The cardiovascular system (B1)

This is taken from class notes and the applied science textbook

What is the cardiovascular system?

it is a body system that allows the blood to circulate around the body to transport and supply nutrients to organisms so that they can survive.

What is the cardiovascular system known as?

the circulatory system

Why is the human circulatory system known as “double”

because blood passes through the heart twice in one complete circulation of the body

What is the meaning of systemic circulation?

parts of the circulatory system that relates to the transport of oxygen and carbon dioxide from the heart to body cells

What is the meaning of pulmonary circulation?

a part of the circulatory system that relates to with the transport of oxygen and carbon dioxide from the heart to the lungs.

What is the function of arteries?

carry blood away from the heart. has very high pressure

What is the structure of an artery?

• small lumen

• thick walls with collagen

• elastic tissue in the wall, so it can expand and recoil

• has smooth endothelium that reduces friction through the lumen

What is an arteriole?

smaller arteries which contain smooth muscle cells wrapped around the endothelium.

What is the function of capillaries?

they allow the exchange of materials between the blood and the cells by tissue fluid. They link arterioles to venules.

What is the structure of capillaries?

• thin walls, one cell thick

• narrow lumen to help the red blood cell release oxygen

• site of diffusion

What are venules?

A group of larger capillaries that can join to form veins.

What is the function of veins?

carry blood to the heart

What is the structure of veins?

• large lumen

• thinner walls, because of low pressure

• have valves to prevent the backflow of blood

How many chambers are there in the heart?

4

How many atria’s in the heart?

2

How many ventricles are there in the heart?

2

Where are the atria placed in the heart?

In the upper chambers

What does the right atrium receive?

deoxygenated blood coming from the superior and inferior vena cava.

Where does the right atrium take the blood received from the vena cava?

To the lungs

What does the left atrium receive blood from?

receives oxygenated blood from the lungs

What does the left atrium do with the blood?

pumps it to the left ventricle

What is the structure of the left atrium?

thicker muscular walls compared to the right atrium

Where does the right ventricle get the blood from?

deoxygenated blood from right atrium

What does the right ventricle do with the blood?

pump through the pulmonary artery to the lungs

Where does the left ventricle get blood from?

oxygenated blood from the left atrium

What does the left ventricle do with the blood now?

pumps the blood to the aorta

What is the structure of the left ventricle?

It is the thickest chamber as it is designed to pump blood against high pressure

What is the function of the septum?

separates the left and right side of the heart

What is the function of the vena cava?

to carry deoxygenated blood into the heart

What is the function of the pulmonary vein?

delivers oxygenated blood from the lungs to the left atrium

What is the function of the aorta?

transport oxygenated blood away from the left ventricle to the rest of the body

What is the function of the pulmonary artery?

transport deoxygenated blood away from the the right ventricle to the lungs

What is the location of the atrioventricular valve?

found between the atrial and ventricular chambers of the heart

What is the function of the atrioventricular valve?

Prevent the backflow of blood between the atria and the ventricle chambers of the heart

What is the atrioventricular valve known as?

bicuspid, mitral or tricuspid valve

What is the location of the sinoatrial node?

in the right atrium

What is the sinoatrial node known as?

SAN

What is the semi-lunar valve?

prevents the backflow of blood between from the aorta and the pulmonary artery

What are other names of the semi-lunar valve?

-pulmonary valve

-aortic valve

What is the function of the sinoatrial node?

generates electrical activity and initiates a wave of excitation at regular intervals

Why is the SAN commonly referred to as a pacemaker?

it continuously generates electrical impulses, and sets a healthy rhythm and pace.

Where is the atrioventricular node found?

found at the top of the septum

What is the atrioventricular node known as?

AVN

What is the function of the atrioventricular node?

picks up the wave of excitation from the atria and delays it so the atria has time to complete the contraction. Also stimulates the bundle of his

What is the bundle of his?

collection of heart muscle cells specialised for electrical conduction

What is the function of Purkinje fibres?

conduct electrical impulses to the ventricles, so it can coordinate the contraction to pump blood efficiently

Where are the Purkinje fibres located?

located in the walls of the ventricle

What is the function of the coronary arteries?

