Unit 5 - Biology Flashcards
Why do veins close?
Veins close to prevent back flow of blood
Do arteries have vales?
No
Do veins have a folded endothelium?
No, veins are flat
Which types of vessels have a smooth endothelium?
Arteries and veins
What is the role of arteries?
Arteries transport blood away from the heart at a high pressure
What is the role of veins?
Veins transport blood from the body’s tissues back to the heart
Why do arteries need to have thick elastic layer?
Arteries are under high pressure so the elastic layer is there to help maintain this high pressure
What are elastic fibres made of?
They are composed of elastin
What do elastic fibres do?
They can stretch and recoil to give flexibility
What does smooth muscle do?
Contracts and relaxes, which changes the size of the lumen
What does collagen do?
Gives structural support to maintain shape and volume of the blood vessel
Which type of blood vessel has the highest pressure?
Artery
Which type of blood vessel has valves?
Veins
What are the smaller branches of veins that feed into the capillaries?
Venules
Which arteries do not carry oxygenated blood?
Pulmonary artery and the umbilical artery
What does the pulmonary artery do?
It carries deoxygenated blood FROM the heart to the lungs
What does the umbilical artery do?
Carries deoxygenated blood from the foetus to the placenta
Why do arteries need a folded endothelium?
Folded endothelium allows the lumen to expand under high blood pressure
Why does the endothelium of arteries and veins need to be smooth?
Reduces the friction for the red blood cells that are travelling through them
Where does the gas exchange happen for CO2 and Oxygen?
Capillaries
Where does the body have the most veins?
In the legs
Explain how veins carry blood against gravity even though they have no pulse of their own
The valves in veins squeeze the blood in a one way direction because the valves are opening and closing
Why do veins need to have thin walls?
To reduce the blood pressure
What do capillaries do?
Link arteries to veins and they let oxygen out of blood as well as letting carbon dioxide into blood
How thick are capillary walls?
One cell thick
Why do capillary walls need to be so thin?
So the gaps in the cells allow substances through
Why does the body need so many capillaries?
So there is more place for gas exchange which gives faster diffusion
Why do capillaries need a large total-cross sectional area?
Slows blood to allow time for O2 and CO2 gas exchange
Why do capillaries have gaps between cells?
Allow for gases, water, sugar, and glucose, and hormones to pass through
What type of valve is the pulmonary valve?
Semilunar valve
What type of valve is the aortic valve?
Semilunar valve
What type of valve is the bicuspid valve?
Atrioventricular valve
What type of valve is the tricuspid valve?
Atrioventricular valve
What does the coronary artery do?
Provides the main blood supply to the heart
What blood comes out of the right side of the heart and goes to the lungs?
Deoxygenated
What blood come from the left side and goes to the body?
Oxygenated
Why do the left ventricles have thicker muscular walls than the right ventricles?
Because the left ventricle has to pump blood into vessels, this requires a bigger force
Why does the atria have much thinner muscular walls than ventricles?
Atria only pumps blood to ventricles next to them. Ventricles pump blood to distant organs and tissues so they need more support from the muscle walls
Why are atrioventricular valves important in the heart?
Atrioventricular valves separate the atria from the ventricles. This allows blood to flow from the atria to the ventricles, but prevent flow in the opposite direction
Why would having a hole in the septum cause dizziness and could be fatal?
The septum stops oxygenated blood and deoxygenated blood from mixing. If they mix, the body and brain won’t receive enough oxygen
What does the systolic number mean in a blood pressure test?
Measures the pressure in your arteries when your heart beats
What does the diastolic number mean in a blood pressure test?
Measures the pressure in your arteries when your heart rests between beats
What are normal blood pressure values?
120/80 or less is considered normal BP for an adult
What would be considered a high blood pressure reading?
140/90 or above
What would be considered a low blood pressure reading?
Below 90/60
What happens if your blood pressure is too high?
High blood pressure can make your arteries less elastic which can decrease the flow of blood and oxygen going through your heart
What happens if the coronary artery becomes blocked?
The narrowing of the artery will decrease the blood flow which there will be a decrease Oxygen, respiration, and ATP which will cause a heart attack
How do you calculate cardiac output?
Stroke Volume x Heart Rate
What is stroke volume?
