Studied by 2 people
circulatory system
a system of blood vessels with a pump and valves to ensure one-way flow of blood
double circulation
circulation to lungs
circulation to body tissues in mammals
advantages of double circulatory system
blood passes through heart twice for each pump
right side (DEOX, pumps to lungs)
left side (OX, pumps to body)
high pressure circulation = greater flow of blood to body tissues
double circ system helps maintain blood pressure
heart: muscle contractions + valves (everytime heart beats)
both atria at same time, both ventricles at same time
blood arrives in VC, enters RA
contraction of RA, pushes through TCV to RV
RV contracts, forces blood through PA to lungs (TCV closes to prevent BF into RA) (SLV closes to prevent BF through PV)
blood enters LA from lungs through PV
LA contracts, passes blood to LV through BCV (BCV closes to prevent BF into LA) (SLV close to prevent BF into LV)
aorta
main artery that carries blood away from heart to body
semi lunar valves
connective tissues, let blood flow through arteries
septum
divides heart into L & R sides, prevents mixing of ox. and deox blood
why is left side thicker than right?
has to pump blood further throughout the body against higher pressure
coronary heart disease
CA supplies blood to heart muscles
if CA blocked, cardiac muscle is short of oxygen
blocked artery = heart attack
risk factors of CHD
diet (saturated fat)
stress (high blood pressure = fats in arteries)
smoking (chemical damage artery lining)
genetic disposition
age (higher age = narrower arteries)
gender (men at greater risk)
physical activity effects on heart rate
heartbeat 70bpm
during exercise heart rate increases to supply muscles w/ oxygen & glucose
allow muscles to respire aerobically so they have sufficient energy to contract
artery
thick walls to maintain BP
narrow lumen (maintains high BP)
elastic to accommodate surge of blood flow
vein
thin walls allow muscle to exert pressure on veins
wide lumen, great volume of blood can pass
valves prevent BF of blood
blood capillaries
one cell thick walls to allow diffusion of materials
pores in walls allow white blood cells to exit
narrow lumen to allow blood cells to pass through slowly, increases oxygen diffusion from red blood cells
experiment = effect of physical activity on pulse rate
measure heartbeat (2 fingers between bone & tendon of wrist, count # of beats in 15 seconds, multiply by 4)
measure right after exercise
multiple trials to be confident in results
red blood cells
red due to hemoglobin
carries oxygen and transports it to tissues
white blood cells
part of the immune system
fights infection by phagocytosis and antibody production
platelets
causes blood clotting where there is damage to blood vessel
protects against organ infection
plasma
transport of blood cells, ions, soluble nutrients, hormones & CO2
Phagocytosis
A type of endocytosis in which a cell engulfs large particles or whole cells
