circulatory system

Question 1

difference between open and closed circulation systems?

Answer 1

open= heart pumps blood into vessels that are open ended, e.g- insects
closed= blood remains in a continuous system of blood vessels, e.g- in humans

Question 2

advantages of a closed circulatory system?

Answer 2

• blood can be pumped faster
• blood flow rate to different organisms can be changed

Question 3

what are the functions of the circulatory system?

Answer 3

• to carry oxygen from the blood to the rest of the body
• to carry digested food from the small intestine to all the other parts of the body that need it
• to distribute heat
• fights diseases using white blood cells

Question 4

explain double circulation system?

Answer 4

pulmonary= pumps blood to the lungs and back to the heart again
systemic= pumps blood to body systems and back to the heart

Question 5

advantages of double circulation system?

Answer 5

• separation of oxygen rich and oxygen poor blood
• blood pressure can be kept high

Question 6

name and explain the systemic systems 3 subsystems?

Answer 6

coronary= supplies blood to the heart
renal= supplies blood to kidneys
hepatic portal circulation= supplies blood to the liver, stomach, intestines

Question 7

define portal system?

Answer 7

blood pathway that begins and ends in capillaries

Question 8

explain characteristics of arteries?

Answer 8

transports blood away from the heart
carries oxygenated blood
has narrow lumens
thick walls of muscle and elastic tissue
transports blood under high pressure
doesn’t have valves apart from the semi-lunar valves

Question 9

explain characteristics of veins?

Answer 9

transports blood towards the heart
carries deoxygenated blood
has wide lumens
thin walls of muscle and elastic tissue
transports blood under low pressure
has valves

Question 10

what are the functions of capillaries?

Answer 10

supplies tissues with substances in the blood, and to remove waste from the surrounding tissue

Question 11

what are venules?

Answer 11

small vessels that drain blood from the capillaries into veins

Question 12

what are arterioles?

Answer 12

tiny branches of arteries that transport blood from arteries to capillaries

Question 13

what is the location of the heart?

Answer 13

between the lungs, behind the breast bone, slightly above the diaphragm

Question 14

what is the structure of the heart?

Answer 14

a hollow structure made of cardiac muscle, surrounded by the pericardium

Question 15

role of the semi-lunar valves?

Answer 15

prevents backflow into the ventricles

Question 16

role of the tricuspid valves?

Answer 16

prevents backflow into right atrium

Question 17

role of bicuspid valve?
when I left, I said bye

Answer 17

prevents backflow into left atrium

Question 18

explain blood flow through the heart?

Answer 18

oxygen poor blood flows from the body into the right atrium and then into the right ventricle. The right ventricle pumps that blood to the lungs, where the blood releases waste gases and picks up oxygen. The newly oxygen rich blood returns to the heart and enters the left atrium, then into the left ventricle. The left ventricle pumps the oxygen rich blood to all parts of the body

Question 19

what is the function of the cardiac muscle?

Answer 19

never fatigues, contraction of the cardiac muscle drives blood around the body

Question 20

what is heartbeat controlled by?

Answer 20

pacemaker in the right atrium. This sends an electric signal to the cardiac muscle

Question 21

what is the contraction of the heart muscle called?

Answer 21

systole

Question 22

what is the relaxation of the heart muscle called?

Answer 22

diastole

Question 23

explain how atrial systole occurs?

Answer 23

messages are transmitted as electric impulses that cause the left and right atria to contract, this contraction is called atrial systole

Question 24

explain how ventricular systole occurs?

Answer 24

the AV node causes the ventricles to contract

Question 25

where is the Sino-atrial node or pacemaker found and what's it's function?

Answer 25

in the walls of the right atrium causes the atria to contract= atrial systole

Question 26

Where is the atrio-ventricular node found and what's it's function?

Answer 26

In the septum causes the ventricles to contract= ventricular systole

Question 27

what are the sounds of heart caused by?

Answer 27

closing of the valves

Question 28

what is the average heart rate per minute?

Answer 28

70-80 bpm

Question 29

what is the average pulse rate per minute?

Answer 29

72 bpm

Question 30

what is blood pressure?

Answer 30

force of the blood pressing against the blood vessel walls

Question 31

what are the effects of smoking on circulation system?

Answer 31

1) nicotine increases heart rate and blood pressure 2) hardens the arteries 3) increased risk of heart disease

Question 32

what are the effects of diet on circulation system?

Answer 32

1) high intake of fat, causes a build up of cholesterol, blocks the arteries and leads to strokes or heart attacks 2) high salt intake, raises blood pressure which can lead to heart attacks 3) lack of protein, lowers blood pressure

Question 33

what are the functions of blood?

Answer 33

1) transport of food, waste products and hormones by plasma 2) transport of oxygen by red blood cells 3) defence against disease

Question 34

what are the components of plasma made up of?

Answer 34

90% water, 7% protein and 3% dissolved materials

Question 35

explain red blood cells?

Answer 35

function= transports oxygen also called erythrocytes, tiny round biconcave-disc, large surface area flexible cell membranes lose their nucleus and mitochondria at maturity

Question 36

explain anaemia and sickle cell anaemia?

Answer 36

* the lack of haemoglobin or red blood cells due to a mutation in the shape of a red blood cell which means they cannot carry oxygen properly

Question 37

explain white blood cells?

Answer 37

defend the body against pathogens also called leucocytes colourless cells with no definite shape posses a nucleus made by bone marrow and mature in the spleen

Question 38

function of lymphocytes?

Answer 38

make antibodies

Question 39

what are monocytes?

Answer 39

large cells that engulf and digest bacteria and other particles by phagocytosis

Question 40

explain platelets?

Answer 40

also called thrombocytes made in the bone marrow no nucleus carry specialised blood clotting chemicals which are released where blood vessels are injured

Question 41

what is the function of platelets?

Answer 41

blood clots reduce loss of blood and prevent the entry of micro-organisms

Question 42

which blood is the universal donor?

Answer 42

O-

Question 43

which blood is the universal acceptor?

Answer 43

AB+