The endocrine system Flashcards
the endocrine system works with what other system to regulate all aspects of body function?
the nervous system
what is the functional unit that the endocrine system uses?
hormones
What kind of signal does the endocrine system use?
chemical (hormones)
What are the functional units of the nervous system?
neurones
what kind of signal does the nervous system use?
electrical (chemical at the synapse)
where are hormones secreted from?
various glands and some organs throughout the body
how are hormones carried through the body? what do they alter?
through the blood stream
alter the activity of specific organs
what are the effectors (targets) of the nervous system? (3)
muscles, glands and other neurones
What are the effectors (targets) of hormones?
specific organs or tissues
what does the antidiuretic hormone target? to do what?
the kidneys
to help regulate the amount of water in the blood
does the nervous system have a fast or slow response?
a very rapid response
does the hormonal (endocrine) system have a fast or slow response?
slower than nervous system but can be rapid (eg adrenaline)
How would you describe the duration of response in the nervous system?
short (until the nerve impulse ceases)
how would you describe the duration of response in the hormonal (endocrine) system?
long (until hormone is broken down)
what breaks down hormones when they are no longer needed?
the liver
hormones are ___________ substances produced by a ______
chemical
gland
what is the main gland in the body?
the pituitary gland
hormones are carried in the _______ ______ and ___________ into the blood _______. they then travel to specific ________ or _______ where they ______ the activity of that ________.
blood stream
dissolve
plasma
organs
tissues
alter
organ
one of the functions of the hormones is homeostasis, what do hormones maintain?
a constant balanced internal environment
One of the functions of hormones is metabolism, how does it do this?
by controlling the body’s energy balance
hormones play a ___ role in the __________ and influence of ___________.
key
development
behaviour
how do hormones affect mood?
oxytocin among other hormones control many aspects of mood and influences our emotional responses
how do hormones influences cognitive function?
oestrogen, progesterone and testosterone play important roles in brain health, including memory and overall cognitive function
in women, what does oestrogen help with regarding cognitive function? (3)
concentration, word recall and processing
What happens to oestrogen during the menopause? What do women complain of because of this?
it is reduced
resulting in women complaining of reduced cognitive function
how do hormones influence growth?
the human growth hormone regulated growth in children
what is the proper name of the human growth hormone?
somatotropin
in growth, once the plates in the bones fuse, what does human growth hormone stop doing?
increasing height
what is human growth hormone still needed for once the plates in the bones have fused?
to help regulate fat and protein in muscle tissue and parts of the metabolism
what 2 hormones are there during pregnancy and after birth?
hCG
prolactin
what do pregnancy tests detect?
hcg
what is hcg produced by?
the placenta
what does prolactin stimulate?
breast lactation
hormones influences our physical appearance as they ________ the ____________ of certain characteristics.
stimulate
development
As we age, what hormones decline?
sex hormones
how does a decline in sex hormones influences our physical appearance?
it leads to hair loss/thinning and wrinkles caused by skin losing elasticity
Which two hormones from the endocrine system help regulate digestive organs? what do they do?
progesterone and oestrogen
regulate how fast food is digested
how do hormones help hunger?
they initiate hunger pangs
what is the satiety (full tummy) hormone called?
leptin
how does the endocrine system influence our circadian rhythm?
by releasing cortisol that peaks in early morning and declines throughout the day
how do hormones help our bodily fluids?
by regulating the volume of water and salts
which hormone helps with regulating water and salts? what does it target?
antidiuretic hormone
the kidneys
how do hormones help our immune response?
several hormones help to regulate our immune response by stimulating or supressing the immune system.
what hormones are involved in the immune response? (4)
cortisol, oestrogen and testosterone, thyroxine
there are various _____ throughout the body that secrete hormones.
glands
What three hormones does the adrenal gland produce?
adrenaline, cortisol and aldosterone
which two hormones from the adrenal gland help regulate blood pressure?
aldosterone and cortisol
what two main hormones are produced by the ovaries?
oestrogen and progesterone
are testosterone and oestrogen produced by both males and females?
yes
what are the main things testosterone and oestrogen help with? (3)
cognitive function
mood
bone health
Where is the pituitary gland located?
in the brain
where is the pineal gland located?
in the brain
what is the pineal gland responsible for?
producing and secreting melatonin which modulates sleep
what does the pituitary gland produce?
most hormones
what hormone is produced by the testes?
testosterone
what main hormone is produced by the thyroid?
thyroxine
what main hormone is produced by the pancreas?
insulin
where is the thyroid gland located?
in the neck
where is the pancreas located?
below and behind the stomach
The hypothalamus is the link between what?
the nervous system and the endocrine system
what are the two hormones produced by the hypothalamus?
oxytocin and ADH (Antidiuretic hormone)
When the pituitary gland releases ____________, the _________________ detects changes in __________ levels and will secrete ____________ and __________ hormones to __________ or _______ the production of hormones in the ___________ gland.
hormones
hypothalamus
hormone
releasing
inhibiting
stimulate
inhibit
pituitary
where are the hormones produced in the hypothalamus sent to for storage?
the pituitary gland
The hypothalamus secretes hormones that regulate which gland?
the pituitary gland
The hormones released by the hypothalamus and pituitary gland can act on what?
other glands to produce other hormones.
what is the thin stalk that joints the pituitary gland to the hypothalamus?
the infundibular
where does the pituitary gland sit?
in the sphenoid bone which protects it
what is the pituitary gland divided into?
2 lobes
what are the two lobes of the pituitary gland?
the anterior and posterior
Which of the two lobes in the pituitary gland is bigger?
The anterior lobe is bigger, about 75% of the total weight.
