventricle Prevents blood flowing backwards

Bicuspid valve: 1 of 4 valves Situated between left atrium and left ventricle Allows blood to flow in the correct direction

Aortic semi-lunar valve: 1 of the 4 valves Situated between left ventricle and aorta Prevents backflow of blood

Pulmonary semi-lunar valve: 1 of the 4 valves Situated between right ventricle and pulmonary artery

Blood vessels:

Arteries always transport blood away from the heart Veins transport blood towards the heart Capillaries are the smallest of the blood vessels and are found around the body’s tissue. This is where gaseous exchange takes place

Arteries and veins consists of three layers: Tunica externa - outermost layer, made of connective tissue Tunica media - middle layer, made of elastic fibres, bigger in arteries than veins Tunica intima - innermost layer, made of a single layer of endothelium

Capillaries are made of a single layer of endothelium (tunica intima).

Arteries Always carry blood away from the heart They have thick muscular walls Thick muscular walls help to carry blood at high pressures Do not have valves They have elasticity Have a smaller diameter Have contractility (measure of cardiac pump performance)

Veins Veins facilitate venous return Return blood towards the heart They have thin walls They have a large diameter They carry blood at lower pressures They have valves to prevent backflow of blood

Capillaries They connect arterioles and venules They are the smallest of all blood vessels and only one cell thick Capillaries are where gaseous exchange takes place Have a higher blood pressure than the veins but lower than the arteries

Arterioles are smaller versions of arteries. Venules are smaller versions of veins. Arterioles are most responsible for controlling blood distribution. Arterioles enable blood to pass to capillaries and they are able to constrict or dilate to control blood flow to certain areas.

D2: function of the cardiovascular system

Red blood cells

The main function is to carry oxygen to all living tissue (muscles). A red blood cell contains a protein called haemoglobin (red pigment). When 4 oxygens and 1 haemoglobin combine, it forms oxyhaemoglobin. Red blood cells are biconcave in shape which gives them a large surface area.

Plasma

Plasma has a responsibility for transportation. It helps to transport: Nutrients CO2 Red blood cells White blood cells Hormones Proteins It also help to maintain blood pressure and homeostasis (37 degrees celsius) Plasma balances electrolytes Plasma maintains blood volume It is made up of 90% water as well as electrolytes such as potassium and sodium

White blood cells

Fight against infections. Produce antibody proteins to attach the organism to and destroy it.

Platelets

Prevent blood loss When you get a cut, platelets will gather sticking to each other to form a plug at the site of injury.

5 main functions of the CV system: Delivering oxygen nutrients Removing waste products (CO2 and lactate) Thermoregulation Fighting infections Clotting blood

Delivering oxygen + nutrients

The key function of the CV system is to supply oxygen and nutrients to the tissues - via the bloodstream. During exercise, we need more oxygen and nutrients. However, when CV system can no longer meet demands, fatigue will occur

Removal of waste products

As well as providing O2 and nutrients, the circulatory system deals with waste. Waste products (lactic acid) is carried from the tissue to your kidneys and liver. Waste products (CO2) is carried from the tissue to the lungs. If these products are not removed, fatigue will occur

Thermoregulation

The distribution and redistribution of heat. Think ‘thermo’ like thermometer, heat/temperature Thermoregulation occurs via two main processes: Vasoconstriction Vasodialation

VASODILATION: with consideration given to blood vessels around the skin, vasodilation increases the diameter of the vessels. There is a decrease in resistance to blood flow. VASOCONSTRICTION: with consideration given to the blood vessels around the skin, vasoconstriction decreases the diameter of the vessels. There is an increase in resistance to blood flow. Less blood flows towards the skin and heat is trapped. Body temperature increases.

Fighting infection

White blood cells are constantly produced in the bone marrow. They are stored in and transported around the body in the blood. They can identify, consume and destroy pathogens. White blood cells also help to produce antibodies that will also destroy pathogens. Antitoxins are produced to neutralise the toxins released by pathogens

Clotting blood

Clotting is a complex process. When a blood vessel wall gets damaged it gets covered in fibrin. Fibrin is the fibre used to bind platelets together to form a clot. Platelets plug the site of the cut to stop any more blood from escaping

D3: nervous control of the cardiac cycle

Key words: Sinoatrial node (SAN) - atrial systole Atrioventricular node (AVN) - bundle of HIS (septum) Purkinje fibres Ventricular systole

Nervous control of cardiac cycle

The electrical system of your heart is the power source that makes the process of filling and pumping possible.

Sinoatrial node (SAN)

Known as the pacemaker. It is located in the wall of the right atrium. The SAN sends an impulse from the right atrium, through the walls of the atria. This causes the atria to contract (atrial systole). This forces blood down the atria into the ventricles.

Atrioventricular node (AVN)

The AVN helps. It is located between the atria and the ventricles. It conducts the impulse between the atria and the ventricles. The AVN delays the impulse to allow the atria to contract before the ventricles. This enables the ventricles to receive all the blood from the atrium

Bundle of HIS

They are located in the septum that separates the ventricles. It branches out into 2 branches.

Purkinje fibres

Located in the walls of the ventricles. Carry the impulse to ventricle walls, causing them to contact (ventricular systole). The concentration causes blood within the ventricles to be pushed up and out of the heart. Either to the lungs or working muscles.

