Circulation

Question 1

What are the components of the circulatory system?

Answer 1

-Heart
-Blood vessels (veins, arteries, capillaries)
-Blood

Question 2

What are the functions of the circulatory system?

Answer 2

-Move blood around the body
-Move oxygen and water to the cells
-Move glucose
-Remove carbon dioxide

Question 3

What is a single circulatory system?

Answer 3

A circulation system where the heart pumps blood to the organs and then the blood travels around the body back to the heart

Question 4

What is systemic circulation?

Answer 4

Carries oxygenated blood from the heart to the cells of the body where oxygen is used and carries the deoxygenated back to the heart

Question 5

What is pulmonary circulation?

Answer 5

Carries deoxygenated blood to the lungs and oxygenated blood back o the heart

Question 6

What does partial pressure mean?

Answer 6

pO2 or ppO2
Concentration of oxygen

Question 7

What is haemoglobin?

Answer 7

Carries oxygen and gives erythrocytes their colour
-Made of 4 polypeptide chains
-Each chain has a haem group containing iron
-Globular shape
-Each haem group picks up 4 molecules of oxygen

Question 8

What is the haemoglobin reaction?

Answer 8

Haemoglobin + oxygen = oxyhaemoglobin
Hb + 4O2 = HBO8
-A reversible reaction

Question 9

What does having a high affinity for oxygen mean?

Answer 9

-Attracted to oxygen
-Easily loads oxygen
-Releases oxygen less readily
-In organisms who live in environments with low oxygen e.g lugworms
-These organisms will have a low metabolic rate (respire more slowly)
-They find it more useful to have haemoglobin which takes in oxygen quicker than it releases it

Question 10

What is the curve on the graph for high affinity for oxygen?

Answer 10

Graph curves to the left

Question 11

What does having a low affinity for oxygen mean?

Answer 11

-Slowly takes up oxygen
-Releases oxygen quicker
-Found in organisms who live in environments with lots of oxygen e.g humans
-They respire and use more oxygen
-It is more important to have haemoglobin which releases oxygen quicker than it takes it in

Question 12

What is the curve on the graph for low affinity for oxygen?

Answer 12

Graph curves to the right

Question 13

What is fetal haemoglobin?

Answer 13

-Has a different quaternary structure to adult haemoglobin
-Higher affinity for oxygen than adult haemoglobin when at the same partial pressure
-Maintains a diffusion gradient across the placenta

Question 14

What is myoglobin haemoglobin?

Answer 14

-Higher affinity for oxygen than adult and fetal haemoglobin
-Stores oxygen in the muscles
-Found in human muscles

Question 15

What is an artery?

Answer 15

Vessels that carry blood away from the heart towards the cells of the body

Question 16

What is a vein?

Answer 16

Vessels that carry blood toward the heart from the cells of the body

Question 17

What is a capillary?

Answer 17

Minute vessels that spread throughout the tissues of the body

Question 18

How is blood pumped around the body?

Answer 18

-Deoxygenated blood is brought into the right atrium from the vena cava
-The pressure of the blood opens the tricuspid valve and forces the deoxygenated blood into the right ventricle
-The blood is then forced into the pulmonary artery to go to the lungs
-After the lungs, the blood enters through the pulmonary vein into the left atrium
-Blood enters the left ventricle through the bicuspid valve
-Blood is then pumped into the aorta and into the body

Question 19

What are the features of the capillaries?

Answer 19

-No valves
-Very thin
-Permeable walls, only one cell thick
-Very small lumen
-Function is to allow exchange of materials between the blood and the tissues

Question 20

What are the features of arteries?

Answer 20

-Small lumen
-No valves (except in the heart)
-Thick walls with smooth elastic to resist high pressure
-Blood is at a high pressure
-Function is to carry blood from the heart to the tissues

Question 21

What are the features of veins?

Answer 21

-Large lumen to reduce resistance to flow
-Valves to prevent back flow
-Thin walls
-Blood at a low pressure
-Function is to carry blood from tissues to the heart

Question 22

How does your heart contract?

