THE ENDOCRINE SYSTEM
The endocrine system is a system of ductless glands that release chemicals (hormones)
into the blood to regulate body functions
ENDOCRINE GLANDS EXOCRINE GLANDS
Endocrine glands secrete their product (hormones) directly into
This is different to
the bloodstream, rather than through a duct
exocrine glands which
The hypothalamus and pituitary gland are neuroendocrine
secrete their substance
glands and function to link the nervous + endocrine systems
into the blood via
Hormones are made by these secretory cells and are secreted
a duct.
directly into the blood.
HORMONES
A hormone is a chemical Hormones are specific and will only activate cells or tissues
messenger that is that possess the appropriate target receptor
transported via the
the endocrine system is slower to initiate, but has a more
bloodstream to act on
prolonged response when compared to the nervous system
distant target cells
CONTROL IN THE SYSTEM
HYPOTHALAMUS
The hypothalamus is the section of the brain that links the nervous and endocrine
systems in order to maintain homeostasis
It receives information from nerves
It secretes certain neurochemicals (called
throughout the body and other parts of
releasing factors) into a portal system which
the brain and initiates endocrine
stimulate or inhibit the pituitary gland
responses
It also secretes certain hormones directly into the bloodstream via neurosecretory
1
cells that extend into the pituitary gland
GnRH FHS LH
Hypothalamus produces which stimulates the
+ luteinising hormone
gonadotropin- releasing anterior pituitary to
which target the ovaries
hormone release follicle stimulating
and testes.
hormone
ADH Anti-Diuretic hormone
which acts on the kidneys. It increases water reabsorption in the kidneys.
, PITUITARY GLAND
The pituitary gland lies adjacent to the hypothalamus and is in direct contact due to a
portal blood system
The pituitary gland is often referred to as
The pituitary gland receives instructions
the ‘master gland’, as it controls the
from the hypothalamus and consists of
secretion of a number of other endocrine
two lobes (anterior and posterior lobe)
glands
2
TSH FSH
stimulates thyroid gland to secrete
(follicle Stimulating hormone)
thyroxin
Female stimulates the release of
Hypersecretion Hyposecretion
s oestrogen from Graafian follicle
Children -
stimulates testosterone
cretinism
Grave’s disease Males secretion spermatozoa
Adults -
formation and development
myxoedema
GROWTH HORMONE LH
promotes skeletal & muscular growth by Female
stimulates ovulation
increasing mitosis and differentiation s
stimulates production of
Hypersecretion Hyposecretion Males
testosterone
Children- Gigantism Children -
Ovulation = progesterone
Adults- Acromegaly Dwarfism
The endocrine system is a system of ductless glands that release chemicals (hormones)
into the blood to regulate body functions
ENDOCRINE GLANDS EXOCRINE GLANDS
Endocrine glands secrete their product (hormones) directly into
This is different to
the bloodstream, rather than through a duct
exocrine glands which
The hypothalamus and pituitary gland are neuroendocrine
secrete their substance
glands and function to link the nervous + endocrine systems
into the blood via
Hormones are made by these secretory cells and are secreted
a duct.
directly into the blood.
HORMONES
A hormone is a chemical Hormones are specific and will only activate cells or tissues
messenger that is that possess the appropriate target receptor
transported via the
the endocrine system is slower to initiate, but has a more
bloodstream to act on
prolonged response when compared to the nervous system
distant target cells
CONTROL IN THE SYSTEM
HYPOTHALAMUS
The hypothalamus is the section of the brain that links the nervous and endocrine
systems in order to maintain homeostasis
It receives information from nerves
It secretes certain neurochemicals (called
throughout the body and other parts of
releasing factors) into a portal system which
the brain and initiates endocrine
stimulate or inhibit the pituitary gland
responses
It also secretes certain hormones directly into the bloodstream via neurosecretory
1
cells that extend into the pituitary gland
GnRH FHS LH
Hypothalamus produces which stimulates the
+ luteinising hormone
gonadotropin- releasing anterior pituitary to
which target the ovaries
hormone release follicle stimulating
and testes.
hormone
ADH Anti-Diuretic hormone
which acts on the kidneys. It increases water reabsorption in the kidneys.
, PITUITARY GLAND
The pituitary gland lies adjacent to the hypothalamus and is in direct contact due to a
portal blood system
The pituitary gland is often referred to as
The pituitary gland receives instructions
the ‘master gland’, as it controls the
from the hypothalamus and consists of
secretion of a number of other endocrine
two lobes (anterior and posterior lobe)
glands
2
TSH FSH
stimulates thyroid gland to secrete
(follicle Stimulating hormone)
thyroxin
Female stimulates the release of
Hypersecretion Hyposecretion
s oestrogen from Graafian follicle
Children -
stimulates testosterone
cretinism
Grave’s disease Males secretion spermatozoa
Adults -
formation and development
myxoedema
GROWTH HORMONE LH
promotes skeletal & muscular growth by Female
stimulates ovulation
increasing mitosis and differentiation s
stimulates production of
Hypersecretion Hyposecretion Males
testosterone
Children- Gigantism Children -
Ovulation = progesterone
Adults- Acromegaly Dwarfism
