section 5: blood and organs Flashcards
list the four main components of the blood
- plasma
- platelets
- red blood cells
- white blood cells
What part of the blood is liquid?
Plasma
What does plasma carry?
- red and white blood cells
- platelets
- digested food products eg glucose, amino acids
- carbon dioxide
- urea
- hormones
- heat energy
What helps blood to clot? Why?
Platelets
- prevent microorganisms from entering the wound (infection)
- prevents blood loss
What, apart from platelets, does the blood need to clot?
- fibrin (a mesh of protein)
- clotting factors (also proteins)
how are RBCs adapted?
- BICONCAVE shape -> Large SA
- small
- haemoglobin -> contains iron
- no nucleus -> more space = more oxygen
What do haemoglobin and oxygen form?
Oxyhaemoglobin
What are pathogens?
Disease causing microorganisms
What do phagocytes do?
- detect pathogens and anything foreign
- ENGULF AND DIGEST them
- non specific - attack anything not usually there
What do lymphocytes do?
- pathogens have ANTIGENS (unique molecules) on surface
- lymphocytes make ANTIBODIES that lock onto & mark the pathogen to be destroyed by other WBCs. These are produced rapidly.
- the antibodies are specific to that type of antigen - will ignore other types
- memory cells are then produced
Expkein the process of vaccination
- involved injecting a person with dead or inactive pathogens
- carry antigens so still trigger an immune response and therefore antibodies
- makes memory cells
Why are memory cells important? (More for vaccinations tbh)
- reduce time it takes to make antibodies, so you are less likely to get really ill or die eg polio or measles
The three blood vessels are?
- arteries
- capillaries
- veins
Arteries carry the blood..?
Away
Veins carry the blood?
To the heart
For the purpose of Capillaries carry the blood..?
In the exchange of materials at the tissues
Arteries carry blood at what pressure
HIGH
What enables the arteries to carry blood under pressure?
- strong and elastic artery walls
- elastic fibres allow arteries to EXPAND
- walls are THICK with layers of muscle compared to the lumen
What is the lumen
The hole in the middle of the blood vessel
What is the purpose of valves?
to prevent the backflow of blood
What is the largest artery in the body?
The aorta
Capillaries are..?
- very small
- very close to every cell in the body for exchange of substances
- supply food and oxygen and take away waste eg CO2
- contain permeable walls for diffusion
- only one cell thick -> increases diffusion rate by decreasing the distance
Capillaries contain..?
(Think: Lumen, wall and nucleus)
- very small lumen
- thin wall (1ct)
- have a nucleus
Veins are at what pressure?
LOWER than arteries
As a result, veins have…?
- less thick walls
- large lumen -> helps blood flow despite the lower pressure
- valves -> help keep blood flowing in the right direction
- elastic fibres and smooth muscle
Largest vein in the body..?
Vena cava
The diagram of a heart is drawn..?
Opposite to you (eg, your left hand side is it’s right hand side)
List the parts on the right side of heart:
- vena cava
- right atrium
- tricuspid valve
- right ventricle
- semi-lunar valve
The right atrium receives the _________ blood? (Oxygenated or deoxygenated)
Deoxygenated
The right side receives the deoxygenated blood through the?
Vena cava
The deoxygenated blood then goes the right ventricle and to the. L————S though the —————————— artery
- lungs
- pulmonary
List the parts on the left of the heart: (5 parts)
- pulmonary vein
- left atrium
- bicuspid valve
- left ventricle
- semi lunar valve
- aorta
The left atrium receives what type of blood (oxygenated or deoxygenated) from where? through the what ————————— vein
- oxygenated
- lungs
- pulmonary
The oxygenated blood exits the heart through the ————— and is pumped throughout the …?
- aorta
- whole body
Name the valve on both sides of the heart
- the semi lunar valve
Which ventricle has the thickest wall of muscle? Why? What does this cause?
- the left
- it has to pump blood to the whole body not just the lungs,
- the blood in the LV is under higher pressure than in the RV
Why does your heart rate increase when you exercise? (Give 2 reasons)
- for more OXYGEN which is necessary for more RESPIRATION which makes more ENERGY
- to remove more CARBON DIOXIDE
How does your heart rate increase with exercise?
- exercise increases the amount of CO2 in the blood
- these high levels are detected by receptors in the AORTA and CAROTID ARTERY
- these receptors send signals to the brain
- the brain sends signals to the heart
- the heart contracts more frequently and with more force
How does the hormonal system affect the heart rate?
- adrenal glands release adrenaline when an organism feels threatened
- adrenaline BINDS to specific receptors within the heart, causing the cardiac muscle to CONTRACT more frequently and with more force
- this increases heart rate and pumps more blood
- this increases oxygen supply for movement
What are the two exceptions to the rule that veins = deoxygenated blood and arteries = oxygenated blood?
- pulmonary vein
- pulmonary artery
bc the pulmonary vein takes oxygenated blood TO the left atrium from the lungs
and
the pulmonary artery takes the deoxygenated blood AWAY from the heart to the lungs (to be oxygenated)
‘Pulmonary’ means to do with what body part?
The lungs
‘Hepatic’ means to do with what body part?
The liver
‘Renal’ means to do with what body part?
The kidneys
What 3 blood vessels lead to the liver?
- the hepatic vein (L)
- the hepatic artery (R)
- hepatic portal vein (R), underneath the HA
Which blood vessel connects the gut to the liver?
The hepatic portal vein
What 2 blood vessels connect the kidneys?
- the renal vein (deoxygenated, LHS)
- the renal artery (oxygenated RHS)
What 2 blood vessels connect the lungs?
- the pulmonary artery (deoxygenated, LHS) - OPPOSITE TO RULE
- the pulmonary vein (oxygenated, RHS) - OPPOSITE TO RULE
What is coronary heart disease?
- when the CORONARY ARTERIES get blocked by layers of fatty material building up (caused by types of ‘bad’ cholesterol)
- causes the arteries to narrow
- this restricts blood flow and reduces the oxygen going to the heart
- can lead to a heart attack
What are the risk factors for coronary heart disease?
- diet high in saturated fat
- smoking
- inactivity/sedentary lifestyle
Why is having a diet high in saturated fat a risk factor for CHD?
- can lead to FATTY DEPOSITS forming inside ARTERIES - can lead to CHD
Why is smoking a risk factor for CHD?
(note: if you struggle with this, recap the smoking flashcards)
- (nicotine) increases blood pressure -> damages the inside of coronary arteries
- chemicals in cigarette smoke can cause damage, which makes the formation of fatty deposits more likely -> narrows coronary arteries
Why is inactivity a risk factor for CHD?
- can cause high blood pressure -> damages the lining of arteries -> increases likelihood of formation of fatty deposits -> narrows the coronary arteries
the word for blood vessels involving the gut
Mesenteric
