What is the ‘hypothalamic-hypothoseal axis’
- Made of the hypothalamus and the pituitary gland
- Coordinates the endocrine glands
- Comprises of the hypothalamic-hypothoseal tract and the hypothalamic-hypothoseal axis
What are the stimuli for insulin release?
- Increase in blood glucose
- Increase in arginine/ leucine
- Increase in fatty acids from lipids
All of these increase blood sugar
What causes type 1 diabetes mellitus and what are the symptoms and treatment?
- Happens in young people
- Insulin dependent
- B cells of pancreas fail to produce insulin
- Body reacts as if glucose levels are LOW
- Lipids, proteins, fats broken down
- Ketone bodies produced (smell like peardrops)
Symptoms
- Ketoacidosis
- High glucose in blood
- Polyuria
- Polydipsia
- Hyperglycemia and dehyrdation
- Fatigue, muscle wasting
- Neuropathy, retinopathy
Treatment
- Insulin injections
What happens when insulin is released?
- Increase in glucose uptake into cells
- Increase in glucose utilisation
- Increase glucose -> glycogen
- Increase protein synthesis from arginine and leucine
- Increase fatty acids -> triglycerides (in adipose tissue)
What molecules use the HHPortal?
- Large molecules
- FSH
- LH
- Release factors
What is the difference between diabetes mellitus and diabetes insipidus?
Diabetes Mellitus
- ‘Sweet’ urine (contains glucose)
- Either when the body doesn’t produce insulin or the body doesn’t respond to insulin
Diabetes Insipidus
- ‘Tasteless urine’
- Nothing to do with insulin
- The posterior pituitary gland fails to produce ADH (Vasopressin)
- ADH acts on the kidney tubules to absorb water
- Polyuria, polydipsia (symptoms of diabetes)
What causes Polycystic ovary syndrome?
- Cells don’t respond to insulin
- Body produces more insulin (Hyperinsulinemia)
- This causes hyperandrogenism (increased weigh gain and hair growth)
- Causes reduces fertility
Where is insulin released from?
The beta cells of the pancreas
What are the stages that make insulin?
Prepoinsulin (made at the ribosome) -> proinsulin -> insulin
What is the pathway of Vasopressin down the HHtract and into the blood?
1) Large neurons in the nuclei of the hypothalamus SYNTHESISE Vasopressin
2) Vasopressin travels downt the HHtract into the posterior pituitary gland
3) At the nerve terminals, Vasopressin is released into a rich plexus of blood vesselss
What hormones does the pancreas secrete?
Amylas and Trypsin
How is the endocrine system different to the ANS?
- Integrative
- Slower acting
- Longer lasting
- Accurate
- Sensitive
What cause myxoedema and what are the symptoms?
- Low TSH in adults
- Not much energy produced
- Low cardiac output and odema
What causes type 2 diabetes and what are the treatments?
- Most common
- In people with obesity
- Non insulin-dependent
- Insulin levels are normal but cells are unresponsive to insulin
Treatment
1) Lose weight
2) Metaformin
- Hyperglyceamic agent
- Increase glucose uptake and prevents breakdown
- Doesn’t cause hypoglycemia
- But GI tract disturbances
What causes cretanism and what are the symptoms?
- Thyroid hormone is too low in CHILDREN
- Mentally immature
- Can’t hear or speak
- Retarded bone growth
What happens when TRH is released from the hypothalamus?
- It causes thyotroph cells in the adenohypophysis (anterior posterior gland) to secrete thyroid stimulatng hormone
- TSH travels through the blood to the thyroid gladn and stimulates follicles to make and release T3 and T4
- T3 and T4 increase body temperature and BMR
What are the endocrine glands?
- Pineal
- Pituartry
- Thyroid
- Parathyroid
- Adrenal
- Pancreas
- Ovaries
- Testes
What is the HHPortal?
- Blood vessel connections from the hypothalamus to the adenohypophysis (anterior pituitary gland)
What is a ‘binding complex’?
Circulates in the blood and binds to hormones, providing the blood with a ‘hormone reservoir’ and minimising fluctuations
What happens if blood glucose gets to high and isn’t regulated?
Bathes neurons, causing neuropathy which is the reduction of the perineurium, causing loss of sensation
- Can cause gangrene or blindness
What is polycystic ovary syndrome?
Many follicles develop instead of just one
What is Grave’s disease and what causes it?
- When thyroid hormone is too high
- An autoimmune disease mostly in females where antibodies mimic the effect of FSH
- Overproduce F3 and F4
- Increase metabolism
- Loss of intercranial pressure (eyes bulge)
What causes TRH to be released from the hypothalamus?
- An decrease in body temperature
- A decrease in T3 or T4
- A decrease in basal metabolic rate?
What is the structure of the pancreas?
- Islets of Langerhands surrounded by serous glands
- The head of the pancreas runs up to the C shaped part of the duodenum
