Unit P Master Outline
P.
Endocrine System
1H16.01
Explain the structure of the endocrine system.
A. Pituitary gland
1. Tiny structure size of grape
2. Located at base of brain
3. Connected to hypothalamus
4. Divided into anterior and posterior lobes
B. Thyroid gland
1. Butterfly-shaped mass of tissue
2. On either side of larynx, over trachea
3. H-shaped
C. Parathyroid glands
1. Four glands, each the size of a grain of rice
2. Attached to posterior thyroid
D. Thymus
1. Endocrine gland and lymphatic organ
2. Located behind sternum, above and in front of heart
3. Begins to disappear at puberty
E. Adrenal glands - located on top of each kidney
F. Gonads
1. Ovary in female
2. Testes in male
G. Pancreas
1. Located behind the stomach
2. Endocrine and exocrine functions
1H16.02
Analyze the function of the endocrine system
A. Types of glands
1. Endocrine
a. Secrete hormones directly into bloodstream
b. Ductless
2. Exocrine
a. Secrete substance through a duct
b. Sweat, salivary, lacrimal and pancreas
B. Function of endocrine system
1. To secrete hormones
2. Hormones are chemical messengers that coordinate and direct
target cells and organs
C. Hormone control
1. Negative feedback – drop in hormone level triggers a chain reaction
a. Blood level of hormone falls
b. Brains gets message and sends out hormone to stimulate gland
c. Gland secretes more hormone
d. When blood level of hormone increases, brain hormones stop
2. Nervous control – in some cases, sympathetic nervous system
causes direct release of hormone from gland (for example, when
stress causes the adrenal medulla to secrete adrenalin)
Summer 2005 P.1
D. Pituitary gland
1. The master gland
2. Anterior pituitary lobe
a. Growth hormone – GH (somatotropin) responsible for growth
and development
b. Prolactin – develops breast tissue, stimulates production of
milk after childbirth
c. Thyroid-stimulating hormone – TSH – stimulates thyroxine
d. Adrenocorticotropic hormone – ACTH – stimulates adrenal
cortex
e. Follicle-stimulating hormone – FSH – stimulates growth of
graafian follicle and production of estrogen in females,
sperm in males
f. Luteinizing hormone – LH – stimulates ovulation and
formation of corpus luteum, which produces progesterone in
females
3. Posterior pituitary lobe
a. Vasopressin – converts to ADH (antidiuretic hormone) in the
bloodstream, acts on kidney to concentrate urine and
preserve H2O in the body
b. Oxytocin – released during childbirth causing contractions of
the uterus
E. Thyroid gland
1. Main hormone, thyroxine, is controlled by secretion of TSH
2. Thyroxine controls the rate of metabolism
3. Calcitonin, another hormone that controls calcium ion
concentration in the body, prevents hypercalcemia
F. Parathyroid glands – produce parathormone which helps control
blood calcium, prevents hypocalcemia
G. Thymus
1. Endocrine gland and lymphatic organ
2. Located behind sternum, above and in front of heart
3. Begins to disappear at puberty
H. Adrenal glands
1. Adrenal cortex secretes corticoids (anti-inflammatory hormones)
and sex hormones
2. Androgens – male sex hormones
3. Adrenalin – hormone from adrenal medulla, powerful cardiac
stimulant, “fight or flight” hormone
I. Gonads
1. Estrogen – development of female reproductive organs,
secondary sex characteristics
2. Progesterone – plays a part in the menstrual cycle
3. Testosterone – male reproductive organs and secondary sex
characteristics
J. Pancreas
1. Islets of Langerhans – insulin production
2. Insulin promotes utilization of glucose by the cells
K. Prostaglandins – tissue hormones
Summer 2005 P.2
1H16.03
Discuss characteristics and treatment of common
endocrine disorders.
