T3 L1: Intro to circulation Flashcards
What is the cause of shock?
Insufficient perfusion
What is perfusion?
Fluid going through tissues
What is syncope?
Fainting. It’s caused by hypotension
Circulation from which side of the heart flows in series?
Pulmonary (right side)
Circulation from which side of the heart flows in parallel?
systemic (left side)
Describe the blood pressure equation
BP= cardiac output x peripheral resistance
What happens during systole?
The heart is pumping blood (the ventricles contract)
What happens during diastole?
The heart is relaxing and being filled with blood (the ventricles relax)
What is a sphygmomanometer measuring and how?
Blood pressure by measuring how much pressure in an air-cuff it takes around a arm to block blood flow through the brachial artery
Which type of vessel sets the total peripheral resistance?
Arterioles
How much of blood is in veins?
nearly 2/3
What are the 3 main layers of a blood vessel and what does each one contain?
- Intima (contains the endothelium, basement membrane and a lamina propria)
- Media (internal elastic membrane and smooth muscle)
- Adventitia (vasa vasorum)
Which type of blood vessels don’t have valves?
Arteries and capillaries
Which side of the heart has variable flow?
The left. Eg. During exercise more blood will flow to muscles
what is the apex beat?
At systole, the apex of the heart moves forward and strikes the chest wall
Describe the flow of oxygenated blood around the heart
- Pulmonary arteries
- left atrium
- mitral (bicuspid) valve
- left ventricle
- aortic valve
- systemic circulation
Describe the flow of deoxygenated blood around the body
- superior and inferior vena cava
- right atrium
- tricuspid valve
- right ventricle
- pulmonary valve
- pulmonary arteries
- lungs
Which heart valves have papillary fibres?
The atrioventricular valves (mitral and tricuspid)
What is a prolapse?
When the papillary fibres of valves fail and the valve starts to turn inside out and therefore doesn’t actually close any more
Which valves cause S1?
The atrioventricular valves (mitral and tricuspid)
Which heart valves cause S2?
The semilunar valves (aortic and pulmonary)
Which valves close at diastole?
Aortic and pulmonary valves (semilunar)
Which valves close at systole?
Mitral and tricuspid (atrioventricular)
What are the 2 ways cardiomyocytes can be stimulated?
By neighbouring cells or by the conducting system
How could formed elements contribute to hypertension?
By blocking vessel walls
What part of blood doesnt directly contribute to pressure?
The formed elements (Eg. red blood cells)
Which organ sets blood volume?
The kidneys
Which 2 systems control the kidenys?
The endocrine system and autonomic nervous system
What is an afferent atriole?
Towards something
What is an efferent atriole?
Away from something
What are the 2 exits of afferent blood in the kideneys?
The Bowman’s capsule or the efferent arteriole
What is the Glomerular filtration rate (GFR)?
The rate at which fluid enters the Bowman’s capsules
What does a high Glomerular filtration rate (GFR) mean to the amount of urine produced?
More fluid lost to urine (more urine)
What effect does high renal blood flow have on Glomerular filtration rate (GFR)?
Higher GFR
What drug class is used as immediate relief for angina pectoris?
Nitrates
What is the long term treatment for angina pectoris?
Same as for CHD
What is angina pectoris?
Chest pain due to over-exertion of heart tissue
What is the treatment for an MI?
MONA ( Morphine for pain, Oxygen to prevent hypoxia, Nitrates to open vessels and Aspirin to prevent clotting)
What is heart failure?
When the blood pumps insufficient blood
