Mass transport in animals

Question 1

What is mass transport?

Answer 1

the efficient movement of bulk substances around an organism

Question 2

Why do large organisms need mass transport systems?

Answer 2

the distances that nutrients need to travel is too great to rely on diffusion alone

Question 3

How and what do we transport in the human mass transport system?

Answer 3

water, dissolved nutrients, and gases via blood

Question 4

What does it mean by double, closed circulatory system?

Answer 4

double- blood is pumped twice around the heart in each complete circuit
closed- blood is contained within blood vessels

Question 5

All mammals have…

Answer 5

a double circulatory system

Question 6

What is the pathway travelled by oxygen?

Answer 6

-down the trachea, then the bronchi, then bronchioles into the alveoli
-across the epithelial cell layer of the alveoli
-across the endothelium cell layer of capillary
-into the blood

Question 7

Name some adaptions that make gas exchange in humans more efficient

Answer 7

-around 300 million alveoli in each lung- many alveoli creating a large surface area
-walls of capillary and alveoli are very thin- short diffusion pathway
-constant ventilation and circulation of the blood- maintains concentration gradient
-red blood cells are slowed as they pass through capillaries- enables more time for diffusion

Question 8

Name the arteries and veins related to the lungs

Answer 8

pulmonary artery, pulmonary vein

Question 9

Name the arteries and veins related the heart

Answer 9

aorta, vena cava

Question 10

Name the arteries and veins related to the liver

Answer 10

hepatic artery, hepatic vein, hepatic portal vein (from the gut)

Question 11

Name the arteries and veins related to the kidneys

Answer 11

renal artery, renal vein

Question 12

What is the circulatory system?

Answer 12

a mass transport system, carrying raw materials and waste products around the body

Question 13

Why is the circulatory system needed?

Answer 13

for mammals with a small SA: V ratio- need to carry materials from specialised exchange organs to their body cells

Question 14

What is the circulatory system made up of?

Answer 14

the heart and the blood vessels

Question 15

Which blood vessel has the lowest pressure and why?

Answer 15

the vena cava, as blood flows from highest to lowest pressure and the vena cava is the final blood vessel to take blood back to the heart

Question 16

Where are the atriums?

Answer 16

top chambers of the heart

Question 17

Where are the ventricles?

Answer 17

bottom chambers of the heart

Question 18

Which is the left and right side of the heart?

Answer 18

the opposite as to what you would expect

Question 19

What is the job of the pulmonary artery?

Answer 19

carries deoxygenated blood from the right ventricle to the lungs

Question 20

What is the job of the pulmonary vein?

Answer 20

carries oxygenated blood from the lungs to the left atrium

Question 21

What is the job of the vena cava?

Answer 21

carries deoxygenated blood from the body to the right atrium

Question 22

What is the job of the atrioventricular valves?

Answer 22

they are valves between the atriums and ventricles, allowing blood to flow from atrium to ventricle but not backwards

Question 23

What is the job of the tendinous cords?

Answer 23

prevents the atrioventricular valves from being turned inside out by the high pressure from the ventricular contractions

Question 24

What is the job of the right atrium?

Answer 24

receives deoxygenated blood from the vena cava- only has a thin wall due to low pressure

Question 25

What is the job of the right ventricle?

Answer 25

fills with blood from the right atrium, thick muscular walls to let it force blood into the pulmonary artery

Question 26

What is the job of the left atrium?

Answer 26

receives oxygenated blood from the pulmonary vein- thin walls due to low pressure

Question 27

What is the job of the left ventricle?

Answer 27

receives blood from the left atrium, has the thickest wall to allow it to pump blood into the aorta and around the whole body

Question 28

What is the job of the semi-lunar valves?

Answer 28

prevent blood from flowing back into the ventricles

Question 29

What is cardiac muscle called and it’s function?

Answer 29

myogenic- it contracts rhythmically even outside of the body, and is found only in the heart. it never fatigues, but a lack of oxygen or nutrients will cause the cells to die and stop beating

Question 30

What is the job of the septum?

Answer 30

keeps the sides of the heart separate

Question 31

What is the job of the aorta?

Answer 31

main artery in the body, carries oxygenated blood from the left ventricle to the rest of the body

Question 32

What are the 4 types of blood vessel?

Answer 32

artery, arteriole, capillary, vein

Question 33

What is the job of an artery, and how are they adapted to do it efficiently?

Answer 33

carries blood away from the heart to other parts of the body/respiring tissues

-thick muscular walls to help withstand the pressure from the heart’s contractions
-elastic walls to help maintain blood pressure and smooth flow through a recoil action
-has a folded endothelium to allow the artery to stretch to maintain high pressure

Question 34

How does an artery change with pressure changes?

Answer 34

stretches to cope with high pressure, recoils under lower pressure

Question 35

What is the job of a capillary, and how are they adapted to do it efficiently?

Answer 35

exchange of gases and nutrients

-they are only one cell thick, to allow a shorter diffusion distance
-can have oxygenated or deoxygenated blood inside
-

Question 35

What is the job of an arteriole, and how are they adapted to do it efficiently?

Answer 35

carries blood from the arteries to the capillaries

-has thick muscles to restrict/allow blood flow into capillaries in a controlled way

Question 36

What is the job of a vein, and how are they adapted to do it efficiently?

Answer 36

carry deoxygenated blood back to the heart, maintaining pressure

-have thinner walls and a larger lumen as they don’t need to withstand high pressures
-have valves to prevent backflow of blood and keep blood flowing in one direction

Question 37

What happens to pressure as you go down a blood vessel and why?

Answer 37

pressure decreases due to friction

Question 38

What happens to veins when muscles contract?

Answer 38

the vein contracts too

Question 39

Why is the maximum pressure similar in both atria?

Answer 39

they have similar amounts of cardiac muscle, so when they relax they have a similar volume and hence a similar pressure

Question 40

Explain why higher blood pressure is produced in the aorta than the pulmonary artery

Answer 40

aorta has thicker, more muscular walls than the pulmonary artery so it can send blood to the whole body, not just the to the lungs.
this means when it relaxes it has a smaller volume, hence higher pressure

Question 41

Why do the left and right ventricles have different maximum pressures?

Answer 41

the left ventricle has much thicker cardiac muscle than the right ventricle, so when it contracts it has a smaller volume, hence a higher pressure

Question 42

On a graph about pressure changes during the cardiac cycle, how can you tell when valves are opening/shutting?

Answer 42

always at where lines crossover, as the pressure causes the valves to open (so one has overtaken the other on the graph)

Question 43

What is the average human heart rate?

Answer 43

72