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A-Level PE > Anatomy and Physiology 🫀 > Flashcards

Anatomy and Physiology 🫀 Flashcards

1
Q

Identify the muscles at the shoulder

A

• Trapezius
• Posterior deltoids
• Anterior deltoids
• Pectoralis
• Latissimus dorsi

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2
Q

Identify the bones at the shoulder

A

• Humerus
• Clavicle
• Scapula

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3
Q

Identify the movement types at the shoulder

A

• Horizontal flexion
• Horizontal extension
• Abduction
• Adduction
• Rotation
• Circumduction

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4
Q

Identify the muscles at the hip

A

• Gluteus
• Hamstring group
• Psoas major

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5
Q

Identify the muscles in the hamstring group

A

• Biceps femoris (long and short head)
• Semitendinosus
• Semimembranosus

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6
Q

Identify the muscles in the quadriceps group

A

• Rectus femoris
• Vastus lateralis
• Vastus intermedius
• Vastus medialis

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7
Q

Identify the bones at the hip

A

• Pelvis
• Femur

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8
Q

Identify the movement types at the hip

A

• Flexion
• Extension
• Abduction
• Adduction
• Rotation
• Circumduction

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9
Q

Identify the muscles at the elbow

A

• Bicep brachii
• Tricep brachii

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10
Q

Identify the bones at the elbow

A

• Radius
• Ulna
• Humerus

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11
Q

Identify the movement types at the elbow

A

• Flexion
• Extension

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12
Q

Identify the muscles at the leg and knee

A

• Quadricep group
• Hamstring group
• Gastrocnemius
• Soleus

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13
Q

Identify the bones at the leg and knee

A

• Femur
• Patella
• Tibia
• Fibula

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14
Q

Identify the movement types at the leg and knee

A

• Flexion
• Extension

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15
Q

Identify the muscles at the ankle and foot

A

• Gastrocnemius
• Soleus
• Tibialis anterior

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16
Q

Identify the bones at the ankle and foot

A

• Tibia
• Fibula
• Tarsals
• Metatarsals
• Phalanges

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17
Q

Identify the movement types at the ankle and foot

A

• Plantar flexion
• Dorsi flexion
• Eversion
• Inversion

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18
Q

Identify the bones at the wrist and hand

A

• Radius
• Ulna
• Carpals
• Metacarpals
• Phalanges

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19
Q

Identify the movement types at the wrist and hand

A

• Supination
• Pronation

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20
Q

Identify the muscles at the core/trunk

A

• Rectus Abdominus
• Latissimus dorsi

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21
Q

Identify the bones at the core/trunk in order

A

Regions of the vertebral column
• Cervical (7)
• Thoracic (12)
• Lumbar (5)
• Sacral (5; fused)
• Coccyx (4; fused)

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22
Q

Identify the movement types at the core/trunk

A

• Flexion
• Extension
• Rotation

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23
Q

What are the two types of muscle contraction

A

• Isometric contraction
• Isotonic contraction

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24
Q

What’s an isometric contraction

A

No movement is produced, the muscle length doesn’t change but tension increases during contraction

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25
Q

What are isometric contractions responsible for

A

The constant length of postural muscles, eg. stabilising the trunk in dynamic activities

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26
Q

How is isometric work completed in training

A

Exerting maximum force in a fixed position
(eg sets of 10seconds with 60second rest)

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27
Q

What’s an isotonic contraction

A

Movements produced; muscle length changes under tension

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28
Q

Identify the two types of isotonic contractions

A

• Concentric
• Eccentric

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29
Q

Outline a concentric contraction including an example

A

The muscle shortens under tension
Eg. The drive phase of a long jumpers jump, the Quadriceps group contracts concentrically because it shortens to produce extension at the knee joint

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30
Q

Outline an eccentric contraction including an example

A

The muscle lengthens under tension
Eg. During the downward part of a weightlifters’ squat, the Quadriceps Vastus group lengthens under tension

• Produces the biggest overload in a muscle, enhancing its development in terms of strength causing more fatigue and therefore DOMS

• Primarily used in plyometric or explosive
strength work, when a muscle contracts eccentrically it acts as a brake to help control the movement

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31
Q

What are the three phases of the stretch shortening cycle

A

• Eccentric phase
• Amortisation phase
• Concentric phase

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32
Q

Outline the eccentric phase of the stretch shortening cycle

A

• Eccentric contraction involves a muscle lengthening under tension. Eg. During the downward part of a jump or squat, the Quadriceps Vastus group lengthens under tension

• It ‘pre-loads’ the muscle allowing it to store elastic energy in anticipation of an explosive movement, acting as a brake to help control the movement

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33
Q

Outline the amortisation phase of the stretch shortening cycle

A

• The phase between the eccentric and concentric contractions. Consists of an isometric hold
• The shorter the amortisation phase, the greater the power of the movement, so long and triple jumpers will have very short amortisation phases

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34
Q

Outline the concentric phase of the stretch shortening cycle

A

• Involves a concentric contraction with the muscle shortening under tension
• Eg. In the drive phase of a jump or squat, the Quadriceps group contracts concentrically because it shortens to produce extension at the knee joint

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35
Q

What are the four roles of muscles

A

• Agonist
• Antagonist
• Synergist
• Fixator

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36
Q

Outline the agonist muscle role

A

• The active muscle under tension that is doing the work and functioning as the prime mover

• It’s responsible for initiating the movement of a joint during the desired movement

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37
Q

Outline the antagonist muscle role

A

Relaxes to allow the agonist to work as movement occurs

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38
Q

Outline the synergist muscle role

A

• A muscle which aids the action of a prime mover by stabilising the joint at which the prime mover acts
• Eg. The trapezius muscle holds the shoulder in place during the bar curling exercise

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39
Q

Outline the fixator muscle role

A

• A muscle which allows the prime mover to work more efficiently by stabilising the bone where the prime mover originates
• Eg. The deltoid muscle stabilises the scapula during the bar curling exercise

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40
Q

What’s an antagonistic pair

A

As one muscle contracts (the agonist) the other relaxes or lengthens (antagonist)

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41
Q

Outline the two ends of a muscle

A

• The fixed or non-moving end is called the origin, eg the tendon attached to the shoulder

• The insertion is known as the moving end,
eg the bicep tendon which is attached to the radius

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42
Q

Outline the three elements of a lever

A

• Fulcrum; the pivot around which the lever moves (a joint)

• Load; what’s being moved (resistance)

• Effort; the force applied to move the load and lever arm (bone)

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43
Q

Outline the three classes of lever

A

• First class: Effort ⬇️ /Fulcrum/ Load
• Second class: Effort ⬆️ /Load/ Fulcrum
• Third class: Fulcrum / Effort ⬆️ / Load

(First and second are rare in the body)

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44
Q

Outline a first class lever

A

• Mimics a seesaw action where the fulcrums between the load and effort

• Mechanical advantage as they have a shorter resistance arm and longer effort arm

• Eg. The heading action at the atlas and axis joint and a throw in in football

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45
Q

Outline a second class lever

A

• Mimics the use of a wheelbarrow, where the load’s between the fulcrum and effort

• (highest) Mechanical advantage as they have a shorter resistance arm and longer effort arm

• Eg. When executing plantar flexion during running and jumping actions

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46
Q

Describe a third class lever

A

• Represents most joint movement in the body where the effort is between the fulcrum and load

• Mechanical disadvantage as the effort arms shorter than the resistance arm

• Mechanical advantage can be increased through the use of equipment, by using a golf club/cricket bat the resistance arm is extended

• Eg. A squat/ upward phase of a bicep curl

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47
Q

What’s the effort arm

A

The distance between the effort and the fulcrum in a lever

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48
Q

What’s the resistance arm

A

The distance between the load and fulcrum

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49
Q

What is mechanical advantage

A

Heavier loads can be lifted with less effort

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50
Q

What’s the advantage of mechanical disadvantage

A

Allows for quick movements over a large range

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51
Q

What’s the equation for mechanical advantage

A

Effort
Mechanical advantage = ———————
Resistance arm

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52
Q

What are Newtons three laws

A
  1. Newton’s first law: Inertia
  2. Newton’s second law: Acceleration
  3. Newton’s third law: Action and Reaction
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53
Q

