mass transport Flashcards

Question

describe the blood flow of deoxygenated blood in the heart so it can be taken to the lungs to become oxygenated i...v..c.. , r..a.., t..v.. ,r..v..,p..v, p..a..,L..

Answer 1

blood enters through the right atrium via the inferior vena cava. the right atrium contracts pushing the blood through the tricupsid valves into the right ventricle, the right ventricle then contracts pumping the blood throught the pulmonary valve up through the pulmonary artery where bloood is taken to the lungs

Answer 2

- inferior as its on the bottom of the heart - superior as its on the top of the heart

Answer 3

because the heart pumps the blood to the rest of the body

Answer 4

now the blood is oxygenated. blood travels through the pulmonmary vein into the left atrium. the left atrium contracts and the blood travels through the micupsid valve into the left ventricle. the left ventricle contracts pushing the blood through the aortic valve into the aorta so can be transpoorted to the rest of the body

Answer 5

they branch off the aorta and provides the heart with its own supply of blood

Answer 6

because a blockage can cause a heart attach or myocardial infarction

Answer 7

the mixing of the blood would result in partially oxygenated blood reaching the tissues and the lungs. this would mean that the supply of oxygen to the tissues would be inadequate and there would be a reduced diffusion gradient in the lungs, limiting the uptake rate of oxygen

Answer 8

describes the series of events that occur during one complete heartbeat. the contraction and relaxation of both the atria and ventricle - diastole, atrial systole, ventricular systole

Answer 9

one cardiac cycle is completed when the heart fills with blood and the blood is pumped out

Answer 10

- both atrial and ventricle muscles are relaxed - volume in the atria is high so the pressure is low - blood enters the atria from veins with a high pressure - semi-lunar valves are shut - as pressure rises in the atria due to the entry of blood, blood starts to move into the ventricles where there is a low pressure - atrioventricular valves are pushed open

Answer 11

-atria muscles contract -volume of atria decreases so pressure increases - ventricles muscles relaxes so there is a low pressure - blood is pushed out from atria to ventricles - atrioventricular valves are open - semi-lunar valves are shut

Answer 12

- ventricle muscles contract - volume decreases so pressure increases - arteries have a lower pressure - blood is pushed out of the heart to the arteries - semi-lunar valves are open atrioventricular valves are forced shut to prevent backflow of blood

Answer 13

CARDIAC OUTPUT (cm3 min-1) = STROKE VOLUME (cm3) X HEART RATE

Answer 14

the volume of blood pumped by the heart during one cardiac cycle

Answer 15

supply o2 and glucose to muscles faster, remove co2 from the muscles faster , remove lactate away fastewre, remove heat away friom the muscles fater

Answer 16

- Their heart muscle is stronger and the volume of each chamber can be increased. - This enables them to increase their stroke volume as thicker muscle can contract with greater force to expel more blood - Athletes pump more blood out in each heartbeat so are able to expel the same volume of blood in fewer beats than an unfit person with a smaller cardiac output

Answer 17

pressure changes in the heart

Answer 18

Any condition that interferes with the coronary arteries

Answer 19

These supply the heart muscle with the glucose and oxygen needed for respiration If the vessels become narrow or blocked, the supply of glucose and oxygen is stopped or reduced. This may lead to death of the cells resulting in a heart attack (Myocardial Infarction)

Answer 20

Cardiovascular disease (CVD) concerns the heart and blood vessels. Principles are the same.

Answer 21

Most CVD starts with ATHEROMA formation

Answer 22

formation of fatty deposits in wall of arteries

Answer 23

formation of blood clot

Answer 24

swelling of weakened artery

Answer 25

disease you get when you have a build up of atheromes

Answer 26

when blood clots reach the brain. mini stroke - blood clot in small blood vessels

Answer 27

A risk factor is a factor correlated with a particular disease

Answer 28

Diet Age and Sex Genetic factors Blood cholesterol/ LDL levels in blood Cigarette smoking High blood pressure

Answer 29

Tissue fluid is a substance that surrounds the body cells, and provides a constant environment for the cells it surrounds.

Answer 30

from tissue fluid

Answer 31

the components in plasma

Answer 32

to fight infections

Answer 33

high hydrostatic pressure at the arteriole end of the capillary pushes fluid out of the blood. Small pores in capillary walls only the small molecules can pass through. e.g Plasma, Water molecules, Minerals and salts, Glucose and urea, Small proteins and amino acids Those that don’t! Large proteins, Red blood cells, Platelets

Answer 34

At the arterial end of capillaries, the high hydrostatic pressure forces many of the components of the blood through small pores in the capillary walls, such as glucose, amino acids, mineral and salts, and plasma Rbc and large proteins are unable to move out, therefore remain in the blood Reducing the fluid in the capillaries, reduces the pressure. At the venous end of the capillary, Hydrostatic pressure is lower, Solute potential is higher (due to proteins remaining in blood) . Water potential in the capillaries is MORE NEGATIVE (low) compared to the tissue fluid. Fluid drains back into the blood by OSMOSIS. 90% of the fluid drains back in, 10% is returned to the blood by the lymphatic system.

