4: Circulation

Question 1

Why do we need a transport system?

Answer 1

Large organisms have to carry substances to every cell in the body, delivering oxygen and nutrients and removing waste so that cells can carry out functions.

Question 2

What are the features of mass transport systems?

Answer 2

System of vessels that carry substances, usually tubes
Way of making sure substances are moved in the right direction
Means of moving materials fast enough to supply needs of organism

Question 3

What is a single circulation?

Answer 3

Fish have this. Heart pumps deoxygenated blood to the gills, the organs of gas exchange etc. Then, travels around the rest of the body.

Question 4

Why don’t birds and mammals have s single circulatory system?

Answer 4

They need more oxygen than fish. Have to maintain a constant temperature and this needs a lot of energy.

Question 5

What is double circulation?

Answer 5

Involves 2 circulatory systems. The systematic and the pulmonary

Question 6

What is the systematic circulatory system?

Answer 6

Carries oxygenated blood from HEART to BODY and acres deoxygenated blood BACK to the heart

Question 7

What is the pulmonary circulation?

Answer 7

Carrels deoxygenated blood to the LUNGS to be oxygenated and carries oxygenated blood form the lungs to the heart

Question 8

Why are the pulmonary and systematic systems separate?

Answer 8

So the blood doesnt mix, and the tissues receives as much oxygen as they can.

Question 9

What is the cardiovascular system?

Answer 9

Mass transport system with series of vessels with the heart a a pump. Blood is the transport medium and its passage through the vessels is called CIRCULATION.

Question 10

What functions do the cardiovascular system do?

Answer 10

Delivers materials needed for the cells and carries waste products away
Carries hormones from one part of the body to another
Defence system of the body
Distributing heat throughout the body

Question 11

What is plasma?

Answer 11

The medium which the blood components are in.
Each different component of the lord has a particular function. The plasma helps to maintain a steady body temperature by transferring heart around the system for deep-debated or as or very active tissues
Acts as a buffer to pH changes

Question 12

What are erythrocytes?

Answer 12

Red blood cells.

Question 13

How many erythrocytes are there?

Answer 13

5 million per mm3 of blood

Question 14

What do erythrocytes contain?

Answer 14

Haemoglobin.

Question 15

What is haemoglobin?

Answer 15

A red pigment that carries oxygen and gives them their colour.

Question 16

Where is haemoglobin formed

Answer 16

In bone marrow.

Question 17

What do mature erythrocytes not contain?

And what is the life span

Answer 17

A nucleus. Limited life of 120 days

Question 18

What is the function of erythrocytes?

Answer 18

Transport oxygen from the lungs to all the cells.

Question 19

Why are erythrocytes well adapted for their function?

Answer 19

Biconcave disc shape of the cells means they have larger surface area to volume ration, so oxygen can diffuse in and out of them rapidly.

Question 20

Why does having no nucleus a benefit for erythrocytes?

Answer 20

Much more space for oxygen to be carried

Question 21

What else other than oxygen, does erythrocytes carry?

Answer 21

Carbon dioxide, a little bit of it produced in respiration back to the lungs. Rest is transported in the plasma

Question 22

What are leucocytes ?

Answer 22

White blood cells

Question 23

Which ones are larger, leucocytes or erythrocytes?

Answer 23

Leucocytes. But they can squeeze through tiny blood vessels as they can change their shape.

Question 24

Where are leucocytes formed?

Answer 24

In bone marrow,although some mature in the thymus gland.

Question 25

What are leucocytes function?

Answer 25

Defend the body against infection

Question 26

what do leucocytes contain?

Answer 26

A nucleus and have colourless cytoplasm

Question 27

What are the different types of leucocytes?

Answer 27

Granulocytes:
Neutrophils, eosinophils, basophils

Agranulocytes:
Monocytes, lymphocytes

Question 28

What are granulocytes?

Answer 28

Have granules in the cytoplasms which can take up stain.

Question 29

What is the shape of the nucleus in granulocytes?

Answer 29

Lobed nuclei

Question 30

What do neutrophils do?

Answer 30

Part of the non-specific immune system.

Engulf and digest pathogens by phagocytosis. Multilobed nuclei.

Question 31

What do eosinophils do?

Answer 31

Non-specific immune system. Stained red by eosin stain. Good against parasites, in allergic reactions and inflammation, and in developing immunity to disease.

Question 32

What do basophils do?

Answer 32

Non specific immune system. Two lobed nucleus. Produce histamines involved in inflammation and allergic reaction.

