Human Endocrine System Flashcards
What does the nervous system and hormones do?
enable animals to respond to external changes and
maintain homeostasis
endocrine gland
- ductless glands that release their secretions (hormones) directly into the blood stream
- blood transports the hormones to the target organs where they perform their function
glands
- any structure that produces and secretes hormones
- hormones can only trigger a reaction in specific cells (target cells)
location of pituitary gland
base of the brain
location of thyroid
front of the trachea (throat) (butterfly)
location of pancreas
- right side of abdomen - below a diaphragm
- releases hormone through duct
location of adrenal glands
above the kidneys
gonads
- mammary glands
- testis
- ovaries
pancreas
controls blood glucose levels
PGH - ADH (anti- diuretic hormone)
-target organ
Kidney (Collecting ducts and distal convoluted tubules of the nephron)
ADH - function
- Osmoregulation
- Makes renal tubules permeable to water
- More water is reabsorbed into bloodstream
- Prevents urination
- Released when dehydrated
ADH
-Negative feedback
More ADH-less aldosterone
PGH - TSH
Thyroid-stimulating hormone
-target organ
Thyroid
TSH
-target organ
Stimulates thyroid to release thyroxin
TSH
-negative feedback
Less TSH-More Thyroxin
More TSH-Less Thyroxin
PGH - FSH
Follicle stimulating hormone
-target organ
Gonads
FSH
-function
Women- follicle development in ovaries
Men- sperm production in testes
FSH
-negative feedback
Men:
More testosterone-less FSH (low sperm count-could lead to infertility)
Women:
More progesterone-less FSH (prevent female from developing any more follicles while she is pregnant)
FSH
-Hyposecretion
Men:
low sperm count-could lead to infertility
Women:
Prevent follicles from forming-lead to infertility
PGH - LH
Luitenising hormone
-target organ
Women: ovaries (Graafian follicle)
Men: testes (Leydig cells)
LH
-function
Women-ovulation
Men: Testosterone production
LH
-negative feedback
More testosterone: less LH
More progesterone: less LH
PGH - GH
Growth hormone
-function
- Increase in bone length
- Increase in muscle mass
- Decrease in adipose tissue (fat
GH
-Hyposecretion
Dwarfism (children)
GH
-Hypersecretion
- Gigantism (children)
- Acromegaly (adults)
PGH - Oxytocin
-target organ
Muscles in uterus
Oxytocin
-function
Causes the muscles of uterus to contract (labour pains)
oxytocin
-positive feedback
More oxytocin-stronger contractions
PGH - Prolactin
-target organ
Mammary gland
Prolactin
-function
Stimulate mammary glands to produce milk
Prolactin
-Hyposecretion
Not enough milk produced – bottle milk to be produced
Thyroid Gland
hormone released : Thyroxin
requires iodine in diet
goes hand in hand with growth hormone
Thyroid Gland
-function
- Increases metabolic rate
- Increases breathing & heart rate
- Growth of organs
- Normal functioning of nervous system
Thyroid Gland
-Negative feedback
More Thyroxin-Less TSH
Less Thyroxin-More TSH
Thyroid Gland
-Hyposecretion
Lack of Iodine-hyposecretion
Children- Cretinism
Adults- Myxoedema
Goitre
Thyroid Gland
-Hypersecretion
hyperthyroidism
Pancreas
-hormone released
-Insulin
released by beta cells which are located in the pancreas
- Glucagon
Pancreas
-target organ
insulin - Fat cells/liver
glucagon - liver
- pancreas
- function (insulin)
β (beta) cells releases insulin
It decreases blood glucose by converting glucose into glycogen inside the cells
Glycogen remains in the liver for future use
- pancreas
- function (glucagon)
alpha cells are activated when the blood glucose levels are low
ά (alpha) cells (which are in the pancreas) releases glucagon when blood glucose levels are low
It increases blood glucose by converting glycogen into
glucose inside the cells
pancreas
-negative feedback
When the blood glucose level is above the normal level-insulin is released
When the blood glucose level is below the normal level-glucagon is released
Graph fluctuates around the normal blood glucose level
Adrenal Gland
-hormone released
Adrenalin
- Adrenal Gland
- target organ
Works on entire body
Heart rate increases
(so that blood can go to the muscle tissues faster in order to provide the oxygen needed for cellular respiration)
Blood pressure
increases
(more blood is being pumped through the blood vessels)
Muscle tone increases
(muscles become tense-contract)
Pupil dilate (pupils become bigger and this allows more light to pass through so that you can see better)
- Adrenal Gland
- target organ
Insulin suppressed
(glucose is used for energy-balekaaa)
Glycogen converted into glucose by the liver
(Glucagon is released)
Breathing deepens
(more oxygen is needed for muscles)
Adrenal Gland
-function
Prepares the body for an emergency
Adrenal Gland
-negative feedback
After the emergency:
Noradrenaline is secreted in order to take the body back to a state of relaxation
Gonads:
Ovaries
Testis
Oestrogen
Progesterone
Testosterone
inhibits the release of FSH
Ovaries
-target organ
Uterus (main shawty) Breast tissue Skeleton Brain Skin
Endometrium
- Ovaries
- function
Thicken endometrium
Formation of secondary sexual characteristics
Maintains thickness of endometrium for pregnancy
Inhibits FSH and LH
- Ovaries
- function
Inhibits FSH and LH
Stimulate blood vessel and alveoli in breasts to later produce milk (hence why pregnant women have bigger breasts)
Ovaries
-negative feedback
FSH and LH
Why?
To ensure that the female does not produce any more egg cells during pregnancy) - progesterone
Ovaries
-hyposecretion
oestrogen - may lead to infertility problems
Testis
-function
Stimulates formation of secondary sexual characteristics
Testis
-negative feedback
More testosterone: less FSH
More testosterone:
less LH
negative feedback
LOW BLOOD GLUCOSE (WHEN HUNGRY)
Alpha cells release glucagon
Glucagon inhibits insulin secretion
Glucagon instructs liver to convert glycogen into glucose – glucose level rises
HIGH BLOOD GLUCOSE (AFTER MEALS)
Beta cells release insulin
Insulin inhibits glucagon secretion
Insulin instructs liver to convert glucose into glycogen – glucose level drops
An individual with this type of diabetes is unable to produce insulin - Type I diabetes
Causes:
Genetic/ Autoimmune/ Neglected type II diabetes
Treatment:
Insulin shots /Special diet/Regular testing
An individual with this type of diabetes is unable to respond to insulin production - Type II diabetes
Causes:
Obesity/Inactivity/Age
Treatment:
Balanced diet/Exercise/Oral medication
Diabetes results in what type of blood condition?
hyperglycemic (high glucose)
homeostasis
maintaining a constant internal equilibrium (balance) in the body