To supply the cardiac muscle with its own oxygen supply

What does myogenic muscle mean?

it can contract and relax without nervous or hormonal stimulation

What is the meaning of atrial systole?

when a wave of excitation spreads along the muscle tissue and causes muscles cells in both the left and right atrium to contract simultaneously.

What is number 2?

pulmonary valve

What is number 1?

superior vena cava

What is number 3?

tricuspid valve

What is number 4?

pericardium

What is number 5?

aortic valve

What is number 6?

mitral valve

What is number 7?

aorta

What is number 8?

right atrium

What is number 9?

right ventricle

What is number 10?

left atrium

What is number 11?

left ventricle

What is number 12?

inferior vena cava

What is number 13?

Pulmonary artery

What is number 14?

Pulmonary vein

How do you calculate cardiac output?

multiplying the heart rate (beats per minute) by the stroke volume (blood pumped per beat)

What is the cardiac output?

the total volume of blood the heart pumps to the body's circulatory system in one minute

Why are blood transfusion important?

relevant for treating medical conditions

How does the ABO system play a role?

it determines blood types based on the presence of the A or B antigen in the red blood cells

How does the Rh system help with blood transfusions?

identifies people with or without the Rh D antigen and Rh d positive blood has more immunity. Negative can be universal donor

What is the meaning of cardiac diastole?

a phase in the cardiac cycle where the heart muscle relaxes and the chambers of the heart fill with blood, this allows the ventricles to expand and blood to flow in.

What is the meaning of ventricular systole?

a phase in the cardiac cycle where the ventricles contract, which forces blood out and into the pulmonary artery and the aorta

What is the first stage of the cardiac cycle?

1) the atria relax and fill with blood from the pulmonary vein and the vena cava.

What is the name for the first stage of the cardiac cycle?

atrial diastole

What is the second stage of the cardiac cycle?

2) the atria contract and force the AV valve open. Blood flows into the ventricles and they fill up.

What is the name of the second stage of the cardiac cycle ?

ventricular diastole

What is the third stage of the cardiac cycle?

3) the AV valve close when the pressure in the ventricles rises above the pressure in the atria, to prevent any backflow of blood into the atria

What is the fourth stage in the cardiac cycle?

4) the walls in the ventricle contract and increase pressure in the ventricles. This forces the semi-lunar valves to open and the blood flows into the pulmonary artery and the aorta.

What is the fifth and final stage of the cardiac cycle?

5) when the pressure in the aorta and the pulmonary artery rises, the semi-lunar valves close to prevent backflow of blood into the ventricles.

What does ECG stand for?

electrocardiogram

What does an ECG do?

detects electrical signals in the heart, this can show if the heart is working properly

What is number 1?

P

What is number 2?

Q

What is number 3?

R

What is number 4?

S

What is number 5?

T

What is the meaning of the P wave?

depolarisation of the atria

What does depolarisation of the atria mean?

the electrical activation of the atria, triggers them to contract and pump blood into the ventricles

What is the QRS wave?

depolarisation of the ventricles

What does the depolarisation of the ventricles mean?

the electrical activation of the ventricle contract and pump blood throughout the body

What is the T wave?

repolarisation of the ventricles

What is the meaning of depolarisation?

an influx of calcium and sodium ions

What is the meaning of repolarisation?

the electrical potential returns to its resting state

What is a normal trace of an ECG?

the distance between the R peaks are equal, steady heartbeat.

What is tachycardia ?

the heart beating faster than normal, heartbeat is not sufficient. P waves are evenly spread, but closer together than usual. Over 100bpm

What is bradycardia?

slow heartbeat and under 60bpm. The P waves are spread out evenly but further than ususal

What is atrial fibrillation?

the atria quivers or twitches instead of beating in a rhythmic manner

What is ventricular fibrillation?

The ventricles contractions is not controlled. The ventricles quiver in a n uncoordinated way, and the heart pumps little to no blood. It can leads to unconsciousness or myocardial infarction

What is sinus arrhythmia?

a variation in the P-P interval can be quick or slow. Can be shown in healthy people. When you breathe in, heart rate increases, when you breathe out, the heart rate slows down.

What is asystole?

when there is no electrical signals in the heart. It has stopped beating

How does caffeine affect heart rate?

caffeine makes the heart beat faster, by increasing electrical activity of the SAN. Also affect the ventricles so it leads to an increase of contraction and relaxation for each heart beat.