Section 5 - Blood and Organs Flashcards
Name the 4 main components of blood (4)
- Plasma - Platelets - Red Blood Cells - White Blood Cells
What is the function of plasma (1)
- Carries everything around the body
What does plasma transport (7)
- Red and white blood cells
- Platelets -
Heat energy - Hormones-
- Urea, from liver to kidneys
- Carbon dioxide, from body cells to the lungs
- Digested food products, gut to all body cells
What are platelets, and how do they help blood clot (4)
- Platelets are small fragments of cells that help blood clot
- Platelets clump together to ‘plug’ the damaged area
- Stops you losing blood, and prevents microorganisms from entering the wound
- Platelets held together by a mesh of a protein, fibrin
What are platelets held together by (1)
- A mesh of protein, fibrin
What do red blood cells do (1)
- Transport oxygen from the lungs to all cells in the body
How are red blood cells adapted to transporting oxygen (3)
- Small and biconcave : large surface area for absorbing and releasing oxygen
- Contain haemoglobin, which contains lots of iron. Reacts in the lungs with oxygen to form oxyhaemoglobin
- Don’t have a nucleas, frees up space for more haemoglobin, so they can carry more oxygen
How does your immune system deal with pathogens (4)
- Pathogens are microorgansisms that cause disease, e.g certain types of bacteria and viruses
- Once pathogens enter your body, they’ll reproduce rapidly unless destroyed.
- Destroying pathogens is the job of your immune system, and white blood cells
- Two types of white blood cell used by the body : phagocytes and lymphocytes
What are pathogens (1)
Pathogens are microorgansisms that cause disease, e.g certain types of bacteria and viruses
What happens once a pathogen gets inside your body (2)
- Reproduces rapidly unless destroyed
- Causing disease
What are phagocytes and what is there job (3)
- Phagocytes detect things that are ‘foriegn’ to the body, e.g pathogens
- They then engulf and digest the pathogens
- They are non specific, they attack anything that’s not meant to be there
What is the job of lymphocytes (5)
- Every pathogen has unique molecules called antigens; on its surface
- When lymphocytes come across foriegn antigens, they produce proteins called antibodies
- Antibodies lock onto invading pathogens and mark them for destruction
- Antibodies produced are specfic to the type of antigen
- Antibodies are produced rapidly and flow round the body, to mark all similar pathogens
How does your body become immune to a disease using lymphocytes (3)
- Lymphoctyes stay in your blood as memory cells after the infection has been fought off
- They reproduce very fast if the same antigen enters the body a second time
- Body becomes immune
How do vaccinations protect from future infections (4)
- By the time your lymphocytes have produced antibodies to deal with a new pathogen, you can get very ill, or die
- To avoid this you get vaccinated against diseases; e.g polio or measles
- Vaccinations inject dead or inactive pathogens into the body; these carry antigens so trigger an immune response, as well as being harmless
- Some lymphocytes remain in the blood as memory cells, so live pathogens will be destroyed by antibodies faster and in greater numbers
What are the three different types of blood vessel, and what do they do (6)
- Arteries : Carry blood away from the heart
- Capillaries : Involved in exchange of materials at the tissues
- Veins : Carry the blood to the heart
What do arteries do and how are they adapted to do this (3)
- Arteries carry blood away from the heart at high pressure
- Artery walls are strong and elastic
- Walls are thick compard to the lumen, containing thick layers of muscle for strength
- Largest atery in the body is the aorta
What do capillaries do and how are they adapted for this (7)
- Involved in the exchange of materials at the tissues
- Arteries branch into capillaries
- Really small
- Carry the blood really close to every cell in the body; to exchange substances
- Permeable walls, allowing substances to diffuse in and out
- Supply food and oxygem. and take away waste, e.g carbon dioxide
- Walls are one cell thick, increases rate of diffusion, by decreasing the distance over which it happens
What do veins do and how are they adapted to do this (6)
- Capilleries eventually join up to form veins
- Blood is at lower prssure, so walls don’t need to be as thick as artery walls
- Bigger lumen, to help blood flow
- Have valves, to keep blood flowing the right direction
- Largest vein in the body is the vena cava
Label A, B and C
A - Artery
B - Capillery
C - Vein
Which of the these blood vessels (vena cava, capillary, aorta) carries blood containing the most oxygen (1)
