Endocrine System Flashcards
What is endocrinology?
The study of hormones
How does secretion and transport occur in the endocrine system?
Thyroid, Catecholamines, Duration of action varies, Transport
How does the body clear hormones?
Destruction tissue, binding in tissues, excretion by liver (BILE), excretion by kidney (urine)
What are the hormone interactions?
Synergism , Permissive, Antagonistic
What are some endocrine disorders?
Thyroid Gland disorders (Hypothyroidism, hyperthyroidism)
Adrenal Gland Disorders
Pancreatic Disorders
Define Glycogenesis
Glycogen can be formed with excess glucose (Hepatocytes, skeletal muscle cells)
define Glycogenolysis
Breakdown of glycogen via glycogen phosphorylase in response to low blood glucose (in hepatocytes; some kidney and intestinal cells)
Define gluconeogenesis
Process of forming new glucose from non-carbohydrate sources (Liver)
When does insulin increase?
in the fed state
What is insulin?
a hypoglycemic hormone that enhance glucose oxidation for energy, glycogen and triglyceride formation, active transport of amino acids into tissue cells, protein synthesis
What does insulin inhibit?
Glucose release from liver, gluconeogenesis
When insulin binds to membrane receptors what does it facilitate?
Diffusion of glucose into muscle and adipose cells
When does glucagon increase?
In the fasted state
Describe the use of glucagon
action is to prevent hypoglycemia, generally antagonist to insulin. Is secreted into plasma glucose when <5.5mmol/L
What are the different types of Diabetes Mellitus
Type 1, Type 2, Gestational, Secondary
Briefly describe Type 1 Diabetes Mellitus
Pancreatic Atrophy and loss of pancreatic Beta cells
What are some symptoms of Type 1 Diabetes Mellitus
Polydipsia, Polyuria, Polyphagia, weight loss and fatigue.
What are the two main causes if Type 1
Immune (Type 1A), Genetic link, mutation to insulin gene.
Non-immune (Idiopathic, Type1B) - Secondary to other diseases eg pancreatitis
Briefly describe type 2 diabetes mellitus
Insulin resistance target cells do not respond normally, Early symptoms are mild but later complications are serious eg cardiac, neurological, renal failure and blindess.
Describe the pathophysiology of type 2 diabetes
Insulin produced by pancreatic Beta cells in insufficient amounts for body’s needs and/or poorly utilized by tissues.
Briefly describe Gestational diabetes
Develops in approx 5% of pregnancies, Detected at 24-28weeks gestation with a OGTT, increase risk of having c section, Perinatal Death , neonatal complications and type 2 diabetes.
What are some acute complications that follow diabetes?
Hypoglycemia, Diabetic Ketoacidosis (DKA),
What are some chronic complications that follow are associated with diabetes?
Hyperglycemia and non-enzymatic glycosylation (NEG), Microvascular disease (Neuropathy, Retinopathy, Nephropathy)
How does Exercise and health impact diabetes?
Lowers the risk of cardiovascular disease, Strengthen immune responses, decrease risk of depression.
What is chronic hyper glycaemia?
High blood glucose concentrations, can be due to a variety of reasons including Chronic pancreatic disorders, endocrinopathies, Drugs that interfere with insulin secretion
What are some drugs that increase BGL levels?
Atypical antipsychotics, B2 Agonists, Corticosteriods, Oral contraceptives, Thyriod hormones.
What are some drugs that decrease BGL levels?
Alcohol, Monoamine oxidase inhibitors, NSAIDs
Why is chronic hyperglycaemia important?
Structural changes to blood vessels lead to inadequate blood supply to tissues which increase the risk of heart attack, stroke, end-stage kidney disease, Ischemia and peripheral gangrene and peripheral neuropathies
Whta are the two way insulin can be given?
IV, SC
Because insulin formations differ what else differs?
Onset time, Peak effect, Duration of action
What are the 5 different types of insulin?
Ultra-short-acting, Short-acting, Intermediate-acting, Long-acting, Premixed biphasic.
What are the different factors the affect insulin absorption?
Exercise of injected area, local massage, temperature, site of injection, Lip hypertrophy, jet injectors, insulin mixtures, insulin dose, Physical status
What are the different factors the affect insulin absorption?
Exercise of injected area, local massage, temperature, site of injection, Lip hypertrophy, jet injectors, insulin mixtures, insulin dose, Physical status
What are some oral hypoglycaemic medications?
Biguanides, sulfonylureas, Thiazolidinediones, Incretin-enhancing agents
What is an Oral Glucose Tolerance Test?
