Module 5 - Homeostasis Flashcards
where are the adrenal glands found?
found above the kidneys
what type of glands are adrenal glands?
endocrine glands
what are the two parts of the adrenal glands?
cortex and medulla
what does the cortex do?
secretes steroid hormones
example of hormones cortex secretes?
cortisol and aldosterone
what are cortisol and aldosterone ?
stress hormones and promotes glucogeneisis
what is glucogeneisis ?
(proteins and lipids made in to glucose) for respiration
what do the hormones in the cortex do?
- cause the kidney to reabsorb more Na+ + H20
- increases blood pressure and volume
- surpressed immune system
what is the role of the medulla?
secretes hormones
example of hormones found in the medulla?
adrenaline and noradrenaline
what do adrenaline and noradrenaline do?
- increase heart rate and breathing rate
- promote glycogenolysis
what is glycogenolysis?
Glucogen -> Glucose (for respiration)
what type of glands is the pancreas part of?
endocrine glands
what is the pancreas found in the body?
- ## found below the stomach
what does the pancreas contain?
the islets of langerhans
what is the islets of langerhans?
- the endocrine tissue
what are the two type of cells?
alpha and beta cells
what do alpha cells secrete?
glucogan
what do beta cells secretes?
insulin
what are the steps of normal blood glucose?
-potassium ion channel is open
- potassium diffuses out of the beta cell
- inside of the cell is relatively negative (-70mv)
- calcium ion channel is closed
what are the steps of high blood glucose?
- blood glucose levels become high
- glucose enters by facilitate diffusion
- glucose is respired to form ATP is the mitochondria
- ATP belong the potassium channel
- membrane depolarises
- calcium ion channels open
- caclium diffuses into the beta cells
- causes the vesicles of insulin to be releases exocytosis
what can you make glucose from?
- non - carbohydrates (e.g. lipids)
- glycogen
what type of reaction is glucose to glycogen and vice versa?
- one way reaction
structure of glycogen?
1-6 glycosisic bonds
-strongly branched polymer
What is glycogenolysis?
- Splitting of glycogen
- promoted by glucagon and adrenaline
what is gluconeogensis?
- making new glucose
- promoted by glucagon
what is glycogensis?
- making glycogen
- the hormone that does this is insulin
what cells secrete glucagon?
alphacells - in the islets of langerhans
what cell secrete adrenaline?
adrenal glands
what cells secrete insulin?
beta cells - in the islets of langerhans
when does this happen for glucagon?
low blood glucose
when does this happen for adrenaline?
low blood glucose
when does this happen for insulin?
high blood glucose
where does glucagon attach to the receptors?
liver
where does adrenaline attach to the receptors?
liver
where does insulin attach to the receptors?
liver and muscles
what does glucagon have the effect on blood glucose?
increases it
what does adrenaline have the effect on blood glucose?
increases it
what does insulin have the effect on blood glucose?
- decreases it
what are the mechanisms of glucagon?
- decreases the rate of respiration
- glycogenolysis (glycogen to glucose)
- glycogeneolysis
(non carbs to glucose)
e.g. lipids and amino acids
what are the mechanisms of adrenaline?
- activates glycogeneolysis
- secretes insulin
- inhbits glycogenosis
- secretion of glucagon
what are the mechanisms of insulin?
- increases the rate of respiration
- glucogensis (glucose -> glycogen)
- increase liver + muscle cells permeability beta glucose
what is diabetes?
An illnesses when blood glucose levels are no controlled
what is hyperglycaenia?
dangerously high blood glucose concentration
what is hypoglycanemia?
dangerously low blood glucose concentration
what is the cause of type 1 diabetes?
immune system kill beta cells in the islets of Langerhans
- they cannot produce insulin
what is the cause of type 2 diabetes?
- obesity
- lack of exercise
- poor diet
- beta cells do not respond to insulin
- liver and muscle cells stop responding to the insulin
what age group is common for type 1 diabetes?
children and young adults
what age group is common for type 2 diabetes?
adults and elderly
what is the effect on blood glucose for type 1 diabetes?
- rise after eating carbs
(hyperglucaenmia) - stays high ->kidneys -> cannot remove all the glucose from urine
what is the effect on blood glucose for type2 diabetes?
- rise after eating carbohydrates
- hyperglycanenmia
what are the treatments for type 1 ?
- insulin injection/pump
- too much insulin can result in hypoglycemia
- avoid simple carbohydrates such as sugars
- eat at regular intervals
regular exercise to use up glucose
what are the treatments for type 2?
- eat healthily
- lose weight
regular exercise - drugs to reduce the amount of glucose replaced
- increases sensitivity to insulin
- produce more insulin
what are the two main treatments of type 1?
- genetically modified bacteria
- using stem cells
how can genetically modified bacteria be made?
using human insulin
what are the advantages of genetically modified bacteria?
- human insulin means fewer immune reactions
- insulin produced is pure - no contamination
can be made in larger quantities - faster
- cheaper
what are the disadvantages of genetically modified bacteria?
- uses genetically modified bacteria
- some people have religious or ethical objections
how can genetically stem cells be made?
inject stem cells into the beta cell of the islets of Langerhans in the pancreas
- uses totipotent embrotonic stem cells
differentiate into functional beta cells which can produce and secrete insulin
what are the advantages of using stem cells?
- patients do not need to inject insulin
- treatments lasts to the lifetime of the patient
what are the disadvantages of using stem cells?
- requires use of embryonic stem cells
- some people have religious or ethical objections
- stem cells may develop other type of cells and cause harms e.g tumours/cancers
What are endotherms?
Organisms that internally control their body temperature by homeostasis e.g mammals, birds
What are ectotherms?
Organisms that depend on external sources of heat e.g. reptiles
Features of endotherms?
- control body temperature
- behaviour - dog sticking out tongue when not
- sweating, cool off in water/shade
- high and constant rate of metabolism
- not dependent on the environment- does not rely on temperature
- high and constant body temperature
Features of ectotherms?
- behaviour e.g basking in sun
- dependent on the environment
- activity depends on the environment- e.g. active when they are warm
- body temperature - variable
