Maimting Internal Environemtns Flashcards
What is homeostasis
Regulation of a cell or organism in order to maintain optimum conditions for function in response to internal and external factors
What role does the hypothalamus play in homoeostasis
The hypothalamus is the main part that detects and regulates all of the bodily things and metabolism
What does you body do when the core temparature decreases
- vasoconstriction
- hair strands stand up
- shivering
- no sweat
What is vasoconstriction
Vasoconstriction is the narrowing of blood vessels to reduce blood flow to skin, helping to conserve heat.
What does the hair standing up do
Helps trap a layer of air between the stands, acting as an insulating layer.
How does shivering help with warming you up
- Shivering requires energy
- Energy is transferred through respiration
- Respiration is an exothermic reaction meaning it releases energy in the form of heat to its surroundings
What things does your body do to decrease core body temperature
- more sweating
- vasoconstriction
- hair lies flat
What does vasodilation do
Vasodilation is the widening of blood vessels to increase blood flow to the skin, helping to release heat
What does sweating do
When sweat is on your skin and the wind blows the heat is drawn from the sweat cooling you down
What are external factors that affect blood sugar levels
- eating
- excersise
- metabolism
Which organ monitors glucose levels
Pancreas
What does the body do when blood glucose levels are too high
The pancreas secretes insulin into the blood stream
What does insulin do
It converts glucose into glycogen, making it easier to store and builds up as fat
What does the body do when blood sugar levels are low
Glucagon is secreted into the blood stream by the pancreas, and it reconverts glycogen into glucose
What does glucagon do
In the liver, the glucagon converts glycogen back into glucose which increases the blood sugar level
What happens when you have type 1 diabetes
The immune system has attacked the hormone producing cells in the pancreas
This means that the pancreas cannot produce insulin or glucagon
What is the problem with type two diabetics
Type two diabetes CAN produce insulin/glucagon, however:
- they do not release enough for the amount of sugars in their bloodstream
- their cells no longer respond to insulin and are resistant
Is type one diabetes genetic
It can be dependant in genetic but the exact cause is unknown
Is type 2 diabetes genetic
Yes as if your family has type 2 them you at a risk of it HOWEBER external factors can also come into play
How do people with type one diabetes manage
They mange their diabetes with an insulin pump combined with continuous blood monitoring system
What happens to the cells when water level is too high in the blood
Water enters the cell by osmosis and makes it hypertonic causing it to swell and may burst
The blood becomes too thick, leading to blood clots
What happens to the cells if blood is too thin
the blood becomes hypertonic, meaning water enters the cells, causing them to swell and may even burst
What is the role of ADH
ADH is able to control the permeability of the tubules in the kidneys
This helps control how much or how little water is absorbed into the blood stream
What does the body do when there is low water concentration in the blood (control mechanism)
- hypothalamus detects low blood water concentration
- pituitary gland produced more ADH
- kidneys resorb more water into the tubules
- less volume of urine produced and more water in blood stream
What happens to the body when there is increased salt concentration in the blood
- the blood is hypotonic
- thirst response takes place
- less urine produced as a result of this
What happens when there is less salt in the blood
-> lysis / hypertonic blood
-> water moves into cells. Cells burst
-> high volume of urine
Urine produced after vigorous exercise is often much darker in colour than urine produced when at rest.
Which reason explains why urine becomes darker in colour?
Increased sweating and increased ADH production.
After the alcohol has been removed from person A’s body, control mechanisms will correct the excess
loss of water caused by the alcohol.
Describe these control mechanisms.
-> hypothalamus detects low water levels
-> this leads to an increase in ADH levels
-> increased permeability of tubules
-> less urine produced, less sweating
Red blood cells burst when they are placed in a solution with a much higher water potential than the red blood cells themselves.
This is called lysis.
Explain why lysis happens.
-> during lysis water moves into cells via OSMOSIS from an area of high water potential to low water potential
-> lots of water moved into cells causing pressure against the CELL MEMBRANE
-> this causes the cell membrane to rupture and burst
What is the main proof of type 2 diabetes (use graph in Maintaing internal environments H)
-> there is too much or too little insulin produced
-> low ability to control insulin levels
The hormone ADH affects the permeability of part of the kidney tubule.
Name the part of the tubule affected by ADH.
Collecting duct
What evidence is there to suggest that selective reabsorption occurs in the kidney tubule?
-> originally the filtrate contains high amounts of glucose, but there is no glucose in the urine
-> the filtrate also originally contains a lot of salt, but in the urine there is lower amount of salt
-> the filtrate also contains a high level of urea, which is all left behind, and is the most present in the urine
-> other substances are still almost present int urine
To lower the blood pressure, a drug can be taken to increase the amount of water excreted by the body.
Which organ would be targeted by the drug and what effect would it have on the urine?
The organ is the kidney
Effect on urine : much more dilute urine
If ADH levels rise, how will this affect urine?
(1 mark)
Higher concentration of urea
Probash is ill and is having tests in hospital.
His doctors monitor his body temperature frequently.
Explain why it is important to monitor Probash’s body temperature frequently
(2 marks)
To make sure that his enzymes don’t go beyond their optimal temperature and denature
Person A’s input of water is 2700ml, but their output is 2900ml
Why do they need treatment for their kidneys
They are loosing more water from the kidneys than is being taken in
Explain why overheating of the body may stop chemical reactions in cells.
Enzymes work at an optimal temperature
An increase in temp will cause them to denature, changing the shape of they active site
This means that the substrate will be unable to bond with the enzyme
The reaction is no longer catalysed
Urine produced after vigorous exercise is often much darker in colour than urine produced when at rest.
Which reason explains why urine becomes darker in colour
Increased sweating and increased ADH production.
What can be used to treat type 2 diabetes but not type 1?
Diet and excersise
Explain the affects of alcohol in the body
-> less ADH released in the body / ADH suppressed
-> less reabsorption of water into the bloodstream / more water excreted out of the body
After the alcohol has been removed from a persons body, control mechanisms will correct the excess loss of water caused by the alcohol.
Describe these control mechanisms.
-> hypothalamus will detect low water levels in the blood
-> leads to increased ADH levels being produced
-> this increases the permeability of the tubules
-> less water in urine meaning overall less volume of urine produced and more absorbed into blood stream
Scientists are using human embryonic stem cells to grow cells to treat type 1 diabetes.
Explain why scientists use embryonic rather than adult stem cells.
-> embryonic stem cells differenciate into more types of cells than adult ones
-> therefore insulin producing cells are easier to develop
