Circulatory System Flashcards
What does the circulatory system do
Moves blood through the body
Carries nutrients to cells and waste away from cells
Chemical massager
Distributes heat/circulation
Defence against invading organisms
Arteries
AWAY from heart (99% of the time)
Under more pressure so thicker walls /and bleed more
The largest artery
Aorta then the pulmonary artery
Pulse
Caused by blood being pumped through and artery
Arteriolas
Fine branch from arteries
Atherosclerosis
Fat in the arteries
Causes the narrowing of blood vessels creating high blood pressure
Hypertension
High blood pressure
Aneurysm
Fluid filled bulge in weakened wall of the artery
Risk of rupturing leading to cell death or stroke
Capillaries
Tiny blood vessels that connect arteries and veins
Site of fluid and gas exchange
Bruising- rupture of capillary beds cause blood to leak into extra cellular space
Veins
Carry blood BACK to the heart
Capillaries merge and become bigger called venules
Venules- lined w smooth muscle
Return of blood through veins
Low pressure when blood enters through venules
Skeletal muscles aid in venous blood flow and VALVES only open in one direction
Varicose veins
Surface veins that become larger and begin to bulge
One way valves are damaged
Causes
Genetic
Prolonged standing
Weight
Crossed legs
The heart is a double pump
The right side responsible for pulmonary circulation
-cycle from the heart to lungs and back
-thinner walls / weaker
The left side responsible for systemic circulation
-cycle of blood from the heart to body and back
-thicker walls / strong
Structure of the heart
Size of human fist
Located center of the chest under the sternum
The outside is covered w a protective sac called the pericardium which helps to lubricate the surface
SA node
Sinoatrial
The hearts pace maker
Located where the vena cava enters the right atrium
AV node
Atrioventricular node
Electrocardiographs (ECG)
Monitors electrical activity of the heart
Used to diagnose heart problems
Cardiac cycle
P- Atrial contractions
QRS - ventricular contaction
T- end of heartbeat
Heart sounds
Are produced by closing valves
Lub Dub
Lub - AV valves closing during contraction (systole)
Dub - semilunar valves closing during relaxation (diastole)
Mumurs
Caused by faulty heart valves which permit the back flow of blood into one of the heart chambers
Blood pressure
Pressure of the blood on the walls of blood vessels
Measured by a sphygmomanometer
Systole -contracted heart
Diastole- relaxed heart
Blood and immunity
Functions
-transports ( nutrients hormones wastes)
- maintain water balance
- maintain body temp (37)
Plasma proteins
Albumin - water balance
Globulin - immune function
Fibrinogen- blood clotting
Erythrocytes (RBC)
Transport oxygen to body cells
Contain hemoglobin
“Heme” iron
“Globin” protein
Makes blood red
In the bone marrow
