Unit 4- The Circulatory System Flashcards
Define Platelet.
A type of blood cell that helps blood clot so injuries scab over. No colour or nucleus
Define White blood cells.
Type of blood cell that engulf and destroy many bacteria’s, fungi and viruses. They form our immune system and protect us from developing infections
Define Neutrophils (neutrocytes)
Most common type of white blood cells in humans. Essential to immune system
Define lymphocytes.
Form of small leucocyte (wbc) with a single nucleus, occurring especially in the lymphatic system
Define Monocytes.
Type of wbc that influence the process of adaptive immunity, when we are given an immunisation injection
Describe the shape of red blood cells
Large surface area, disc like in shape
What to red blood cells contain?
Haemoglobin, an iron rich protein responsible for assisting the transportation of oxygen to all cells
Where are red blood cells made?
In the bone marrow
What is the lifespan of red blood cells?
120 days
What are red blood cells also called?
Erythrocytes
Define plasma
Liquid that the red blood cells float in and the fluid given by paramedics to bring up blood pressure
What are the six functions of the blood?
1) Transportation of gases
2) Transportation of nutrients
3) Transportation of waste
4) Maintain temperature
5) Fights infections
6) Clots wounds
Explain “transportation of gases”
Blood transports oxygen away from the lungs and around the body and transports CO2 to the lungs from the body
Explain “transportation of nutrients”
Blood transports nutrients to the cells in our body, such as glucose
Explain “transportation of waste”
Blood takes away waste products such as lactic acid (produced in aerobic respiration)
Explain “maintain temperature”
By maintaining good circulation, the blood flow keeps your core body temp at steady 37°C
Explain “fights infection”
White blood cells help kill pathogens and microbes that stray into the body. They also build immunities
Explain “clots wounds”
Substances like platelets and fibrin in the blood help clot wounds
What type of blood does the right hand side of the heart receive?
De-oxygenated blood
How does the right side of the heart receive blood?
From the Vena Cava to the Right Atrium
Where does the de-oxygenated blood pass through?
The Tricuspid valve into the Right Ventricle
How does blood get to the lungs?
Pumped under high pressure from the right ventricle to the lungs via the pulmonary artery
What type of blood does the left hand side of the heart receive?
Oxygenated blood
How does the heart receive the oxygenated blood?
From the lungs via the pulmonary veins into the left atrium
How does the oxygenated blood get to the aorta?
Through the bicuspid valve into the left ventricle
What are the benefits of having blood travel at a high pressure?
It ensures that blood travels effectively to other parts of the body via the arteries, arterioles and capillaries
Which heartbeat do the semilunar valves make up?
2nd
How do the semilunar valves open?
Ventricles contract, introventricular pressure rises and blood is pushed against them, forcing them open
How do semilunar valves close?
Ventricles relax and intraventricular pressure falls causing blood to flow back from the arteries, filling the cusps of the semilunar valves, forcing them to close
How much blood does the average human body contain?
5 litres
What is the circulatory system made up of?
The heart, the lungs and the blood vessels
What 3 parts make up the circulatory system?
Pulmonary circulation
Coronary circulation
Systemic circulation
What is pulmonary circulation
The lungs
What is coronary circulation?
The heart
What is systemic circulation?
The rest of the circulatory system
What does the heart act as?
A double pump
What does the 1st pump do?
Carries oxygen-poor blood to your lungs where it unloads CO2 and picks up oxygen to deliver back to the heart
What does the 2nd pump do?
Delivers oxygen rich blood to the rest of the body
Define Diastole
The phase of the heart beat where the heart muscle relaxes and allows chambers to fill with blood, forming one part of a blood pressure reading
Define systole
Phase of heart beat where heart muscle contracts and pumps blood from the chambers to the arteries
Describe the stages of the Cardiac Cycle
- Venous return to right atrium
- Venous flow arrives in right ventricle
- Venous blood is sent in the lungs via the pulmonary artery
- After oxygenation, blood returns to left atrium
- Red blood arrives in left ventricle
- Red blood is sent in arteries to tissues
What percentage of the blood does plasma make up?
55%
What is plasma composed of?
Mainly water, glucose, amino acids, salt, CO2 and other poisonous waste
What is the other 45% of blood composed of?
Red blood cells, white blood cells and platelets
What does ECG stand for?
Electrocardiogram
What is an ECG?
A test that records the rhythm and electrical activity of an individual’s heart
How is an ECG carried out?
Small sticky patches called ‘electrodes’ are put on your arms, legs and chest which are connected to an ECG recording machine which picks up heartbeat signals
What are the 3 types of blood vessels?
Arteries
Veins
Capillaries
What are arteries?
Blood vessels that carry OXYGENATED blood AWAY from the heart
Describe the structure of arteries
Made up of thick elastic fibres and muscle
What is the largest artery called?
Aorta
How do arteries maintain the flow of blood?
When blood enters, they expand and recoil
What do arteries branch out into?
Smaller distributive arteries and then eventually arterioles.
How do distributive arteries regulate blood flow?
They have muscular walls
What can happen if arteries contract too much, too frequently?
Blood pressure can increase harmfully
What are capillaries?
Microscopic tubes covered by a sieve like membrane
How are capillaries structured?
Walls only 1 cell thick, with a sieve like membrane
How do capillaries receive oxygen?
Arteries take blood with oxygen and nutrients to capillary beds that surround and interweave between tissues and cells
What is the function of capillaries?
To supply the tissues with oxygen and nutrients, whilst removing waste
What are Veins?
Small blood vessels known as venules join together to form veins
Describe the structure of veins
Large internal diameters with thinner walls than arteries that contain less muscle and elastic tissue
What is the function of veins?
