B3.3 Homeostasis Flashcards
How is carbon dioxide removed from the body?
- Waste product of respiration removed by breathing out
How is urea removed from the body?
- Waste product made by the liver removed by the kidneys in urine
How is urea made?
- Waste product of the break down of excess amino acids in the liver
What happens if the water level and ion level is too high in the body?
- Water damages the cell if there is not enough or too much
How do healthy kidneys produce urine?
- High pressure and membranes filter out small molecules into the Bowman’s Capsule
- Big molecules stay in the blood
- All sugar molecules reabsorbed by active transport
- Sufficient ions reabsorbed by active transport
- Sufficient water reabsorbed
- Urea, excess ions and excess water released into the ureter, then released from the body as urine
What happens to people who suffer from kidney failure?
- Waste substances build up in the blood
- Kidneys cannot control water/ion level
- Can lead to death
What are the solutions to kidney failure?
- Dialysis
- Kidney transplant
What happens during dialysis?
- Blood flows between a selectively permeable membrane surrounded by dialysis fluid
- Dialysis fluid contains same concentration of useful substances as healthy blood
- Only excess water/ions and waste products transferr into the fluid
- This cleans the blood/restores to healthy level
What are the problems with dialysis?
- Temporary solution
- Risk of clots and infections
- A fluctuate build up of toxins
- Limits diet
- Time consuming, needs to be done 3-4 times a week for 3-4 hours
- Expensive
What is the problem with a kidney transplant?
- Rejected by immune system
- Recipient’s antibodies may attack antigens on the donor organ as they may recognise it as ‘foreign’
How are transplanted kidneys prevented from being rejected?
- Immunosuppressants suppress immune system of recipient
- A donor type with a similar ‘tissue-type’
How is temperature monitored?
- Temperature receptors in the skin send messages to the thermoregulatory centre in the brain
- Body temperature monitored and controlled by thermoregulatory centre which has receptors to detect temperature of blood flow
What happens if body temperature is not normal?
- Behaviour, skin receptors detect change cause behaviour changes
- Physiological, thermoregulatory centre detect change to blood flow temperature and sends out messages to fix this
What happens if core body temperature is too hot?
- Hair lies flat
- Sweat produced by sweat glands, evaporates from skin, cooling body
- Blood vessels supplying skin dilate so blood flows closer to the skin, transferring heat more easily
Why does skin look red when too hot?
- Increased blood flow close to the skin to transfer heat more easily
What happens if core temperature is too cold?
- Hair stands up to trap insulating layer of hair
- No sweat produced
- Blood vessels constrict, reducing blood flow close to the skin
- Muscles contract causing ‘shivering’ - needs respiration which releases energy, warming the body
What are the roles of the kidney?
- ‘cleans’ the blood, removing poisonous substances like urea
- Adjust ion and water level so only sufficient amounts are kept
- Helps to maintain homeostasis
Which organ controls the glucose concentration of the blood?
- Pancreas
What is insulin used for?
- Hormone produced by the pancreas which allows glucose to move into the cells
What happens if the concentration of glucose is too high in the blood?
- Too much glucose in the blood
- Insulin secreted by the pancreas
- Too much glucose and insulin in blood vessels
- Glucose removed by liver
- Insulin makes liver turn glucose into glycogen
- Blood glucose removed
If there is too much glucose in the blood, what does adding insulin do?
- Insulin makes the liver turn glucose into glycogen
If there is too little glucose in the blood, what does the pancreas secrete?
- Glucagon
What happens if the concentration of glucose is too little in the blood?
- Blood with too little glucose
- Glucagon secreted by the pancreas
- Too little glucose in the blood and glucagon
- Glucagon makes liver turn glycogen into glucose
- Glucose added by the liver
- Blood glucose increased
If there is too little glucose in the blood, what does adding glucagon do?
- Glucagon makes the liver turn glycogen into glucose
What is Type 1 Diabetes?
- A disease caused by glucose rising to a high level because pancreas cannot produce enough insulin
How is Type 1 Diabetes controlled?
- Careful attention to diet
- Exercise
- Injecting insulin