A. Gigantism
1. Hyperfunction of pituitary – too much growth hormone
2. In preadolescence – overgrowth of long bones leads to excessive
tallness
B. Dwarfism
1. Hypofunction of pituitary in childhood
2. Small size, but body proportions and intellect normal
3. Rx – early diagnosis, injection of growth hormone
C. Hyperthyroidism
1. Overactive thyroid gland
2. Too much thyroxine leads to enlargement of gland
3. Symps – consuming large quantities of food but lose weight
4. Goiter – enlargement of gland
5. Exophthalmos – bulging of eyeballs
6. Rs – partial or total removal of gland, drugs to reduce thyroxine,
radiation
D. Hypothyroidism
1. Not enough thyroxine
2. May be due to lack of iodine (simple goiter)
3. Symps – dry, itchy skin; dry and brittle hair, constipation, muscle
cramps at night
E. Tetany
1. Hypoparathyroidism, decreased calcium levels affect functions of
nerves
2. Symps – convulsive twitching develops, person dies of spasms in the
respiratory muscles
3. Rx – Vitamin D, calcium and parathormone
F. Diabetes Mellitus
1. Cause – decreased secretion of insulin
2. Symps – polyuria, polyphagia, polydipsia, weight loss, blurred vision,
and possible diabetic coma
3. If not treated, excess glucose in blood (hyperglycemia) and secreted
in urine (glycosuria)
4. If too much insulin given, blood sugar can get too low (hypoglycemia)
and person can develop insulin shock
5. Type II diabetes is not insulin-dependent – most common, usually
familial, occurs later in life, usually treated with diet
6. Test for diabetes – blood sample at home, normal blood sugar is 80100 mg
Summer 2005 P.3
Unit P: Endocrine System
Terminology List
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ACTH
ADH
adrenal glands
adrenalin
androgens
calcitonin
corticoids
endocrine glands
estrogen
exocrine glands
FSH
gonads
GH (somatotropin)
hormones
insulin
islets of Langerhans
LH
negative feedback
ovary
oxytocin
pancreas
parathormone
parathyroid glands
pituitary gland
progesterone
prolactin
prostaglandins
TSH
target organ cells
testes
testosterone
thymus
thyroid gland
thyroxine
vasopressin
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Disorders and Related Terminology
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10.
acromegaly
diabetes mellitus
dwarfism
gigantism
goiter
hyperglycemia
hyperthyroidism
hypoglycemia
hypothyroidism
tetany
Unit P: Endocrine System
OVERHEAD TRANSPARENCY
MASTERS
Summer 2005 P.5
Endocrine System
ENDOCRINE GLANDS
 Secrete hormones directly into bloodstream
 Ductless
EXOCRINE GLANDS – secrete substances
through a duct (sweat, salivary, lacrimal and
pancreas)
Function of the Endocrine System – to
secrete hormones – chemical messengers that
coordinate and direct target cells and organs.
Hormonal Control
NEGATIVE FEEDBACK
 Drop in hormone level triggers a chain
reaction to increase secretion, for example
1. Blood level of hormone falls
2. Brain gets message and sends out
hormone to stimulate gland
3. Gland stimulates more hormone
4. When blood levels of hormone increase,
the brain hormones stop
Summer 2005 P.6
Nervous Control – in some cases, sympathetic
nervous system causes direct release of
hormone from gland (for example, when stress
causes the adrenal medulla to secrete
adrenalin)
PITUITARY GLAND
 Tiny structure the size of a
grape
 Located at the base of the
brain
 Connected to the
hypothalamus
 Divided into anterior and posterior lobes
 The “Master Gland”
Anterior Pituitary Lobe
 GROWTH HORMONE - GH
(SOMATOTROPIN) responsible for growth
and development
 PROLACTIN – develops breast tissue,
stimulates production of milk after childbirth
 THYROID-STIMULATING HORMONE – TSH
- stimulates thyroxine
Summer 2005 P.7
 ADRENOCORTICOTROPIC HORMONE –
ACTH – stimulates adrenal cortex
 FOLLICLE-STIMULATING HORMONE –
FSH -stimulates growth of graafian follicle
and production of estrogen in females, sperm
in males
 LUTEINIZING HORMONE – LH – stimulates
ovulation and formation of corpus luteum,
which produces progesterone in females
Posterior Pituitary Lobe
 VASOPRESSIN – converts to ADH