Total volume of blood pumped by ventricles during one contraction of the heart
What is heart rate?
Number of beats per minute
What is cardiac output?
Cardiac output is the volume of blood that the heart pumps each minute
What is bradycardia?
If you have bradycardia then the heart will beat less than 60 times per minute.
What are the blood groups?
A, B, AB, O
Which is the most common blood group?
O
Why is O the most common blood group?
It’s more highly expressed in the gene pool. A and B are mutations only seen in the past 20,000 years and haven’t spread through the population yet
What is the universal blood donor?
O-
How is a baby’s blood type determined?
A child receives one of the three alleles from each parent, giving rise four possible blood types
Describe the circulation of blood through the heart
Blood enters the left atrium through the pulmonary vein, which takes oxygenated blood FROM the lungs. It’s pushed into the left ventricle, which contracts to push blood through the aorta under high pressure. Oxygenated blood travels from the aorta to the rest of the body, providing it with oxygen. Deoxygenated blood arrive at the heart via the superior and inferior vena cava, entering the right atrium. It is pushed into the right ventricle, which contracts to push blood through the pulmonary artery. Deoxygenated blood travels from the pulmonary artery to the lungs, where it picks up more oxygen
What is the liquid part of blood?
Plasma
How much of the blood is plasma?
Approximately 55%
What shape is a red blood cell?
Biconcave
What component of blood is the largest?
White blood cell
What component of blood is the smallest?
Platelets
What is plasma made of?
Water, CO₂,
How do they identify the different blood groups?
By the different antigens
How do we recognise if someone is in the O blood group?
O doesn’t have any antigens
Why does O blood group not have antigens?
Antibodies cannot attach to O group
What is the Rhesus protein?
The Rh protein is an inherited protein that can be found on the surface of the red blood cell
What does the negative and positive sign next to blood groups symbolise?
Whether or not they have the Rh protein in their blood or not
What happens if the antibodies and antigens are the same shape?
The person would get an agglutination which would cause blood clots and could be fatal
Does O blood have antibodies?
Yes but they don’t have antigens
What does “itis” show?
That there is an inflammation (e.g arthr”itis” is an inflammation of joints)
What is atherosclerosis?
A buildup of plaque in the arteries
What are the 5 elements of the cardiac conduction system?
Sino-atrial node, atrio-ventricular node, bundle of his, left and right bundle branches, Purkinje fibres
What is a heart aneurysm?
Aorta has started to bulge and the blood pressure decreases because the aorta is bigger
What is Cardiovascular Disease?
Coronary artery becomes narrower and less flexible because of fatty deposits/plaque in the artery
What is plaque?
Fatty deposits
How does smoking increase the chances of atherosclerosis?
Cigarettes include chemicals that when we smoke, they get into our blood stream. These chemicals can bind to fat which binds fat molecules together, so then there is a buildup of fat stuck in the arteries
Why does atherosclerosis cause angina?
Because when atherosclerosis causes so much blockage that there’s not enough oxygen getting through the heart, the heart will respire anaerobically which causes lactic acid to produce. This is what causes angina
What is the difference between stable angina and unstable angina?
Stable angina is chronic and long term because unstable angina is acute and causes a ruptured plaque
What does ruptured plaque mean?
A piece of the fatty deposit stuck to the coronary artery walls breaks off
What is cholesterol?
Main ‘fat’ that causes atherosclerosis
Where is cholesterol produced?
The liver
What does HDL and LDL stand for in cholesterol?
High Density Lipoprotein
Low Density Lipoprotein
What is LDL (what is its job)?
LDL is a lipoprotein that takes cholesterol to cells
What is HDL?
HDL is a lipoprotein that takes cholesterol from cells to the liver
What are the names of the two fats?
Saturated fat and unsaturated fat
What’s an example of a food that contains lots of saturated fat?
Red meat
Why does smoking cause CVD?
Nicotine raises heart rate and BP. Carbon Monoxide reduces oxygen so the heart works harder. Chemicals increase risk of blood clots.
How does high blood pressure increase chances of atherosclerosis?
Higher blood pressure puts strain on artery walls which speeds up damage and atherosclerosis
Do diets high in saturated fat decrease HDL?
Yes but they increase LDL
What are statins?
