Homeostatis Flashcards
what is homeostatis?
the maintenance of static internal environment in the body despite changes in the extrenal environment
what factors does the body need to keep constant?
(one about plants)
(guard cells close when a plant loses water)
removal of waste products (e.g. CO2 and urea)
blood pH level
body temprature control - 370C
blood - water content/blood concentration
blood pressure
blood sugar
blood ion level
label this diagram to show why temprature control is important
what does hyperglycemia mean?
too much glucose in the blood
what does hypoglycemia mean?
too little glucose in the blood
what influences blood glucose levels to rise?
glucose in food and drink absorbed into blood
what influences blood glucose levels to drop?
glucose moves into cells from blood and is used in respiration
why is it important to keep blood glucose levels constant?
(talk about hyperglycemia and hypoglycemia)
hyperglycemia –> osmosis from cells to blood - cells shrink
hypoglycemia –> you can faint
complete this blood glucose regulation diagram for when you eat a bar of chocolate
Complete this blood glucose regulation flow diagram : when you eat a bar of chocolate
complete this blood glucose regulation diagram for when you run all the way to school
what are α and β cells?
α = alpha
β = beta
Complete this blood glucose regulation flow diagram : when you run all the way to school
what is the difference between glucose, glycogen and glucogan?
glucose = sugar
glycogen = polysaccharide
glucogan = hormone
tip to remember: when glucose is gone it releases glucagon
what is diabetes?
occurs either when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin it produces
what are the symptoms of diabetes (basic)
frequent urination
thirst
dehydration
Type 1 diabetes is an autoimmune disease. What does autoimmune mean?
your immune system attacks your own cells (in this case β cells)
how can diabetes be diagnosed/ tested?
a test for type 1 and 2 is urine –> you should have no glucose
you can also test your blood sugar levels
how can type 1 diabetes be treated? (basic)
insulin inections
how can type 2 diabetes be treated? (basic)
diet and exercise
complete this homeostatis summary gap fill
complete this diabetes diagram
how many people suffer from diabetes in the UK?
3.2 million
describe how the number of newly diagnosed people with diabetes has changed in the uK between 2001 and 2009
the number increased from approc 100,000 to 225,000
what is type 1 diabetes?
deficient insulin production in the pancreas
what causes type 1 diabetes?
exact cause is not known nor is it preventable with current knowledge
thought it derives from the immune system attacking the insulin producing cells in pancreas
at what age are most people diagnosed with type 1 diabetes?
10-14 years old
what is type 2 diabetes?
body’s ineffective use of insulin
what causes type 2 diabetes?
caused largely by the result of excess body weight and physical inactivity
at what age do most people develop type 2 diabetes?
80-89 years old
what are some of the first symptoms of diabetes?
excess excretion of urine
thirst
constant hunger
wieght loss
vision change
fatigue
how can type 1 diabetes be treated?
replace missing insulin with insulin injections (lifetime treatment)
how can type 2 diabetes be treated?
control of blood glucose levels through diet and exercise
why can type 2 diabetes not be treated with insulin injections?
they already produce insulin - their bodies don’t use it properly (resist it) and their muscles are unable to use glucose
name two of the long-term consequences of suffering from diabetes?
increase the risk of heart disease
kidney failure
suggest why insulin has to be injected and canot be taken orally
it must be injected to go into the bloodstream quickly and also otherwise it would be digested in the stomach
suggest why increasing numbers of young people develop type 2 diabetes?
culture chage - “couch potato” fast food, unhealthy living
suggest how type 1 diabetes might be cured in the future
transplant the Islets of Langerhan into the body
pancreas transplant
what is thermoregulation?
the ability of the body to keep its temprature close to 37 degrees centigrade (warm blooded organisms only)
why is thermoregulation important?
it means all chemical reactions taking place in the cells can go on at a steady pace
at higher tempratures enzymes are destroyed: too much kinetic energy - loses its shape and falls apart (are denatured)
what is hyperthermia?
what happens when the body temprature increases significantly abover 37o
what is hypothermia?
what happens when the body temprature decreases significantly below 37oC
you may not survive
enzymes don’t have enough energy (kinetic) to react
complete this temperature control flow diagram
dermis
makes new epidermis at the top and contains all the nerves, blood vessels, sebaceous glands, sweat glands and hair roots
epidermis
the outside of your skin
the top layer is dead and provides protection from dirt and strong sunlight
the middle layer contains living cells
the bottom layer is divides continually to provide new cells for the epidemis
hair
made from keratin (protein)
hair erector muscle
pulls hair uprights when muscle contracts
sebaceous gland
produces oily substance called sebum which makes the skin waterproof, prevents it from drying out and acts as a mild antiseptic to destroy fungi and bacteria
sensory nerves
help you feel pain, pressure or temperature
skin arterioles
suppky skin capillaries with oxygenated blood
skin capilaries
provide food and oxygen to the skin cells
subcutaneous layer (asidpose tissue)
fatty tissue
helps you keep warm
protects your organs and bones from injury
sweat duct
for transport of sweat from sweat gland to the sweat pore
sweat gland
produces sweat which contains 99.5% water, 0.25% urea and 0.25% sodium chloride
sweat pore
for sweat to come out
3x106 of of these cover the human skin
label this changes in skin diagram (effector of thermoregulation)
using thermoregulation: why do people’s skin look pale in cold weather?
the arterioles in the skin’s surface narrow (vasoconstriction), and so there is a dramatic decrease in blood flow to the capillaries which are next to the skin (through the arterioles)
using thermoregulation: why doe whales have a layer of adipose tissue whereas polar bears have thick fur?
whales live in freezing cold waters and so need the adipose tissue to keep warm. It would be impractical for wales to have fur. Similarly, fur keeps polar bears insulated as the fur traps air to keep warm. It would be impractical for polar bears to carry around too much fat.
using thermoregulation: why do people’s faces go bright red when they exercise?
the arterioles in the skin’s surface widen (vasodilation) and so more blood flows through the arterioles into the capillaries on the skin’s surface. This is done so more heat is lost by radiation
using thermoregulation: why are hot and dry climates more pleasant to live in than hot and humid?
when you sweat in a dry climate, you cool down easily as sweat evaporates by diffusion down a concentration gradient. However, in a humid climate the water molecules can’t evaporate which is uncomfortable.
complete this summary gap fill on thermoregulation
in terms of thermoregulation, what happens when it’s too cold?
- the hair erector muscle contract pulling the hair upwards. this traps air which is a poor conductor of heat and so less heat is lost
- arterioles in skin surface narrow (vasoconstriction). less blood flows into the capillaries on the skin surface, so less heat is lost by radiation
- sweat glands close and less sweat is produced
- shivering
- general increase in general metabollic rate
- changes in behaviour (e.g. dressing, moving into sun, activity)
in terms of thermoregulation, what is the respons when it’s too hot?
- hairs lie flat so more heat is lost by radiation
- arterioles in skin widen (vasodilation). they allow more blood to flow through capillaries in skin surface. so more heat is lost by radiation
- sweat glands open. the sweat evaporates and this cools you down
- changes in behaviour (e.g. undressing, moving into shade)
