(6) Cardiovascular System Flashcards
How much blood goes to the muscles during exercise?
84%
What affects myocardial blood flow in the heart?
- changes in aortic pressure
- compression myocardial vessels
What is a coronary artery bypass?
- treats the buildup of plaques in the arteries in the heart
How is the blood supply of an artery measured?
coronary angiogram
Why do you do a warm up?
start process of coronary artery dilation
What does nitric oxide do?
makes arteries bigger improving blood flow
What occurs as a result of coronary artery dilation?
- nitric oxide
- metabolites
- sympathetic stimulation
When does the body use the sympathetic system?
during exercise when adrenaline (“fight or flight”)
When does the body use the parasympathetic system?
“rest digest”
When does angina occur?
not enough blood supply to where an artery is supplying
How does the electrical system of the heart work?
- vagus nerve delivers to SA node
- signal from SA node to AV node
- AV node to bundles of His / Purkinje that go down around ventricles (contract)
What are the implications of the electrical system of the heart?
- Increased HR
- Increased activity of sympathetic nerves to the heart neurotransmitter noradrenaline
- increased activity of parasympathetic nerves to the heart neurotransmitter acetylcholine
- Increased blood-borne adrenaline
What are the two areas that are looked at when measuring electrical activity?
- Rate (fast, slow)
- Rhythm (regular, regular irregular, irregular irregular)
What is the difference between a cardiac arrest and a heart attack?
A cardiac arrest is a problem with the electrical system whereas heart attack is a circulation problem
What are the muscle layers of the heart?
- endocardium
- myocardium
- epicardium
- pericardium
How do we measure muscle function of the heart?
Echocardiography
How are veins and arteries different?
- arteries have thicker walls (higher pressure)
- veins don’t need as much pump
- arteries have valves to stop blood going back to heart
How does blood get back to the heart?
- venous return
- blood volume
- inspiration
- cardiac suction effect
- skeletal muscle pump
What happens with stagnant blood?
- clots
- DVTs
What are the measurement seen for the CV system?
- BP
- MAP
- Cardiac output
- central venous pressure
How is the arterial blood pressure measured?
catheter with a probe into an artery usually at elbow
What is MAP?
Mean arterial pressure (perfusion) around the body
What does a MAP <60 mean?
not enough blood supply to everywhere, would not get them up out of bed
What are the risks for exercise and the heart?
- related to CV disease
- in acute setting
- use of prescribed meds
What are the benefits of exercise for the heart?
- reduces risk of further CV disease
- lower BP
- improves blood flow
- improved muscle mass
What are some acute responses of the CV system to exercises?
- increased HR, stroke volume, CO
- Redistribute blood to muscles increases and other tissues decreases
- BP increase / decrease
- Improves O2 efficiency
- increased coronary blood flow
- increased plasma volume
What are some chronic adaptations of the CV system to exercise?
- HR & CO decreased
- Stroke volume increases
- redistribution blood to muscles decreases and other tissues increases
- BP lowers
- Improve O2 efficiency
- increases coronary blood flow
- increases plasma volume