Group of medicines that can help lower the LDL cholesterol in blood
How do statins work?
They lower the LDL in blood by inhibiting enzyme in the liver. This prevents the build up of plaque in the heart
Are statins easy to take?
Yes, easy to take without supervision
How long do you have to take statins?
For life
Are statins expensive?
No
Can statins reduce strokes?
Yes
Can statins reduce blood clots?
Yes
Do stains reduce CHD risk?
Yes
Do statins cause memory problems and inflammation?
Yes
Do statins treat or cure CHD?
Treat
Do statins increase the chance of developing diabetes?
Yes
Outline three benefits of using statins
Statins lower LDL cholesterol in blood which reduces the risk of CHD. Stains are also easy to take and no supervision is needed when taking them
Outline three risks of using statins
Cause memory problems, cause inflammation, increased chance of diabetes
What is an antihypertensive drug?
Drugs that lower blood pressure, these are giving to people with hypertension
State two structural difference between arteries and veins
Veins have valves. Arteries have a folded endothelium
What antibodies would someone with blood type A- have?
Anti B antibodies
What antibodies would someone with blood type AB- have?
Anti B and Anti A antibodies
What antibodies would someone with blood type O+ have?
Anti AB antibodies
What is the purpose of platelets in blood?
Goes to the site of a cut and clot the blood
Heart cells are myogenic. How so?
The heart has its own heart beat, own electrical impulse generated from the SAN
What role do high-density lipoproteins (HDL) provide?
The role of HDL is to transport excess cholesterol from the rest of the body to the liver for elimination from the body.
What is vasoconstriction in the RAAS system?
Higher blood pressure
What is RAAS (renin-angiotensin-aldosterone system)?
Regulation system of blood volume, electrolyte balance, and system vascular resistance
What is the order of RAAS?
Angiotensinogen, renin from kidneys, Angiotensin I, ACE from lungs, Angiotensin 2, stimulates adrenal gland, aldosterone
What does angiotensinogen mean?
Low blood pressure
What is renin?
An enzyme that creates angiotensin
What is aldosterone?
A hormone that regulates blood pressure by managing levels of sodium and potassium in blood
What is angiotensin?
Hormone that regulates blood pressure by narrowing blood vessels and triggering water and sodium intake
Describe the cardiac conduction system in the heart
The SAN releases wave of excitation. The wave spreads across the atrial walls (atrial diastole). This wave of excitation reaches the AVN and then there is a delay. The wave passes down the bundle of his septum to the apex. Then wave passes through Purkinje fibres across ventricle walls, which causes ventricular systole.
How do you calculate beats per minute on an ECG trace?
Measure the difference between two peaks and then divide it by 60 (for example 60/0.95). If the answer is a decimal then round this to 1sf
If someone’s heart rate is 40 beats per minute, what condition do they have?
Bradycardia
If someone’s heart rate is 110 beats per minute, what condition do they have?
Tachycardia
Name a gas that is excreted through the alveoli
Oxygen
What’s the deepest inner layer of the lungs?
Visceral pleura
What’s the middle inner layer of the lungs?
Pleural cavity
What’s the outer inner layer of the lungs?
Parietal pleura
What does the pleural membrane do?
One side lines the body cavity wall and the other side lines the lungs
What is the proper name for the air tube?
Trachea
What is the proper name for the food tube?
Oesophagus
Why does the trachea have ‘C’ rings?
To allow movement of the neck without abstraction
Name the process used to reabsorb water from the filtrate into the blood
Osmosis
Why do ventilators have humidifiers?
It moistens the air to avoid dehydration but the air also needs to be moist because gases need to be able to diffuse
When someone is on a ventilator to help them breathe, why is the expelled air taken away?
Exhaled air contains carbon dioxide which would have negative affects on the breathing rate if it wasn’t taken away
In ventilation, what does inspiration and expiration mean?
Inhalation and exhalation
In inspiration, how does the ribcage move?
Upwards and outwards
In inspiration, how do intercostal muscles move?
They contract
In inspiration, what happens to the volume of the thorax? (lungs)
It increases
In inspiration, what happens to the pressure in the thorax? (lungs)
It decreases compared to atmospheric pressure
In expiration, how does the ribcage move?
Down and inwards
In expiration, what happens to the intercostal muscles?