Outline Newton’s first law of Inertia

A

• A body continues in a state of rest or uniform velocity unless acted upon by an external force

• Eg. A golf ball will remain in a state of rest unless a force, applied by a golf club, makes it move. That same golf ball will then move at a constant velocity unless a force acts on it to slow it down (eg air resistance) or change its direction (eg gravity)

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54
Q

Outline Newton’s second law of acceleration

A

• (F=ma) When a force acts on an object, the rate of change of momentum experienced by the object is proportional to the size of the force and takes place in the direction which the force acts

• Eg. When a golf ball’s struck by a golf club, the rate of change of momentum (or velocity) is proportional to the size of the force acting on it by the club

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55
Q

Outline Newton’s third law of action and reaction

A

• For every action, there’s an equal and opposite reaction

• Eg. When a tennis player hits the ball the racket exerts a force on the ball and the ball exerts and equal and opposite force on the racket, the racket exerts the ‘action force’ and the ball exerts the ‘reaction force’ which is felt by the player in the increased resistance at the time the racket strikes the ball

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56
Q

Outline centre of mass

A

• The point in the body where mass is concentrated/distributed evenly in all directions

• It moves as the shape of our body changes but when we’re stood still with our arms by our side it’s at naval height

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57
Q

Define stability

A

The capacity of an object to return to its original position after being displaced

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58
Q

How can stability be regained

A

• Lowering centre of mass
• Amending position
• Widening the base of support

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59
Q

Identify three things that affect stability

A

• Position/height of the centre of mass
• How much mass there is
• Base of support

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60
Q

Define base of support

A

The area beneath and between the points of contact an object or person has with the ground

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61
Q

How does the base of support affect stability

A

• The broader, wider the base of support, the more stability
• If the centre of mass lines up with the base of support (line of gravity) there’s more stability and it’s said to be in equilibrium, however if slight movement to the object would make it topple it’s said to be in unstable equilibrium

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62
Q

What’s balance

A

The ability to maintain your centre of mass over a base of support (can be static or dynamic)

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63
Q

Outline toppling

A

Caused by the weight acting vertically at the centre of mass and therefore to one side of the near edge of the base of support

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64
Q

Sporting examples of stability/centre of mass

A

• The development of the Fosbury flop technique in high jump
• The low position adopted by sumo wrestlers

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65
Q

Identify the musculoskeletal responses to a warmup

A

• Faster speed of contraction and relaxation of the muscle fibres due to a higher muscle temperature causing enhanced enzyme activity

• Greater strength of contraction due to an increased elasticity of warmer muscle fibres

• Faster speed of contraction due to an increased speed of nerve transmission to the muscle fibre

• Prepares tendons to improve the stability and contractile activity of skeletal muscles that are ready to react to increased activity

• Reduction in muscle viscosity, leading to an improved co-ordination in the efficiency of antagonist muscle contractions

• Reduced risk of injury despite an increase in speed of strength of contraction due to an increase in blood flow and oxygen to the muscle

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66
Q

Identify the skeletal responses to a warmup

A

• Improved range of motion around a joint

• Increased production of synovial fluid from articulate cartilage, which is squeezed in and out of the cartilage at points of contact, providing lubrication and nutrients to the joint

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67
Q

Identify drawbacks to implementing warmups

A

• Static stretching can reduce force of contraction

• Evidence for both static and dynamic stretching to reduce risk of injury is inconclusive

• The intensity and duration of a warm up vary depending on the needs of the sport, so need to possess knowledge of an adequate sport-specific warm up

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68
Q

Identify the components and role of the cardiovascular system

A

• Includes the heart and blood vessels

• Involved in carrying nutrients and hormones to cells
• Removing waste products (e.g. Co2)
• Help protect the body from infection and blood loss
• Maintaining homeostasis of a constant body temperature (thermoregulation) and fluid balance

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69
Q

Identify the components and role of the circulatory system

A

• Refers to the transportation throughout the body and includes the heart, blood, blood vessels, lymph, lymphatic vessels and glands

• Involved in carrying nutrients and hormones to cells
• Removing waste products (e.g. Co2)
• Help protect the body from infection and blood loss
• Maintaining homeostasis of a constant body temperature (thermoregulation) and fluid balance

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70
Q

Identify the components and role of the respiratory system

A

• A network of organs and tissue that helps the body to breathe, including the nasal cavity, pharynx, larynx, trachea, bronchus, bronchioles and alveoli

• Responsible for taking in oxygen and dispelling carbon dioxide from the body

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71
Q

Outline the relationship between the cardiovascular, circulatory and respiratory systems

A

All three systems work together to deliver oxygen to the tissues and remove Co2, to do this effectively they’re divided into 2:

• Pulmonary circuit carries deoxygenated blood from the right ventricle to the lungs at high pressure and oxygenated blood back to the left atrium via the pulmonary vein

• Systemic circuit carries oxygenated blood from the left ventricle around the body at high pressure and deoxygenated blood back to the right atrium via the Vena Cava at low pressure (venous return)

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72
Q

Define venous return (VR)

A

The transport of blood from the capillaries through the venules, veins then either the Superior or Inferior Vena Cava back to the right atrium of the heart

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73
Q

Identify the mechanisms that affect venous return

A

• Pocket valves: One way valves that prevent backflow

• Skeletal muscle pump: Veins are situated between skeletal muscles which, when contracting and relaxing, help push/squeeze blood

• Respiratory pump: During exercise breathing becomes deeper and faster causing pressure changes in the thorax/abdomen which helps force blood back to the heart

• Venomotor control: Contraction and relaxation of smooth muscle in the middle layer of the vein walls also helps push blood toward the heart, increasing volume of blood returning to the right atrium. During inspiration, venous return increases due to reduced pressure in the thoracic cavity drawing more blood into the right atrium

• Blood volume: An increase in blood volume in the veins leads to greater blood pressure. Frank-Starling mechanism means the heart will be able to cope with an increased blood volume. The greater myocytic stretch, the greater the systolic contraction

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74
Q

Describe the pathway of air as it’s breathed in

A

• Breathed in through the nose. The nasal cavity’s divided into two by the septum

• Pharynx is part of the alimentary canal (food passes through for digestion).
• Larynx is lower than the pharynx and known as the voicebox; containing vocal chords that control pitch and volume of voice as air passes through and makes a sound. It’s found in the upper trachea

• Trachea is made up of cartilage, and is an incomplete ring to keep the airway open and allow for swallowing. It’s 10-12cm long and splits left and right to allow air to flow to the bronchi

• Bronchus (one to each lung) splits further into lobar bronchi that split again to form bronchioles that allow for passage of air into the alveoli

• Alveoli are very important air sacs that allow gaseous exchange. Huge capillary network around alveoli (site for gaseous exchange) with around 150million per lung

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75
Q

Identify a key adaptation of the structures of the respiratory system before the bronchioles

A

• Ciliated linings and mucus glands to provide a ‘cleaning and filtering’ mechanism for incoming air

• Air is warmed by mucus membranes, moistened and then cilia trap dust and dirt particles which are moved to the throat to be exhaled

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76
Q

Describe the structure and function of the lungs

A

• Extend from the clavicle to the diaphragm and contain all pulmonary vessels
• One of the major organs; the left lungs slightly smaller due to the position of the heart

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77
Q

Outline the structure and function of the pulmonary pleura

A

• Self enclosed serous membrane covering the lungs. It lines the thoracic cavity, middle wall of the thorax and the diaphragm.

