Cardiovascular System Flashcards
What kind of tissue is blood?
Blood is connective tissue
What % of the blood that leaks out of the capillaries returns via the venules?
85%
What % of the blood that leaks out of the capillaries returns via the lymph vessels?
15%
What % of blood is liquid (plasma) ?
55%
What % of blood plasma is water?
92%
What % of the formed elements in blood is white blood cells?
1%
What are the 3 components of formed elements in blood?
Red blood cells
White blood cells
Platelets
Where are the pluripotent stem cells located?
In bones
How long do RBCs live?
90-120 days (3-4 months)
Why can’t RBCs repair themselves?
They contain no nucleus or organelles
What is anaemia?
Reduced oxygen carrying capacity of blood
What is haemophilia?
Inherited deficiency of clotting causing spontaneous bleeding on minor trauma
What is jaundice and what causes it?
Jaundice is the yellowing of skin and eyes. It is caused by bilirubin in the blood
What are leucocytes?
White blood cells
What are WBCs involved in?
Body defense
How do WBCs escape from blood vessels?
Squeeze between the gaps between the cells that make up the blood vessel walls
What is leukaemia?
Abnormal WBCs multiplying uncontrollably
What do platelets (thrombocytes) do?
Platelets Help plug holes in blood vessel walls and make blood clot (haemostasis)
Why do clots often form in veins?
Blood flows slowly there
What is the pericardium?
The pericardium is the fibrous “balloon” in which the heart sits
What does it mean to say that the circulation of the blood is a double circulation ?
For each circulation of the blood round the body the blood goes through the heart twice
What is the name of the blood vessels that carry blood from the heart to the lungs?
Pulmonary arteries
What is the name of the blood vessels that carry blood from the lungs back to the heart?
Pulmonary veins
What are the 2 main blood vessels bringing deoxygenated blood back to the heart?
SVC
IVC
What is the main blood vessel sending oxygenated blood around the body?
Aorta
How many valves are there in the heart, and what are the 2 main types of valve?
There are 4 valves in the heart
The two main are semi lunar and cuspid
What is oedema?
Swelling
What is the myocardium?
The muscle layer of the heart wall
What is special about 1% of the heart muscle cells?
They are autorhythmic
The SA node generates impulses 90-100 x per minute. The parasympathetic Nervous System slows this down to what?
75 x per minute
What is an ectopic pacemaker?
Parts other than the SA node becoming excitable
Give another name for an abnormal heart rhythm
Arrhythmia
The first thing the heart does is supply itself – how?
Via coronary arteries
What are anastamoses?
Connections between the coronary arteries
What is the number 1 risk factor for Coronary Artery Disease?
Smoking
What is angina pectoris?
temporary lack of oxygen to the heart
what is an aneurysm?
A bulge in the artery wall
What’s the difference between an embolus and a thrombus?
Embolus- bit broken off on the move
Thrombus- static blockage
What is a heart attack?
Heart muscle cell death due to lack of oxygen
What may cause a heart murmur?
Leaking heart valves
What are 3 things that control heart rate?
Autonomic nervous system
Hormones
Age
Gender
Fever
Low body temperature
Why do muscular arteries have a lot of smooth muscle?
To control blood flow to specific areas
Which part of the nervous system connects with the blood vessels – sympathetic, parasympathetic, or both?
Sympathetic nervous system
Why are venules and veins thinner than arteries and arterioles?
There is less pressure
What stops blood in veins flowing backwards?
Valves
What is a DVT?
A blood clot in the deep veins of the legs
What is a ‘normal’ volume of blood?
5 litres
What are the 3 factors effecting blood flow in blood vessels?
Blood vessel diameter
Blood thickness (red blood vessels and plasma)
Length of blood vessels
What is the officially defined ‘normal’ blood pressure?
120/80
What is Essential hypertension?
Not dependent on another condition (ie lifestyle)
