Circulatory system

Question 1

Explain open circulatory system?

Answer 1

blood pumped from heart through blood vessels to blood filled cavity called haemocoel. organs submerged in blood in haemocoel and gaseous diffusion occurs. blood flow back to heart openings called ostia through use of body muscles

Question 2

Explain closed circulatory system?

Answer 2

heart pumps blood through arteries to tissue cells. gaseous diffusion occurs through capillaries and blood goes back through veins to heart by one way valves. deoxy blood is pumped to lungs with high pressure and becomes oxygenated and co2 is expelled.
high pressure= more effective
more oxygen= more activity

Question 3

Function of Aorta?

Answer 3

transport o2 blood from left ventricle to all parts of body

Question 4

Function of right atrium?

Answer 4

receive deoxy blood from vena cava lower and upper limbs
thin walls as blood pumped through atrio ventricular opening to right ventricle

Question 5

Function of right ventricle?

Answer 5

receive deoxy blood from RA and thicker wall to pump blood through pulmonary artery to lungs

Question 6

Function of left atrium?

Answer 6

receive oxy blood from lungs through pulmonary veins
thinner wall to pump blood through trio ventricular opening to left ventricle

Question 7

Function of left ventricle?

Answer 7

receive o2 blood from left atrium and has thickest wall as pumps blood at high pressure through aorta to all parts of body

Question 8

Function of pulmonary artery?

Answer 8

transport deoxy blood from right ventricle to lungs

Question 9

Function of pulmonary veins?

Answer 9

transport 02 blood from lungs to left atrium

Question 10

Function of septum?

Answer 10

separating wall in heart to prevent mix of 02 and deoxy blood

Question 11

Function of coronary vein?

Answer 11

carry deoxy blood away from heart

Question 12

Function of coronary artery?

Answer 12

supply cardiac muscle with 02 blood

Question 13

Function of tricuspid valve?

Answer 13

found between RA and RV
has three flaps which are attached to inelastic chordae tendinea which are attached to walls of RV by protrusions called papillary muscles.
RA filled with blood and push flaps open, blood through trio ventricular opening to RV.
RV filled with blood and blood under chordae tendinea push flaps closed. papillary muscles contract which makes chordae tendinea tight and prevent from flapping into RA. valve closed and blood cannot flow back

Question 14

Function of bicuspid valve?

Answer 14

found between LV and LA
function corresponds to tricuspid valve

Question 15

Function of semilunar valves?

Answer 15

found at base of pulmonary artery and aorta.
inside blood vessel. semilunar membrane sacks with flaps away from ventricles. LV contracts and push flaps open. LV relax and blood flow back. sacks fill and push flaps together. valve close and blood cant flow back.

Question 16

Heart layers?

Answer 16

pericardium
myocardium
endocardium

Question 17

Where is heart found?

Answer 17

thoracic cavity, protected by ribs and sternum and held in place by blood vessels

Question 18

Function of heart?

Answer 18

pump blood through out body which provides 02 and nutrients to cell and takes CO2 and waste away from cells

Question 19

Explain mechanisms controlling heartbeat and rate?

Answer 19

blood high in CO2 leaves systemic circuit
chemoreceptors in carotid artery send impulse to medulla oblongata.
medulla oblongata send impulse to pace maker which is Sino atrial node which is group of specialized cells that determine heart rate according to body needs,
SA node sends impulse through atria to Atrio ventricular node in septum ( atria contract simultaneously).
Impulse sent down bundle of his to pukinje fibers in walls of ventricles and ventricles contract faster. blood sent to lungs and CO2 expelled- heart rate gets lower

Question 20

What is automatism?

Answer 20

ability to contract and relax without external stimuli. contracting origin in muscle cells

Question 21

explain lub- dub sounds?

Answer 21

lub is tricuspid and bicuspid valves closing
dub is softer and it is semilunar valves closing

Question 22

What happens and how long is atrial systole?

Answer 22

0,1 seconds- atria filled with blood and contract. blood push tricuspid and bicuspid valves open and blood goes to ventricles

Question 23

What happens and how long is ventricular systole?

