The Circulatory system

Question 1

What is the main function of the circulatory system?

Answer 1

• Transportation of substances around the body
• Gases need to be transported to the cells and also out of the body
• Nutrients need to be transported to the cell
• Wastes need to be removed

Question 2

The circulatory system is made up of…..

Answer 2

• The blood as the carrying substances
• tubes to direct flow (blood vessels)
• a pump (the heart)

Question 3

Blood

The blood consists of

Answer 3

The tissue that physically transports the substances

Millions of cells that work together to perform a specific function

• plasma
• red blood cells
• white blood cells
• platelets

Question 4

Plasma

Answer 4

• Fluid part of the blood - 90% water

- Carries glucose, carbon dioxide, hormones and wastes etc.

Question 5

Red blood cells

Answer 5

• are synthesised in the bone marrow

- contain haemoglobin which carries oxygen around the body

Question 6

Red blood cells shape

Answer 6

• are biconcave in shape

- when oxygen is no longer present in the blood the red blood cell loses its red colour

Question 7

White blood cells

Answer 7

• an important part of the immune system
• can produce antibodies and destroy harmful microorganisms
• made in the bone marrow

Question 8

Platelets

Answer 8

• clump together to form clots

- protect the body by stopping bleeding

Question 9

name the three types of blood vessels

Answer 9

• artery which carries blood away from the heart
• capillary which carries blood to and from the body’s cells
• vein which carries blood back into the heart

Question 10

arteries

Answer 10

• carry blood away from the heart and to the body

- they must carry blood at high pressure

Question 11

the walls of arteries are what?

Answer 11

tough and elastic

thick and muscular

Question 12

veins

Answer 12

return the blood back to the heart at low pressure

Question 13

the structure of veins are what?

Answer 13

large lumen ( inner space)
thinner walls
valves present to prevent backflow

Question 14

the vein valve opens to what?

Answer 14

allow blood to the heart - the valves allow blood to flow in the correct direction

Question 15

vein valve closes to what?

Answer 15

prevent black flow - it closes if the blood starts to flow in the wrong direction

Question 16

describe the walls of capillaries

Answer 16

only one cell thick

carries blood to and from the body cells

Question 17

arteries summary

Answer 17

speed - high
width - medium
pressure - high

Question 18

capillaries summary

Answer 18

speed - medium
width - narrow
pressure - medium

Question 19

veins summary

Answer 19

speed - low
width - wide
pressure - low

Question 20

the heart is located where?

Answer 20

directly on top of the diaphragm behind the sternum and is positioned in between the left and right lungs

Question 21

describe the circulation of blood

Answer 21

deoxygenated blood is pumped from the heart to the lungs through the pulmonary artery

oxygenated blood returns to the heart through the pulmonary vein

oxygenated blood is pumped at high pressure from the heart to the body through the aorta

Deoxygenated blood returns to the heart through the vena cava

Question 22

pulmonary circulation carries

Answer 22

deoxygenated blood from the heart to the lungs

oxygenated blood back from the lungs to the heart, ready to be pumped out to the body

Question 23

systemic circulation carries

Answer 23

oxygenated blood to the rest of the body through the arteries
deoxygenated blood back to the heart through the veins

Question 24

the right side of the heart carries….

Answer 24

blood to the lungs

Question 25

the left side of the heart carries....

Answer 25

blood to the body

Question 26

what carry blood to and from the lungs

Answer 26

the pulmonary artery and vein

Question 27

what carry blood to and from the body

Answer 27

the aorta and the vena cava

Question 28

the upper chambers of the heart are called

Answer 28

the atrias

Question 29

the lower chambers of the heart are called

Answer 29

the ventricles

Question 30

what separates the left and right side of the heart?

Answer 30

the septum which is a muscle

Question 31

name the hearts valves

Answer 31

semi-lunar valve (2) tricuspid valve bicuspid valve

Question 32

What are the three main phases of a heartbeat

Answer 32

1. the two atria contract, pushing blood down into the ventricles 2. the ventricles contract, forcing blood out of the heart to the body and lungs 3. the heart muscle relaxes and the atria fill with blood

Question 33

the heart rate (or pulse rate) is what?

Answer 33

the number of ties the heart beats per minute (bpm)

Question 34

why does the heart pump blood

Answer 34

so that gases and nutrients can travel around the body

Question 35

stroke volume is what

Answer 35

the amount of blood pumped out of the left ventricle per beat

Question 36

cardiac output is what

Answer 36

the amount of blood pumped out of the left ventricle of the heart per minute

Question 37

what's the equation to find the cardiac output

Answer 37

cardiac output = stroke volume x heart rate

Question 38

what is the effect of exercise on the heart

Answer 38

- the heart gets bigger - the muscular walls become thicker - stroke volume at rest increases, leading to a lower resting heart rate

Question 39

circulatory system plays an important role in regulating the body temperature describe vasodilation

Answer 39

if the body gets too hot, capillaries near the surface of the skin widen - this is vasodilation

Question 40

vasodilation

Answer 40

blood is diverted to the skin where the heat can easily radiate away water from the blood is excreted as sweat to cool the body

Question 41

vasoconstriction

Answer 41

if the body gets too cold, the capillaries near the surface of the sin get narrower blood is diverted away from the skin to limit heat loss

Question 42

tissue fluid

Answer 42

which all cells sit in has a similar composition to plasma small chemicals e.g. nutrients (glucose, amino acids, oxygen, ions, water) and wastes (carbon dioxide etc.) are exchange via diffusion across the capillary wall through the tissue fluid

Question 43

lymphatic system

Answer 43

a network of vessels that drains the lymph fluid from the tissue back into the circulator system it is part of the immune system and is one of the body's major defences against infection and cancer

Question 44

lymphatic exchange

Answer 44

fluid leaks from capillaries to form the tissue fluid (interstitial fluid) tissue fluid surrounds and bathes the cells, supplying them with nutrients and oxygen and removing wastes

Question 45

does some tissue fluid return directly into the capillaries? what is this fluid called?

Answer 45

yes. this fluid is called lymph and is similar in composition to tissue fluid but contains more leukocytes (white blood cell)

Question 46

describe the lymph nodes

Answer 46

are oval/bean shaped structures scattered throughout the body filter lymph by trapping foreign particles in a meshwork of elastic and reticular fibres inside the node

Question 47

the movement into and out of the capillary depends on what?

Answer 47

the balance between blood pressure and the osmotic pressure at the end of a capillary bed

Question 48

at the beginning of the bed what is higher?

Answer 48

blood pressure is higher than osmotic pressure, therefore there is a net movement of plasma and nutrients (from capillaries) into the extracellular space

Question 49

during blood and lymph exchange

Answer 49

glucose, amino acids, oxygen, ions and water diffuse from capillaries to the surrounding cells carbon dioxide and other wastes diffuse from the surrounding cells into the capillaries

Question 50

plasma proteins and red blood cell concentration increases at the end of the capillary bed, here:

Answer 50

osmotic pressure is higher than blood pressure, therefore there is a net movement of water (from tissue fluid) back into the capillaries

Question 51

is all fluid returned to the capillaries

Answer 51

no, most, but not all

Question 52

where is excess fluid collected?

Answer 52

by the vessels of the lymphatic system and become lymph