Aorta
Which of these blood vessels (vena cava, capillary, aorta) carries blood at the lowest pressure (1)
Vena Cava
Which of these blood vessels (aorta, capillary, vena cava) is most suited for gas exchange (2)
- Capillaries
- Short diffusion distance/one cell thick/low pressure
Explain how excercise increases heart rate (3)
- When excercising, muscles need more energy, meaning more respiration
- Therefore need to get more oxygen into the cells and remove more carbon dioxide
- For this to happen, blood has to flow faster, so your heart rate increases
How does your heart rate increase due to excerise (4)
- Exercise increases the amount of carbon dioxide in the blood
- High levels of carbon dioxide are detected by receptors in the aorta and caraotid artery
- These receptors send signals back to the brain
- The brain sends signals to the heart, causing it to contract more frequently and with more force
How does the hormonal system help to control heart rate (4)
- When an organism is threatened, the adrenal glands release adrenaline
- Adrenaline binds to specific receptors in the heart
- This causes the cardiac muscle to contract more frequently and with more force, so heart rate increases and the heart pumps more blood
- This increases oxygen supply to the tissues, getting the body ready for action
High levels of blood cholesterol can lead to narrowing of arteries. Suggest how this might affect the ability of the heart to function (8)
- Less oxygen/glucose/blood
- Less aerobic respiration/more anerobic
- More lactic acid
- Heart works harder
- Increase in pressure
- Coronary artery
- Clots
- Death/heart attack
Pulmonary means to do with the ……
Hepatic means to do with the …….
Renal means to do with the ……..
Lungs
Liver
Kidneys
What are the 3 main jobs of the Kidney (3)
- Removal of urea from the blood (urea is produced in the liver from excess amino acids)
- Adjustment of salt levels in the blood
- Adjustment of water content of the blood
What 3 processes happen as blood passes through nephrons (3)
- Ultrafiltration
- Reabsorption
- Release of wastes
Explain the process of ultrafiltration (6)
- Blood from the renal artery flows through the glomerulus
- High pressure builds up
which squeezes water, urea, salts and glucose out the blood and into the Bowman’s capsule
- Membranes between the blood vessels in the Glomerulus and the Bowman’s capsule act like filters;
- big molecules like proteins and blood cells are not squeezed out, they stay in the blood
- Filtered liquid in Bowman’s capsule is known as glomerular filtrate
Explain the process of selective reabsorption (4)
- Useful substances reabsorbed back into the blood
- All the glucose is reasborbed from the proximal convoluted tubule, by active transport
- Sufficent salt is reabsorbed, excess isn’t
- Sufficent water is reabsorbed from the collecting duct to the blood stream
After selective reabsorbtion and ultrafiltration, how/what substances are released from the body (3)
- Substances like water, salts and urea
- Form urine
- Continues out the nephron, through the ureter and down to the bladder
- Bladder stores it until being released via the urethra
How do kindeys adjust the body’s water content (3)
What are the 3 main ways the body loses water (3)
- Sweating
- Weeing
- Breathing
What is osmoregulation (1)
- The body balancing water coming in against water going out
If a person is sweating a lot or hasn’t drunk enough water, what do the kidneys do (3)
- Kidneys reabsorb more water
- So less is lost in the urine
- So water balance is maintained
What is the amount of water reabsorbed in the kidney nephrones controlled by (2)
- A hormone
- ADH
What does ADH do (2)
- Makes nephrons more permeable
- So more water is reabsorbed back into the blood
What is the brain’s role in controlling water content (3)
- Monitors water content of the blood
- Instructs pituitary gland to release ADH into the blood
- According to how much is needed
What is osmoregulation controlled by and what is this (2)
- Negative feedback system
- If water content is too high or low, a mechanism will be triggered that brings it back to normal
If there is too much water in the body, what happens (4)
- Brain detects water gain
- Pituitary gland releases less ADH
- Lack of ADH means kidney reabsorbs less water
- Hydrated
If there isn’t enough water in the blood, what happens (4)
- Brain detects water loss
- Pituitary gland releases more ADH
- ADH makes kidney reabsorb more water
- Hydrated
Where is glucose reabsorbed from? (1)
Proximal convoluted tubule
Where is sufficent water reabsorbed from and where does it go (2)
- From the collecting duct
- Into the bloodstream