To carry DE-OXYGENATED blood back to the heart
Why are veins buried between our muscles?
Because of the lower pressure, the movement of our muscles help move blood along
Why do veins have valves?
To ensure blood flow in the right direction and prevent back flow
What can happen with blockages in the veins?
Varicose veins
How are materials allowed in and out of cells?
Capillaries
Describe hydrostatic pressure?
Water in the plasma is forced out of capillaries by the pressure of the hearts contraction, taking with it dissolved nutrients and oxygen from the oxyhaemoglobin in the red blood cells
Which blood protein is unable to pass through the capillary membrane?
Albumin
Why must fluid in the tissue return to the circulatory system?
An individual’s limbs would swell with accumulated tissue fluid (oedema) which can be fatal
How is tissue fluid returned to capillaries?
Osmosis
Define osmosis
Movement through a semi-permeable membrane from a weak solution to a strong solution
How is fluid drawn back into the capillaries?
The albumin remaining in the capillaries make the solution stronger, which draws in the fluid (osmotic pressure)
What does water bring back to the capillaries?
Dissolved CO2 and other waste products
What percentage of fluid isn’t reabsorbed by the capillaries and drains to the lymphatic system?
10%
Where does the extra-cellular fluid drain to?
Lymph capillaries, leading to lymph vessels to join circulatory system at top of chest
How does the lymphatic system help maintain correct blood volume?
Remaining 10% of fluid is reabsorbed into the blood
How is the lymphatic system similar to the immune system?
Lymph is similar to blood plasma in that in contains lymphocytes which screen returning tissue fluid for pathogens
Define ‘glands swelling’
Nodes swell while fighting off infections
Define hypertension
High blood pressure
What makes up coronary heart disease
Angina
Heart Attacks
What are the two types of Angina?
Stable angina
Unstable angina
What is the difference between stable and unstable angina?
Stable angina attacks usually have a trigger, whereas unstable angina attacks are more unpredictable and can continue despite resting
What causes Angina?
Reduced blood flow to the heart muscles, caused by a build up of fat in the arteries
What are angina attacks a warning sign of?
Heart attack or a stroke
What are the symptoms of angina?
Tight, dull or heavy chest pain that spreads to your left arm, neck, jaw or back
How is angina treated?
Life-long medication that will treat attacks, prevent further attacks and reduce risk of heart attacks and strokes
What is the most common type of medication used to treat angina?
Glyceryl trinitate
Describe lymph nodes
Small, beanshaped organs
What is produced in the lymph nodes?
Lymphocytes
What are lymph nodes a source of?
Antibodies in the immune system
Where are lymph nodes found?
Behind ears, armpits, groin
What are the two types of surgery to treat angina?
Coronary artery bypass graft (CABG)
Percutaneous coronary intervention (PCI)
What is a Coronary artery bypass graft?
Where a section of blood vessel is taken from another part of the body and used to reroute blood around the blocked section of artery
What is a Percutaneous coronary intervention (PCI)
Where a narrowed section of artery is widened, using a tiny tube called a ‘stent’
What medication is used to treat unstable angina?
Low-dose aspirin
Dopidogrel
Injection of blood thinner
What medication are used to prevent angina attacks?
Beta blockers
Calcium channel blockers
What do beta blockers do in terms of angina?
Make the heart beat slower with less force
What do calcium channel blockers do in terms of angina?
Relax arteries and increase blood flow to the heart
What do coronary arteries do?
Carry oxygenated blood from the aorta to the heart
What is a heart attack also called?
Myocardial Infarction (MI)
What causes a heart attack?
A build up of fatty deposits in the arteries
Define atherosclerosis
Build up of fatty deposits that narrow arteries
What is coronary artery disease?
Build up of fatty deposits in artery
What are the symptoms of a heart attack?
Chest pain that radiates to jaw, neck, arms and back
Shortness of breath
Weakness or fatigue
Overwhelming sense of doom
Which heart attack treatment is offered if symptoms started within the past 12 hours?
Primary percutaneous coronary intervention (PCI)
Which heart attack treatment is offered if symptoms started within the past 12 hours but a PCI cannot be accessed?
Medication that breaks down blood clots
Which heart attack treatment is offered if symptoms started more than 12 hours ago?
Treatment decided after an angiogram, PCI or bypass surgery
How can heart attacks be prevented?
Regular exercise
Don’t smoke
Limit alcohol
Manage stress
Define Hypertension
High blood pressure
What are the causes of hypertension?
Genetics Diet high in salt or fat High cholesterol Kidney/hormone problems Diabetes
What are the symptoms?
Chest pain Dizziness Blood in urine Nose bleeds Shortness of breath
How is hypertension monitored
Measuring blood pressure twice a day and having regular doctor check ups
How is hypertension treated?
Improving lifestyle (healthy eating, regular exercise)
What is the composition of blood?
Erythrocytes Lymphocytes Neutrophils Monocytes Platelets Plasma
Define myogenic
beats automatically without stimulation by nerves
What coordinates the heart beat?
Pacemaker at top right hand side of the heart
How is BMI calculated?
Weight (kg) / height (m)2
How is blood pressure calculated?
A cuff is placed round your arm and restricts blood flow
Pressure is released while stethoscope listens to your pulse
Pressure recorded at 2 points to make up the blood pressure reading
What machine is used to measure blood pressure?
A sphygmomanometer
What is the function of the SA node?
Make atria contract
How is the electrical current from the SA node prevented from passing through to the ventricles?
Layer of tissue between atria and ventricles
What is the function of the AV node?
Receive the current at the top of the ventricles and slow it down to let the ventricles fill with blood
What is the function of the Purkyne fibres?
Carry current between ventricles to apex of heart
