Revision for Applied Science

The structure and function of the circulatory system

The structure of the lungs and the function of the lungs, monitoring the respiratory system

The basic principles of medical X-ray radiography. CAT scans and MRI scans. advantages and disadvantages of the use imaging methods.

Tempreature control

Blood glucose control: treatment of diabetes, the procedure of measuring the blood sugar level 

Analysing Blood 

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The structure and function of the circulatory syst

  • describe the structure of the heart including the roles of the four chambers, the valve in double circulation and the characteristic features of arteries, veins and capillaries.

The heart is a stong muscle which pumps about 5dm cubed of blood per minute around the body. Blood passes through the network of capillaries into the lungs where oxygen is absorbed and carbon dioxide is removed from the blood.oxygenated blood carries nutrients around the body to the blood and waste products are removed. 

Double Circulation The Human heart consists of four chambers; two atrias (atriums) and two ventricles.Blood can pass to the right atrium to the right ventricle whilst standing up.The Atruims and ventricles are seperated by the atrioventrical valve (AV Valve). The role of valve is to prevent the backflow of blood. Blood moves under pressure. Valves are placed at places where blood can enter and leave the heart. 

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The Diagram of the Heart

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The Functions of the Heart

The Heart has two functions:

1. to pump blood to and from the lungs in order for oxygen to be absorbed and carbon dixide to be removed 

2. to pump blood to and from the body to meed the requirements of the cells in the body. 

Pulmonary circulation is powered by the cardiac muscle on the right hand sit54r3de. The left hand side provides the pressure to pump blood around the body.The two sides of the heart differ in size, as a consequence. Greater pressure is needed to pump blood around the body's organfrom the heart.

Contractions of the wall of the atria moves blood past the atrioventricular valve into the ventricles. the triscuspid is on the right hand side and the biscuspid is on the left hand side. Ventricular contractions moves blood through the semilunar valve of the pulmonary artery and aorta. In a healthy heart deoxygebated blood and oxygenated blood are kept apart. 

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Functions of the Heart

The heart structure has four chambers which only allow blood to enter and leave the heart called the valve . In the upper chamber of the heart blood is being returned to the heart this the atria.the right atrium recieves blood with little or no oxygen because the blood has already circulated the body delivering the nutrients and oxygen to all the relevant places. newly oxygenated blood fills up the left atrim returning from the lungs. when the atria contract hey push blood through the tricuspid and the bicuspid into the relaxed ventricles. the left ventricle pumps blood through the aorta to body. the contractions of the heart is driven by the electrical systyem of the heart. 

Blood Vessels 

the role of veins to return blood back to the heart. the blood in them is under relatively low pressure. there are three blood vessels, capillaries, areteries and veins. Arteries- are able to withstand high blood pressure. confined to prevent over inflation. capillaries- are one cell thick,hsve spaces between them which make them 'leaky'.  this is where the solutes such as oxygen, sugsrs, waste products and hormones.

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Control of heart rate

  • explain how heart rate is affected by nervous and hormonal inputs.

A healty heart beats about 60 to 80 times a minute this is the normal in-built rythm.electrical impulses make the heart muscle contract.After it contracts the heart muscle relaxes. the contraction is (systole) and the relaxation is (diastole). they work in an alternatimg pattern. this pumps blood around the body in the cardiac cycle. 

A single heart is produced like this 

1. The sinoatrial node (SAN) sends electrical impulses to the atria. these contract(atrial systole) and pump blood into the ventricles. 

2.the electrical impluses continues to the atrioventrcular node (AVN), an area between the atria and the ventricles. the ventricles contracts which is also known as ventricle systole, this forces blood through the pulmonary artery to the lungs and through the aorta to the rest of the body.

3.the atria relaxses this known as the atrail diastole. blood enter the atria from the pulmomary vein or vena cava 

4.the ventricles relax this is known as ventricular diatole.the valves(bicuspid and triscuspid) open and blood enters the ventricles from the atria.

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Controlling Blood Flow

cardiac output = heart rate x stroke volume

during strenous excersie the heart beat increases drastically. Heart rate is controlled by the nervous system  and hormones. when you wwork harder your heart beats pumps more blood around the body per minute. so the heart rate increases and the stroke volume increases also. when the stroke volume increases more blood can be transported to the muscles and the lungs.more oxygen is transported and more energy is released in respiration. carbon dioxide is carried away more quickly.

nervous control

the cardiovascular centre in the brains medulla oblongata, recieves information about the concentration of carbon dioxide in the blood. if the concentration of carbon dioxide is too hgh, impulses are sent to the accelerator nerves to activate the SAN (Sinoatrial node) heart rate is increased and carbon dioxide is carried away to the lungs to be removed through gas exchange. when the concentration returns to nomal the inhibory nerves send impulses to the SAN to reduce the heart rate.

