transport in humans

density of substances in the blood?

plasma (least dense), white blood cells and platelets (mid), RBC (most dense)

what does plasma contain?

plasma proteins, hormones, dissolved nutrients, blood cells, carbon dioxide and urea

why does RBC have no nucleus?

so that RBC will have more space to contain more haemoglobin to transport more oxygen

WBC or RBC bigger?

WBC! also WBC has a nucleus

what the 2 types of WBC?

phagocyte and lymphocyte

functions of WBC?

protects the body against harmful microorganisms AND responsible for tissue rejection after a tissue or organ transplant.

how do each WBC type protect the body against harmful microorganisms?

phagocytes, bacteria go through phagocytosis, where they get engulfed and destroyed. for lymphagocytes, they produce antibodies that bind and cause bacteria to lose or neutralise viruses.

platelets got nucleus?

nah

functions of platelets?

clot blood to prevent further blood loss from the body, and to prevent harmful microorganisms from entering the body

process of clotting blood?

when tissue/platelets are damaged, they release an enzyme called thrombokinase. thrombokinase converts prothrombin to thrombin in the presence of calcium ions. thrombin then converts soluble fibrinogen proteins into insoluble fibrin threads. fibrin threads then entangle blood cells (RBC) to form a clot.

blood flow direction through arteries? (away/towards the heart)

arteries carry blood AWAY from the heart

blood flow direction through veins? (away/towards the heart)

veins carry blood back TOWARDS the heart

oxygen content in arteries, veins and capillaries?

arteries carry oxygenated blood (except the pulmonary artery!), veins carry deoxygenated blood (except the pulmonary vein!)

pressure of blood in arteries, veins and capillaries?

in arteries, pressure of blood is high and fluctuating (blood pumped from the heart passes through in pulses, so elastic walls stretch and recoil). in veins, pressure of blood is lower and steady. in capillaries, pressure of blood is lower than artery, higher than vein.

flow of blood in arteries, veins and capillaries?

in arteries, blood flow is rapid and in spurts. in veins, blood flow is slow and smooth. in capillaries, blood flow is very slow and smooth .

structure of arteries

thicker wall, more muscle and elastic tissue, smaller lumen than vein. valves are absent! (except for aorta and pulmonary artery)

structure of veins

thinner wall, less muscle and elastic tissue, larger lumen than arteries. values are present!

structure of capillaries

one-cell thick wall, no muscle and elastic tissue, smallest lumen, valves absent

adaptation of arteries and relation to function?

arteries have thick muscular walls, to withstand high pressures of blood flow from the heart. arteries have highly elastic walls, to allow walls to stretch and recoil and maintain pressure in artery.

adaptation of veins and relation to function?

veins have valves, to prevent the back flow of blood. veins have large lumens to reduce resistance to blood flow, and allow blood to be transported back to the heart.

adaptation of capillaries and relation to function?

capillaries have one-cell thick walls, to decrease diffusion distance. they are also branched, to increase surface area to volume ratio. this is to ensure there is a higher rate of exchange of materials via diffusion. capillaries have a partially permeable wall to allow only smaller particles to pass through and prevent large particles from passing through.

what are the cells that can exit the blood vessels, and those that can’t?

WBC can exit, RBC and platelets cannot.

function of tissue fluids?

it serves as a medium for dissolved substances to move between capillaries and tissue cells

what do tissue fluids NOT contain?

RBC and plasma proteins (cuz they are too large to pass through the partially permeable capillary wall)

what substances can pass through the capillary wall?

from blood to tissue fluid, from RBC, oxygen! from plasma, digested nutrients (e.g. glucose, amino acids and fatty acids). from tissue fluid to blood, from RBC, carbine dioxide and metabolic waste. from plasma, nothing!

what substances can NOT pass through the capillary wall?

plasma proteins, they’re too large! yet again!

four chambers of heart

left atrium, left ventricle, right atrium, right ventricle

which side of the heart contains oxygenated and deoxygenated blood?

right side of the heart contains deoxygenated blood from the body, left side of the heart contains oxygenated blood from the lungs.

why is having a hole in your heart a sickness?

having a hole in your septum would cause oxygenated blood in left side to mix with the deoxygenated blood, reduced the amount of oxygen pumped to body. insufficient oxygen will be supplied to the body, so ppl become more fatigued during vigorous activity.

atrium and ventricle functions (for left and right)

left atrium pumps oxygenated blood to the left ventricle. right atrium pumps deoxygenated blood to the right ventricle. left ventricle pumps oxygenated blood to the rest of the body. right ventricle pumps deoxygenated blood to the lungs.

atria thickness of walls

atria has thinner walls, only needs to exert a smaller force to pump blood a shorter distance to the ventricles.

ventricle thickness of walls

ventricle has thicker walls, to exert a large force to pump blood a further distance to the body. left ventricle has thicker than right ventricle.

four blood vessels of heart

vena cava, pulmonary artery, aorta, pulmonary vein

arteries blood flow direction?

arteries are pulmonary artery and aorta, and they carry blood AWAY from the heart

veins blood flow direction?

veins are pulmonary vein and vena cava, and they carry blood TOWARD and INTO the heart

four blood valves of heart

pulmonary valve, tricuspid valve, aortic valve, bicuspid valve

tricuspid valve flow direction

allow blood to flow from the right atrium into the right ventricle

pulmonary valve flow direction?

allow blood to flow from right ventricle to pulmonary artery

bicuspid valve flow direction?

allow blood to flow from left atrium to right ventricle

aortic valve flow direction?

allows blood to flow from the left ventricle into the aorta

steps of flow of blood through the heart (RIGHT side)

1. deoxygenated blood from rest of the body enters the right carrying via vena cava.

2. right atrium contracts, tricuspid valve opens and blood flows into the right ventricle.

3. right ventricle contracts, tricuspid valve closes, semilunar valves opens and blood flows through the pulmonary artery to the lungs.

steps of flow of blood through the heart (LEFT side)

1. oxygenated blood from the kungs enters the left atrium via the pulmonary vein.

2. left atrium contracts, bicuspid valve opens and blood from s into the left ventricle.

3. left ventricle contracts, bicuspid valve closes, semi-lunar valves opens and blood flows through the aorta to the rest if the body.