• Secretes pleural fluid into the pleural cavity to reduce friction between lung tissue and ribs
• Aids inspiration as pleural pressure reduces and expiration as pleural pressure increases

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78
Q

Outline the structure and function of the diaphragm

A

• Dome-shaped muscle that separates the thoracic and abdominal cavities

• Contracts and moves down for inspiration and relaxes back to a dome shape during expiration, working with the intercostal muscles

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79
Q

Outline the structure and function of the external and internal intercostal muscles

A

• External:
- Attach to each rib, when they contract the rib cage moves up and out and when they relax the rib cage lowers into its normal position

• Internal:
- More active during exercise to pull ribs down more to increase ventilation rate

80
Q

Outline the process of breathing

A

The mechanism of breathing is brought about by changes in air pressure in the lungs (intrapulmonary pressure) relative to atmospheric pressure and muscular action of the diaphragm and 11 pairs of intercostal muscles

81
Q

Describe the process of inspiration

A

• There’s a higher partial pressure of oxygen (pO2) in the atmosphere compared to the lungs so oxygen moves down the trachea, bronchi and bronchioles into the alveoli down a pressure gradient

• The internal intercostal muscles relax and the external intercostals contract to move the ribs and sternum upwards and outwards, while the diaphragm contracts, becoming flatter and increasing the volume of the thoracic cavity

• The pressure between pleural membranes is reduced which allows elastic pulmonary tissue to expand, increasing lung volume

• Pulmonary pressure falls below atmospheric pressure so movement of air into the lungs occurs due to a pressure gradient until lung pressure equals atmospheric pressure

82
Q

Describe the process of expiration

A

• The external intercostals relax, causing the ribs and sternum to move downwards and inwards and the diaphragm relaxes decreasing the volume of the thoracic cavity

• The pressure between pleural membranes increases which compresses elastic pulmonary tissues, decreasing lung volume

• Pulmonary pressure is driven above atmospheric pressure, so atmospheric air is forced out of the lungs via respiratory passages until lung pressure equals the atmospheric pressure again

83
Q

How does exercise affect inspiration

A

• More air’s forced into the lungs

• Further increase in the volume of the thoracic cavity

• Additional muscles in the chest and torso contract, including the scalenes, pectoralis major/minor and the sternocleidomastoid)

84
Q

Explain how exercise affects expiration

A

• Internal intercostals and abdominal muscles contract powerfully, acting on the ribs and body cavity

• Further decrease of volume of the thoracic cavity

• More air forced out of the lungs

85
Q

Define tidal volume

A

Volume of air breathed in or out per breath

86
Q

Define inspiratory reserve volume

A

Volume of air that can be forcibly inspired after a normal breath

87
Q

Define expiratory reserve volume

A

Volume of air that can be forcibly expired after a normal breath

88
Q

Define residual volume

A

Volume of air that remains in the lungs after maximum expiration

89
Q

Define vital capacity

A

The greatest volume of air that can be expelled following maximum inspiration

90
Q

Define minute ventilation

A

Volume of air breathed in or out per minute

91
Q

Define functional residual capacity

A

The amount of air remaining in the lungs after a normal expiration
• (residual volume + expiratory reserve volume)

92
Q

Define total lung capacity

A

The maximum amount to air that can fill the lungs
• (vital capacity + residual volume)
• (tidal volume + inspiratory reserve volume + expiratory reserve volume + residual volume)

93
Q

Outline the function of the heart

A

• A double pump system that pumps oxygenated blood to working muscles and the systemic system and deoxygenated blood to the lungs and pulmonary system
• LORD (left oxygenated right deoxygenated)

94
Q

Identify and provide the function of the structures of the heart

A

• Right atrium: takes deoxygenated blood from the vena cava and passes it to the right ventricle
• Right ventricle: takes deoxygenated blood from the right atrium

• Pulmonary artery: deoxygenated blood from the right ventricle to lungs (picks up oxygen)
• Pulmonary vein: oxygenated blood from the lungs to the left atrium

• Left atrium: takes oxygenated blood from the luminary vein and passes it to the left ventricle
• Left ventricle: takes oxygenated blood from the left atrium
• Aorta: artery carrying oxygenated blood from the left ventricle to working muscles (thick walls as blood travels far)

• Inferior/superior vena cava: vein carrying deoxygenated blood from the right ventricle to the lungs CHECK INFO ON THIS

• Semi-lunar valve: separates ventricles from the pulmonary artery/vein
• Bicuspid valve: separates ventricle and atrium on the left side
• Tricuspid valve: separates the ventricle and atrium on the right side

• Septum: the wall that divides both sides of the heart
• Myocardia: involuntary muscle tissue of the heart

95
Q

Outline the structure of the blood

A

• 55% plasma: made mostly of water and transports Co2, glucose, hormones and urea; lack of water leads to slower transport of less ions and glucose increasing onset of fatigue

• 45% corpuscles: including
- Playelets that facilitate clotting (thrombokinase- plasma protein) and release chemicals that cause fibrin to form a mesh across wounds
- WBCs that produce antibodies and regulate the immune system
- RBCs- Haemoglobin and oxygen (oxyhaemoglobin) for oxygen transport and volume of RBCs (haematocrit: % of total blood volume)

96
Q

Outline the equation for blood pressure and how it’s measured

A

• Blood pressure= cardiac output x resistance flow

• Highest when bloods pumped into the aorta and lowest during ventricular diastole, measured by a sphygmomanometer, recorded in mmHg

97
Q

Describe the types of blood vessels

A

• Arteries carry oxygenated blood away from the heart at high pressure (except pulmonary artery). They have thick, muscular, elastic walls that contract and relax, widening the lumen to regulate blood

• Arterioles are smaller arteries that distribute blood to capillary beds

• Veins carry deoxygenated blood towards the heart at low pressure (except pulmonary vein). They have a large lumen with thin walls and contain valves to prevent backflow of blood

• Venuoles receive blood from capillary beds and link with veins

• Capillaries are one cell thick and the one link between veins and arteries, moving blood between the two, they allow gaseous exchange to occur

98
Q

Define heart rate

A

The number of beats per minute (bpm)

99
Q

Define stroke volume

A

• Volume of blood pumped by the left ventricle of the heart per beat, determined by the venous return and elasticity and contractility of the myocardium

• Difference between end diastolic volume and end systolic volume

100
Q

Define end diastolic volume

A

Before contraction: the volume of blood in the ventricles at the end of diastole (the relaxation phase)

• An increase in EDV means an increase of pre-load of the heart (stretch of myocardia) which will increase stroke volume (=EDV-ESV)

101
Q

Outline End systolic volume

A

After contraction: refers to the volume of blood remaining in the ventricles at the end of systole (the contraction phase)

• A healthy heart ejects 60-70% of EDV during ventricular systole, so ESV is a good indicator of health and performance

102
Q

Define cardiac output

A

Volume of the blood pumped by the left ventricle of the heart in one minute

• Q= SV x HR

103
Q

Define ventricular contractility

A

Capacity of the ventricles to contract

104
Q

Define blood pooling

A

• Venous return is required a force to push the blood back towards the heart, insufficient pressure means blood sits in the pocket valves of the veins causing blood pooling known as ‘heavy legs’

• Increased cardiac output sent to the muscles in the legs actually sits here with insufficient pressure to return to the heart. Pressure-volumes sufficient to maintain venous return during rest but not during or immediately after exercise so additional mechanisms are needed to maintain venous return

105
Q

Describe the conduction system of the heart

A

• Cardiac impulse is initiated from the sino-atrial node (anatomical pacemaker) located in the posterior wall of the right atrium

• Impulse travels through the left and right atrial walls causing both atria to contract

• Cardiac impulse reaches and activates the atrio-ventricular node in the right atrium

• AV node helps delay the impulse allowing the contraction of the atria to finish before the ventricles begin to contract

• Impulse is passed to the bundle of His in the septum, that splits into left and right branches and spreads the impulse down to the bottom of the left and right ventricles

• Impulse spreads up through the walls of the ventricles via a network of purkinje fibres causing both ventricles to contract

• Ventricles relax and the cycles repeated with the next cardiac impulse initiated from the SA node

106
Q

Identify what the conduction system and cardiac cycle are defined as being and the difference between the two

A

• The cardiac cycle is the contraction and relaxation of the heart and the movement of blood through the chambers whereas the conduction system refers to the myogenic (generates it’s own impulse) properties of the heart

• The cardiac cycle is controlled by the conduction system after the SA node initiates a cardiac impulse that causes the heart to contract

107
Q

Describe the stages of the cardiac cycle

A
  1. Cardiac diastole: All chambers are relaxed and blood flows into the heart

Atrial systole: Atria contract after the SA node initiates a cardiac impulse causing a wave-like contraction over the atria, forcing blood into the ventricles. This is an active process however most of the blood enters via passive movement.

