The Endocrine System Flashcards
Balance within the body
Homeostasis
The endocrine system works in conjunction with the _______ system to maintain homeostasis within the body
nervous
Hormone levels are regulated through ________ ________ mechanisms
Negative Feedback
Positive feedback systems _________ change
REINFORCE (also only used for Labour!)
The Endocrine System is run by ________ FEEDBACK LOOPS
NEGATIVE
(NERVOUS SYSTEM OR ENDOCRINE SYSTEM?) Rapid response to change
Nervous System
(NERVOUS SYSTEM OR ENDOCRINE SYSTEM?) Electrical/Chemical Signals
Nervous System
(NERVOUS SYSTEM OR ENDOCRINE SYSTEM?) Sustained response to change
Endocrine system
(NERVOUS SYSTEM OR ENDOCRINE SYSTEM?) Hormonal Signals
Endocrine system
(NERVOUS SYSTEM OR ENDOCRINE SYSTEM?) Signals relayed through neurons
Nervous system
(NERVOUS SYSTEM OR ENDOCRINE SYSTEM?) Signals related through the bloodstream
Endocrine system
(NERVOUS SYSTEM OR ENDOCRINE SYSTEM?) Affects whole-body functioning
Endocrine system
(NERVOUS SYSTEM OR ENDOCRINE SYSTEM?) Affects specific locations
Nervous system
More than
Hyper
Less than
Hypo
a lot of solute
concentrated
little solute
dilute
regulates the pituitary, via nerves and hormones
HYPOTHALAMUS
produces releasing hormones (factors) that stimulate the Anterior Pituitary Gland to release a stored hormone
HYPOTHALAMUS
Many hormones released from Hypothalamus & Pituitary are Tropic Hormones meaning…
They stimulate OTHER GLANDS to release other hormones
_________ pituitary stores but does not produce hormones (oxytocin and ADH). Connected to hypothalamus via nerves
Posterior
________ pituitary synthesizes hGH, prolactin, TSH, ACTH, FSH, and LH. Stimulated by hypothalamus with hormones
Anterior
_______ (gland) -> produces thyroxine and calcitonin
Thyroid
___________ (gland) -> produces parathyroid hormone
Parathyroid
Adrenal _______ -> produces norepinephrine and epinephrine involved in the short-term stress response
MEDULLA ( = middle)
Adrenal ______ -> produces cortisol and aldosterone involved in the long-term stress response
CORTEX (= outside)
________ : has specialized clusters of cells (known as islets of Langerhans) secrete hormones into the bloodstream responsible for glucose regulation
Pancreas
Beta cells secrete what?
INSULIN
alpha cells secrete what?
GLUCAGON
Hormones interact with ________ proteins specific to their target tissue, inducing a change, which leads to a cascade of events within each cell
receptor
What are the two types of Hormones?
- Water Soluble Hormones (proteins, peptides, and amino acid derivatives)
- Fat Soluble Hormones (steroids)
_____ Soluble Hormones cannot cross the lipid membrane, and thus interact with cells by binding to external receptor cites
WATER
___ Soluble Hormones are able to diffuse across the lipid membrane, and this interact with cells by binding to receptor sites within the cytoplasm
FAT
_____ ______ hormone (hGH)
- secreted by the ANTERIOR PITUITARY
- increases protein synthesis, cell division and growth (of bone and muscle tissue in particular), and metabolic release of stored fats
HUMAN GROWTH HORMONE
Too much hGH as a young child creates the disorder _________
Gigantism (HYPERSECRETION)
Too little hGH as a child creates the disorder pituitary ________
dwarfism (HYPOSECRETION)
too much hGH as an adult creates __________
Acromegaly (HYPERSECRETION)
_________
- secreted by the Thyroid Gland after stimulation by Tropic Hormone TSH (released from Anterior Pituitary)
- Increases the rate at which the body metabolizes fats, proteins, and carbs
THYROXINE
_______________: Grave’s Disease (Immune system attacks Thyroid)
Hyperthyroidism
______________: tired, weight gain
Hyperthyroidism
The Hypothalamus and Anterior Pituitary control the secretion of Thyroid Hormones through ___ negative feedback loops
TWO
What is the Thyroid (Thyroxine) negative feedback loop?
Hypothalamus -> (releasing factors/TRH) -> Anterior Pituitary -> TSH (Tropic) -> Thyroid Gland -> Thyroxine (increases rate of metabolism)
What are the two disorders of Thyroid Gland?
- Hypothyroidism
- Hyperthyroidism
____thyroidism: the thyroid gland does not make enough thyroid hormone
HYPO!
what causes Hypothyroidism?
Inflammation of the Thyroid Gland, which damages the gland’s cells or autoimmune disease in which the immune system attacks the thyroid gland
what are symptoms of Hypothyroidism?
Cold, Fatigue, Dry skin, Hair loss, Weight gain, Sleep a lot, Goiter
what is Cretinism?
Hypothyroidism in children -> leads to abnormal mental and physical development, growth retardation
_____thyroidism: the thyroid gland makes too much thyroid hormone. The condition is often referred to as an “overactive thyroid”
HYPER
what causes Hyperthyroidism?
Getting too much iodine, Graves disease (autoimmune disease), inflammation (thyroiditis) of the thyroid due to viral infections, non-cancerous growths of the thyroid gland or pituitary gland
what are symptoms of Hyperthyroidism?