Answer 22

-The sinoatrial node (SAN, hearts natural pacemaker) in the top right of the atrium creates and sends impulses across the atrium
-The impulse creates a contraction which pushes blood into the ventricles
-The atrioventricular node (AVN) sends an impulse down the bundle of his to the purkyne tissues
-The purkyne tissue causes contraction and pushes blood back to the atrium to be released

Question 23

What is the cardiac cycle?

Answer 23

The cycle of contraction and relaxation in the heart

Question 24

What is systole?

Answer 24

The contraction of the heart
-Atrial systole is when the atria contract together and force blood into the ventricles
-Ventricular systole is when the ventricles contract

Question 25

What is diastole?

Answer 25

When the heart relaxes and fills with blood

Question 26

What is tissue fluid?

Answer 26

The liquid which surrounds the cells, allowing for transport between blood and cells

Question 27

How is tissue fluid formed through pressure?

Answer 27

Hydrostatic pressure from the heart contractions forces fluid out of the capillaries -Fluid moves out of tiny gaps in the capillary walls -Dissolved gases and nutrients move with it -Larger plasma proteins and cells do not

Question 28

How is tissue fluid formed through osmosis?

Answer 28

Hydrostatic pressure causes a loss of water from the capillaries giving them a negative water potential -Water moves down the water potential gradient into the capillaries

Question 29

What is lymph?

Answer 29

Not all fluid passes back into the capillaries, the excess output needs to be collected to avoid swelling -The excess is drained into the vessels of the lymphatic system

Question 30

What is atherosclerosis?

Answer 30

-The arteries become narrowed due to the build up of plaque on the inside of the arteries -The fatty acids take up space in the artery causing less space for the blood to travel through -This causes high pressure in the artery

Question 31

What factors increase the chance of atherosclerosis?

Answer 31

-Obesity -Smoking -Alcohol -High cholesterol and triglyceride levels

Question 32

What is a stroke?

Answer 32

When part of the blood circulation to the brain is cut off

Question 33

What are the two types of stroke?

Answer 33

-Ischemic stroke = caused due to a blocked artery to the brain, usually due to fatty build ups -Hemorrhagic stroke = caused by a leaking or burst blood vessel in the brain, usually due to high blood pressure

Question 34

What is an aneurysm?

Answer 34

An abnormally large bulge in a blood vessel cell wall which can potentially burst causing internal bleeding

Question 35

What are the two kinds of heart attack?

Answer 35

-Angina = where plaque builds slowly in the coronary arteries which reduces the volume of blood flow to the heart muscle -Myocardial infarction = where the coronary artery becomes completely blocked and part of the heart muscle is starved of oxygen

Question 36

What is the Bohr effect?

Answer 36

-Increased carbon dioxide levels lower the pH levels of the blood -This affects the ability of the haemoglobin to transport oxygen -A lower pH causes haemoglobin to release more oxygen -A higher pH causes haemoglobin to hold onto more oxygen

Question 37

How is carbon dioxide transported?

Answer 37

-Binds to haemoglobin into carbaminohaemoglobin -Dissolves as CO2 -Hydrogen carbonate ions

Question 38

What is the function of an erythrocyte?

Answer 38

Contains haemoglobin to carry oxygen around the body

Question 39

What is the function of neutrophils?

Answer 39

Engulf and digest pathogens by phagocytosis

Question 40

What is the function of eosinophils?

Answer 40

Important in the response against pathogens and help develop immunity

Question 41

What is the function of basophilis?

Answer 41

Produce histamines in inflammation and in allergic reactions

Question 42

What is the function of monocyte?

Answer 42

Engulf pathogens by phagocytosis

Question 43

What is the function of a lymphocyte?

Answer 43

Important in the specific immune response of the body

Question 44

What is the function of plasma?

Answer 44

Important for transporting and helps maintain body temperature

Question 45

What is the function of platelets?

Answer 45

Involved in the clotting mechanism of blood