Week 7- Cardiovascular Pathophysiology Flashcards
What law relates initial fibre length to strength of contraction?
Frank Starling Law
What law relates the pressure on a wall to the transmural pressure and radius of the vessel?
Law of LaPlace
What are the fibrous bands of connective tissue that connect the heart valves to the papillary muscle?
Chordae tendinae
Whats on the x axis of the Frank Starling curve?
Preload
Whats on the y axis of the Frank Starling curve?
Cardiac output
How does the Frank Starling curve move during exercise?
It becomes steeper and cardiac output is higher (therefore plateaus at a higher level)
How does the Frank Starling curve move during heart failure?
It becomes less steep and cardiac output is lower (plateaus at a lower level)
What would happen to the resistance in vessels after prolonged hypertension?
It increases
What would happen to vessels after prolonged hypertension?
Vessel walls thicken, lumen decreases in size, radius of the whole vessel stays the same
What 2 physiological factors affect heart rate?
Autonomic nervous systemic (both sympathetic and parasympathetic)
Baroreceptor reflex
What 3 factors affect stroke volume?
Preload
Afterload
Contractility
Which neurotransmitter decreases heart rate? What system is it involved with?
Acetylcholine- via parasympathetic system
Which neurotransmitter increases heart rate? What system is it involved with?
Adrenaline- via sympathetic nervous system
Who may have an increased stroke volume?
Pregnant women, athletes, during exercise
Who may have a reduced stroke volume?
After a heart attack, those with hypertension
What membrane lines the thorax and lungs?
Pleura
What is the FVC
The max vol of air that can be exhaled following a deep inhalation
What happens to alveolar ventilation when dead space increases?
Alveolar ventilation becomes lower
What is maximum ventilation?
137 L/min
What 2 factors impact maximum ventilation?
Age and sex
What is the limiting factor for maximum ventilation?
Respiratory muscle fatigue
What is maximum cardiac output?
25 L/min
What happens to the flow volume loop in restrictive disease?
Volume is lower, flow rate during both inspiration and expiration decreases
What happens to the flow volume loop when theres fixed airway obstruction?
Volume remains the same but flow rate during inspiration and expiration decreases
