Lecture 14 Flashcards
What make up the 3 components of the cardiovascular system
1) Heart
2) Blood vessels
3) Blood
What does the heart, blood vessels, and blood do
Heart
– Muscular pup
Blood vessels
– Conduits for blood to flow
Blood
– Circulates through body and carries material through cells
– Communication
What 6 systems are affiliated with the cardiovascular system
1) Lymph, cerebrospinal fluid (CBF) extracellular fluid
2) Lymph and CSF vessels
3) Kidney
4) Spleen, thymus, tonsils
5) Lungs
6) Bone marrow
How is the kidney and spleen, thymus, tonsils related to the cardiovascular system
Kidney
– Erythropoietin, filtering
Spleen, thymus, tonsils
– Reservoirs for blood/immune cells
How are the lungs and bone marrow related to the cardiovascular system
Lungs
– O2, CO2 removal
Bone marrow
– Stem cell pool
What make up the circulatory system
Cardiovascular + lymphatic system = circulatory system
What are examples of cardiovascular diseases
Coronary artery disease
Stroke
Heart attack (myocardial infarction)
Heart failure
Hypertension
Diabetes
What is the Pathway of Blood Vessels
1) Deoxygenated blood returns to R side of heart (enters through R atrium) from venous circulation
2) Atria receives blood
3) Heart contracts, pumps blood to ventricles
4) Right ventricle - to the lungs - to left atrium
5) Oxygenated blood leaves left ventricle via the aorta
How is blood dispersed through the body
60% systemic veins and venules
15% systemic arteries and arterioles
12% pulmonary blood vessel
8% heart
5% capillaries
What are characteristics of arteries and arterioles
Arteries
– Thick muscular walls (smooth muscle)
– Designed to handle high pressures
Arterioles
– Less muscle as pressure dropping
– Lots of innervation to control smooth muscle constriction
– Main site of BP regulation
What are the characteristics of capillaries
– No muscle - no control over diameter or connective tissue, no ability to withstand pressure
– Movements of fluid and solutes maximized here
What are characteristics of venules and veins
Venules
– Main site of lymphocytes (WBC) crossing from blood to lymph nodes
Veins
– Thin walled, fairly muscular
– Easy expansion and recoiling
What is Dyslipidemia
Imbalance of cholesterol in blood vessels
What is artherosclerosis
Thickening or hardening of the arteries
What is the optimal exchange for blood
Large surface area + low velocity
What is cardiac output
Cardiac output: amount of blood pumped by heart per minute, rate of heart x stroke volume
Where is the pressure gradient in the heart
Pressure gradient between left and right side of heart
Do veins move with or against gravity
Blood is moved against gravity toward heart
What allows veins to move against gravity
– Expansion of thoracic cavity during breathing
– Contracting skeletal muscles
– Valves (prevent blood flowing backward)
Explain Varicose veins
– One-way valve malfunctions
– Allows backwards floor of blood and pooling
– Generally occurs in superficial veins in thigh and calf
What is the heart muscle made from
Made out of cardiac muscle tissue called myocardium
What are the 3 ways the heart is different from skeletal muscle
1) Neural input
2) Neural conduction
3) Metabolism
Explain how neural input of the heart is different from skeletal muscles
Involuntary, autonomic
Explain how neural conduction of the heart is different from skeletal muscles
Gap junctions, very fast, contract as a unit
Explain how metabolism of the heart is different from skeletal muscles
– Very high in oxidative capacity
– Lots of mitochondria (35% volume compared to 5% volume in skeletal muscle)
– Fatigue resistant: beats over 3B times over lifetime
Explain where blood flows when the AV valve closes
– Caused by closure of tricuspid (right) and mitral (left) valves
– Blood moving from RA to RV
Explain where the blood flows when the semilunar valve closes
– Caused by closure of pulmonary and aortic (semilunar) valves
– From LV to pulmonary artery
What sound does the AV valve closing make
“LUB” (1st heart sound)
What sound does the semilunar valve closing make
“DUB” (2nd heart sound, louder)
What is stenosis
Stenosis - narrowing of heart valve
What causes stenosis
May be congenital, due to calcification, or scarring from rheumatic fever
What are the symtoms of stenosis
Can cause fatigue, shortness of breath, exercise intolerance or heart failure
Around how many valve replacements are there per year
There are nearly 300,000 aortic valve replacements per year
What are the 3 types of artificial heart valves
1) Ball and cage
2) Tilt-dise
3) Leaflet
What are the 4 problems with artificial valves
1) Durability - in theory, material could last thousand of years (carbon, titanium)
2) Clot formation - requires constant anticoagulant therapy
3) Can get stuck
4) Resistance to flow; vulnerability to backflow and regurgitation
What is FRS
Framingham risk score
What does FRS determine
Estimation of 10 yr cardiovascular disease risk
What factors influence FRS
– Age
– HDL-c
– Total-c
– SBP
– Smoking status
– Diabetes diagnosis