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hormonal control

adredaline is scecreted from the adrednal glands into the blood. this happens in stressful situations.the hormone increases and the activity of the SAN and the heart rate increases.

Whilst you are excersisng there is arise in blood carbon dioxide levels which is detected by chemoreceptors in the aorta ,in the arteries and medulla.sensory nerves transmit electrical signals to the cardiovascular centre in the medulla of the brain.The electrcal signals are transmitted through an accelerator nerve to the sinoatrial node of the heart. the sinoatrial node generates electrical impulses which makes the heart rate faster. when carbon dioxide levels fall, signals are sent through vagus nerve to slow down the activity of the sinoatrial node to decrease the heart rate.                          

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  • explain how to measure blood presssure data (using a manual sphgmomanometer.

blood pressure is generated by the force of the heart pumping blood into the arteries. it can be measured using a manual sygphomomanometer or electric wrist monitor.

the procedure

the cuff is placed on the wrist of the paitent and is inflated to a high enough pressure to stop the flow of blood in the artery.the pressurew is reduced slowly until there is an intermittent blood flow which is detected. this is ths systolic blood pressure (Contractions). the pressure is reduced further until a constant blood flow is detected. This is the diastolic blood pressure (relaxation). the unit is millimetres of mecury.blood flow is intermittent whilst taking the firsst reading because,it can only be forced through the artery when the pressure is higher than that of the cuff, which is during ventricular systole, where thee ventricles are contracting.

 

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Advantages to an Electric Sygphonanometers

  • the advantages to electric sphygmomanometer

are that they are battery powered, they are more portable, and also they are lighter. they have a cuff which is easy to put on, which is easier for individuals who want use it at home unaided. 

blood pressure may be affected by the lifestyle, genetics and or medical condition in relation to an individual .

hardening of arteries (arterioscleriosis) causes high blood pressure (hypertension) this can happen as people get older. the artery wall becomes less elastic. hypertension could be life threatening by causing blood vessels to burst into vital organs . in order to bring the blood pressure back to normal a healthy lifestyle needs to be considered and controlled. losing weight and reducing salt intake are often recommended.                              

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How do you measure ventilation?

  • explain how to measure the brething rate 

breathing rate is the number of inhalation and exhalations produced in one minute. the rate can be determined by simple observation or reading of a spirogram.tidal volumes, lung volumes and other capacities can be assesed using a spirometer.

peak expiratory flow rate

it is the maximum flow forced during expiration. 

the procedure

before any reading is taken it is important that the mouth piece is clean and the meter is at zero.once this is done the subject needs to take as deep a breatha possble and blow through the meter. the subjects lips has to be as firmly sealed around the mouthpiece as possible so that no air is able to escape. this is repeated three times and the highrst reading is taken.

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Monitoring the heart

  • recognise traces for a normal heart, sinustachycardia,bradychardia, sinus arrhyrhmia and ventricular fibrillation
  • describe the electrocardiogram traces
  • identify the risks and benefits arising from the diagnosis and or treatment of paitents with circulatory or respiratory disorders

In a normal trace the heart beat to a regular rythm. an electrocardiogram is a graphical representation of the heart activity. 

the tachycardia

the rythm of the heart is faster about 100 beats per minute. this can happen as a result of excersie or a fever. the syptoms are that blood flow is restricted or circulating properly which could lead to a heart attack.

the bradycardia -the rythm of the heart is slower about 60 beats per minutes. the symptoms include tiredness, dizziness, short lived breathing, fainting and painful or difficult breathing.

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ECG Traces

(http://ars.sciencedirect.com/content/image/1-s2.0-S0022191099002085-gr2.gif)

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Irregular heartbeats

sinus arrhythmia

this often shows up in young people as a change in rythm or ventilation. heart rate increases with ispiration and decreases with expiration. the symptoms can be life threatening causing cardiac arrest and leading to suddendeath. the coukd be milder symtoms such as the heart beat palpitating.

ventricular fibrillation

this is where ventricular contractions are irregular or uncoordinated. this leads to little or no blood being pumped around the body which could make the paitent lose consciousness and going into cardiac arrest and die without CPR.

