Anatomy and Physiology - Year 13 Mock

• What is the role of the bursa?

  Sack of synovial fluid that helps create friction free movement
• Motor units muscle contraction pathway?

  • Nerve impulse initated in the motor neurone cell body
  • Conducted down axon of motor neuron by a nerve action potential to the synaptic cleft
  • Acetycholine secreted into synaptic cleft to conduct nerve impulse across gap
  • If electrical charge above threshold muscle fibre contraction
  • All or none manner
• What is venous return?

  The volume of blood returning to the heart
• What are the mechanisms of venous return?

  • Pocket valves
  • Smooth Muscle
  • Muscle pump/Respiratory pump
  • Gravity
• What is frank starlings law?

  Increased VR leads to increased SV as the increased stretch on the ventricle walls increases the strength or force of the contraction
• Why does SV peak at submaximal levels?

  Because it no longer has enough time to fill due to the increased HR
• What are the two hormonal control mechanism that influence HR during exercise?

  • Adrenaline - Speeds up rate of contraction
  • Noradrenaline - Increases strength of contraction
• What are the 4 neural mechanisms affecting HR during exercise?

  • Chemoreceptors
  • Baroreceptors
  • Thermoreceptors
  • Proprioreceptors
• What are the two intrinsic mechanisms affeting HR during exercise?

  • Temperature
  • Venous return
• What centre in the brain controls sympathetic and parasympathetic stimulation?

  Cardiac control centre
• What nerve does the sympathetic nervous system use?

  Accelerator nerve
• What nerve does the parasympathetic nervous system use?

  Vagus nerve
• What does carbon dioxide dissolve in plasma as?

  Carbonic acid
• What center in the brain controls vascular shunt?

  Vasomotor control centre
• What are the four most common types of heart conditions?

  • Artherosclerosis
  • Angina
  • Myocardial Infarction
  • Stroke
• How does exercising decrease the risk of CHD?

  • Lowers average resting blood pressure so reduces strain on the artery wall
  • Reduces the number of Low density lipoproteins and increase amount of high density lipoproteins
  • Reduces stress levels so decreases risk of hypertension
• What are three lifestyle factors affecting CHD?

  • Diet
  • Alcohol
  • Smoking
• What is external respiration?

  • The exchange of oxygen and carbon dioxide between the lungs and blood
• What is internal respiration?

  • The exchange of oxygen and carbon dioxide between the blood and muscle tissue
• How is 97% of the bodys oxygen transported by haemoglobin?

  Oxyhaemoglobin
• Carbon dioxide transport?

  Dissolved in water as carbonic acid

  Carried by haemoglobin as carbahinohameoglobin
• At rest IC sends message to diaphragm via the phrenic nerve and the external intercostals via the intercostal nerves
• What are the IC muscles during exercise that are stimulated?

  • Sternocleidomastoids
  • Scalenes
  • Pectoralis minor
• What are the EC muscles during exercise that are stimulated?

  • Internal intercostals
  • Recuts abdominus
  • Obliques
• IC increases depth of breathing and EC increases rate of breathing
• Partial pressure is the pressure exerted by a gas in a mixture of gasses
• What are the four factors causing the partial pressure curve to shift to the right?

  • Increase in blood and muscle temperature
  • Decrease in PP02 within muscle tissue, increasing diffusion gradient
  • Increase in PPco2 within thge muslce tissue increasing the co2 diffusion gradient
  • Bohr effect - increase in the acidity of blood
• What 5 actions need to be considered during inspiration?

  • Muscle action
  • Movement
  • Change in thoracic cavity volume
  • Change in lung air pressure
  • Inspiration or Expiration
• Explain the effect of altitude on performance?

  • P02 in air is lower than at sea level
  • Air inspired has less pp02 so diffusion gradient is low
  • Less 02 passed into capillary blood
  • Blood arriving at muscle tissue has a low pp02 meaning diffusion gradient is very low
  • Smaller amount of 02 diffused into muscles
  • Muscles work anaerbically much sooner and tire quicker
• Benefits of altitude training?

  • EPO released so more RBCs
  • Increased aerobic capacity
• Approaches to altitude training?

  • Arrive late or smash and grab approach
  • Arrive early
  • Train high race high
  • Live high train low
• What is linear motion?

  Motion along a line with all parts moving at the same speed in the same direction
• What is angular motions?

  Motion around a fixed point or axis
• What is general (bola) movement?

  motion which combines linear andd angular motion
• What is newtons first law of inertia?

  A body continues in a sate of rest or uniform velocity unless acted upon by an external force
• What is newtons second law of acceleration?

  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 in which the force acts
• What is newtons 3rd law?

  • For every action there is an equal and opposite reaction
• Net force is the sum of all the forces acting on the body
• What factors affect friction?

  • Roughness of the ground surface
  • Roughness of the contact surface
  • temperature
  • size of the normal reaction
• What factors affect air resistance?

  • Velocity
  • Shape
  • frontal cross section area
  • Smoothness of the surface