Homeostasis Flashcards
What is homeostasis
Keeping the internal conditions of the body constant
What is excretion
The removal of waste products
What is urea
Broken down amino acids
Amino acids are broken down into urea by the liver
What is urine
Urea + water which gets excreted from the body
What is metabolism
Chemical reactions in the body
What is the kidney
The organ that filters the blood and produces urine
What is the bladder
The organ in which urine is stored
What is the ureter
The tube leading from the kidney to the bladder
What is the urethra
The tube leading from the bladder to outside the body
What is the nephron
The small structure in the kidney where filtration takes place
What are the regions of the nephron
Glomerulus Bowmans capsule First coiled tubule Loop of Henle Second coiled tubule Collecting duct
What is ultrafiltration
Where the blood is filtered under high pressure in the Bowmans capsule
What is reabsorption
Where useful molecules move back into the blood having gone into the nephron
What is a hormone
A chemical released by a gland that makes a target organ respond in a certain way
What is the hypothalamus
Region of the brain that has special cells to detect properties of the blood
What is a homeotherm
An animal that can keep its body temperature constant
What is an endotherm
An animal that can carry out chemical reactions in cells to warm the body
What is vasodilation
The widening of small blood vessels (capillaries)
What is vasoconstriction
The narrowing of capilliaries
What is shivering
Rapid contraction and relaxation of muscles - releasing heat
What is a gland
An organ that secretes or releases a substance
What is insulin
A hormone released by the pancreas
What does insulin do in your body cells
Allows your body to use sugar
Prevents your blood sugar level from getting too high
What is glucose
Small sugar (C6H12O6)
What is glycogen
Large sugar (lots of glucose joined together)
What is glucagon
A hormone released by the pancreas. Makes liver convert glycogen back into glucose
What is diabetes
A disease where the body doesn’t make enough insulin to control blood sugar levels
What 3 substances do we excrete
Co2
Water vapour
Urea
Where is adrenaline made
The adrenal gland
Which 2 homeostasis hormones are made in the pancreas
Insulin
Glucagon
Where is insulin made and what is its function
Pancreas - decreases glucose levels in the blood
Where is glucagon made and what is its function
Pancreas - increases glucose levels in the blood
Where is ADH made and what is its function
Pituitary gland - controls water balance of blood
As the temperature goes up we produce _________ urine and the volume of sweat produced goes _____
Less
Up
Why do we feel more thirsty in hot weather
Because we sweat which means we lose more water
Some CO2 can be carried by haemoglobin, the rest dissolves in the blood and forms carbonic acid which makes blood pH go _______. Why is this a bad thing?
Down
This is bad because because enzymes in the blood may denature
When muscles respire anaerobically they convert ___________ to __________ acid. Some of this is moved to the ________ to be converted back into ____________. Due to the transportation of the _________ acid in the blood - the pH of the blood _____________
Glucose Lactic acid Liver Glucose Lactic Decreases
Chemoreceptors in the medulla oblangata (and the main artery in the neck) of the brain monitor CO2 level in and blood pH. They send a signal to the heart to increase heart rate. How does this help?
The heart rate increases the speed at which blood moves around the body and increases the speed at which co2 goes to the lungs
What is normal body temperature
37ºC
What might happen to enzymes if the body gets too hot
They could denature
What might happen if the body gets too cold
Molecules slow down
What is the part of the brain that monitors temperature
Thermoregulatory centre
How do our bodies cool down?
