Week 9- Endocrine Flashcards
what r hormones
Hormones are chemicals released by glands, in small amounts, that travel in
the bloodstream.
how do hormones work
The hormones bind to specific receptors on cells in target organs.
This triggers a response in the target cell, resulting in a change of activity.
examples of some hormones
insulin
Glucagon
Adrenalin
ADH (anti diuretic hormone)
Thyroxine
Oxytocin
Testosterone
Oestrogen
Progesterone
LH
FSH
what is homeostasis
maintain an equilibrium within the
body to allow optimum functioning of
physiological systems
3 types of hormones and their half lives
Amines: approx 1 day
Peptides: minutes-hour
Steroid: hours
some endocrine system glands
Skin
Kidney
Liver
Intestines
Heart
what is the master gland
Pituitary Gland:
Small bean sized structure, found at
the base of the brain and has 2 parts
an anterior & posterior
*It is found close to the hypothalamus
adh full form
anti diuretic hormone
why is adh released
released when the body is dehydrated where the volume of
water in blood plasma has dropped.
how does adh work
hypothalamus triggers the release
of ADH from the posterior pituitary
into the blood stream
target organ is the kidney
Urine output is reduced as water is
retained in the blood
helps to return water levels back
towards normal. This is an example of negative feedback
the walls of the nephrons reabsorb
water from the forming urine and return it back to the
bloodstream
where is thyroid gland found
neck
how does thyroid regulation work
If levels of thyroid hormone drop,
hypothalamus releases TRH, which in turn triggers the anterior pituitary to secrete TSH into the blood.
thyroid gland responds by secreting
thyroid hormones T3 & T4 into the blood
Increased metabolic rate and increased levels of thyroid hormone in the blood, triggers the cessation of flow of TRH from the hypothalamus and TSH from the pituitary
gland
when is oxytocin released
*Released during labour to increase
uterine contractions
*helps lactates when baby begins to suckle via let down reflex
FSH full form and function
*Follicle stimulating hormone
*Released early in the menstrual cycle days 1-10
*Triggers the maturation of a follicle into an ovum in the ovary
LH full form and function
*Luteinising hormone
*sharp rise in LH around days 12-14
*causes the ovum to be released from the ovary (ovulation)
what is insulin
A peptide hormone secreted by
the pancreas, in response to
increased glucose in the blood
how does insulin work
Binds to receptors on cell
membranes in liver and muscle cells
how is glucose stored
*The cells of the liver and muscle
cells respond by taking in more
glucose and converting it to
glycogen for storage
*More conversion of glucose into
fat in adipose cells
wht type of disease is diabetes
diabetes is a chronic disease
types of diabetes
type I and type II (mellitus diabetes)
common symptoms of diabetes
- Increased thirst and hunger
- Need to urinate excessively
- Tiredness
- Weight loss
- Presence of glucose in the urine, which can
lead to frequent UTIs & genital itching &
regular episodes of thrush. - Blurred vision
- Changes in sensation due to nerve damage.
how does type 1 diabetes affect body
*Pancreas is unable to produce
insulin
*It may result as an autoimmune
response, the body’s immune
system attacks its own cells
controls for type 1 diabetes
- Controlled by injections or
infusions of insulin 2 or four times
a day.
*cannot be taken by mouth because it is a polypeptide so would be digested. - Blood sugar levels need to be
checked regularly. - dose of insulin must be
matched exactly to the glucose
intake. - Unconsciousness result if too
much insulin is taken; the blood
glucose level can drop too low.
how does type 2 diabetes affect body
*Insulin receptors on the cell membrane lose their responsiveness to insulin. Also could be due to an inadequate supply
of insulin