Increased metabolism, difficulty concentrating, heat intolerance, increased appetite, increased sweating, nervousness, restlessness, weight loss, goiter
how is Hyperthyroidism treated?
treated by removing a portion if the thyroid gland
The thyroid requires ______ to produce thyroxine
Iodine
Insufficient iodine in the diet thus inhibits thyroxine production, meaning there will be no signal to stop the secretion of ___
TSH
The constant simulation of the Thyroid Gland by TSH leads to the development of a ______
goitre
______
- Enlargement of the Thyroid Gland
- May be due to Iodine deficiency or overactive Thyroid
- Under relentless influence of TSH, cells of the thyroid continue to develop and the thyroid enlarges
Goiter
__________
- secreted by the thyroid
- plays a role in the regulation of blood calcium levels
- high concentrations of calcium in the blood trigger the release of it which stimulates the uptake of calcium into bones (thus lowering blood calcium levels).
CALCITONIN
___________ Hormone (PTH)
- secreted by the parathyroid
- plays a role in the regulation of blood calcium levels
- low concentrations of calcium in the blood trigger the release of PTH, which stimulates bone cells to reabsorb calcium into the blood (thus raising blood calcium levels)
PARATHYROID
(TRUE OR FALSE) Calcitonin and PTH are said to work antagonistically
TRUE
What is Epinephrine and Norepinephrine produced by?
the adrenal medulla
What does Epinephrine and Norepinephrine regulate?
body’s short term response to stress
When presented with a stressful situation, neurons from the hypothalamus relay a signal to _______ _______ to secrete Epinephrine and Norepinephrine
Adrenal Medulla
Why is short-term response rapid?
because hormone release is mediated by the nervous system
What hormones are involved in a “fight or flight” response to prepare body for emergency situation?
Epinephrine and Norepinephrine
What is short term response to stress controlled by?
the sympathetic nervous system
what does short term response to stress increase?
heart rate, breathing rate, blood flow, blood glucose levels and redirects blood flow to brain and muscles
what is cortisol produced by after ACTH stimulation?
the adrenal cortex
what does cortisol promote?
the break down of fats and proteins (amino acids) to glucose sugar
is cortisol a long term response to stress?
YES (increases the energy available for use by cells)
what are long term health issues with cortisol?
impaired thinking, increased blood pressure, increased risk of diabetes and infection
what is Aldosterone produced by?
Adrenal Cortex
which hormone increases blood pressure by increasing the absorption of sodium (and therefore water) into the bloodstream?
Aldosterone
is aldosterone a long-term response to stress?
YES (increases delivery of oxygen and other nutrients to cells)
does ADH or Aldosterone respond when the body is dehydrated?
ADH
does ADH or Aldosterone respond when blood pressure is low?
Aldosterone
results from damage to the adrenal cortex, causing the body to produce inadequate amounts of cortisol and aldosterone
Addison’s Disease
what are symptoms of Addison’s disease?
Low blood sugar, Ion imbalances, Low blood pressure, Rapid weight loss, General weakness
how is Addison’s disease treated?
injections of glucocorticoids and mineralcorticoids
what is Insulin secreted by?
Beta cells of the islets of Langerhans (pancreas)
what does insulin do?
makes cells more permeable to glucose after a meal, thereby decreasing blood glucose
what does insulin promote?
the temporary storage of glucose as glycogen in the liver
what is glucagon secreted by?
alpha cells of the islets of Langerhans
what are the two things glucagon promote?
1) the breakdown of glucose in the liver to glucose, which is then released into the bloodstream
2) the breakdown of fatty tissue into glucose, thereby increasing blood glucose
insulin and glucagon are regulated by negative feedback mechanisms, working ________________ to maintain normal blood glucose levels
antagonistically
Diabetes ________
- the inability to produce enough insulin or respond appropriately to insulin
mellitus
what does diabetes mellitus cause?
blood glucose levels to rise sharply after meals
Diabetes ________
- lack of insulin to lower blood glucose and transport it to cells
- cells can’t obtain glucose required for metabolism; individuals become fatigued
- body compensates by metabolizing fats and proteins. This releases ketones, a toxic by-product which causes bad breath
Mellitus
Type ___ Diabetes: Diagnosed in childhood
- immune system produces antibodies that attack and destroy the beta cells of the pancreas
- leads to decreased insulin production
one
how is type 1 diabetes treated?
daily insulin injections
Type ___ Diabetes: Develops over time
- cell receptors stop responding to insulin, or beta cells produce less insulin
- often associated with poor diet and lack of exercise
two
how is type 2 diabetes treated?
insulin injections before meals
what is Antidiuretic hormone secreted by?
Posterior Pituitary
what does Antidiuretic hormone regulate?
water reabsorption by kidneys
which hormone makes body excrete less, and more concentrated urine?
ADH
what does hyposecretion of ADH cause?
Diabetes Insipidus
Diabetes _________
- affected individuals produce large volumes of dilute urine, resulting in the loss of ions from the blood
- continuous risk of dehydration
Insipidus
Diabetes _________
- can occur during pregnancy, as components of the placenta are known to break down ADH
Insipidus
How is Diabetes Insipidus treated?
administering ADH
