Homeostasis (ch 7) Flashcards
what is meant by homeostasis
the process where automatic control systems like the nervous system and hormones maintain a constant internal environment
what do receptor cells do
detect stimili (changes in the environment) theb send it to coordination centers then coordination centers send information to the effectors which make changes
how is carbon dioxide produced
as a product of respiration
how is carbon dioxide removed
through the lungs (breathing out)
what happens if carbon dioxide isnt removed properly
buildup of carbon dioxide can become acidic and cause your enzymes to denature
whats the test for carbon dioxide
limewater turns cloudy
whats the test for water
anhydrous copper sulfate turns blue
what is deamination
when excess protien gets broken down by the liver to amino acids then ammonia then urea to be filtered by the kindeys and excreted through the bladder
where is urea created
the liver
whatre the 3 functions of the liver
- deaminate excess amino acids to form urea
- detoxify poisoning substances like ethanol in alcohol
-breakdown old red blood cells to store iron
whatre the 4 glands in the endocrine system
Pituitary gland
adrenal glands
pancreas
thyroid glands
whatre hormones
chemicals secreted by endocrine glands into the bloodstream then travel to target organs
what do hormones do and how do they act
they regulate the functions of organs and cells, they act quickly but have long lasting effects
whatre the 4 internal conditions that have to stay constant
- water content
- blood glucose levels
- ion content
- temperature
where is the anti diuretic hormone secreted
Pituitary gland
what does ADH control
the amount of water reabsorbed by kidneys
where does blood get filtered
kidneys (specifically nephrons)
how does water leave the body
when we breathe out, sweat and urinate
how do ions and urea leave the body
sweat and the rest gets filtered out of the blood by kidney then sent to urethra in bladder to be excreted
what molecule gets fully reabsorbed in the kidneys
glucose
what 2 molecules undergo selective reabsorption in the kidneys
ions and water
why cant molecules like cells and proteins be filtered through nephrons
its too large to fit through the glomerulus
what happens to excess ions water and urea
they go to the urea to get excreted by the bladder
whats the process that healthy kidneys undergo
1- blood is filtered through the nephrons
2- all glucose is reabsorbed
3- ions and excess water go through selective reabsorption
4- waste is sent to the bladder to be removed as urine through the urethra
what happens when your water content is too high
- piutiary gland will secrete less adh to make the kidney reabsorb less water so you end up with more dilute urine
what happens when youre dehydrated
the pituitary gland secretes more adh which allows your kidneys to reabsorb more water so you end up with more concentrated urine
how does kidney damage occur
through accidents or genetics
whatre the 2 treatments for kidney failure
- dialysis
- kidney transplants
what happens in kidney transplants
the damaged kidney is replaced by a healthy one from a donor.
- overall cheaper than dialysis cause patient doesnt need to go to hospitals as often
- you need to take immunosuppressants to avoid your antibodies attacking the donor organ
- immunosuppressants can decrease immunity and cause patuent to be at risk of other diseases
what happens in dialysis
- function of kidneys is carried out using a partially permeable membrane
- blood thinner added then blood goes into dialysis machine. dialysis fluid has the same concentration of ions and glucose as healthy blood.
- done 3 times a week and process takes 3-4 hours
- only temporary till a donor organ is found
issues ; blood clots tts forming, strict diet and very time consuming.
what 2 hormones does the pancreas secrete
glucagon which increases glucose levels and insulin which lowers it
whats the function of insulin
- allows glucose to move into cells faster and sends glucose to liver and muscle cells to be converted into glycogen for storage this overall decreases blood glucose levels
what happens if glycogen stores are full
glucose is broken down and converted into lipids and fats
whats the function of glucagon
it causes glycogen stores in the liver and muscles to be broken down into glucose
how is type 1 diabetes treated
insulin injections (intravenous so they enter the bloodstream directly), a controlled diet with minimum carbohydrate intake and regular exercise
what is type 1 diabetes
usually genetic and starts from younger ages, lifelong condition where your pancreas doesnt produce enough insulin so as a result your cells dont respire which makes you feel tired. as a result you break down protien and fats to use as fuel which results in weight loss
what is type 2 diabetes and what is it caused by
- where your body cells dont respond to the insulin made by your own pancreas, caused by obesity and minimal exercise
how is type 2 diabetes treated
- balanced diet, loosing weight and exercise
if this doesnt work drugs can be given to reduce glucose absroption and help cells respond to insulin more effectively
what center in the brain regulates body temperature
thermoregulatory center in the hypothalamus
what is the optimum internal body temperature
37 degrees , if its too high enzymes will denature and if its too low enzymes will slow down their activity
how does the hypothalamus regulate the internal body temperature
it acts as a thermometer and measures any changes in the blood flowing through the brain. skin receptors are also sensitive to temperature changes and send stimuli (signals) to the thermoregulatory center
what is vasodilation
when the blood vessles that supply blood to the skin capillaries dilate which allow more blood flow
what is vasoconstriction
when the blood vessles that supply blood to skin capillaries constrict so less blood flows near the skin
what happens when your internal body temperature rises
a signal is sent to the thermoregulatory center in the brain which sends a signal to the blood vessles that supply blood to your skin capillaries to dilate which increases blood flow (vasodilation). you also sweat which causes water to evaporate off your skin and release heat energy to the environment
why is it harder for your core body temp to cool down when its humid
the sweat from your skin takes longer to evaporate since theres lots of water particles in the air which decreases diffusion rates
what happens when your internal body temperature falls
a signal is sent to the thermoregulatory center in the brain which sends a signal to the blood vessles that supply blood to your skin capillaries to constrict which decreases blood flow (vasoconstriction). you also shiver and the rapid contraction and relaxation of your muscles causes them to respire and respiration releases heat energy as a waste product which is then passed onto your tissues.
