Lecture 1: Circulation Flashcards
What is a circulation in series?
Flows in one after the other
What is a circulation in parallel?
Branching paths, concurrent, either or
What is the equation for blood pressure?
BP = CO x PR
What is the name of the sounds used for the measurement of BP?
Korotkoff
What % of blood volume is in the veins?
64%
What cross section does the right ventricle have?
Crescent, thin walled
What cross section does the left ventricle have?
Circular, thick walled
Describe the pulmonary circulation.
Lungs only, low pressure, high flow, low resistance
Describe the systemic circulation.
Multiple organs, high pressure, variable flow, variable resistance
What is the apex beat?
At systole when the apex of the heart moves forward and strikes the chest wall
When do valves open/close?
Open: when pressure on the inflow side is higher
Close: when pressure on the outflow side is higher
What controls blood volume?
Kidneys
What is the filtration unit of the kidney?
The nephron - contains a glomerulus (the filter)
What controls the kidneys?
The endocrine system and the autonomic nervous system
What is the result of contracting the afferent artery in the nephron?
Decreased filtration
What is the result of dilating the afferent artery and constriction of the efferent artery in the nephron?
Increased filtration
How many glomerulus per kidney?
1 million
What is the glomerular filtration rate?
Fluid entering all bowman capsules in ml/min
Increase renal blood flow - increase GFR
What is the definition of hypoxia/anoxia/hypoxaemia?
Insufficient O2 supply to a region or to entire body
Causes:
- Low Hb
- Consumption greater than flow
- failure of gas exchange in the lung
What is the definition of ischaemia?
Insufficient blood flow to a region
Causes:
- Vessel (clog, constriction)
- Insufficient blood volume
- Insufficient pressure
What is angina pectoris?
A symptom
Chest pain due to over exertion of (damaged) heart tissue
With or without physical exertion
Treat with nitrates
Cause: ischaemia of the heart tissue due to an obstruction of coronary artery
What is the treatment for MI?
Morphine
Oxygen
Nitrates
Aspirin
What causes heart failure?
Heart pumps out insufficient blood
What are the symptoms of heart failure?
Fatigue, dypnoeia, oedema
What is shock?
Critically low perfusion, medical emergency, affects critically ill patients
What causes syncope?
Insufficient blood flow to the brain