Normal and healthy measurements

blood pressure for an 18 year old male is 120/80 mm Hg. The blood pressure for a 20 year old male is 125/80 mm Hg. the blood pressure for a 40 year old male is 135/85 mm Hg. For a 20 year old female it is 123/80 mm Hg and for a 40 year old female it is 133/85 mm Hg. 

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Ethics and ethical treatment

ECG's are a powerful diagnostic tool which can sometimes be misleading and inaccurate information.taking drugs such as warfain can be harmful if the wrong dose is taken. warfain prevents the clots from forming.

Doctors may feel that using the ECG is inappropiate and unable todiagnose or treat a paitent.

1. due to religion and beliefs

2. its against the person's wishes

3. if there is no benefit to the treatment, if the side effects outweigh the benefits.

risks and benefits arising from the diagnosis and or treatment of paitent with circulatory or respiratory disorders

the medical procedure could be too dangerous the paitent may alreday be too unwell and quality of life, after the procedure the quality of life of the paitent may be poor after the surgery.

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Lung Structure

  • describe the structure of the lungs, trachea and bronchial tubes.
  • expalin how gas is exchanged. how oxygen reaches the cells within tissues and how carbon dioxide is removed

the function of the the lungs is to swap gases between the atmosphere and our blood. to be able to this they have to be thinand have a large surface area for gases to diffuse across. to have a way of getting air in and out of the lungs. the trachea has a 'C' shaped rings of cartilage that prevents the collapses of it and make it more flexible. alveoli and blood capillaries provide the large thin surface while air travels through the trachea and brochial tubes. 

The trachea and Bronchus features the cartilage, cilia, smooth muscles and goblet cells. the large bronchiole doesnt have a cartilage and the Alveolusdoesnt have any of the listed above.

the pricipal role of blood is to transport nutrients in the blood around the body. Oxygen and Glucose is transported to the cells and Carbon Dioxide and heat is carried away. in the alveoli of the lungs, blood is refreshed with oxygen while carbon dioxide diffuses out to be in expired air.

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how humans breathe?

During ihalation ribs and the sernum are raised by the contraction of the external intercostal muscle. the diaphragm is pulled down by the contractions of muscle fibres in the diaphragm. the volume of the thorax increase whilst the air pressure inside the thorax decreases. the air movement is from the enviromnet to the air space inside the lungs.

During exhalation ribs and sernum are lowered by gravity and the contractions of the internal intercostal muscles. the diaphragm is moved up by the contractions of the abdonimal muscle wall. the volume of the thorax decreases whilst the air pressure inside the thorax increases. the air movement is from the air space inside the lungs to the enviroment.

when excersing- oxygen, carbon dioxide and glucose levels change. the heart rate and blood flow increases as well as the breathing rate and tidal volume. gas exchange is more efficient.

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Gas Exchange

the alveoli and the human capillary network of the human lungs provide an efficient exchange surface for gases

because...... 

it has a very large surface area. the barriers are very thin. permeable to gaseous exchange. they are moist, it makes it easier to absorb gases across the membrane. red blood cells are flexible and are forced to change shape in order to fit through a narrow capillary. diffusion gradients exist, which show the direction in which the gases travel. 

Transport to cells 

the transport of oxygen- oxygen is transported around the bloodstream by red blood cells.haemoglobin is present in the blood and reacts 4 molecules of oxygen in order to make oxyhaemoglobin. this also reversible, for example if the concentration of oxygen is too high the oxyhaemoglobin will break down its molecules and release molecules. 

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Transport away from the cells 

carbon dioxide diffuses from a respiring cell to the blood plasma. to be transported in one of three ways:

it can be dissolve in the blood plasma, as molecular carbon dioxide. leaves the blood plasma, to enter the red blood cells and combine with haemoglobin to form carbaminhaemoglobin.  

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Drugs and Drug Testing

  • state the principle of how blood tests are used to find out if there is alcohol, a recreational drug or a performance enhancing drug 
  • state the principle of how blood tests, including ELISA are used to find antibodies of a disease e.g. AIDS 

the basic procedure when a blood sample is obtained 

blood samples are usually taken from the veins at the elbow.a band called a turqoinet is placed around the upper arm to stop the flow of blood leaving the vein, making the vein more obvious to the doctor. the surface of the skin is cleaned, and hypodermic needle is placed into the vein with a low pressure syringe attached to it - this is where blood is withdrawn from. the syringe is sealed. low pressure is then added the wound with a small cotton wool. then tape may be put over the wound. the hypodermic needle is dispensed in the waste container. and the blood sample is sent for analysis. 

when it gets to the laboratory.... 

the methods of detection include gas chromatography, high performance liquid chromatography,UV absorption and mass spectrometry

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Testing for alcohol 

scientist usually test for alcohol using gas chromatography. this analyses the liquid mixture which could be vaporised. 

