The Circulatory System

Question 1

why do we have a circulatory system

Answer 1

to transport materials around the body

Question 2

what does the circulatory system consist of?

Answer 2

heart, arteries, veins, capillaries

Question 3

closed circulation

Answer 3

the blood remains inside the blood vessels
eg dogs, humans most animals

Question 4

open circulation

Answer 4

the blood is not always found in the blood vessels
eg. insects, spiders, crabs, lobsters

Question 5

arteries

Answer 5

blood is carried away from the heart under high pressure

Question 6

veins

Answer 6

blood is carried to the heart under low pressure with valves to prevent backflow

Question 7

capillaries

Answer 7

join arteries and veins

Question 8

adaptations of capillaries for the exchange of materials

Answer 8

one cell thick=very permeable
large no of capillaries located close to every body cell

Question 9

the Heart

Answer 9

a muscular pump needed to pump blood all over the body

Question 10

what is the heart made of

Answer 10

made of cardiac muscle surrounded by a double membrane called the pericardium

Question 11

where is the heart located?

Answer 11

in the thorax
in-between the lungs slightly to the left above the diaphragm

Question 12

what type of muscle is cardiac muscle

Answer 12

involuntary ie does not tire

Question 13

what is the main structure of the heart

Answer 13

divided into 2 sides by a muscular wall called the septum

Question 14

what are the 4 chambers of the heart

Answer 14

right atrium, right ventricle, left atrium, left ventricle

Question 15

what are the 4 major blood vessels of the heart

Answer 15

vena cava, pulmonary vein, pulmonary artery and aorta

Question 16

what does the pulmonary circuit involve

Answer 16

heart->lungs->heart

Question 17

what does the systemic circuit involve

Answer 17

heart->body->heart

Question 18

explain double circulation

Answer 18

deoxygenated blood is pumped from the heart back to the lungs
blood receives oxygen and returns to the heart
the oxygenated blood is then pumped then pumped to the rest of the body
the oxygen leaves the blood to be used for respiration
blood returns back to heart to restart the cycle

Question 19

what are the 2 circuits ofcirculation

Answer 19

pulmonary
systemic

Question 20

what are the benefits of double circulation

Answer 20

separation of oxygenated and deoxygenated blood
blood is under controlled higher pressure to reach all parts of the body
higher pressure ensures appropriate metabolism to allow for more activity

Question 21

what is the blood supply to the heart

Answer 21

coronary artery

Question 22

where exactly does the coronary artery deliver blood to?

Answer 22

to the heart muscle

Question 23

what causes a heart attack

Answer 23

blockage of the coronary arteries from the build-up of plaque

Question 24

what is the cardiac cycle

Answer 24

every time your heart beats the cardiac cycle occurs
it is controlled by the SA & AV nodes

Question 25

what does SA node stand for

Answer 25

sinoatrial node

Question 26

what does AV node stand for

Answer 26

atrioventricular node

Question 27

what are the 2 nodes?

Answer 27

a type of nervous tissue that acts as a pacemaker

Question 28

how does the cardiac cycle work

Answer 28

1. blood enters the heart into the atria atria + ventricles relaxed valves closed 2. blood pumped from atria to ventricles SA node sends signal causing atria to contract (ATRIAL SYSTOLE) tricuspid + bicuspid vales open vena cava + pulmonary vein close to prevent blood entering the atria 3.blood leaves the heart atria relaxed AV node sends signal -ventricles contract (VENTRICULAR SYSTOLE) tricuspid + bicuspid valves shut semilunar valves open blood leaves, ventricles relax, valves close & cycle starts over again

Question 29

pulse

Answer 29

alternate expansion and contraction of the arteries

Question 30

what is the average pulse for an adult

Answer 30

72bpm

Question 31

blood pressure

Answer 31

the force exerted by the blood against the walls of the blood vessels

Question 32

how do you measure blood flow

Answer 32

by measuring the pressure required to stop blood flow in the artery of the upper arm

Question 33

what are the 2 values measured when measuring blood pressure

Answer 33

systolic + diastolic pressure

Question 34

systolic pressure

Answer 34

pressure as the blood passes through due to ventricular contraction

Question 35

diastolic pressure

Answer 35

when there is no pulse, or the ventricles are relaxed

Question 36

who is at most risk for high blood pressure?

Answer 36

overweight have a relative with high blood pressure smoke eat a lot of salt don't do enough exercise are over the age of 65

Question 37

what are the 3 factors affecting circulatory health

Answer 37

smoking diet exercise

Question 38

how does smoking effect circulatory health

Answer 38

tobacco contains harmful chemicals such as nicotine and carbon monoxide nicotine increases heart rate + blood pressure carbon monoxide reduces the amount of oxygen carried by blood

Question 39

how does diet effect circulatory health

Answer 39

eating foods high in saturated fat cause high cholesterol which leads to a build-up of plaque which can lead to heart attacks and strokes foods high in salt lead to high blood pressure obesity leads to blood being under higher pressure due to the excess weight

Question 40

how does exercise effect circulatory health

Answer 40

increased exercise leads to a healthier heart the heart muscle is strengthened and the resting heart rate decreases

Question 41

what is the lymphatic system?

Answer 41

a one-way system of dead ending vessels

Question 42

how do lymph vessels work?

Answer 42

they collect fluid from around the cells and return it to the blood

Question 43

what are lymph nodes

Answer 43

they are swellings in lymph vessels which help fight infection

Question 44

how does the lymphatic system work?

Answer 44

water from the blood is forced out of capillaries this is called tissue fluid or interstitial fluid, extracellular fluid t

Question 45

what does tissue fluid consist of?

Answer 45

white blood cells and small proteins

Question 46

how is tissue fluid drained?

Answer 46

in 2 ways: 90% is drawn back into the capillaries 10% enters the lymph vessels - this creates lymph

Question 47

what is lymph

Answer 47

a milky white fluid full of proteins, white blood cells and fats made as a result of tissue fluid entering the lymph vessels

Question 48

what are lymph vessels

Answer 48

muscular walls of vessels body movements

Question 49

do lymph vessels have valves?

Answer 49

yes, to ensure lymph only flows towards the shoulders

Question 50

what are the 2 main lymph vessels

Answer 50

the thoracic duct (left) lymphatic duct (right)

Question 51

where do the thoracic and lymphatic duct empty?

Answer 51

into the bloodstream at the subclavian veins under the collar bones

Question 52

what are lymph nodes

Answer 52

they are swellings on a lymph vessel

Question 53

what is the function of a lymph node

Answer 53

they contain lots of white blood cells to fight infection

Question 54

where are the glands found?

Answer 54

tonsils neck armpits groin ect

Question 55

how do nodes fight infection

Answer 55

by filtering bacteria from the lymph by maturing lymphocytes and storing them

Question 56

what are the functions of the lymphatic system

Answer 56

to collect tissue fluid and return it to the blood the defend the body against infection absorbs and transports fats in the digestive system

Question 57

how do you distinguish between the front and back of the heart

Answer 57

flat side of the heart is flat on the front of the heart the coronary artery is running from the top right to bottom left

Question 58

how do you tell the difference between the left and right side of the heart

Answer 58

the left side of the heart is thicker

Question 59

why do you use the neck or the wrist to measure pulse?

Answer 59

because the artery is closer to the surface of the skin

Question 60

what does it mean if you return to a resting pulse faster?

Answer 60

the faster you return to a resting pulse the greater a fitness level you have