Ventricular diastole: Passive movement of blood from atria to ventricles. The semi-lunar valves close to prevent backflow in the Aorta and Pulmonary artery

Atrial diastole: Relaxation of atria, allowing blood to fill them. Atrial blood pressure rises above ventricular pressure, forcing AV-valves to open as blood moves into both ventricles

Ventricular systole: Impulse reaches the AV node, spreading to the bundle of His and purkinje fibres causing a second contraction across ventricle walls. AV-valves close and semi-lunar valves open to allow blood to leave the heart.
- Oxygenated blood leaves from the left ventricle via the aorta and deoxygenated blood leaves from the right ventricle via the pulmonary artery

108
Q

Describe the neural control of the cardiac cycle

A

• Sensory receptors pick up stimuli and transmit information to the central nervous system which are relayed to the Medulla Oblongata

• The Medulla Oblongata contains the Cardiac Control Centre (CCC) which regulates the heart. Motor nerves are nerves which stimulate muscle tissue causing motor movement

• It’s is controlled by the autonomic nervous system responsible for involuntary control (broken into sympathetic + parasympathetic)

109
Q

Identify the types of receptors in the body and explain their role in the cardiac cycle

A

• Baroreceptors are sensitive to stretch within blood vessel walls in aorta, carotid arteries inform the Cardiac Control Centre that blood pressure has increased

• Chemoreceptors are sensitive to chemical changes in the muscles, aorta, carotid arteries and inform the Cardiac Control Centre that oxygen and pH levels have decreased or that lactate, H+ and Carbon dioxide presence has increased

• Proprioceptors are found in muscle spindles and Golgi tendons, which respond to mechanical stimuli and joints inform the Cardiac Control Centre that motor activity’s increased

110
Q

Explain the hormonal control of the cardiac cycle

A

• The sympathetic nervous system stimulates the release of adrenaline before (anticipatory rise) and during exercise from the adrenal glands. This is to stimulate the SA node to increase HR and strength of ventricular contraction, which increases stroke volume.

• The parasympathetic nervous system stimulates the release of acetylcholine to decrease HR when exercise has finished

111
Q

Outline the functional, intrinsic control of the heart before and after exercise

A

• Before: temperature increases, increasing speed of nerve impulses and therefore HR. (This increases venous return and ESV/EDV

• After: Temperature decreases, decreasing HR, venous return and in turn stroke volume

112
Q

Define and outline bradycardia

A

• Defined as a resting heart rate below 60bpm

• Cardiac hypertrophy is caused from prolonged sub-maximal aerobic training creating stronger elastic recoil of myocardium
• Ventricular hypertrophy produces a more powerful contraction, which increases stroke volume therefore increasing cardiac output.
• An increased end diastolic volume results in more powerful heart contraction that pumps more blood per beat, so less beats per minute are needed

• The functional adaptation caused is an increased Vo2 max

113
Q

Identify responses of the respiratory system to exercise

A

• Increased breathing rate (frequency)
- Increases inspiration of oxygen and expiration
of carbon dioxide as a greater amount of
oxygen is required to maintain exercise intensity

• Increased tidal volume
- Respiratory muscles contract more forcefully
due to an increased demand for oxygen

• Increased rate of gaseous exchange at the alveoli
- Changes in partial pressure of carbon dioxide
and oxygen mean the pressure gradient
increases for higher rates of gaseous exchange

114
Q

Identify adaptations of the respiratory system to exercise

A

• Increased number of alveoli
- Increased efficiency of gaseous exchange,
increased vital capacity, increased Vo2 max

• Increased capiliarisation at the alveoli
- Increased efficiency of gaseous exchange,
increased vital capacity, increased Vo2 max

• Hypertrophy of respiratory muscles
- Decreased residual volume (increases the
volume of the thoracic cavity at rest therefore
increasing the concentration gradient),
decreased resting breathing rate, increased tidal
volume

• Increased elasticity of respiratory muscles
- Decreased resting breathing rate, increased tidal
volume

115
Q

Identify responses of the cardiovascular system to exercise

A

[Before exercise]
• Anticipatory rise
- Thought of participating causes the sympathetic
nervous system to release adrenaline, activating
the fight or flight response.

[During exercise]
• Increased heart rate
- Increases with exercise intensity, slowing down
prior to maximum HR values and plateaus
during sub-maximal work, representing an
optimal steady state HR (meets o2 demands for
that intensity)
- Decreases rapidly immediately after exercise
stops due to decreased oxygen demand to
working muscles. It will then gradually and more
slowly decrease but remain elevated to allow the
body to reduce its oxygen debt through EPOC.

• Adrenaline secretion
- SNS increases adrenaline secretion, stimulating
the SA node, thereby increasing heart rate.

• Increase in muscle temperature
- Increases conduction of nerve impulses across
the heart, further increasing heart rate

• Increase in stroke volume
- As an athlete starts running, SV increases
linearly with speed and intensity up to 40-60% of
maximum running speed where it plateaus as SV
maximum values are reached during sub-max
exercise
- The hearts ability to fill is based on venous
return. SV primarily increases due to more blood
returning to the heart, the ventricles have an
ability to stretch to cope with an increased
venous return and the hearts capacity to empty
is dependant on an increased EDV that provides
greater stretch of the atria/ventricular walls, a
greater stretch force of ventricular systole and
therefore a decreased ESV

• Increased cardiac output
- Increases with exercise intensity from rest
values of 5L/min up to maximum values of
20-40L/min in highly trained endurance athletes.
Cardiac output primarily increases to supply
increased oxygen demand from working
muscles

• Blood pressure
- Changes dependant on the type/intensity of
exercise:
- Steady state aerobic: systolic pressure
increases due to increased cardiac output.
Diastolic pressure remains the same/ may drop
in high level athletes as blood feeds into
muscles due to arteriole dilation
- High intensity isometric/anaerobic exercise:
systolic and diastolic pressure increases due to
increased resistance in blood vessels. EG.
Weightlifters hold their breath causing
significant increase in S/D BP
- High blood pressure (hypertension) can cause
potential complications and low blood pressure
(hypertension) means insufficient O2 and
nutrients reach cells , regulated by the
vasomotor control centre in the Medulla which
initiated vascular shunting mechanisms
(vasoconstriction to inactive areas and
vasodilation to working muscles)

116
Q

Identify adaptations of the cardiovascular system to exercise

A

• Decreased resting HR, can lead to Bradycardia

• Increased maximum HR
- Myocardium becomes able to contract more
often per minute because there an increased
blood supply to the myocardium

• Increased cardiac hypertrophy, contractility,
which causes an increased SV

• Increased capiliarisation around skeletal muscle
tissue and lung alveoli
- Increased efficiency of gaseous exchange,
increased Vo2 max

• Improved recovery HR
- Due to more efficient gaseous exchange at both
the lungs and muscles

• Increased elasticity of blood vessels (the muscle
wall)
- Reduces blood pressure, decreases stress on
the heart which benefits health + performance

• Enhanced buffering of blood lactate
- There’s a greater tolerance to blood lactate
levels because OBLA occurs at a higher intensity
so the body’s more resistant to fatigue, enabling
performers to continue for longer at higher
intensities