Answer 35

once tissue fluid has exchanged metabolic materials with the cells it bathes.

Answer 36

Not all tissue fluid returns to the capillaries. The excess drains into the lymphatic system, where it forms lymph.

Answer 37

Lymph is a colourless/pale yellow fluid similar to tissue fluid but containing more lipids AND LESS PROTEINS.

Answer 38

It helps to keep the volume of tissue fluid constant.

Answer 39

The lymph drains back into the blood near the vena cava.

Answer 40

- hydrostatic pressure of tissue fluid that has left the capillaries - contraction of body muscles that squeeze the lymph vessels - valves in the lymph vessels ensure that fluid inside them moves away from the tissues in the direction of the heart.

Answer 41

The lymphatic system is a secondary circulatory system and a major part of the immune system. It consists of: Made up of blind-ending vessels, which allow tissue fluid to flow passively into them. Flow is helped by muscle contraction and one-way valves. lymph nodes – sac-like organs that trap pathogens and foreign substances, and which contain large numbers of white blood cells

Answer 42

1. Blood is responsible for collecting and distributing oxygen, nutrients and hormones to the tissues of entire body. 1. Lymph is responsible for collecting and removing waste products left behind in the tissues. 2. Blood flows in a closed continuous loop throughout the body via the arteries, capillaries, and veins. 2. Lymph flows in an open circuit from the tissues into lymphatic vessels. Once within these vessels, lymph flows in only one direction due to valves in the lymph vessels. 3. Blood is pumped. The heart pumps blood into the arteries that carry it to all of the body. Veins return blood from all parts of the body to the heart. 3. Lymph passively flows from the tissues into the lymph capillaries. Flow within the vessels is aided by other body movements such as deep breathing and the action of nearby muscles and blood vessels. 4. Blood consists of the liquid plasma that transports the red and white blood cells and platelets. 4. Lymph that has been filtered and is ready to return to the cardiovascular system is a clear or white fluid. 5. Blood is visible and damage to blood vessels causes obvious signs such as bleeding or bruising. 5. Lymph is invisible and damage to the lymphatic system is difficult to detect until swelling occurs. 6. Blood is filtered by the kidneys. All blood flows through the kidneys where waste products and excess fluids are removed. Necessary fluids are returned to the cardiovascular circulation. 6. Lymph is filtered by lymph nodes located throughout the body. These nodes remove some fluid and debris. They also kill pathogens and some cancer cells. 7. Blood vessel damage or insufficiency produces swelling that containing low protein fluid. 7. Lymphatic vessel damage or insufficiency produces swelling containing protein-rich fluid.

Answer 43

Proteins lower the water potential in the blood. Smaller molecules leave the blood to join the tissue fluid and lymph, without protein there are no larger molecules left behind. The water potential of blood is not lowered sufficiently to cause tissue fluid to return to the blood. This results in lymph build up in the tissues of the person.

Answer 44

Elephantiasis is due to obstructions of the lymphatic vessels by a parasitic worm (or sometimes consistent contact with volcanic ash). Due to the blockage of the lymphatic ducts the tissue fluid cannot return to the blood system and so collects in the limbs of the sufferer

Answer 45

Hodgkin disease can spread through the lymphatic vessels in a stepwise fashion from lymph node to lymph node.

Answer 46

- A drug called diethylcarbamazine - Simple cleansing - Has been shown to alleviate the symptoms of elephantiasis.

Answer 47

Chemotherapy - New drugs and combinations are being studied. Some are already used to treat other cancers, Stem Cell Transplants - Used for recurrent or advanced-stage Hodgkin disease. Monoclonal Antibodies - (manmade antibodies) have been made to target cancer cells.

Answer 48

- the humidity of the atmosphere is usually less than the air spaces next to the stomata. as a result there is a water potential gradient from the air spaces through the stomata to the air. - provided that the stomata is open, water vapour molecules diffuse out of the air spaces into the surrounding air - water loss by diffusion from the air spaces is replaced by water evaporating from the cell walls of the surrounding mesophyll cells. by changing the size of the stomatal pores, plants can control their rate of transpiration

Answer 49

- mesophyll cells lose water to the air spaces by evaporation due to heat supplied by the sun - these cells now have a lower water potential and so water enters by osmosis from neighbouring cells. - the loss of water in neighbouring cells lowers their water potential - they in turn take water from their neighbours by osmosis

Answer 50

Transpiration is the loss of water vapour via the stomata.

Answer 51

The “stream” of water flowing up through the plant

Answer 52

a passive process so requires no energy

Answer 53

tubes that transport water and minerals through a plant

Answer 54

- cells are dead (from end to end) - thick walls impregnated with lignin - one-way flow only

Answer 55

Capillarity. - Adhesion of water to the side of a tube. Root pressure - caused by this accumulation of water in the xylem. The cohesion-tension theory

Answer 56

1. Water evaporates from the stomata in the leaf. This creates a LOWER pressure 2. This loss of water by TRANSPIRATION more water is pulled up the xylem vessel to replace it (moves due to negative pressure) 3. Due to Hydrogen bonds between water molecules (cohesion) this creates a column of water. 4. Water molecules also adhere to the walls of the xylem. This helps to pull the water column upwards 5. As the column of water is pulled up is creates tension, pulling the xylem in to be narrower 6. Water enters the roots by OSMOSIS to replace water moving up the xylem

Answer 57

Transpiration is at its highest during the day, so xylem vessels are at greatest tension, so tree shrinks in diameter.

