1.2 & 1.3 regulation of responses in exercise Flashcards
what is the anticipatory rise ?
- increase in heart rate just before taking part in exercise.
- caused by an increase in activity from the sympathetic nervous system
what is the sympathetic nervous system and when is it activated ?
- part of the Autonomic Nervous System and is found in the brain
- active when ‘fight or flight’ response is required and can result in increases HR
what is adrenaline ?
hormone which results in an increase in HR, blood pressure and alertness
describe the process of vascular shunting (redistribution of blood)
- increase in Co2 and lactic acid detected by the Chemoreceptors
- Chemoreceptors stimulate the vasomotor
- Vasomotor signals for the redistribution of blood f.
- vasodilation & constriction occur & pre-capillary sphincters adjust blood f. into the capillaries.
define vasodilation and vasoconstriction
dilation - b.v dilate allowing more blood for the active muscles
constriction - b.v constrict taking blood away from inactive areas and organs
what is the vasomotor centre and where is it located
- located in the medulla oblongata in the brain
- responsible for the regulation of HR, B.P, redistribution of b.f
describe the journey of blood through the heart
Vena Cava - right atrium - tricuspid valve - right ventricle - pulmonary artery - lungs - pulmonary vein - left atrium - bicuspid valve - left ventricle - aorta - body
what are the 2 types of circulation
. pulmonary - deoxygenated b. from the heart to the lungs & oxygenated b. back to the heart
. systematic - oxygenated b. to the body from the heart & return of deoxygenated b. from the body to the heart
what does ‘myogenic’ mean
generates own impulses (heart if myogenic)
describe the process of the Cardiac Conduction System
- elec signal begins in SAN
- impulse travels through atria, causing them to contract & pass blood to the ventricles, before reaching AVN
- AVN delays impulse for 0.1 secs whilst the atria fully contacts
- impulse travels down bundle of HIS (in the septum)
- bundle pf his separates into smaller branches purkinje fibres. these spread around ventricles cause them to contract
what is the sympathetic nervous system
- increases the heart rate via the accelerator nerve
what is the parasympathetic nervous system
- decreases the heart rate via the vagus nerve
how do Chemoreceptors effect heart rate
- during Ex. Chemo R. detect an increase in cO2
- nerve impulses sent to the medulla oblongata and the SNS is activated
- impulses sent to the SAN node for contractions to increase
- increase in HR & supply of o2 for the body
how do Baroreceptors effect heart rate
- detect increase of decrease in b.p by detecting stretching of the arterial wall
- increase in arterial pressure results in B.R sending message to the medulla O.
- ## the parasympathetic system is activated & impulses are sent to the SAN for contraction to decrease
how do Proprioceptors effect heart rate
- located in muscles, joint, tendons
- during Ex. they detect an increase in muscle movement
- impulse sent to the Medulla O. & the sympathetic NS is activated
- impulse sent to the SAN & heat rate is increased
