Week 4 - The Cardiovascular System

Question 1

what is homeostasis?

Answer 1

maintaining a relatively constant internal environment in the face of a constantly changing external environment

Question 2

what is the core concept in physiology?

Answer 2

homeostasis

Question 3

what are examples of physiological variables?

Answer 3

body temp, blood composition, heart rate, red blooc cell concentration

Question 4

what causes variation in physiological state?

Answer 4

sex, age, fasted/fed and exercise/red

Question 5

how is homeostasis regulated?

Answer 5

nervous and endocrine system

Question 6

what is the nervous system vs endocrine system?

Answer 6

nervous - transmits signals along dedicated pathways within seconds
endocine - signalling via hormones over long time and long-lasting

Question 7

where are hormones transported?

Answer 7

blood

Question 8

how many types of blood vessels are there?

Answer 8

5

Question 9

what are the names of the 2 cardiovascular loops?

Answer 9

pulmonary and systemic circulation

Question 10

what way is a heart depicted on paper?

Answer 10

the left side of the heart is depicted on the right, (it is the persons left)

Question 11

which chamber of the heart is thicker and why?

Answer 11

left side (on right side of diagram) because it is pumping blood out of the heart

Question 12

what percentage of our total body weight does the blood make up?

Answer 12

8%

Question 13

average blood volume in the body?

Answer 13

5 litres in women, 5.5 in men

Question 14

what are leukocytes?

Answer 14

white blood cells

Question 15

what makes up the most of blood?

Answer 15

55% plasma

Question 16

what makes up 45% of blood?

Answer 16

erthyrocytes - red blood cells

Question 17

what blood vessels emerge from ventricles?

Answer 17

arteries

Question 18

what blood vessels emerge from atria?

Answer 18

veins

Question 19

in what order is blood pumped out of the ventricles?

Answer 19

ventricle, artery, arteriole, capillary, venule, vein, atrium

Question 20

what benefit is smooth muscle to blood vessels?

Answer 20

contraction and relaxation - allow change of diameter

Question 21

what is it called when a blood vessel contracts?

Answer 21

vasoconstriction

Question 22

what happens when a blood vessel contracts?

Answer 22

blood vessels narrow, blood pressure increases

Question 23

what is it called when a blood vessel relaxes?

Answer 23

vasodilation

Question 24

what happens when a blood vessel relaxes?

Answer 24

more blood can flow through, blood pressure decreases

Question 25

give an example of vasdilation

Answer 25

when temperature increases, blood vessels widen and during exercise

Question 26

give an example of vasconstriction

Answer 26

when temperature drops

Question 27

where does blood go following systemic circulation?

Answer 27

it goes into right atrium, then ventricle, contraction pushes blood out of pulmonary artery

Question 28

where does blood go following pulmonary circulation

Answer 28

it has been oxygenated in the lungs and enters left atrium and then ventricle, contraction forces blood out of aorta beginning systemic circulation

Question 29

what causes contraction in the heart?

Answer 29

electrical currents

Question 30

the heart is autorhythmic, what does this mean?

Answer 30

it will still beat without nerve connections

Question 31

how does the heart generate its own pulse?

Answer 31

pacemaker cells in SA node

Question 32

where is SA node?

Answer 32

right atrium

Question 33

describe electrical current and blood flow in heart:

Answer 33

blood enters atria, SA node initiates contraction and blood enters ventricles, purkinje fibres initiate contraction of blood out of heart through artery

Question 34

what is it called when heart chambers contract?

Answer 34

systole

Question 35

what is it called when heart chambers relax?

Answer 35

diastole

Question 36

how long is cardiac cycle?

Answer 36

0.8 seconds

Question 37

what is the heart rate when cardiac cyle is 0.8sec long?

Answer 37

60/0.8 = 75bpm

Question 38

describe the flow of blood

Answer 38

unidirectional

Question 39

what does the lup dup heart sound come from?

Answer 39

valves opening and closing

Question 40

in an ECG what does P wave represent?

Answer 40

artial excitation/ systole

Question 41

in an ECG what does QRS complex represent?

Answer 41

ventricular excitation/ systole

Question 42

in ECG what does T wave represent?

Answer 42

Resting state return

Question 43

what does ECG allow?

Answer 43

testing for cardiac abnormalities

Question 44

why is the body a good conductor of electricity?

Answer 44

blood is full of electrodes