Answer 58

Wind (air movement) Humidity Temperature Light

Answer 59

the transpiration rate/ water uptake by the plant

Answer 60

water loss by transpiration + water consumption for cell expansion and photosynthesis

Answer 61

1. the leafy shoot must be cut underwater, the apparatus must be filled underwater and the shoot fixed to the potometer under water to prevent air locks in the system 2. allow the plant to equilibrate (5 mins) before the introduction of the air bubble. take at least 3 readings of rate of bubbles of rate of bubbles movement, and use the reservoir to return bubble to zero on each occasion. calculate the mean of readings. records air temperature. 3. scale can be calibrated by introducing a know mass of mercury into the capillary tubing and using p=m/v (p=mercury, m=measured v= measured distance of bubble movement can be determined). 4. rate of water uptake per unit area of leaves can be calculated by measurement of leaf area

Answer 62

to prevent leakage of air

Answer 63

to prevent the bubble moving due to its density compared with water

Answer 64

this is used to prevent the air bubble entering the plant, and to move the bubble back along the capillary tube

Answer 65

when we remove the end of the capillary tube, movement corresponds to water uptake by the cut shoot.

Answer 66

The movement of organic substances around a plant e.g. SUCROSE (most important) to where they are needed.

Answer 67

- Two main components - sieve tube elements and companion cells

Answer 68

- living cells that form the tubes for transporting solutes. - No nucleus - few organelles. - to block liquid

Answer 69

Each sieve tube element has a companion cell. They carry out living functions for sieve cells. Lots of mitochondria - provide ATP for active transport of organic substances

Answer 70

sources to sinks

Answer 71

Where the substances are being PRODUCED, so are at a HIGH CONCENTRATION

Answer 72

WHERE SUBSTANCES BEING USED UP OR CONVERTED TO OTHER MOLECULES, SO AT A LOW CONCENTRATION. (therefore used by respiring cells)

Answer 73

At the SOURCE: Sucrose is actively transported into sieve tube elements, using companion cells (using ATP from the mitochondria) Increased concentration of sucrose, lowers the water potential of sieve cells in phloem, therefore water enters by osmosis from xylem vessel. The increase in volume of water, creates a high hydrostatic pressure at the source end of the phloem. At the SINK: At the sink, sucrose are removed from the phloem to be used up for respiration and or converted into insoluble starch for storage. These cells have a low sucrose content and so sucrose is actively transporting into sink cells from the sieve tubes, which cause the water potential to decrease, therefore water moves into these cells by osmosis from sieve tube elements the removal of water, decreases the volume of the sieve tube elements, and therefore hydrostatic pressure decreases. PRESSURE gradient causes flow of solute from source to sink.

Answer 74

Because solutes move from source to sink, form a high concentration to a low concentration, where they're are needed

Answer 75

14CO2 will be used as normal in photosynthesis and the 14C is incorporated into new sugars. Because the 14C is radioactive, it can be traced. Autoradiograph shows where the radioactive tracer has travelled to.

Answer 76

Outer section of the stem is removed around the complete circumference. This removes the bark and phloem.

Answer 77

tissue above the ring are swollen and tissue below the ring is beginning to wilt. this is because at the top half there will be a build up of sucrose and the bottom half will wilt because no sugar can reach the roots

Answer 78

- aphids feed on plant tissue by penetrating the stem with their mouthparts. and then we use the aphids to check the amount of sucrose taken in.

Answer 79

metabolic inhibitors reduces the productivity of an enzyme by (usually) forming a weak bond to an enzyme so no pressure gradient can be formed.

Answer 80

Function of sieve plates is unclear- would be a hindrance? Not all solutes move at the same speed- how would that be possible if mass flow? - they should do so if movement is by mass flow Sucrose is delivered to all regions at the same speed, regardless of their concentrations.

Answer 81

plants which are adapted for hod dry weather conditions by minimising the the transpiration rate

Answer 82

sunken stomata - trap a layer of moist air. the water vapour in the moist air reduces the water potential gradient between the the leaf air spaces and the exterior therefore decreases the rate of transpiration by evaporation. waterproof thick waxy cuticle layer - acts as a barrier so less water can escape to reduce water loss by evaporation shiny cuticle - helps to reflect a lot of the sunlight way less stomata - less stomata means less water loss but they can also respond to low water availability by closing the stomata thick stems - store water in their stems which minimises water loss large root systems - allow them to maximise the amount of water they get from the ground to reduce water loss pointed spines - reduce the surface area for water loss

mass transport Flashcards

(112 cards)