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Learning outcome
• Student should be able to :
– Define endocrine system.
– Define hormone.
– Determine endocrine organs & secreted hormone.
• Pituitary (anterior/posterior)
– Explain the function of hormones.
Definition
• The endocrine system is the system of glands,
each of which secretes different types
of hormones directly into the bloodstream to
regulate the body.
• The word endocrine derives from the Greek
words "endo" meaning inside, within, and "crinis"
for secrete.
• The endocrine system is an information signal
system like the nervous system, yet its effects and
mechanism are classifiably different.
Hormone
• Hormones : are substances (chemical
mediators) released from endocrine tissue
into the bloodstream where they travel to
target tissue and generate a response.
Figure 6-2b, c: Long distance cell-to-cell communication
Figure 11-3: Autonomic control centers in the brain
Endocrine
gland
Hormone released
Target tissues/ organs
Thyroid gland
Thyroid-stimulating
hormone (TSH)
Anterior
pituitary gland Follicle-stimulating hormone Gonads
(FSH)
Principal functions
Stimulates the thyroid gland
to release thyroxine
 Stimulates the
development of the
follicles in the ovaries in
females
 Stimulates
spermatogenesis in
males
 Stimulates ovulation,
development of corpus
luteum & secretion of
oestrogen &
progesterone in females
 Stimulates the secretion
of testosterone in males
Luteinising hormone (LH)
Gonads
Adrenocorticortrophic
hormone (ACTH)
Adrenal glands
Stimulates the adrenal
cortex to release hormones
Growth hormone (GH)
Soft tissues, bones
Stimulates growth, protein
synthesis & fat metabolism
Prolactin (PRL)
Mammary glands
Stimulates milk synthesis
&secretion from the
Antidiuretic
Posterior hormone (ADH)
pituitary
gland
Oxytocin
Kidneys
Stimulates water
reabsorption by
the renal tubules
in the kidneys
Uterus &
 Stimulates the
mammary glands
contractions of
the uterine
muscles during
childbirth; & the
release of milk
from the
mammary
glands in
female
 Causes sperm
ejection in
males
Endocrine Hormone Target  Function
gland
organ
Thyroid
gland
 Effect of
hormonal
imbalance.
Thyroxine All
 Increases the  Deficiency causes:
tissues
cretinism,
metabolic
myxedema
rates of most
body cells
 Excessive causes:
high metabolic rate,
 Increases
increased heartbeat,
body
temperature
hyperactivity,
insomnia, goitre.
 Regulates
growth &
development
Endocrin Hormone Target Function
Effect of hormonal
e glands
organs
imbalance
Adrenal Aldoster Kidneys •Increases the •Deficiency –more
cortex
one
reabsorption of water been excreted
mineral salts in •Excessive-body retain
the kidneys
more water
Cortisol Liver,
•Raises blood
•Deficiency-addisons
adipose glucose level by disease
tissue
stimulating the
•Excessive- cushing’s
conversion of lipid syndrome
and protein to
glucose
•Response to
stress
Androgen Gonad- •Regulate the
•Deficiencysex organ maturity of sex
underdeveloped sex
organs and the
organs in adult
dev. Of secondary •Excessive-early
Endocrin Hormone Target
e glands
organ
Function
Effect of hormonal
imbalnace
Adrenal Adrenali Cardiac  Increases the  Excessive- raises
medulla ne &
blood glucose, raises
& other
level of sugar
the blood pressure
noradren muscles & fatty acids
aline
in the blood
 Increase heart
activity, rate &
depth of
breathing
 Increases the
metabolic rate
& constrict
some blood
vessels
Endocr Hormone Target
ine
organs
glands
InsulinPancre B cells
Liver,
as
muscles &
the adipose
tissues
Glucagon
- a cell
Function
Effect of
hormonal
imbalance
Decreases blood Deficiencyglucose levels elevated blood
glucose level,
Promotes the
diabetes mellitus,
conversion of
body thin and weak
glucose to
glycogen
Excessive- low
blood glucose,
weakness, light
headedness
Increases blood Deficiency- weak
glucose levels and lack energy
Excessive- over
Promotes the
active
conversion of
glycogen to
glucose
Endoc Hormon Target Functions
rine e
organs
glands
Oestrog Gonads  Stimulates the
Ovari en
, skin,
development of the
es
muscle
female secondary
s&
sexual
bones
characteristics &
maturation of the
ova
 Promotes the repair
of the uterine lining
Progest Gonads  Stimulates the
erone
development of the
uterine lining & the
formation of the
placenta
 Inhibits ovulation
Effect of hormonal
imbalance
 Deficiency- hinders
normal
development of
secondary sexual
characteristic.
 Excessive- visual
disturbance,
headaces, memory
difficulty(PMS)
 Deficiencymiscarriage
 Excessive- hinders
contraction of the
uterus during birth
Endocr Hormone Target
ine
organs
gland
Testes Androgen Gonads,
(testostero skin,
ne)
muscles &
bones
Finish- thank…….
functions
Effect of
hormonal
imbalance
DeficiencyStimulates the
development of male during pubertyhinders the
secondary sexual
development of
characteristics &
spermatogenesis
sexual organAfter pubertycauses
impotence
Summary
Summary
Summary
Assignment