Body Systems L12 Notes Flashcards
What are the indicative values of a non-athlete when resting & during excersise for Cardiac output, heart rate, stroke volume & heart weight.
Non-Athlete Resting Non-Athlete Excersised ~5 ~20 75 190 65 105 250-300
What are the indicative values of an athlete when resting & during excersise for Cardiac output, heart rate, stroke volume & heart weight.
Athlete Resting Athlete Excersised ~5.5 ~30 55 180 100 165 500
What are the indicative values of a non-athlete when resting for Cardiac output, heart rate, stroke volume & heart weight.
Non-Athlete Resting ~5 75 65 250-300
What are the indicative values of a non-athlete when exercising for Cardiac output, heart rate, stroke volume & heart weight.
Non-Athlete Excersised
~20
190
105
What are the indicative values of an athlete when exercising for Cardiac output, heart rate, stroke volume & heart weight.
Athlete Excersised ~30 180 165
What are the indicative values of an athlete when resting for Cardiac output, heart rate, stroke volume & heart weight.
Athlete Resting ~5.5 55 100 500
What are the indicative values of cardiac output for an athlete & non-athelete both when relaxed & exercising?
Non-Athlete Resting Non-Athlete Excersised Athlete Resting Athlete
Excersised
CO (L/min) ~5 ~20 ~5.5 ~30
What are the indicative values of heart rate for an athlete & non-athelete both when relaxed & exercising?
Non-Athlete Resting Non-Athlete Excersised Athlete Resting Athlete
Excersised
HR (bpm) 75 190 55 180
What are the indicative values of stroke volume for an athlete & non-athelete both when relaxed & exercising?
Non-Athlete Resting Non-Athlete Excersised Athlete Resting Athlete
Excersised
SV (ml) 65 105 100 165
Describe the innervation of the heart
- Cardioregulatory centre & chemoreceptors -> medulla oblongata
Via -> Sensory Nerve Fibres
-» Baroreceptors -> wall of internal carotid artery
-» Carotid body chemoreceptors
-» Baroreceptors -> Aorta - Adrenal Medulla
i) Via -> Parasympathetic nerve fibres
-» Sinoatrial (SA) Node
ii) Via -> Sympathetic nerve fibres
-» Heart - Adrenal Medulla
Via -> Sympathetic nerve fibres -> adrenal gland
>Release adrenaline/noradrenaline -> circulation
-»Heart
What parts of the sensory nervous system and the heart do the sensory nerve fibres connect?
- Cardioregulatory centre & chemoreceptors -> medulla oblongata
Via -> Sensory Nerve Fibres
-» Baroreceptors -> wall of internal carotid artery
-» Carotid body chemoreceptors
-» Baroreceptors -> Aorta
What parts of the sensory nervous system and the heart do the parasympathetic nerve fibres connect?
- Adrenal Medulla
i) Via -> Parasympathetic nerve fibres- > > Sinoatrial (SA) Node
What parts of the sensory nervous system and the heart do the sympathetic nerve fibres connect?
2. Adrenal Medulla Via -> Sympathetic nerve fibres i) ->> Heart ii) -> adrenal gland >Release adrenaline/noradrenaline -> circulation ->>Heart
What is a chronotropic effect?
• Chronotropic Effect:
- Influence effecting heart rate.
What is a negative chronotropic effect? Give an example & describe how it is carried out.
Negative chronotropic effect: Slows Heart Rate Eg. Acetlycholine ->> Via positive end -> muscarinic (ACh)-receptor gated K-channels Component of ‘vagal tone’
What is a positive chronotropic effect? Give an example & describe how it is carried out.
Positive chronotropic effect:
Increase Heart Rate
Eg. Noradrenaline & adrenaline
-» Via stimulation -> hyperpolarisation-activated ion channels
What is bradycardia?
Bradycardia:
Chronotrophic effect which slows heart rate under pathological conditions.
What is tachycardia?
Tachycardia:
Chronotropic effect which incr. heart rate under pathological conditions.
Describe the characteristics of an average adult heart rate
• Adult Heart rate:
- 60-80 (-100) bpm
- Very little / no sympathetic cardiac activity
- At rest -> SAN Node considered under high vagal tone
Slows inherent heart rate of ~110 bpm
What is the end-diastolic volume?
• End-Diastolic Volume:
Volume of blood in ventricle at end of loading / filling
What is the end-systolic volume?
• End-Systolic Volume:
Volume of blood in ventricle at end pf contraction (systole)
What is the equation for calculation of stroke volume using EDV & ESV?
• Stroke Volume = ( End-Diastolic Volume ) – ( End-Systolic Volume )
Describe characteristics of ventricular filling
• Ventricular filling:
Relies -> atrial filling
-> Determined ->Venous return of blood.
Incr. rate of ventricular filling
-> incr. stroke volume
Incr. EDV
-> incr. initial length / stretch -> cardiac muscle fibres
-» incr. stroke volume & cardiac output
State the Frank-Starling Law of the Heart
• Frank-Starling Law of the Heart:
The force / tension developed in a muscle fibre depends -> extent to which fibre stretched.
Name the factors affecting Venous Return / Central Venous Pressure
Posture
Muscle pump
Respiratory pump
Describe how posture affects venous return / central venous pressure
- Posture:
- Blood volume influenced by gravity -> posture.
- Standing venous pooling in legs
»Decr. venous return.
Describe how the muscle pump affects venous return / central venous pressure
- Muscle pump:
- Venomotor tone involving constriction -> veins -> skeletal muscles.
- Venous return facilitated -> valves
»Prevent backflow of blood
Describe how the respiratory pump affects venous return / central venous pressure
- Respiratory Pump:
- Inspiration creates internal pressure difference by lowering intra-thoracic pressure & incr. intra-abdominal pressure.