bio b7.2 - transport in animals

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