Topic 3: Blood vessels, respiration, breathing, ATP and ADP Flashcards
What are the components that are present in blood plasma?
Water: solvent for carrying substances
Salts; osmotic balance, pH buffering and regulating membrane permeability
Plasma proteins; osmotic balance, pH buffering, clotting, immunity
Other dissolved substances; nutrients, waste products (urea), gases (CO2), hormones
What are the cellular elements in blood
Erythrocytes (RBC) transport oxygen.
Leukocytes (WBC) defence and immunity
Platelets - blood clotting
What are the four parts of an artery/vein
Lumen
Tunica Intima
Tunica Media
Tunica Externa
Difference between the lumen in an artery and a vein
Lumen is smaller in the artery than it is in the vein
Diff. between the tunica media in artery vs vein
Artery- thicker and helps maintain high blood pressure, thicker layer of muscle cells so they can withstand high pressure -> blood leaves the heart under high pressure
Vein -thinner and less elastic, no need for thick muscular and elastic layer in veins as they don’t have to withstand pressure, thin layer of collagen and elastic fibres
Diff. between the tunica external in artery vs veins
artery - Tough outer layer of collagen and connective tissue
Veins - thick, tough layer of collagen and connective tissue
Do artery carry blood away or towards the heart?
Away at very high pressure
What do the walls of artery do?
Under high pressure the wall of artery is pushed outwards, widening the lumen and stretching elastic fibres. When pressure falls at the end of a heart beat (diastolic pressure) the elastic fibres recoil and squeeze blood in lumen pushing the flow forward.
What are the adaptions of capillaries?
Connects arteries w/ veins, responsible for the exchange of materials between blood and internal/external environment. One cell thick - coated w/ thin protein gel (basement membrane) which acts as a filter for substances. Pores allow part of blood plasma to leak out through basement membrane - larger proteins and blood cannot leave
What are the adaptions of veins?
Collects blood from organs and transports blood from capillary networks back to heart. Under low pressure, blood drains out continuously from capillaries. Valves prevent back flow - blood gets caught in flaps of pocket valve which fills with blood, blocking lumen as blood flows towards heart it pushes flaps to the side opening the valve. Blood flow in veins is assisted by gravity and pressure exerted by muscle contraction. When muscles contract they squeeze adjacent veins like a pump.
Pressure changes in blood vessels
Blood leaving heart into arteries is under high pressure, travels in waves or pulses following each heartbeat. Once blood has reached capillaries it is under much lower pressure, no pulse. Pressure is almost 0mm by the time it reaches the veins
Velocity Changes in blood vessels
Blood travels very quickly through arteries, reaches low speed in capillaries, when blood reaches veins the speed inc.
Pulse rates
pulse rates can be measured by using the wrist, neck or digital devices. Every time heart beats a wave of blood under pressure passes along arteries - can be felt as a pulse.
What is Coronary heart disease?
Directly from the aorta two arteries branch off to supply the heart muscle with oxygen and nutrients; blockages in the coronary arteries leads to an occlusion of the blood vessels. Narrow or blocked by deposits of fat - made up of lipids or cholesterol.
Consequences of coronary heart disease?
Restricted blood flow, langina, risk of blood clots if calcium salts deposit in atheroma the artery hardens. blood clots can entirely block flow of blood to heart muscle
Causes of coronary heart disease?
Blood clots that occlude blood flow. Hypertension- raised blood pressure inc. chance of blood clot formation. Genetics - linked to mutations. Unhealthy lifestyle habits. Diet rich in cholesterol and saturated fats. Smoking. Stress.
What are four properties that gas exchange surfaces share?
Permeable; oxygen and carbon dioxide can diffuse across freely.
Large: total surface area is large in relation to the volume pf the organism
Moist: surface is covered by a film of moisture (terrestrial)
Thin: can diffuse across a short distance
What are the adaptions of alveoli for gas exchange?
Type 1 alveoli don’t do much as they are just there to form shape of the lungs; Type 2 pneumocystis. Type 2 secreted surfactant - phospholipid and protein film, reduces surface tension, prevents each Aeolus from collapsing. Alveoli increases surface area
What are the adaptions of bronchioles for gas exchange?
Small tubes that connect alveoli to trachea
What are the adaptions of capillaries for gas exchange?
Dense network surrounding each alveoli, one cell thick to shorten diffusion distance of gases.
True or False: diffusion can only happen if there is a conc. gradient.
TRUE
Why does carbon dioxide diffuse from blood to air?
lower conc. of co2 in the air.