• Increased blood volume and Haemoglobin count

117
Q

Define an unhealthy lifestyle and lifestyle choices

A

• When a person makes lifestyle choices known to be detrimental to one’s health

• Lifestyle choices are choices made which affect daily life and have a direct impact on health and fitness, such as diet, smoking, alcohol, drugs, exercise engagement and work-life balance

118
Q

Outline a sedentary lifestyle

A

A lifestyle involving little to no exercise or physical activity and can lead to health issues such as
• Poor posture
• Muscle atrophy
• Decreased Vo2 max
• Decreased basal metabolic rate

These issues can lead to hypokinetic diseases, conditions caused by a lack of exercise, such as:
• Obesity
• Osteoporosis
• Coronary heart disease
• Hypertension (high blood pressure)
• Depression
• Diabetes

119
Q

Define exercise

A

Physical activity that maintains health and fitness

120
Q

Define health

A

A state physical, emotional and social well-being, not merely the absence of disease or infirmity

121
Q

Describe the effect of smoking on the respiratory and cardiovascular systems and identify long term effects

A

Respiratory:
• Build up of tar which decreases the surface area of capillaries surrounding alveoli, leading to a decrease in diffusion routes

Cardiovascular:
• Build up of plaque on arterial walls, decreasing elasticity and reducing the ability to dilate and constrict, leading to hypertension
• Leads to a decrease in blood flow and oxygen carrying capacity of the red blood cells, leading to more carbon monoxide and reducing oxygen delivery to tissues and organs

Long Term risks of smoking:
• Thrombosis
• Cancer
• Heart attacks
• Strokes
• Atherosclerosis
• Arteriosclerosis
• Coronary heart disease
• Hypertension

122
Q

Outline atherosclerosis

A

• High deposits of cholesterol and low density lipoprotein (LDL) accumulation within arterial walls that form fatty plaque.
This narrows the lumen of blood vessels and increases the strain on the heart

• Atherosclerosis can be caused by poor diet and smoking and increases the risk of hypertension, heart angina and heart attacks.

123
Q

Define both heart angina and heart attacks, explaining the difference between the two

A

• Heart angina is a partial blockage of the coronary artery causing intense chest pain which occurs when there’s an inadequate oxygen and blood supply to part of the heart muscle wall

• Heart attacks are a severe or total restriction of blood supply to the heart muscle wall, more likely as a result of blood clots from larger coronary arteries that get stuck in smaller ones

124
Q

Define arteriosclerosis

A

Loss of elasticity and the stiffening or hardening of arteries that reduces the ability of the arteries to dilate and constrict and therefore the regulation of blood pressure and vascular shunting

125
Q

Explain the difference between atherosclerosis and arteriosclerosis

A

• Atherosclerosis is due to deposits of cholesterol and low density lipoprotein forming fatty plaque, narrowing the lumen

• Arteriosclerosis is the stiffening or hardening of arteries

126
Q

Outline depressants

A

• Drugs affect the central nervous system and directly influence how we feel and behave
• Depressants slow the function of the CNS, slow responses/reaction time and affect concentration

• E.g. alcohol, heroin, cannabis

127
Q

Outline hallucinogens

A

• Drugs affect the central nervous system and directly influence how we feel and behave
• Hallucinogens provide no sense of reality and cause paranoia

• E.g. ketamine, LSD

128
Q

Outline stimulants

A

• Drugs affect the central nervous system and directly influence how we feel and behave
• Stimulants speed up the CNS, make us more alert and confident, increase heart rate and blood pressure and increase temperature and anxiety

• E.g. caffeine, nicotine, amphetamines

129
Q

Outline obesity

A

• A surplus of adipose tissue (fat) resulting from excessive energy intake relative to energy expenditure (positive energy balance)

• If we consume food without completing the necessary exercise, we become overweight (male- >25% body fat and female- >35% body fat)

Obesity is the result of an unbalanced diet, high in sugar, saturated fat, low density lipoprotein and cholesterol associated with Western diets, leading to excess calorie intake and compounded by lack of exercise. This increases the amount of plaque built up in the blood vessels (atherosclerosis) and increases the risk of:
• Coronary heart disease
• Arthritis
• Hypertension
• Type 2 Diabetes
• Thrombosis

130
Q

Identify the three types of muscle fibre

A

• Slow oxidative (slow twitch- type I)
• Fast oxidative glycolytic (fast twitch- type IIa)
• Fast glycolytic (fast twitch- type IIx)

131
Q

Outline slow oxidative (SO) muscle fibres

A

• Use the anaerobic system to contact slowly over a prolonged period, generating a low level of force and so have a high level of resistance to fatigue

• Recruited to provide energy for sub-maximal aerobic work and recover very quickly within 90seconds.

• Muscle fibre damage is not associated with SO fibres so recruitment in aerobic activity can be safely performed daily. Aerobic work:relief ratios are very low; 1:1 is commonly used

132
Q

Identify the characteristics of slow oxidative muscle fibres

A

• Fibre size: Small
• Motor unit size: Small
• Colour: Red
• Mitochondrial density: High
• Capillary density: High
• Myoglobin content: High
• Triglyceride levels: High
• P/C stores: Low
• Glycogen stores: Low

133
Q

Outline fast twitch (FOG and FG) muscle fibres

A

• Use the anaerobic system to contract quickly over a relatively short period of time, generating a high level of force.

• They have a low resistance to fatigue and so fatigue quickly and take longer to recover. Training should reflect this e.g. low (2-6) repetitions with high (3-4 minutes) rest

• Only provide 2-20 seconds of contraction so are designed to work anaerobically

• Fast glycolytic use stores of phosphocreatine for rapid energy and force production

134
Q

Identify the characteristics of fast oxidative glycolytic muscle fibres

A

• Fibre size: Large
• Motor unit size: Large
• Colour: Pink
• Mitochondrial density: Low
• Capillary density: Moderate
• Myoglobin content: Moderate
• Triglyceride stores: Moderate
• P/C stores: Moderate
• Glycogen stores: High

135
Q

Identify the characteristics of fast glycolytic muscle fibres

A

• Fibre size: Largest
• Motor unit size: Largest
• Colour: White
• Mitochondrial density: Lowest
• Capillary density: Lowest
• Myoglobin content: Low
• Triglyceride stores: Low
• P/C stores: High
• Glycogen stores: High

136
Q

Identify the effects of training on muscle fibre types

A

Increase in size (hypertrophy) is caused by an increase in the number and size of myofibrils per fibre

137
Q

Outline recruitment of fibres

A

• Recruitment of fibres refers to the number of motor units stimulated.

• Whether or not motor units are stimulated depends if the all or none law, and the order of which they’re stimulated is dependant on the size principle.

• The greater the number of motor units recruited, the greater number of muscle fibres that will contract, increasing the force of contraction. For maximal contraction, all motor units must be stimulated. The strength of force of contraction exerted by a muscle is determined by gradation of contraction

138
Q

Explain the size principle

A

• During voluntary muscle contractions, the orderly pattern of recruitment is controlled by the size of the motor unit

• Fibre recruitment occurs in order of size, so irrespective of contraction, small motor units containing slow oxidative fibres will always be recruited first, followed by FOG, then FG fibres

• The smaller the unit, the lower the threshold and therefore the smaller the contraction.
• Type IIx have the largest motor units and will be recruited after type I and IIa fibres if the exercise intensity is high enough (e.g. in weightlifting/interval training)

139
Q

State the all or none law

A

• A minimum amount of stimulation’s required to meet a threshold and start a muscle contraction.

• If an impulse is strong enough then all the muscle fibres in a motor unit will contract. However, if the impulse is less than the required threshold, no muscle contraction occurs. The action potential’s at full strength or not at all.