Shows how the body handles a glucose load
What are some factors the increase insulin secretion?
Increased blood glucose, Increased blood free fatty acids, Gastrointestinal hormones, Glucagon, growth hormone,
Parasympathetic Stimulation
What are some factors the decrease insulin secretion?
Decreased blood glucose, Fasting, alpha Adrenergic activity, leptin
Define Osteopenia
decreased mineralised bone mass greater than expected for age, race or gender
Define osteoporosis
Metabolic bone disease with decreased mineralised bone mass, increase in fractures.
Define Osetomalacia
Inadequate bone mineralisation in adults
Define Rickets
Inadequate bone mineralisation in children
What are some treatments for osteoporosis?
Calcium, Vitamin D, Bisphosphonates, Cslcitonin,
What are some drugs that affect reproductive function?
Uterine motility, Erectile Dysfunction, Contraception
What are modifying Uterine Motility?
Oxytocics (Produce Contractions)
Tocolytics (Inhibits Contractions)
What are Oxytocics and its adverse effects?
Stimulate Uterine Contractions, Ergometrine and oxytocin. Rapidly absorbed (Parental/oral), Metabolised by liver, excreted urine/faeces
Adverse Effects: Usually related to excess drug, Uterine hypertonicity and spasm, Uterine rupture, foetal bradycardia.
What do tocolytics do?
Relaxation of uterine smooth muscle : Salbutamol, Nifedipine
What are the two main types of female contraception?
Combination of oestrogen, Progestogen
What are the key roles of the thyroid hormone?
Maintenace in blood pressure, Regulation of tissue growth and development, Development and maturation of skeletal and nervous systems, reproductive capabilities
What are the effects of the thyroid hormone on the body?
Normal Foetal development, oxygen consumption,
Cardiovascular Effects: increase in adrenergic sensitivity.
Sympathetic Effects: Increase in B-adrenergic receptors (Heart, SkM, adipose, lymphocytes), Increased catecholamine sensitivity.
What are the different classifications of thyroid disease?
Hormone excess, Hormone deficiency, Hormone Resistance, non-functioning tumours.
What are some common symptoms of hyperthyroidism?
unexplained weight loss, Heat intolerance, sweating, palpitations, tremors, Dyspnoea, Fatigue.
What are the pharmacological treatments of hyperthyroidism?
Radioiodine (Emits both B and Y radiation), Thioureylenes (Oral Carbimzole and propylthiouracil, Decreases output by inhibition of iodine incorporation into thyroglobulin , reduction of clinical manifestations ( Return to base line pulse etc)
Iodine/iodide, temporary inhibition of TH production due to negative feedback loop
B receptor antagonists (eg propranolol) to decrease tachycardia, tremors
Noradrenergic-antagonists (eq guanethidine) eye drops to relax smooth muscle to alleviate eyelid retraction.
Glucocorticoids (eg prednisone) to alleviate severe exophthalmia and also topical/intradermal/systemic glucocorticoids to decrease signs of dermopathy
What are some symptoms of hypothyroidism?
Deficiency of TH, Extreme fatigue, bradycardia, decreased cardiac output, decreased blood volume, atherosclerosis, increased body weight, scaly skin, cold intolerance, hoariness’, constipation, cognitive impairment.
Briefly explain adrenal glands.
Paired, pyramid shaped organs superior to the kidneys, structurally and functionally they are two glands in one.
Adrenal Medulla - Nervous tissue; part of the sympathetic nervous system
Adrenal Cortex- Three layers of glandular tissue that synthesis and secrete corticosteroids.
define the Adrenal Medulla
Chromaffin cells secrete adrenaline 80% and noradrenaline 20%
These hormones cause; blood glucose, blood vessels to constrict, the heart to beat faster, blood to be diverted to the brain, heart and skeletal muscle.
Adrenaline stimulates metabolic activities, bronchial dilation and blood flow to skeletal muscles and heart.
Noradrenaline - peripheral vasoconstriction, BP
What are Mineralocorticoids (aldosterone)?
Regulates electrolytes in ECF
Aldosterone is the most potent mineralocorticoid
What are Glucocorticoids (Cortisol) ?
Cortisol is released in a diurnal pattern with peak in early morning and decline as the day progresses and can change with stressors, depression and liver disease
What are Glucocorticoids (Cortisol) ?
Cortisol is released in a diurnal pattern with peak in early morning and decline as the day progresses and can change with stressors, depression and liver disease
Keeps blood glucose concentrations relatively constant
Maintain blood pressure by increasing the action of vasoconstrictors.