Answer 23

0.3 seconds- ventricles filled with blood and contract. tricuspid and bicuspid valves close and semilunar valves open. oxy blood from LV go to aorta to body and deoxy blood from RV go to pulmonary artery to lungs

Question 24

What happens and how long is general diastole?

Answer 24

0.4 seconds- both atria and ventricles relax and deoxy blood fills RA from vena cava and O2 blood fills LA from lungs. semilunar valves close and cycle repeat

Question 25

Nerves that increase/ decrease heart rate?

Answer 25

sympathetic nerves increase
parasympathetic nerves decrease

Question 26

Hromones that increase heart rate?

Answer 26

adrenaline and thyroxine

Question 27

Artery structure, function and diagram?

Answer 27

Structure: thick outer fibrous connective tissue wall
thick muscle and elastic fiber layer
small lumen
no valves
Function: carry O2 blood away from heart
able to withstand high pressure of LV
Diagram:
thick outer wall
thick muscle layer
endothelium
small lumen

Question 28

capillary structure, function and diagram?

Answer 28

structure- single thin endothelium layer
function
connect arteries to veins and allow for gaseous diffusion in tissue cells
diagram:
endothelium
small lumen

Question 29

vein structure, function and diagram?

Answer 29

structure
thin outer connective tissue fibrous
thin muscle and fiber layer
large lumen
valves to prevent blood backflow
function
transport deoxy blood to heart
diagram
thin outer wall
thin muscle layer
endothelium
large lumen

Question 30

define blood pressure?

Answer 30

force exerted by blood on blood vessel walls

Question 31

factors maintaining blood pressure?

Answer 31

narrowness of arterioles
heart rate

Question 32

Systolic vs diastolic BP?

Answer 32

systolic: max blood pressure in aorta when LV contracts
90-129
+-120
Diastolic: min blood pressure in aorta when LV relaxes
69-89
+- 80

Question 33

what to measure bp with?

Answer 33

sphygomamonometer

Question 34

Explain pulmonary circuit?

Answer 34

deoxy blood from right ventricle goes through pulmonary artery to arterioles to lung capillaries. blood oxygenated and CO2 expelled. blood through venules to pulmonary vein to left atrium

Question 35

explain systematic circuit?

Answer 35

oxy blood from left ventricle to aorta to arterioles to capillaries in tissue cells. gas diffusion occurs and deoxy blood goes through venules to veins to vena cava to right atrium

Question 36

explain Coronary circuit?

Answer 36

coronary artery stemming from aorta forms crown around heart turn to arterioles and capillaries within cardiac muscle and supply cardiac muscle with oxygen and take out co2. deoxy blood through venules to coronary vein to vena cava to right atrium

Question 37

explain hepatic circuit?

Answer 37

small intestine/ stomach venule of deoxy blood form hepatic portal vein which goes to liver and venules and liver capillaries and gaseous diffusion and venules and hepatic vein to vena cava

Question 38

High blood pressure vs low blood pressure?

Answer 38

abnormally higher than 140/90
low for long period due to inherited or dehydration- can faint
100 or lower systolic

Question 39

What is a stroke and why occurs?

Answer 39

blood clot forms in brain capillaries and shortage of blood or bleeding into brain tissue leads to loss of brain function and symptom is paralysis.
due to age, smoke, hypertension, high cholesterol, diabetes

Question 40

explain heart attack?

Answer 40

high cholesterol fat deposits occur in coronary arteries. blood clot forms and breaks off creating blockage. 02 to blood is interrupted and cardiac muscle dies

Question 41

explain congenital cardiovascular defect?

Answer 41

child born with heart defect due to genes or virus/ drugs taken by mother during pregnancy

Question 42

Explain 5 treatments for heart diseases?

Answer 42

stents- expandable tube in coronary arteries to keep arteries open and prevent blockage
bypass surgery- vein from leg is taken and attached to coronary artery to bypass blockage
heart transplant- heart not functioning properly and replaced with healthy heart
valve replacement- surgeons replace not function valve in heart with synthetic valve
pacemaker- SA node not working correctly- surgeon install battery powered artificial pacemaker in chest