Question 33

What doe agranulocytes do?

Answer 33

Don’t have grades to take up stain in their cytoplasm. Have unloved nuclei.

Question 34

What do monocytes do?

Answer 34

Part of specific immune system, largest WBC. Move out of blood into tissues to for MACROPHAGES, that also play a part in the specific immune system. Engulf pathogens by phagocytosis

Question 35

What d lymphocytes do?

Answer 35

Small leucocytes with very large nuclei, vital in specific immune response.

Question 36

What are platelets?

Answer 36

Toy fragments of large cells called MEGAKARYOCYTES.

Question 37

Where are megakaryocytes found?

Answer 37

Bone marrow.

Question 38

What do platelets do?

Answer 38

Involved in clotting in the blood

Question 39

How does haemoglobin transport oxygen?

Answer 39

It is a large globular protein made up of 4 petite chains, with an iro prosthetic group, which can pick up 4 oxygen molecules in a reversible reaction to from oxyhemoglobin .

Question 40

What does the first oxygen do to a haemoglobin molecule?

Answer 40

Binds to haemoglobin alters the arrangement of the molecule making it easier for the other oxygens to bind. Same fo the other way around, its harder for the last oxygen to get removed

Question 41

What is the effect on concentration during haemoglobin and oxygen transfer?

Answer 41

Conc of oxygen is relatively Lowe wen blood enters lungs. Oxygen moves into RBC from air into lungs, the free oxygen conc in cytoplasm stays Low, and this maintains a steep conc gradient for air in he lungs to RBC, therefore more oxygen gets diffused.

Question 42

What effect does the strong affinity have on oxygen?

Answer 42

A small change in the proportion of oxygen in the surrounding air can have a big effect on saturation of the blood with oxygen

Question 43

What does the oxygen dissociation curve show?

Answer 43

Percentage of saturation of haemoglobin with oxygen, and partial pressure of oxygen. The curve is like a titration cure, with 2 curves like a slanted s.

Question 44

Why does the dissociation curve show a slanted s?

Answer 44

As deoxygenated blood approaches the lungs, the step part of the curve means their is a small increase in partial pressure causes a large increase in percentage of saturation.

High partial pressure of oxygen i the conditions in the lungs.

As oxygenated blood approaches the tissues, a small decrease in partial pressure causes a large decrease in percentage saturation

Question 45

What is the Bohr effect?

Answer 45

The way which haemoglobin picks of oxygen is affected by the proportion of carbon dioxide in the tissues. When the partial pressure of carbon dioxide is high, the affinity of haemoglobin for oxygen is reduced.

Basically, an increase in pressure of carbon dioxide causes the oxygen dissociation curve to become more like a curves r rather than s.
Lower pressure,more r shaped.

Question 46

What is fetal haemoglobin and what happens for it to get oxygen?

Answer 46

Found in developing foetus. When a foetus is in the uterus, it i dependent on its mother to supply with oxygen. Oxygenated blood from mother runs through placenta close to the deoxygenated fetal blood. If the blood has the same affinity for oxygen, little oxygen is transferred.
If fetal haemolgobin ha higher affinity for oxygen, can remove oxygen form maternal blood. Also runs in opposite directions, counter current exchange which maximises the oxygen transfer.

Question 47

What is myoglobin?

Answer 47

Respiratory pigment found in muscle tissues of vertebrates. Small, red and bright proteins which give red meat its colour. Structure is similar to single haemoglobin chain.

Question 48

What happens to myoglobin?

Answer 48

Has much higher affinity for oxygen than haemoglobin, so it can become easily saturated with oxygen. Once myoglobin is bound to oxygen molecule, it doesnt give it up easily, so acts as an oxygen store.

Question 49

When is oxygen released from myoglobin?

Answer 49

When oxygen levels in very active muscle tissue are low, and carbon dioxide levels are high, myoglobin releases its store of oxygen when it is most needed.

Question 50

Why can elephant seals dive deep?

Answer 50

They can stay under water for 2 hours, but only dive not so deep for 30 mins. Seals cant breathe underwater, so adaptations of the blood allow them to swim underwater.
They have 2x as much volume of blood as any land mammal, and extra pace in their circulatory system to store oxygenated blood
More erythrocytes per unit blood than land mammals, and they also contain more haemoglobin , therefore 3x more haemolgobin as land mammal
Over 10 times more myoglobin in muscles than humans, pigment is so dense, their muscles look black.