Circulatory System

Question 1

What is the circulatory system made up of?

Answer 1

blood, blood vessels and the heart

Question 2

What is the structure of blood?

Answer 2

• plasma (55%)
• erythrocytes, leucocytes, and thrombocytes (40-45%)

Question 3

What is plasma? and what is it’s purpose?

Answer 3

• mixture of water containing sugar and salts
• transports components of blood throughout the body

Question 4

What is the structure of erythrocytes? and what is their purpose?

Answer 4

• red blood cells
• biconcave shape
• transport O2 from lungs to cells throughout the body

Question 5

What is the structure of leucocytes? and what is their purpose?

Answer 5

• approximately 1% of blood
• protect body from infection

Question 6

What is the structure of platelets? and what is their purpose?

Answer 6

• small fragments of cells
• when blood vessels are injured, plates activate
• platelets adhere to the lining of vessel to form clots and stop bleeding

Question 7

How is oxygen trasnported?

Answer 7

97% of oxygen is transported in erythrocytes as oxyhaemoglobin

Question 8

Why are erythrocytes good for transporting oxygen?

Answer 8

• contain haemoglobin that combines with oxygen
• no nucleus = more room for haemoglobin
• biconcave = large surface area + volume

Question 9

What are the 3 ways Carbon dioxide is transported? + percentages

Answer 9

• dissolving in plasma (7-8%)
• carbaminohaemoglobin ( 22%)
• bicarbonate ions in the plasma (70%)

Question 10

How are nutrients and waste transported?

Answer 10

they are dissolved and transported in the blood plasma

Question 11

What are some important inorganic ions dissolved in the blood plasma?

Answer 11

any of the following:
sodium, calcium, potassium, chloride, iodide

Question 12

What are some important organic nutrients dissolved in the blood plasma?

Answer 12

any of the following:
glucose, vitamins, amino acids, fatty acids

Question 13

What is the purpose of blood clotting?

Answer 13

minimise blood loss and prevent infection after damaging blood vessels

Question 14

What does blood clotting involve?

Answer 14

• vasoconstriction
• platelet plugs
• coagulation

Question 15

Structure of heart? and function?

Answer 15

• surrounded by a membrane called the pericardium = prevents heart overstretching
• made up of cardiac muscle + connective tissue
• pushes blood around body

Question 16

What is the flow of Blood in heart?

Answer 16

1. deoxygenated blood enters through superior and inferior vena cava to the right atrium
2. through to tricuspid valve into right ventricle
3. pushes blood into pulmonary valve and out to the lungs to get oxygenated
4. oxygenated blood from the lungs enters left atrium through the pulmonary veins
5. goes through the bicuspid valve into the left ventricle
6. pushed through the aortic valve and into the aorta
7. The aorta carries the blood throughout the body

Question 17

What are the 3 types of blood vessels? and their functions?

Answer 17

1. arteries
   
   • carry blood away from heart
2. veins
   
   • carry blood towards heart
3. capillaries
   
   • carry blood between cells, facilitating transport in and out of cells

Question 18

What is the difference between vasoconstriction and vasodilation?

Answer 18

vasoconstriction - contract muscles to reduce diameter
vasodilation - relax muscles to increase diameter

Question 19

Structure of veins?

Answer 19

• do not contain muscular walls, pressure remains constant and contains valves

Question 20

Structure of capillaries?

Answer 20

contain a single layer of cells, allows substances to easily pass between blood and surrounding cells

Question 21

What is the systole phase?

Answer 21

when the heart muscles contract (pump phase)

Question 22

What is the diastole phase?

Answer 22

when the heart muscles relax (filling phase)

Question 23

What is the cardiac output?

Answer 23

• how quickly blood flows around the body
• amount of blood leaving the ventricles per minute