biology chapter 9

Question 1

in which part of our body does the haemoglobin turn into oxyhaemoglobin

Answer 1

in the lungs

Question 2

what is a circulatory system

Answer 2

a circulatory system is a system with a pump and valves

Question 3

why is a valve used in a circulatory system

Answer 3

valves prevent the back flow of blood in the heart to ensure that blood flows in one direction

Question 4

what is blood circulation

Answer 4

the flow of blood

Question 5

what is a tissue fluid

Answer 5

a tissue fluid is the tiny spaces between tissue cells that contain a colourless liquid known as a tissue fluid

Question 6

how can substances be transferred between the capillaries and tissue cells

Answer 6

dissolved food substances and oxygen diffuse from the blood capillaries into the tissue fluid and then into the cells. metabolic waste products diffuse from the cell into the tissue fluid and then through the blood capillary walls into the blood

Question 7

what is the structure of an arteries like

Answer 7

• thick muscular walls with much elastic tissue
• have a small lumen relative to diameter
• semilunar valves absent

Question 8

what is the function of the arteries

Answer 8

• to carry blood out or away from the heart
• carry oxygenated blood

Question 9

what is the flow of the arteries like

Answer 9

• blood under high pressure
• blood flows rapidly

Question 10

what is the structure of the veins like

Answer 10

• thin muscular walls with little elastic tissue
• large lumen relative to diameter
• semilunar valves present

Question 11

what is the function of the vein

Answer 11

• carry blood towards the heart
• carry deoxygenated blood

Question 12

what is the flow of the veins

Answer 12

• blood under low pressure
• blood flows slowly

Question 13

what is the structure of the capillaries like

Answer 13

• one cell thick wall with no muscular or elastic tissue
• large lumen relative to the diameter

Question 14

what is the function of the capillaries

Answer 14

• link arteries to veins
• blood changes from oxygenated at the arteriole to deoxygenated at the venule end

Question 15

what is the flow of the capillaries like

Answer 15

• pressure of blood reduces as blood flows from the arteriole to venule end
• blood flows slowly

Question 16

what kind of circulation does a fish have

Answer 16

single circulation

Question 17

what kind of circulation do mammals have

Answer 17

double circulation

Question 18

what is the pulmonary circulation

Answer 18

circulation linking the lungs to the heart is known as the pulmonary circulation

Question 19

what does the double circulation of mammals contain

Answer 19

pulmonary circulation and systemic circulation

Question 20

what is the systemic circulation

Answer 20

circulation of blood around the body is called the systemic circulation

Question 21

advantages of double circulation

Answer 21

• mammals benefit from double circulation as it pumps blood at a high pressure, supplying oxygen and glucose to the cells more quickly.
• four chambered hearts ensure that oxygenated and deoxygenated blood are separated

Question 22

describe unicellular organisms

Answer 22

unicellular organisms do not need a special transport system, simple diffusion

Question 23

describe the multicellular organisms

Answer 23

requires a transport system because simple diffusion alone cannot bring food and nutrients to the cell. the diffusion speed is insufficient.

Question 24

what are the differences between single and double circulation

Answer 24

single circulation (fish)
- heart has 2 chambers
- blood passes through once the heart for every circuit of the body

double circulation (mammals)
- heart has 4 chambers
- blood passes through twice for every circuit of the body
-

Question 25

what is the pericardium

Answer 25

a bag that surrounds the whole heart made up of two layers of membranes used to help reduce friction when the heart is beating

Question 26

how does the heart work

Answer 26

- when the ventricles relax, it produces a softer sound (dub) - when the atria relax, it produces a loud sound (lub)

Question 26

what does each "lubdub" sound represent

Answer 26

one heartbeat

Question 26

describe what happens in the heart when producing a sound

Answer 26

the two atrias contract, while the ventricles relax. blood vessels from the atria into the ventricles. when the ventricles contact, and the atrias relax, the bicuspid and the tricuspid valves close producing a loud 'lub' sound. blood passes from the right ventricle into the pulmonary arch, and from the left ventricle to the aorta

Question 26

what is a ventricular systole

Answer 26

contraction of ventricles

Question 27

what is a ventricular diastole

Answer 27

relaxation of ventricles

Question 28

describe the blood pressure

Answer 28

- measured in the unit mmHg - systolic blood pressure : 120-140 - diastolic blood pressure : 75 - 90 instrument used to measure blood pressure: sphygmomanometer

Question 29

what are the different ways to examine the heart

Answer 29

blood pressure, pulse, ECG

Question 30

describe the pulse

Answer 30

- expansion and contraction of an artery, caused by the heart pushing blood through it - pulse is produced after every contraction - number of pulses = number of heartbeat per minute

Question 31

describe the electrocardiogram (ECG)

Answer 31

- monitoring the activity of the waves - consists of the PQRST wave ( P- relaxation of atrium) (QRS- ventricular contraction) (T- relaxation of the ventricle)

Question 32

how does physical activity increase the pulse rate or the number of heartbeats per minute

Answer 32

during physical exercise, more energy is needed for muscle contraction. this leads to an increase in aerobic respiration. the heart will have to beat faster so that oxygen and glucose can be transported more quickly to the muscles

Question 33

what happens at the left atrium

Answer 33

receives oxygenated blood from the lungs

Question 33

what happens at the right atrium

Answer 33

receives deoxygenated blood from the rest of the body

Question 34

what happens at the right ventricle

Answer 34

pumps deoxygenated blood into the lungs

Question 34

what happens at the left ventricle

Answer 34

pumps oxygenated blood to the rest of the body

Question 35

what are the main components of the blood

Answer 35

plasma, red blood cells, white blood cells and platelets

Question 36

what are the components of the circulatory system

Answer 36

heart, arteries, arterioles, blood capillaries, venules and veins

Question 37

what can the blockage of the coronary arteries cause

Answer 37

heart attack

Question 38

what is a heart attack

Answer 38

during a heart attack, the blood flow to a part of the heart may be completely blocked. due to the blocked blood flow, the part of the heart does not receive enough oxygen and nutrients. that region of the heart muscle dies.

Question 39

causes of coronary heart disease include

Answer 39

diet rich in saturated fats, emotional stress, smoking

Question 40

risk factors for heart disease includes

Answer 40

- smoking - unhealthy diet - gender - age -stress - lack of exercise

Question 41

how can the coronary heart disease be prevented

Answer 41

- a proper diet - proper stress management - quit smoking - regular physical exercise

Question 42

what are the three main kinds of blood vessels

Answer 42

arteries, capillaries and veins

Question 43

describe the plasma

Answer 43

yellowish liquid, contains mainly water, proteins, lipids functions: - transports blood cells and ions around the body - transport metabolic waste products like urea to kidney for excretion

Question 44

describe the platelets

Answer 44

- cell fragments of cytoplasm produced in the bone marrow - contains an enzyme that plays a part in the clotting of blood to prevent blood loss

Question 44

describe the red blood cell

Answer 44

structure: - circular biconcave disc shape - contains the red pigment called haemoglobin - do not have a nucleus and mitochondria function: - transports oxygen from the lungs and nutrients to other parts of the body - no nucleus and mitochondria for more space for haemoglobin

Question 45

describe the white blood cells

Answer 45

contains two main type of cells: phagocytes and lymphocytes phagocyte is larger than the lymphocytes. phagocyte has a lobed nucleus and are irregular in shape. lymphocytes have a large spherical nucleus. lymphocytes are smaller than phagocytes