Circulatory System

Question 1

Why do organisms need a circulatory system

Answer 1

To transport nutrients, waste products and gases to and from between the cells and the environment

Question 2

What is blood

Answer 2

Blood is a tissue

Question 3

What does blood consists of

Answer 3

Fluids that has different types of cells suspended in it

Question 4

What fluids are present in blood

Answer 4

Plasma (55%)
Red blood cell (45%)
White blood cell and platelets (>1%)

Question 5

What are the functions of blood

Answer 5

Transport medium for oxygen, carbon dioxide, nutrients and waste products
Protection against pathogens through white blood cells
Protection against blood loss through blood clotting
Regulation of pH, body temoerature and water content of cells

Question 6

What is plasma

Answer 6

Pale yellowish liquid
Contains 90% water, 10% proteins and dissolved substances like salts, glucose, waste products

Question 7

Function of plasma

Answer 7

Transport substances together with blood cells and platelets around the body

Question 8

Function of red blood cells

Answer 8

Transport oxygen to other body parts

Question 9

Structure adaptations of red blood cells

Answer 9

Circular, biconcave shape
Absence of nucleus
Contains haemoglobin

Question 10

Explanation for Circular, biconcave shape

Answer 10

Increases surface area to volume ratio of cell to increase rate of diffusion of oxygen

Question 11

Explanation for absence of nucleus

Answer 11

Allows more haemoglobin to be packed in the cell and hence more oxygen can be transported

Question 12

Explanation for contains haemoglobin

Answer 12

Haemoglobin combines reversibly with oxygen

Question 13

Structure of white blood cells

Answer 13

Circular or oval or irregular in shape
Has nucleus

Question 14

Function of white blood cells

Answer 14

Produce anitbodies which identify and neutralize pathogens
Engulf pathogens

Question 15

What are platelets

Answer 15

Contain clotting factors and enzymes needed for blood clotting

Question 16

Function of plateltes

Answer 16

Involved in the process of blood clotting

Question 17

Define blood clotting

Answer 17

It forms a plug to seal broken blood vessels and preventing further blood loss
Prevents foreign microorganisms from entering the body through the broken tissue

Question 18

Why is blood clotting important

Answer 18

Crucial in preventing excessive bleeding when we are injured

Question 19

Blood transfusion combination

Answer 19

O can donate to everyone
AB can receive from everyone
O can only receive from O
AB can only donate to AB
A to whichever got A in it
B to whichever B got in it

Question 20

Why is blood transfusion incompatible dangerous

Answer 20

Receiver’s immune system attacks the donor blood which can be life threatenting.

Question 21

Structure of artery

Answer 21

Thick elastic muscular wall
Smaller lumen
No valves
Fast rate of blood flow
High pressure of blood

Question 22

Function of artery

Answer 22

Transport blood away from the blood

Question 23

Function of thick elastic muscular wall

Answer 23

Helps to withstand high pressure of blood flowing through

Question 24

Structure of vein

Answer 24

Thin, less elastic and less muscular wall
Larger lumen
Has valves
Rate of blood flow is slow
Pressure of blood is low

Question 25

Function of vein

Answer 25

Transport blood towards the heart

Question 26

Function of valves

Answer 26

To prevent backflow of blood

Question 27

Structure of capillary

Answer 27

One-cell think wall No valves Slow rate of blood flow Pressure of blood is low

Question 28

Function of capillary

Answer 28

Allows for the exchange of oxygen, carbon dioxide, nutrients and watse products between tissue fluids and blood by diffusion

Question 29

Function of one-cell think wall

Answer 29

To reduce distance for higher rate of diffusion of oxygen, carbon dioxide, nutrients and waste products

Question 30

How does the blood in veins get pushed back to the heart against gravity

Answer 30

The valves present in them and the contraction of skeletal muscules

Question 31

How does blood flow

Answer 31

From heart to arteries, which branch out capillaries. Capillaries unite to form veins. Blood eventually returns back to the heart by veins

Question 32

Substances diffusing from tissue fluids to cell

Answer 32

Oxygen ang nutrients (glucose and amino acids) diffues from blood in capillary into tissue fluid then into cell

Question 33

Substances diffusing out from cells

Answer 33

Carbon dioxide and waste products (urea) diffuse from cells into tissue fluids then into blood in capillary

Question 34

How does coronary heart disease occur

Answer 34

An unhealthy lifestyle may result in the build-up of fallty deposits along the walls of the coronary arteries over many years. This narrows the lumen of the coronary arteries, reducing blood supply to the heart muscules. If a coronary artery is blocked significantly, the supply of blood to heart muscules may be reduced drastically. The heart will be starved of oxygen and glucose, leading to tissue death and hence a heart attack.

Question 35

What happens when a heart damage occurs.

Answer 35

Permanent Rest of the healthy heart muscules will need to work harder to pump blood in order to compensate for the damaged heart muscules

Question 36

Risk fatcors of coronary heart diseases

Answer 36

Consuming food high in cholesterol and fats Smoking, lack of exercise, stress Family history of heart disease