(BSH) Bullsh*t
Blood vessels dilate (so blood flows nearer the edge of the skin) heat is lost by radiation
Sweating
Hairs lie flat
How does sweating cool you down
The sweat evaporates taking heat from the body - thus the body cools down
What 3 things happen when we are too cold and need to heat up
Blood vessels constrict
Hairs stand up
Shiver
What part of the skin provides protection
The epidermis
What part of the skin monitors temperature regulation
Sense organ
Capillaries
What part of the skin is involved in excretion
Sweat gland
Why does our skin go red in hot weather
Because blood flows nearer the surface
Hairs on the skin each have their own ____________ muscles which are important in ______________
Erector
Insulation
How does the body respond to high pH
By increasing the heart rate - meaning that CO2 will leave the body sooner
How does the body respond to high blood glucose
Cells in the pancreas detect high blood glucose and releases insulin
Insulin travels through blood to the liver
The liver takes glucose out of the blood and converts it into glycogen and releases it into the blood
When might we have low blood glucose
When we exercise and use it up
How does the body respond to low blood glucose
The pancreas detects this drop in blood glucose and releases glucagon
Glucagon travels to the liver via the blood
The liver breaks down the blood glycogen and turns it into glucose and releases it into the blood
What is type 1 diabetes
15% of cases
Common in childhood
When no insulin is made
What is type 2 diabetes
85% of cases
Common in adulthood
Either not enough insulin is produced or insulin doesn’t work properly
Results in pancreatic failure
Symptoms of diabetes
Thirsty because more urine is produced
Glucose builds up in lens of eye - blurred vision
Tiredness
Weight loss
Explain how the bodies of people with diabetes work
Not enough insulin produced
Therefore glucose levels increase
Kidneys work hard to remove these high levels of glucose so more urine is produced
Thirsty because more urine is produced
The outside part of the kidney is called the __________.
The inside part of the kidney is called the __________.
Cortex
Medulla
What happens in the cortex
Filtration occurs
What happens in the medulla
Water reabsorption
What happens in the bladder
Urine is stored
What goes through the ureter and via what process
Urine is forced through to the bladder via peristalsis
What is the function of the renal artery
Supplies the kidney with unfiltered, oxygenated blood
What is the function of the renal vein
Drains the kidney of filtered deoxygenated blood
Why do women suffer from bladder infections more than men
The end of the urethra is closer to the bladder than in men
What substances does the lungs remove
Carbon dioxide
What substances does the skin remove
Water
Salt
What substances does the liver convert into urea
Excess protein and amino acids
ADH is a hormone that is produced in the _________________. It is then stored and released by the ___________ gland
Hypothalamus
The pituitary
What does the hypothalamous monitor in the blood
Water content
Where does ADH go to via the blood
The collecting duct
What does ADH do when it gets to the collecting duct
Makes it more permeable to water
What is the collecting duct
The tube at the end of the kidney nephron
Why is it important that the collecting duct is permeable to water
So that water moves out of the nephron and back into the blood
Which hormone will be released if you are dehydrated and what will it do
ADH
Make the collecting duct permeable so that water will move out of it and back into the blood
What happens when the brain detects that you are hydrated
The pituitary stops releasing ADH
So it won’t make the collecting duct as permeable to water
And water will not move out of the nephron into the blood
What process takes place in the glomerulus
Ultra-filtration
Small molecules are forced into the __________ ___________ by ultra-filtration
Bowmans capsule
What happens in the first convuluted tubule
Glucose is reabsorbed into the blood
How is glucose reabsorbed into the blood in the first convuluted tubule
By active transport
What happens in the loop of Henle
Salt and water are reabsorbed
How is salt reabsorbed in the loop of Henle
Diffusion
How is water reabsorbed in the loop of Henle
By osmosis
What happens in the second convuluted tubule
Doesn’t matter - just label it
What happens in the collecting duct
More water can be reabsorbed here - controlled by ADH
If we have too much glucose then the pancreas will release ____________
Insulin
If we have too little glucose then the pancreas will release _____________
Glucagon
Our body temperature and water levels are monitored by the _______________
Hypothalamous
Our blood sugar levels are monitored by the _________
Pancreas
How does blood enter the Bowmans Capsule
Through high pressure, thin capillary walls
What does insulin do in the liver
Turns glucose into glycogen
Where in particular does ultra-filtration take place
The glomerulus
Sufficient ______ is reabsorbed. Excess ______ isn’t
Salt
Salt
Smaller organisms have a __________ surface area to volume ration
Bigger
Organisms with a bigger surface area to volume ratio can gain or lose heat at a ___________ rate. Why is this?
Faster rate
Because their is more area for the heat to transfer across
Due to their big surface are to volume ratio, __________ organisms lose body heat more easily in hot climates. It also means they are very vulnerable in _______ climates
Smaller
Cold
Why do organisms with a smaller surface area to volume ratio gain or lose heat more slowly?
Because there is less area for the heat to transfer across
Due to surface area to volume ratio, animals living in cold conditions have a __________ shape to keep their surface area to a minimum, ___________ heat loss
Compact
Reducing