Effects of sympathetic and parasympathetic nervous system

The autonomic nervous system is the part of the nervous system that regulates body function such as breathing and your heart beating and it is involuntary

The system divides into: sympathetic nervous system Parasympathetic nervous system

Sympathetic: during exercise, it causes your heart rate to increase (as well as breathing rate) Parasympathetic: returns your heart rate to resting levels

D4: responses of the cardiovascular system

The five responses: Increased heart rate Increased cardiac output Increased blood pressure Redirection of blood flow

Anticipatory rise: Increase in heart rate prior to exercise Caused by sympathetic nervous system Chemical hormone adrenaline is released into the bloodstream Adrenaline is released from the adrenal glands

Increased in heart rate

Heart rate increases to ensure more oxygen reaches the muscles. Nerves in the brain detect cardiovascular activity. Once detected, heart rate and pumping strength will increase. Regional blood flow is altered in promotion to intensity.

Increase in cardiac output

Product of heart rate x stroke volume During exercise, cardiac output will increase. Stroke volume does not increase much beyond light intensity Thus, the increase in CO2 comes from the increase in heart rate Your CO2 will decrease with age as you max heart rate decreases

Increase in blood pressure

This pressure results from 2 forces: Systolic pressure: pressure exerted when your heart contracts Diastolic pressure: pressure exerted when your heart relaxes During exercise your systolic blood pressure increases. Your heart's now working harder to supply more blood, rich in oxygen to your working muscles. Diastolic pressure stays the same or slightly decreases

Redirection of blood flow

Redirection of blood flow happens due to vasoconstriction and vasodilation. To ensure that blood and oxygen reach the essential areas during exercise, redirection of blood flow occurs. During exercise, vasodilation happens around the skeletal muscle and skin to ensure muscles have a large amount of oxygen and so we can lose heat.

D5: adaptations of the cardiovascular system

The 7 adaptations are: Cardiac hypertrophy Increasing in resting and exercising stroke volume Decrease in resting heart pressure Reduction in resting blood pressure Decrease heart rate recovery time Capillarisation of skeletal muscle and alveoli Increase blood volume

Cardiac hypertrophy

Occurs most predominantly within the walls of the left ventricle. An enlargement/thickening of the walls of the heart. Similar to how a skeletal muscle can undergo hypertrophy so can cardiac muscle. This hypertrophy enables greater strength of contractions, increasing the volume of blood being pumped out of the heart per contraction (stroke volume) This is a long term adaptation that occurs due to continuous aerobic training.

Increase in resting/exercising stroke volume

During rest and exercise, after prolonged endurance training, stroke volume will increase. The impact of this, increases the efficiency of oxygen and nutrient delivery Cardiac output = heart rate x stroke volume Due to an increase in stroke volume, the heart can therefore pump more blood per minute (cardiac output)

Decrease in resting heart rate

The result of cardiac hypertrophy and an increase in stroke volume through long term exercise is that your resting heart rate falls

Reduction in resting blood pressure

Exercise causes your blood pressure to rise for a short time. However, when you stop, your blood pressure should return to normal. The quicker it returns to normal, indicates a higher level of fitness. Regular exercise does contribute to lower blood pressure. If you already have high blood pressure (hypertension) it is advised that steady aerobic exercise will reduce it.

Decreased heart rate recovery time

Heart rate recovery is a measure of how much your heart falls during the first minute after you exercise. The fitter you are, your heart rate will return to resting levels due efficiency of the cardiovascular system.

Increased blood volume

Your blood volume represents the amount of blood circulating in your body. Varies from person to person, but does increase due to training. An increase in blood volume will: Enable the delivery of more oxygen to working muscles Regulate body temperature Delay the onset of fatigue Enable activity at higher intensity for longer durations

Capillarisation of skeletal muscle and alveoli

Long term, aerobic exercise will lead to an increase in the number and size of capillaries at the skeletal muscle and alveoli. Blood flow to these areas increases due to increase in number and size and as a result, the movement of gaseous exchange and transportation of nutrients such as glucose

D6: additional factors

The 3 additional factors are: Sudden arrhythmic death syndrome High and low blood pressure hyperthermia/hypothermia

Sudden arrhythmic death syndrome

SADS is a genetic heart condition. It causes death due to a cardiac arrest. This can happen in healthy and young people with no heart disease. The cardiac arrest happens due to a ‘ventricular arrhythmia’. This is a disturbance in the heart's rhythm. There have been a number of high-profile cases where elite sportspeople have suffered from SADS such as the footballer Fabrice Muamba.

High and Low blood pressure

High blood pressure (hypertension) When you begin exercising, your blood pressure will increase, your heart is having to contract with more force; increasing the ‘force the blood exerts against vessel walls’. If you already suffer from high blood pressure, a sudden increase in the demand of the heart can be dangerous. Low blood pressure (hypotension) This means that your blood is moving slowly around the body. It restricts blood reaching vital organs and muscles so affects aerobic performance. Symptoms include: dizziness, tiredness, fainting

Hyperthermia

A prolonged increase in body temperature. Occurs when the body produces and absorbs too much heat. If you are exercising in already hot environments it becomes more difficult for the body to dissipate heat. Breathable clothing is essential.

Hypothermia

When your body becomes too cold. Your core temperature drops below 35 degrees celsius. Symptoms include: shivering, confusions, increased risk of heart stopping. Adequate clothing is essential,