The hypothalamus makes 2 hormones called oxytocin and antidiuretic hormone (ADH) which are transported along the _____-_________ ______ to the __________ pituitary gland for storage. They are later released into the _______ in response to _____ _________ from the _____________.
neuro-secretory cell
posterior
blood
nerve impulses
hypothalamus
the hypothalamus releases stimulating or inhibiting hormones to control the pituitary gland, these are released into the ________ lobe via the ____________ ______ ________, a group of capillaries at the base of the hypothalamus.
anterior
hypophysial portal system
what are the two classifications of hormones?
lipid-soluble (also known as steroid hormones)
water soluble
lipid soluble or steroid hormones are ________ based and made from _______ _____.
protein
amino acids
lipid soluble hormones ________ into the cell __________ and is met by the ___________ _______ and _______ into it. The lipid soluble hormone and its receptor enter the __________ and bind to the ____. This causes the ____ to make ________ and enact a change.
diffuse
cytoplasm
receptor protein
locks
nucleus
DNA
DNA
proteins
What can’t water soluble or non steroid hormones do?
diffuse across the cell membrane
why can’t water soluble or non steroid hormones diffuse across the cell membrane?
as they are not fat soluble
What do water soluable/non steroid hormones do instead of diffusing across the cell wall?
they bind to receptor cells which are located in the membrane of the cell wall.
once the water soluble hormone binds to the receptor cell, what happens?
The receptor then stimulates a second messenger within the cell.
once the water soluble hormone stimulated a second messenger within the cell, what happens?
This starts a chemical reaction in the cytoplasm, This second messenger activates enzymes to enact a change.
In homeostasis, ________, __________, and _____________ have to be kept as constant as possible.
the ___________ system plays a huge part in homeostasis and uses _________ _________to achieve this.
Water, glucose, temperature
endocrine
negative feedback
how is homeostasis maintained?
If the level of something rises, control systems reduce it and if the level falls, control systems raise it.
why is negative feedback called negative feedback?
It’s called negative because it does the opposite of the stimulus.
what is a positive feedback loop?
a series of events that amplify a change, causing the cycle to repeat eg labour and birth
What two hormones are released by the adrenal medulla?
Adrenalin (epinephrin) and nor adrenalin (norepinephrine)
what 3 groups of steroid hormones are released by the adrenal cortex?
3 groups of steroid hormones
Glucocorticoids – hydrocortisone, corticosterone and cortisone.
what are the hormones produced by the adrenal medulla and adrenal cortex important for?
Essential for life, regulates metabolism and responses to stress.
When the body is faced with a stressor which threatens homeostasis, what 2 systems does the hypothalamus activate?
he sympathetic nervous system and the adrenal cortical system.
The sympathetic nervous systems uses what to activate the muscles to get the body ready for action? what does it do?
neurotransmitters
it speeds up and tenses
in fight or flight, what does the sympathetic nervous system activate? what does it do?
the adrenal medulla
This secretes adrenalin and nor adrenalin (called epinephrin and norepinephrine here) into the blood stream.
in fight or flight, at the same time as activating the nervous system, what does the hypothalamus release?
At the same time, the hypothalamus also releases CRF (corticotropin releasing factor) into the pituitary gland (remember the infundibular stalk).
in fight or flight, what happens when the hypothalamus also releases CRF into the pituitary gland?
This stimulates the pituitary gland to secrete ACTH (Adrenocorticotropic hormone) which moves through the blood stream and targets the adrenal cortex.
in fight or flight, what happens after the pituitary gland secretes ACTH which targets the adrenal cortex?
The adrenal cortex releases approximately 30 hormones which constitutes the fight or flight response
how long does it take to come down from the fight or flight response?
approx 20 - 60 minutes
where are stress hormones destroyed?
by the liver
the pancreas is a _______ gland, both _________ and __________.
mixed
endocrine
exocrine
that is the endocrine part of the pancreas?
the islets of langerhans
how many islets of langerhans are there?
about 1 million
How many types of cells are in the islets of langerhans?
4
what are the names of the 4 types of cells in the islets of langerhans
Alpha cells
Beta cells
Delta cells
F cells
what do alpha cells (in the islets of langerhans) secrete?
glucagon
what do beta cells (in the islets of langerhans secrete)?
insulin
What do Delta cells secrete? :
somatostatin (growth hormone)
What do F cells secrete in the islet of langerhans?
pancreatic polypeptide (reduces appetite when full)
What is diabetes mellitus?
a condition where the beta cells (producers of insulin) in the pancreatic islets are destroyed so don’t produce insulin
What happens in diabetes mellitus?
blood glucose can increase dramatically and glucose spills over into the urine
what type of disease is type 1 diabetes mellitus?
an autoimmune disease
what sort of onset does diabetes mellitus have and at what age?
sudden onset, mainly in children
What happens to the beta cells in type 1 diabetes mellitus?
they are destroyed so insulin is no longer produced
what is the cause of type 1 diabetes mellitus?
unknown, could be genetic or viral infection
Which of the types of diabetes mellitus is more likely to develop diabetic ketoacidosis?
type 1 diabetes mellitus
What is diabetic ketoacidosis?
where a lack of insulin causes harmful substances called ketones to build up in the blood, can be life threatening
what are the 3 treatments of type 1 diabetes mellitus?
- blood monitoring throughout day
- injecting insulin
- closed loop monitoring (insulin pump and glucose monitor)
what is the most common form of diabetes mellitus?
type 2
what happens to the islets in type 2 diabetes mellitus?
they still make insulin but the tissues become resistant
what are 4 causes of DM2?
obesity
sedentary lifestyle
aging
genetic factors
how is type 2 DM treated?
usually through controlling diet