140
Q

Outline gradation of contraction

A

• Refers to the strength of force of contraction exerted by a muscle, that depends on three factors

  1. Recruitment
    Refers to the number of motor units stimulated
  2. Wave summation
    Refers to the frequency of the stimuli. For a
    motor unit to maintain a contraction, it must
    receive continuous impulses, usually at a
    frequency of 80-100 stimuli per second. Can
    lead to Tetanic contractions.
  3. Synchronisation
    Refers to if motor units are stimulated at the
    same time. If all motor units are stimulated at
    the same time, known as spatial summation,
    maximum force can be applied.
    Fatigue can be delayed by rotating the motor
    units stimulated
141
Q

Outline Tetanic contractions

A

• A sustained muscle contraction caused by a motor neurone emitting action potentials at a very high rate

• Tetanic contractions occur after several stimuli cause a muscle to contract in rapid succession. If the stimuli are delivered at a high enough frequency, twitches will overlap

142
Q

State the role of a tendon

A

Join bone to muscle

143
Q

State the role of a ligament

A

Join bone to bone

144
Q

Outline the central nervous system

A

Consists of the brain and the spinal chord and sends action potentials to a motor unit which travels to a motor neurone

145
Q

Outline the structure and function of a motor unit

A

• Motor units are made up of a single neurone that innervates (supplies) a group of skeletal muscles.

• They recieve signals from the central nervous system and stimulate all muscle fibres in that particular motor unit initiating muscular contraction

(Motor unit = motor neurone + muscle fibres)

146
Q

Outline a motor neurone

A

• Specialised cells which transmit an action potential to muscle fibres, sometimes called nerve cells

• They connect to an axon that connects to a skeletal muscle

147
Q

Outline the structure and function of the axon of a neurone

A

• A long, slender fibre of a motor neurone

• Conducts electrical impulses away from the neurones cell body to the muscle fibre

148
Q

Outline the neuromuscular junction

A

• The site where an axon terminal of a motor neurone and motor end plate of the muscle fibre meet.

• There is a gap called the synaptic cleft that separates the axon terminal and motor end plate

149
Q

State the elements of a muscle

A

• Epimysium
• Perimysium
• Fascicles
• Endomysium
• Muscle fibre
• Sarcolemma
• Sarcoplasm
• Sarcoplasmic reticulum
• Myofibrils

150
Q

State what the epimysium is in a muscle

A

The outermost layer of connective tissue that surrounds the entire muscle

151
Q

State what the perimysium is in a muscle

A

Connective tissue surrounding the fascicles

152
Q

State what the fascicles are in a muscle

A

Individual bundles of muscle fibres

153
Q

State what the endomysium is in a muscle

A

Connective tissue that surrounds each muscle fibre within the fascicles

154
Q

State what the muscle fibre is in a muscle

A

Made up of many myofibrils bundled together, known as cells

155
Q

State what the sarcoplasm is in a muscle

A

• The cytoplasm of a muscle fibre (cell) that contains a network of membranous channels surrounding the myofibril

• It’s a water solution containing ATP and phosphates and contains important organelles such as the mitochondria

156
Q

State what the sarcoplasmic reticulum is in a muscle

A

The membranous channels that are storage sites for calcium ions and play an important role in muscle contraction

157
Q

State what the myofibrils are in the muscle

A

• Thread-like structures containing contractile proteins such as actin, myosin, troponin and tropomyosin.
• Sarcomeres are striated muscle tissue cells that act as a basic contractile unit of a myofibril

• Muscle fibres are made up of many myofibrils bundled together

158
Q

State what the sarcolemma is in a muscle

A

The cell membrane surrounding the muscle fibre

159
Q

State what the sarcomere is in a myofibril

A

A striated muscle tissue cell and basic contractile unit of a myofibril, each sarcomere’s composed of two main protein filaments: actin and myosin

160
Q

Describe myosin

A

A thick contractile protein filament comprised of protrusions known as myosin heads that bind to form cross-bridges

161
Q

Describe actin

A

A thin contractile protein filament, containing ‘binding sites’ associated with two globular proteins called troponin and tropomyoisn

162
Q

Outline the role of troponin

A

Plays an important role during excitation-contraction, where Ca2+ binds to troponin, then it interacts with tropomyosin to unblock the myosin head binding sites, which allows for a cross bridge to start the contraction process

163
Q

Outline the role of tropomyosin

A

A thread-like globular protein that blocks myosin head binding sites on the actin filament, preventing actin cross-bridge formation. This prevents contraction in a muscle without nervous innervation and the binding of Ca2+ to troponin

164
Q

Outline Sliding Filament Theory

A

• Skeletal muscles contract once stimulated by an electrical impulse from the CNS and this process for muscular contraction can last for as long as there are adequate ATP and calcium stores

• SFT explains how the movement of thick and thin filaments relative to each other leads to the contraction of whole muscles in order to bring about movement of the limbs attached to those muscles

SFT is made up of 5 phases:
• Resting
• Excitation
• Contraction
• Recharge
• Relaxation

165
Q

Describe the process of Sliding Filament Theory

A

Resting
• No impulses are being generated and therefore the muscle’s relaxed. Actin and myosin filament sites are being blocked by the proteins troponin and tropomyosin

Excitation
• An electrical impulse from the CNS causes an action potential to be passed along a motor neurone to the neuromuscular junction, causing the release of acetylcholine and depolarisation of the motor end plate
• The muscle action potential travels throughout the entire fibre, activating T-tubules which causes calcium to be released from the sarcoplasmic reticulum
• The high calcium concentration causes calcium to bind with tropomyosin from the active site of the actin filament. The myosin filaments can now bond with actin, forming a cross-bridge. ATP’s attached to the myosin to release energy for contraction

Contraction
• Myosin pulls the actin filaments inwards and shortens the muscle. This occurs along the entire length of every myofibril in the muscle cell
• The breakdown of ATP releases energy while breaking the cross bridge. A new ATP molecule attaches to the myosin head, causing it to detach from the actin and the cross-bridge is broken

Recharge
• When the ATP’s broken down, the myosin head can reattach to a binding site further along the actin filament and repeat the ‘power stroke’
• The repeated pulling of actin over myosin is known as the Rachet mechanism

Relaxation
• The impulse stops, calcium is pumped back into the sarcoplasmic reticulum and actin returns to it’s resting position causing the muscle to lengthen and relax

166
Q

Describe the initiation of sliding filament theory

A

• Axon terminal has more negative charge than outside a bulb, the action potential makes this more positive

• Calcium voltage gated channels open to allow calcium in creating a more positive environment. Acetylcholine’s released which diffuses across the synaptic cleft and binds to receptors on the Ligand gated sodium ion channels

• These channels allow sodium ions (Na+) in the myofibril and potassium ions (K+) to exit. Once a threshold is achieved, the muscle fibre is depolarised and the action potential has reached the muscle fibre

• Depolarisation is a change within a cell/fibre where it undergoes a shift in electrical charge inside the cell

• Calcium ions (Ca2+) are released from the sarcoplasmic reticulum down the t-tubules in myofibrils to start the sliding filament theory

167
Q

Identify aerobic adaptations of the anatomical systems of the body, including the muscular-skeletal, respiratory, cardiovascular and neuromuscular systems

A

Muscular-skeletal system
• Increased bone density
• Increased mitochondria and myoglobin content
• Increased capilirisation of muscle tissue
• Increased tendon strength
• Increased glycogen stores
• Increased presence of oxidative enzymes

Respiratory system
• Decreased minute ventilation
• Increased vital capacity (not total lung capacity as
we can’t significantly reduce residual volume)
• Hypertrophy of respiratory muscles
• Increased Vo2 max
• Increased capilirisation of the alveoli (increased
rate of gaseous exchange)
• Increased number of alveoli
• Increased tidal volume, increased partial
pressure of oxygen, increased rate of gas
exchange

Cardiovascular system
• Decreased resting heart rate (bradycardia)
• Decreased blood pressure
• Decreased end systolic volume
• Increased end diastolic volume
• Quicker recovery heart rate
• Increased Stroke volume and cardiac output
(increased venous return)
• Increased contractility/elasticity of the
myocardium
• Increased elasticity of the blood vessels
• Increased thickness of ventricle walls
• Increased RBC and Haemoglobin content

Neuromuscular
• Increased type 1 muscle fibres
• Hypertrophy if type 1 muscle fibres