They relax
In inspiration, how does the diaphragm react?
Contracts and flattens
In exhalation, how does the diaphragm react?
Relaxes and moves up
What happens to the volume of the thorax (lungs) in expiration?
Decreases
What happens to the pressure in the thorax (lungs) in expiration?
Increases
In inhalation, where does the air go?
Into lungs
In expiration, where does the air go?
Out of lungs
What are the four roles of kidneys?
Regulating salt content, regulating water content (osmoregulation), regulating blood pressure, regulating acid-base balance
What is the difference between urethra and the ureter?
Ureter is the small tube that connects the bladder and the kidneys. The urethra is the tube that connects the bladder to the body’s exterior so the urine can exit the body
Are dialysis machines a short-term or long-term solution?
Short-term until a transplant can replace the kidney that isn’t working
What is osmoregulation?
Water balancing (the kidney regulates water content)
What is the main chemical the kidney excretes?
Uric acid
What is excretion?
Elimination of waste productions in the body
How do carrier proteins work?
The chemicals to be transported join to the carrier protein. Energy from ATP is used to change protein shape. As the protein changes shape, it pushes the chemical through (against its concentration gradient). Then the protein changes back to its original shape
Is a channel protein passive or active?
Passive
Is a carrier protein active or passive?
Active and passive
Why can’t glucose smoothly diffuse?
It’s not fat soluble
What does semi-permeable mean?
Allows small substances through but not large
What do the channel proteins do?
Allows molecules to move from a high concentration area to a low concentration area during facilitated diffusion
What is osmosis?
Movement of water from higher water concentration to lower water concentration through a semipermeable membrane
What is active transport?
Active transport is a process that is required to move molecules against a concentration gradient
Is active transport from low to high concentration or high to low concentration?
Low to high
What does exocytosis mean?
Releasing large molecules outside the cell
What does endocytosis mean?
Absorbing large molecules into the cell
What does the right pulmonary artery do?
Carries deoxygenated blood to right lung
What does the superior vena cava do?
Carries deoxygenated blood from the upper body
What does the right pulmonary vein do?
Carries oxygenated blood from right lung
What does the sinoatrial node do?
It’s the heart’s pacemaker, responsible for the regular contraction of the heart muscle
What does the bundle of his do?
Transmits impulses from the AV node to the ventricles
What does the inferior vena cava do?
Carries deoxygenated blood from the lower and middle body
What do the purkinje fibres do?
Sends nerve impulses to the ventricles of the heart
What does the septum do?
Divides left and right side of the heart
What does the semilunar valve do?
Valves prevent backward flow of blood
What does the left pulmonary vein do?
Carries oxygenated blood from the left lung
What does the left pulmonary artery do?
Carries deoxygenated blood to left lung
What does the aorta do?
Carries oxygenated blood to the body
What are the three treatments for CVD?
Anti-hypertensive drugs, statins, transplantations/immunosuppressants
What is the spirometer?
An instrument that measures the breathing rate
Where do you find cardiac muscle?
In the heart
What do goblet cells produce?
Mucous
Why do goblet cells produce mucous?
To trap pathogens
What does tidal volume show?
Tidal volume shows your regular breathing rate
What is the inspiratory reserve?
The most amount of oxygen you can take in with the most amount of effort
What is the expiratory reserve volume?
The most amount of oxygen you can breathe out with the most amount of effort
What is residual volume?
The volume of air remaining in the lungs after maximum forced expiration
What does the medulla do in the kidneys?
Regulates the concentration of urine
What is the bowman’s capsule?
A cup shaped structure containing the glomerulus
Where does ultrafiltration of urine take place?
Bowman’s capsule
What is the glomerulus?
The glomerulus is a structure made of capillaries in which the pressure forces all solutes in the blood plasma to be forced through the capillary walls. This includes amino acids, glucose, urea, water. Proteins don’t pass through because they are too large.
What does the loop of Henle do?
Reabsorb water and sodium chloride from the filtrate
What does the collecting duct do?
Collects urine and transports it to the ureters where it’s temporarily stored in the urinary bladder
Where does ultrafiltration of the kidneys start?
The glomerulus
Where does ultrafiltration of the kidneys end?
Collecting duct
What state is the heart at the beginning and end?
Atrial diastole