Method 

a specific amount of blood is put in a sealed chamber of the machine - if ethanol is present then it will be vaporised. the ethanol is quantified by the gas chromatography (the amount of vapour depends on concentration of ethanol in the blood). the purity of the ethanol vapour is checked. 

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Blood Testing and ELISA too

Blood test have been developed on the principle of antigen- antibody specificity. these are also known as immunoassay. disease organisms possess specific antigens . each antigen is recognised by its own. specific antibody and forms an antigen - antibody. 

antibodies are labelled in three ways: an enzyme, a radioactive isotope, a fluorescent compound.

ELISA is used to test a patient to see whether they have a disease 

An antibody which specifically recognises the virus antigen is immobilised on a solid support such as the bottom of a 96 well plate. a sample is added to the antibody. any virus antigen is binded with the antibody when the rest of the sample is washed away. a second antibody is linked to an enzyme .upon it incubation it binds to the anti body antigen.and the ulinked secondary antibody is washed away.a substrate for the enzymes is added which induces a colour change how intense the colour is indicates how much antigen is present. 

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Risk Assessment for Blood tests

the service or treatment is for taking a sample blood test. the hazards include needle stick injury, sharp injury, inappropriate disposal of hypodermics, contaminated dressings and exposure to blood borne diseases. who might affected? the clinical staff such as doctors,nurses and non clinical staff such as drivers porters and cleaners. this could happen whilst taking the blood sample or through the inappropriate disposal of dressing and hypodermics. 

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Releasing Energy: Respiration

  • compare respiration and the burning of fuels
  • describe circulatory and respiratory systems as part of respiration process

burning fuels and respiration are similar because they release energy that is found inside molecules. respiration can be either aerobic or anaerobic. 

burning is fossil fuel + oxygen = carbon dioxide+water +heat and light.. 

aerobic respiration only happens when there is oxygen present. anaerobic respiration can take place without the presence of oxygen

aerobic- glucose+oxygen=carbon dioxide +water+energy (38 a t p)

anaerobic - glucose= lactic acid + energy 

the circulatory system delivers oxygen to respiring cells and takes carbon dioxide away from cells to be released from the lungs.

respiration is important for growth, movement, reproduction. respirarion provides energy in the form A T P 

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respiration is vital to the activities of every living cell. respiration releases energy from food. glucose  is the main substrate for respiration, but if it is not available it may use glycogen. respiration uses oxygen  and produces carbon dioxide and water  as waste products. the energy is stored is short term molecules A T P   

aerobic produces 38 molecules of ATP, where as Anaerobic produces 2 

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Releasing Energy: Respiration

  • compare respiration and the burning of fuels
  • describe circulatory and respiratory systems as part of respiration process

burning fuels and respiration are similar because they release energy that is found inside molecules. respiration can be either aerobic or anaerobic. 

burning is fossil fuel + oxygen = carbon dioxide+water +heat and light.. 

aerobic respiration only happens when there is oxygen present. anaerobic respiration can take place without the presence of oxygen

aerobic- glucose+oxygen=carbon dioxide +water+energy (38 a t p)

anaerobic - glucose= lactic acid + energy 

the circulatory system delivers oxygen to respiring cells and takes carbon dioxide away from cells to be released from the lungs.

respiration is important for growth, movement, reproduction. respirarion provides energy in the form A T P 

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respiration is vital to the activities of every living cell. respiration releases energy from food. glucose  is the main substrate for respiration, but if it is not available it may use glycogen. respiration uses oxygen  and produces carbon dioxide and water  as waste products. the energy is stored is short term molecules A T P   

aerobic produces 38 molecules of ATP, where as Anaerobic produces 2 

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Comments

Arianna Placidi

really helpful thank you!! :)

Anton Agejev

useful and informative. thanks. however, no diagram of the heart is shown

Lauren

Finding these really useful! Such a God send as I haven't bought the AS/A2 book in time! :D

Going to print these out later and use them for revision. Thanks again! :)

Chloe Gillingwater

Does anyone have their exam tomorrow @ 1-00pm? If so, good luck! 

Rue

Yeah, exam tomorrow D: good luck! :) 

Alex

I have my exam tomorrow! Dreading it!

shoaibzaman

2k16 exam revising now though

Abdullattif

Where's the heart?  :/

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