168
Q

Outline energy

A

The capacity of the body to produce work. It comes in multiple forms:

• Kinetic energy is the energy of an object due to its motion e.g. someone running

• Chemical energy is the energy released from chemical reactions e.g. ATP being hydrolysed for muscle contraction to take place

• Potential energy is stored energy that, when released, is converted to kinetic energy e.g. energy between phosphates in ATP

• Mechanical energy is the energy of an object due to motion or position; a combination of potential and kinetic energy

• Electrical energy is the movement of charged particles e.g. creation of an action potential in a neurone

169
Q

Outline Adenosine Triphosphate (ATP) as an energy source

A

• The chemical energy of a cell is supplied by the breakdown of ATP. ATP consists of a nitrogenous base (adenine), a ribose sugar and three phosphate groups held together by bonds that store energy

• Splitting the outermost bond between adenine and phosphate releases energy to fuel body processes. The enzyme ATPase helps hydrolyse ATP in an exothermic reaction to release energy

• ATP resynthesis is required as there’s only a limited amount of ATP in muscle cells to produce maximal, powerful contractions (for approx 2-3 sec). So ATP must be constantly resyntheised to provide a constant supply of energy

• There are three ways to resynthesise ATP, all of which supply the energy required to rebuild the bond between the two phosphates and resynthesise ADP and an organic phosphate to ATP in a coupled reaction (products of the reaction used in another reaction)
These three ways are:
1. ATP/PC system
2. Glycolysis/anaerobic glycolysis
3. Aerobic glycolysis
The energy systems work together to provide constant energy supply

170
Q

Outline and evaluate the ATP/PC system

A

• The ATP/PC system is anaerobic and occurs in the sarcoplasm. There are limited stores and one phospocreatine produces one ATP, only supplying enough energy to resynthesise ATP for 3-10 seconds during a maximal sprint

• A decrease in ATP and a decrease in ADP stimulates the release of creatine kinase. Creatine kinase breaks down phosphocreatine bonds, releasing energy in an exothermic reaction. They’re coupled to re-synthesise ADP to ATP

[+] Fast reaction as it doesn’t require oxygen, PC in
the muscles js an available source and the
reaction is auto-stimulated by a change in ATP/
ADP levels
[+] Recovery is fast due to quick re-synthesise
because it’s a small compound and there are
no fatiguing byproducts to break down
[+] Has energy for high explosive movements

[-] Only a small amount of ATP is stored in the
muscle cell
[-] 1 PC re-synthesises just 1 ATP, so only provides
energy to re-synthesis ATP for 8-10 seconds

171
Q

Outline and evaluate the (anaerobic) glycolytic system (lactate system)

A

• Anaerobic system that occurs in the sarcoplasmic, for energy re-synthesis during the first 2-3 minutes of high-intensity anaerobic activity. It lasts 30 seconds before OBLA

• Glucose is supplied as an energy fuel from digestion of carbohydrates. A decrease in PC stores activates glucose phosphorylase to break down glycogen to glucose through glycolysis.
• During glycolysis the enzyme phosphofructokinase (PFK) initiates the partial breakdown of glucose to pyruvic acid. As there’s insufficient oxygen m, pyruvic acid is broken down into lactate and H+ ions by lactate dehydrogenase
• Two ATP are produced per one molecule of glucose

[+] Resynthesises two ATP molecules
[+] Quick energy supply due to large glycogen
stores in the liver/muscles readily available)
and required fewer reactions than aerobic
glycolysis
[+] Provides energy for high-intensity exercise lasting 10-180 seconds

[-] Produces lactic acid that accumulates in the blood. This lowered pH inhibits enzyme action
[-] Stimulates pain receptors so the net effect is
increased pain and fatigue, which means
decreased performance

172
Q

Outline and evaluate the aerobic system and beta oxidation

A

Breaks down glycogen, glucose and fats to provide energy. Unlike the lactic acid system, the oxidative system uses oxygen to break down one molecule of glucose to produce a total of 38 ATP. Oxygen inhibits the accumulation of lactate.

There are three stages as well as beta oxidation:
1. Glycolysis
2. Krebs cycle
3. Electron Transport Chain

[+] Large ATP re-synthesise of 38 ATP molecules
[+] Glucose provides energy for low/moderate
intensity, high duration exercise lasting
between 3minutes and 1/2 hours dependant
on intensity
[+] Efficient ATP re-synthesis with good oxygen
supply as energy stores are large and readily
available
[+] Limited fatiguing by-products as carbon
dioxide and water are easily removed

[-] Slow re-synthesis due to complex series of
reactions so limited energy for ATP during high
intensity, short duration work
[-] Requires more oxygen supply
[-] Initial delay of oxygen from the cardiovascular
system at the start of exercise

173
Q

Describe the glycolysis stage of the aerobic system

A

• Glucose is supplied as an energy fuel from digestion of carbohydrates. A decrease in PC stores activates glucose phosphorylase to break down glycogen to glucose through glycolysis.

• During glycolysis the enzyme phosphofructokinase (PFK) initiates the partial breakdown of glucose to pyruvic acid.

• Two ATP are produced per one molecule of glucose

• Pyruvic acid is diverted further in the aerobic stent and combined with coenzyme A to form acetyl coenzyme A (acetyl coA) and releases carbon dioxide

174
Q

Describe the Krebs cycle stage of the aerobic system

A

• Acetyl coA from glycolysis combines with oxaloacetic acid to form citric acid. This is further broken down in a series of complex reactions in the mitochondrial matrix where four things happen:

  1. Carbon dioxide and water is produced and removed by the lungs
  2. Hydrogen atoms are oxidised in the electron transport chain (ETC)
  3. Energy’s released to re-synthesise 2 ATP
  4. Oxaloacetic acid is regenerated so the process continues in a cycle
175
Q

Describe the Electron Transport Chain (oxidative phosphorylation) stage of the aerobic system

A

• Hydrogen is carried to the ETC by hydrogen carriers NAD and FAD in the cristae folds of the mitochondria

• Hydrogen splits into the hydrogen ions and electrons and these are charged with potential energy

• The hydrogen ions are oxidised to form water, while providing energy to re-synthesise ATP (34 produced)

176
Q

Describe beta oxidation as a part of aerobic respiration

A

• Glucose (C6 H12 O6) produced 38 ATP but 16-carbon free fatty acids (C16 H32 O16) produces 131 ATP

• Triglycerides are broken down by lipase enzymes into three free fatty acids (FFA) and a glycerol which is used as energy to fuel the aerobic system

• FFA’s are converted into acetyl coenzyme A which is broken down by the Krebs cycle and ETC through beta-oxidation. This process produces greater energy but takes longer

177
Q

Define lactate threshold

A

The point at which we lose the ability to oxidised lactate, usually around 4mmol/L

178
Q

Outline OBLA (onset of blood lactate accumulation)

A

• OBLA occurs at lactate threshold and is the point where the production of lactate exceeds the speed of its removal.

• When lactate accumulates it reaches a point in the blood where it’s too acidic. This is known as acidosis

179
Q

Outline factors affecting the energy system used

A

• Energy system thresholds is the point at which one energy system is displaced by another to become the predominant energy system to provide re-synthesis of ATP. Intensity and/or duration must be altered once a fuel source is depleted

• Each physical activity requires a different percentage of energy from each energy system, dependant on the intensity and duration of the activity, not the event.

• During high intensity exercise, lactate production will start to accumulate above resting levels (lactate threshold). When blood lactate thresholds reach 4mmol/L this leads to OBLA, which will continue to increase if exercise intensity is maintained or increased, leading to muscle fatigue

• The duration of the glycolytic system can be improved if the Lactate threshold is increased through targeted aerobic training, prolonging the point at which OBLA is reached.

