Transport in humans and plants

Question 1

What is the role of phloem?

Answer 1

Phloem transports sucrose and amino acids from the leaves to other parts of the plant.

Question 2

What is the role of xylem?

Answer 2

Xylem transports water and mineral ions from the roots to the leaves and other parts of the plan

Question 3

What is transported in the blood plasma?

Answer 3

Digested food (nutrients) from the small intestine to the body’s cells.
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Carbon dioxide from respiring tissues to the lungs (transported as hydrogencarbonate ions).
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Urea (a waste product from protein breakdown) from the liver to the kidneys.
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Hormones from endocrine organs to target tissues and organs.
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Heat energy from respiring tissues (e.g., muscles, brain) to cooler body regions or the skin.

CO2 , digested food molecules, urea, hormones; distributing heat

Question 4

What do the tricuspid/ biscupid valves do?

Answer 4

The tricuspid valve and bicuspid valve prevent blood from flowing backward from the ventricles to the atria.

Question 5

what do the semilunar valves do?

Answer 5

The semilunar valves are located near the entrance of the pulmonary artery and aorta, preventing backflow from these arteries into the ventricles.

Question 6

What does the aorta do?

Answer 6

The aorta is the main artery that carries oxygenated blood from the left ventricle to the rest of the body.

Question 7

What does the pulmonary artery do?

Answer 7

The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs

Question 8

What does the pulmonary vein do?

Answer 8

The pulmonary vein carries oxygenated blood from the lungs to the left atrium.

Question 9

Vena Cava

Answer 9

The vena cava is a large vein that carries deoxygenated blood from the body back to the right atrium.

Question 10

Pacemaker

Answer 10

The pacemaker, a group of cells located in the right atrium, initiates the heartbeat. [6] The pacemaker is regulated by nerves connected to the brain and hormones in the blood, such as adrenaline.

Question 11

why is the left ventricle thicker

Answer 11

The wall of the left ventricle is thicker than the wall of the right ventricle. This is because the left ventricle needs to pump blood to the entire body, while the right ventricle only pumps blood to the lungs.

Question 12

what is CHD?

Answer 12

Coronary heart disease occurs when the coronary arteries, which supply blood to the heart muscle, become narrowed or blocked.

Question 13

How does the heart rate change during exercise?

Answer 13

The heart rate increases during exercise to deliver more oxygen and glucose to the working muscles. This increased blood flow also helps to remove waste products, such as carbon dioxide and lactic acid, from the muscles.

Question 14

phagocytes, lymphocytes

Answer 14

-> white blood cells

Question 15

Platelets

Answer 15

Tiny cell fragments- When a blood vessel is damaged, platelets clump together at the site of injury and release chemicals that activate clotting factors in the blood plasma. This process leads to the formation of a blood clot, which helps to stop bleeding.

Question 16

phagocytes- lobbed nucleus

Answer 16

engulf and digest pathogens, breaking them down with enzymes

Question 17

Lymphocyte- large nucleus

Answer 17

Lymphocytes secrete antibodies, which are proteins that target specific pathogens.

Question 18

what is a closed circulatory system?

Answer 18

The blood stays inside blood vessels as it travels around the body

Question 19

Arteries

Answer 19

carry oxygenated blood away from the heart under high pressure

Question 20

arteries structure

Answer 20

1. Thick layer of muscle and elastic fibers
2. Thick walls
   Allows them to withstand the high blood pressure and stretch
3. Smaller lumen to help keep high pressure

Question 21

Veins

Answer 21

carry blood with low oxygen towards the heart

Question 22

veins structure

Answer 22

veins have a larger lumen and thin muscular and elastics walls
this is because the blood is under low pressure ( muscles in legs and arms help push blood along veins when moving)

Question 23

why do veins have valves?

Answer 23

to prevent blood flowing backwards due to gravity so blood makes it back to the heart

Question 24

what do capillaries do ?

Answer 24

connect arteries and veins

Question 25

capillaries structure

Answer 25

very narrow, thin walls- only one cell thick for short diffusion distance to speed up diffusion ( O2 and glucose out of blood into cells)

Question 26

What about the capillaries' lumen

Answer 26

very narrow/ small lumen which only allow 1 red blood cell to pass- slows blood flow to increase the time that O2 can diffuse into cells ( also distance of diffusion reduced)

Question 27

what circulation system do humans have?

Answer 27

Double!

Question 28

what does myogenic mean?

Answer 28

Able to contract with no external stimulus ( the heart)

Question 29

What is the coronary artery ?

Answer 29

Blood vessel that supplies the heart muscle cells with O2

Question 30

where is the heart located?

Answer 30

between lungs , in middle of chest, behind and slightly to the left of the sternum

Question 31

what is the transpiration stream?

Answer 31

movement of water through the xylem vessels from root to leaves

Question 32

how do mineral ions move into root hair cells?

Answer 32

by active transport

Question 33

Then what do the mineral ions do?

Answer 33

They dissolve in water and move with water in the xylem

Question 34

Nervous control of heart rate

Answer 34

The medulla is an area in the brain responsible for initiating changes in the heart rate- responds to raised levels of CO2 during exercise

Question 35

what detects if there is too much CO2 in the blood?

Answer 35

sensors in the aorta and carotid artery

Question 36

what will the medulla do if there is too much CO2 in blood

Answer 36

the medulla will send nerve signals down the accelerator nerve to the heart to make it contract faster

Question 37

when the CO2 levels return to normal, what will the medulla do?

Answer 37

sends nerve signals down the decelerator nerve to the heart to make it contract less

Question 38

What is adrenaline- also known as epinephrine

Answer 38

hormone that initiates fast changes in body preparing for sudden action

Question 39

what is adrenaline produced by?

Answer 39

adrenal glands ( on the kidneys) in certain situation

Question 40

what does adrenaline do when it is released?

Answer 40

increase heart rate to supply muscles for aerobic respiration to release energy to flight or fight

Question 41

Leaky valves

Answer 41

from high pressure- replaced with mechanical valves made of titanium or biological donors from pigs and humans

Question 42

what drugs are used to slow down CHD?

Answer 42

Statins- by reducing blood cholesterol levels and slow down rate at which fatty material is deposited

Question 43

CHD can also be treated with ...

Answer 43

A stent - metal mesh placed in the coronary artery . tiny balloon inflated to open blood vessel and stent, balloon removed, stent ensures the blood vessel remains widened

Question 44

CHD and surgery?

Answer 44

Bypass surgery - where the blocked artery is replaced with bits of veins

Question 45

what happens when the pacemaker cells stop working?

Answer 45

they cause arrythmia- abnormal heart rhytm

Question 46

Treatment of Arrythmia

Answer 46

the pacemaker cells can be replaced with an artificial pacemaker- device that weighs between 20g to 50g and is connected to heart by 2 wires. They control when heart beats by sending strong electronic signals to the heart

Question 47

what is atheroma or plaque?

Answer 47

fatty material build on the lining of coronary arteries which reduce the supply of O2 to the heart

Question 48

why is a heart attack caused by the blockage of the coronary arteries?

Answer 48

This is because O2 and glucose ( which are in the blood) cannot reach the heart muscle cells so they cannot respire and dont beat