Applied anatomy and physiology Flashcards
What does physical activity impact in health?
- heart disease
- high blood pressure
- effects of cholesterol
- stroke
What does physical activity impact in fitness?
- cardiac output
- stroke volume
- heart rate
How does physical activity impact heart disease and describe what it is?
- helps to prevent CHD
- process of CHD is called atheosclerosis and the fatty deposis are called atheroma
- high blood pressure, high levels of cholesterol, lack of excercise and smoking cause atherosclerosis
- limits supply of O2 to the heart resulting in a heart attack
How does physical activity impact high bood pressure and describe what it is?
- the force exerted by the blood against the blood vessel walls
- high BP can put extra strain on the heart
- if untreated can lead to heart attack, kidney disease, stroke or dementia
- regular aerobic excercise can reduce blood pressure
- lowers systolic and diastolic pressure
How does physical activity impact the effects of cholesterol and describe what it is?
- consists of two types of lipoproteins LDL and HDL
- LDL is low density and transports cholesterol to the tissues and is linked to increased risk of heart disease
- HDL is high density and transports extra cholesterol back to the liver to be broken down and lowers the risk of heart diseas
- regular physical activity lowers bad LDL and increases good HDL
How does physical activity impact stroke and describe what it is?
- occurs when blood supply to the brain is cut off, lading to the death of the brain cells
- can lead to brain injury, disability and death
- ischaemic stroke is when a blood clot stops the blood supply
- haemorrhagic stroke is when a weakened blood vessel bursts
- regular exercise helps to lower BP and helps maintain a healthy weight
- this decreases chance of stroke by 27%
How does physical activity impact stroke volume and what is it?
- volume of blood pumped out by the heart in each contraction
- resting SV is 70ml
- SV is increased by increased venour return, greater elasticity of cardiac fibres and greater contractility of cardiac tissue
- SV increases as exercise intensity increases
- once a performer reaches 60% of max effort SV plateaus because ventricles do not have time to fill up
How does physical activity impact heart rate and describe what it is?
- number of times the heart beats per minute
- on average it beats 72 times per min
- HR increses in direct proportion to exercise intensity
- max HR is calculated by subtracting your age from 220
- Experts have a larger HR range due to a lower resting HR and higher max HR
- regular aerobic exercise results in cardiac hypertrophy
- stroger heart leads to higher SV and lower HR
How does physical activity impact cardic output and describe what it is?
- volume of blood puped out by the heart per minute
- Q = SV x HR
- when exercising Q increases due to an increase in HR and SV
- Q increases until max intensity is reached and then it plateaus
- Experts have higher SV but lower HR so their Q is equal to an untrained person
- Increased Q means you transport more blood to working muscles and therefore more O2 so it is easier to work at a higher intensity for longer
Where is the cardiac control centre found?
Medulla oblongata
What is the cardiac control centre connected to and how?
Sino atrial node via the peripheral nervous system
What does the peripheral nervous system consist of?
Parasympathetic and sympathetic nervous systems
What does the sympathetic nervous system do?
- prepares the body for exercise
- fight or flight
- increases heart rate
- connected via accelerator nerve
What does the parasympathetic nervous system do?
- relaxes the body
- rest and digest
- decreases heart rate
- connected via vagus nerve
What are the three ways of regulating heart rate?
Hormonal, neural and chemical
What does neural regulation involve?
Sypathetic and parasympathetic nervous systems
What does chemical regulation involve?
Receptors and O2, CO2 and pH levels of the blood
What is the cardiac control centre stimulated by?
Receptors
What do chemoreceptors do and where are they found?
- detect changes in the blood acidity (caused by change in CO2 conc.)
- carotid and aortic arch
What do baroreceptors do and where are they found?
- detect changes in blood pressure
- heart/pulmonary vessels, aortic arch and carotid sinus
What do proprioceptors do?
Detect changes in muscle movement
How is heart rate regulated by chemoreceptors? (increase)
- increase in blood CO2 conc.
- decrease in blood pH
- chemoreceptors detect change
- send impulse to CCC
- sympathetic nervous impulse sent down accelerator nerve to SAN
- heart rate increases
How id heart rate regulated by baroreceptors? (decrease)
- increase in blood pressure
- baroreceptors detect changes
- send impulse to CCC
- parasympathetic nervous impulse sent down vagus nerve to SAN
- heart rate decreases
How is heart rate regulated by propriocepptors? (increase)
- increase in muscle movement
- proprioceptors detect changes
- send impulse to CCC
- sympathetic nervous impulse sent down accelerator nerve to SAN
- heart rate increases