180
Q

Provide examples of energy thresholds

A

• E.g. a cyclist cycling at a low intensity (aerobic), but then reaches a steep hill for two miles and exceeds the intensity threshold of the aerobic system, thus the lactic acid system will become the predominant system

• E.g. A games played will need to constantly switch between the three systems . During team games the aerobic system is continually re-synthesising ATP/PC during recovery periods. This allows the body to use the energy systems intermittently

181
Q

Identify the factors that influence fatigue

A

• PC availability
• Glycogen availability
• Oxygen availability
• FFA availability
• Fitness levels
• Enzyme activation

182
Q

Explain how PC availability influences fatigue and OBLA

A

• Sufficient PC stores allow the body to use the ATP/PC system for high intensity, short duration activity. Without PC stores, high intensity, explosive activity can’t be continued

• PC stores are limited but available at the start and after a period of recovery during exercise. They can be conserved through pacing and re-synthesising PC stores during recovery periods

183
Q

Explain how oxygen availability influences fatigue and OBLA

A

• Sufficient oxygen available means the aerobic system can provide the energy to re-synthesise ATP

• If oxygen levels fall below the demand for exercise the aerobic threshold is reached and the glycolytic system begins to break down glucose anaerobically to re-synthesise ATP

184
Q

Explain how glycogen availability influences fatigue and OBLA

A

• Glycogen is quicker to breakdown that free fatty acids (FFA) so allows a higher aerobic intensity of exercise

• Therefore when glycogen is depleted aerobic intensity is reduced. When glycogen stores are fully depleted, the body switches to beta oxidation using FFAs as a fuel source (hitting the wall)

185
Q

Explain how free fatty acid availability influences fatigue and OBLA

A

• FFAs have to be used for aerobic energy production when glycogen stores are almost fully depleted unless exercise intensity is reduced. This brings on a sudden onset of fatigue known as ‘hitting the wall’.

• They require 15% more oxygen to breakdown than glycogen and so mean the athlete must work at a lower intensity

• Once OBLA is reached, the body has insufficient oxygen to burn FFAs aerobically to re-synthesise ATP

186
Q

Explain how fitness levels influence fatigue and OBLA

A

• The more aerobically fit, the more efficient the cardiovascular system is to take in, transport and use oxygen to resynthsise ATP

• Aerobic athletes can use FFAs earlier in sub-maximal exercise, conserving glycogen stores, increasing the aerobic threshold and delaying OBLA

• Untrained athletes reach OBLA at 50-55% of Vo2 max compared to 85-90% for trained athletes

• Trained athletes have increased ATP/PC, glycogen stores, anaerobic enzymes and lactate tolerance, increasing the threshold of the ATP/PC and glycolytic systems

187
Q

Explain how enzyme activation influences fatigue and OBLA

A

Catalyse the breakdown of PC/glycogen/glucose/FFAs. Without enzymes, there’s no reactions

188
Q

Outline the recovery process

A

• Restores the body to it’s pre-exercise state:
1. During exercise to allow the performer to maintain performance (e.g. repeated sprints)
2. After exercise to speed up recovery in preparation for the next performance

189
Q

Outline exercise induced muscle damage (EIMD) referring to the impact it has and how we can manage it

A

• Experienced immediately following bouts of strenuous exercise in which the body’s not accustomed to where significant muscle damage has been caused

• EIMD is amplified if exercise includes high frequency of eccentric muscle contractions (e.g. Plyometrics)

• EIMD can impact subsequent exercise, restricting adherence to a training programme by causing soreness, change in range of motion, loss of strength and the release of muscle proteins such as creatine kinase

• EIMD can be managed by gradually introducing eccentric muscle actions over a number of weeks or performing a prior bout of eccentric muscle exercise to reduce severity of symptoms

190
Q

Outline delayed onset muscle soreness (DOMS)

A

• Caused due to the body increasing inflammation as a protective response to tiny microtears caused as a result of strenuous, high intensity exercise

• DOMS gradually appears post exercise, peaking around 36 hours

• Effects can be limited by an appropriate cooldown, soft tissue massage, compression clothing and ice baths
• The recovery process including rest, hydration, stretching, contemporary methods, nutrition and massage

191
Q

Outline excess post-exercise oxygen consumption (EPOC)

A

• Additional oxygen consumed during recovery that is above that of at resting level to return the body to its pre-exercise state. This can take from 15 minutes to 48 hours.

• EPOC measures the quantity of oxygen of the exercise-induced disturbance of the body’s homeostasis and the subsequent recovery demand

• EPOC is split into two stages:
1. Fast alactacid component
2. Slow lactacid component

192
Q

Describe the fast alactacid component of recovery (EPOC)

A

• Uses extra oxygen that’s taken in during recovery to restore ATP and phosphocreatine (PC).
Re phosphorylation of phosphagen stores helps to primarily restore the muscle store of ATP and PC

• Myoglobin has a high affinity for oxygen, it stores oxygen in the sarcoplasm that’s diffused from Haemoglobin in the blood.

• After exercise oxygen stores are low which causes increased breathing and heart rates as physiological responses to return the body to homeostasis because they increase oxygen intake which causes myoglobin resaturation

• This requires approximately 3-4L of oxygen and takes 3 minutes to fully restore ATP/PC stores (50% restored in 30 seconds and 75% in 60seconds)

193
Q

Describe the slow lactacid component of recovery (EPOC)

A

• Second phase of EPOC that takes place after three minutes. It’s primarily responsible for lactate metabolism and re-conversion.

• Lactate is either:
1. Oxidised and removed from the body as carbon
dioxide and water
2. Converted to pyruvate to use in aerobic
respiration
3. Transported to the liver and converted to blood
glucose and glycogen (Cori cycle)
4. Converted to amino acids

• The slow lactacid component supports elevated metabolic functions taking place after exercise, namely:
• High body temperature remains for several
hours after vigorous exercise
• Hormones i.e. adrenaline remain in the blood
stimulating metabolism
• Cardiac output remains high helping reduce
temperature

• Requires approximately 5-8L of oxygen and can remove lactate from between 1-48 hours after exercise, dependant on exercise intensity. It is responsible for the removal of carbon dioxide, glycogen replenishment.

194
Q

Explain how the slow lactacid component of EPOC removes carbon dioxide

A

• Increased carbon dioxide levels created as a by-product are carried by a combination of blood plasma within red blood cells as carbonic acid (carbon dioxide and water) and carbohaemaglobin (carbon dioxide and haemaglobin) to the lungs where it’s expired

• Additionally, heightened metabolic function and chemoreceptor stimulation of the cardiac and respiratory control centres post exercise ensure respiration and heart rate remain elevated to aid in the removal of carbon dioxide

195
Q

Explain how the slow lactacid component of EPOC replenishes glycogen

A

• Consumption of a high carbohydrate diet can restore glycogen fully within the first 2 hours of recovery.

• Must utilise the ‘2 hour window of opportunity’ and then continue replenishment 10-12 hours post exercise but complete recovery can take up to 48 hours to fully replenish

• Fast twitch muscle fibres can replenish glycogen stores faster than slow twitch muscle fibres

196
Q

Outline priming

A

• A way of manipulating a warm up to speed up oxygen consumption predominately for endurance and games players

• involves drastically increasing warm up intensity to include a bout of higher intensity exercise and allocating a recovery time before performance

• Priming is used to delay the onset of lactate accumulation allowing us to exercise at a steady state (70-80% of Vo2 max) for longer.
• It does this by speeding up how quickly the aerobic energy pathway is activated by increasing oxygen uptake, reducing the requirement of the anaerobic energy provision

197
Q

Identify and explain the effects of priming

A

Increased oxygen uptake
• Due to heart rate remaining higher than rest,
oxygen uptake is higher at the start of exercise
(EPOC)

Oxidation of lactate
• Occurs during the recovery phase to imitate
steady state activity

Increased rate at which energy systems work

Increased enzyme activity of aerobic and anaerobic enzymes
• to breakdown glycogen stores in the liver and
muscles in advance of exercise

Increased muscle fibres recruited
• Therefore localised fatigue is reduced

• This all reduces the requirement of the anaerobic energy provision

A-Level PE (6 decks)

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