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25 Cards in this Set
- Front
- Back
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What is osmoregulation? |
The control of water balance and ion balance in the blood |
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How can water be lost and gained in the body? |
Through faeces, exhalation, sweating and urine Through food, drink and respiration |
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How is a low water potential detected and what happens in the brain? |
There is an increase in ion conc in the blood which osmoreceptors in the hypothalamus detect They then send nervous impulses to the posterior pituitary gland to secrete ADH |
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What happens to ADH once it enters the kidney? |
It binds to the cell membrane of the cells lining the collecting duct and causes the release of cAMP Vesicles fuse with the cell membrane and contain aquaporins which makes the membrane permeable and allows water molecules to move into the tissue fluid and out of the tubule by osmosis |
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What happens if more ADH is released into the blood? |
More aquaporins are inserted into the collecting duct membrane making it easier for water to move into the tissue fluid by osmosis |
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What is the mechanism of ADH an example of? |
Negative feedback |
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What is released and where, when the embryo implants itself into the uterus? |
hCG is released from the developing placenta |
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What do modern day pregnancy tests rely on? |
Monoclonal antibodies |
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What are monoclonal antibodies? |
Antibodies from a single clone of cells that are produced to target particular cells or chemicals in the body |
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How are monoclonal antibodies manufactured? |
A mouse is injected with the hCG and B cells produce appropriate antibodies and I removed and fused with myeloma cells so they can rapidly divide and form new antibodies |
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What are the steps for a pregnancy test? |
1. The wick is soaked in urine in the morning when hCG levels are the highest 2. The test contains mobile monoclonal antibodies with coloured beads that form hCG-antibody complexes if the woman is pregnant 3. Urine carries the complex until the first window 4. Here there are immobilised monoclonal antibodies that bind to the complex and show a coloured line 5. The urine continues through to the next window 6. This is the same as the first window but the antibodies bind to antibodies regardless if it's in a complex |
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Why is the last window on a pregnancy test needed? |
To show that the test is working |
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How can anabolic steroids and drugs be detected? |
These are broken down and excreted through urine so urine samples can be analysed through mass spectroscopy or GC to identify substances |
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What can cause kidney failure? |
Kidney infections where podocytes or tubules become damaged High blood pressure which can damage basement membrane Genetic conditions such as polycystic kidney disease where fluid-filled cysts form |
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How can you tell from a urine sample if kidneys not functioning properly? |
Large proteins blood or glucose can be seen |
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What are the 6 effects of kidney failure? |
Build up of toxic urea that can poison cells Weakened bones Build-up of mineral ions and salt in the blood lowering the water potential Pain and stiffness High blood pressure Anaemia where RBC production can decrease causing tiredness |
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What is the glomerular filtration rate? |
How much blood is filtered through the glomerulus per minute |
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How is the glomerular rate measured? |
It is measured indirectly by measuring the amount of creatinine in the blood which can indicate a low kidney function |
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What are the factors that need to be taken in when calculating creatinine levels in the blood? |
Age and sex, males have more creatine in the blood and the older you get the less creatine circulates in your blood Creatine supplements |
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What is haemodialysis? |
A machine artificially filters the patient's blood that is supplied through an artery and it runs between partially permeable dialysis membranes where urea and excess salts diffuse out of the blood into the fluid |
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How is maximum exchange ensured in dialysis? |
There is countercurrent exchange where blood flows opposite to fluid to maintain a step conc gradient |
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What is peritonal dialysis? |
This is done inside the body and uses the peritoneum (membrane surrounding the abdomen) Urea and excess minerals move out of the capillaries into the tissue fluid across the peritoneum into the dialysis fluid |
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How can the rejection of a transplanted organ be reduced? |
Tissue matching where the antigens on the donor organ and matched closely to the receiver Immunosuppressant drugs but this will reduce the patient's ability to respond to infectious diseases |
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What are the advantages and disadvantages of dialysis? |
Ads: It is readily available Disads: the patient needs to regulate the diet, it can be expensive and the patient needs to be on the machine several times a week |
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Where is ADH produced and how does it get to the posterior pituitary gland? |
Specialised nerve cells called osmoreceptor cells produce it and it passes along the axon of the cell to the gland |