(antidiuretic hormone) in the bloodstream,
acts on kidney to concentrate urine and
preserve H2O in the body
 OXYTOCIN – released during childbirth
causing contractions of the uterus
Summer 2005 P.8
THYROID GLAND
 Butterfly-shaped mass of tissue
 On either side of larynx, over trachea
 H-shaped
 Main hormone – THYROXINE – is controlled
by the secretion of TSH
 Thyroxine controls the rate
of metabolism
 CALCITONIN – controls
calcium ion concentration
in the body, prevents
hypercalcemia
PARATHYROID GLANDS
 Four glands, each the size of a grain of rice
 Attached to posterior thyroid
 Produce PARATHORMONE which helps
control blood calcium level, prevents
hypocalcemia
THYMUS
 Endocrine gland and lymphatic organ
 Located behind the sternum, above and in
front of the heart
 Begins to disappear at puberty
Summer 2005 P.9
Summer 2005 P.10
ADRENAL GLANDS
 Located on top of each kidney
 Adrenal cortex secretes hormones known at
corticoids – they are anti-inflammatory
 They are: mineralcorticoids, glucocorticoids,
and sex hormones
 ANDROGENS are male sex hormones
 Adrenal medulla secretes epinephrine
(adrenalin) and norepinephrine
 ADRENALIN is a powerful
cardiac stimulent – “fight or
flight” hormones that prepare
the body for an emergency
situation
GONADS
 Ovary in female
 Testes in male
 Estrogen – development of female
reproductive organs, secondary sex
characteristics
 Progesterone – plays a part in the menstrual
cycle
 Testosterone – male reproductive organs
and secondary sex characteristics
Summer 2005 P.11
PANCREAS
 Located behind the stomach
 Endocrine and exocrine functions
 Involved in production of INSULIN by
ISLETS OF LANGERHANS
 Insulin – promotes utilization of glucose by
the cells, fatty acid and amino acid transport,
and facilitates protein synthesis
Other Hormones
PROSTAGLANDINS – tissue hormones, can
cause constriction of blood vessels, muscle
contractions. Can be used to induce labor.
Summer 2005 P.12
Summer 2005 P.13
GIGANTISM
 Hyperfunction of pituitary – too much growth
hormone
 In preadolescent – overgrowth of long bones
leads to excessive tallness
ACROMEGALY
 Hyperfunction of pituitary – too much growth
hormone in adulthood
 Overdevelopment of bones in face, hands
and feet
 Attacks cartilage – so the chin protrudes,
lips nose and extremities enlarge
 Rx – drugs to inhibit growth hormone,
radiation
DWARFISM
 Hypofunction of pituitary in childhood
 Small size, but body proportions and
intellect are normal
 Sexual immaturity
 Rx – early diagnosis, injection of growth
hormone
Summer 2005 P.14
HYPERTHYROIDISM
 Overactive thyroid gland
 Too much thyroxine secreted leading to
enlargement of gland
 People with this disease consume large
quantities of food but lose body fat and
weight
 Most pronounced symptoms are
enlargement of gland (GOITER) and bulging
of eyeballs (EXOPHTHALMOS)
 Rx – total or partial removal of
thyroid gland, drugs to reduce
thyroxine, radiation
HYPOTHYROIDISM
 Not enough thyroxine secreted
 May be due to lack of iodine (simple goiter)
 Major cause of other types is inflammation
of thyroid which destroys the ability of the
gland to make thyroxine
 Symps – dry and itchy skin, dry and brittle
hair, constipation, muscle cramps at night
TETANY
 In hypoparathyroidism, decreased calcium
levels affect function of nerves
 Convulsive twitching develops, person dies
of spasms in the respiratory muscles
Summer 2005 P.15

Rx – Vitamin D, calcium and parathormone
DIABETES MELLITUS
 Caused by  secretion of insulin
 Can be insulin dependent (juvenile) or noninsulin dependent
 Symps – polyuria, polyphagia, polydipsia,
weight loss, blurred vision, and possible
diabetic coma
 If not treated, excess glucose in blood
(hyperglycemia) and glucose secreted in
urine (glycosuria)
 Since glucose not available for cellular
oxidation, body starts to burn up protein and
fat
 If too much insulin is given, blood sugar may
go too low (hypogycemia  insulin shock)
 If blood sugar gets too high – hyperglycemia
 diabetic coma
 Type II (non-insulin dependent) is most
common, usually familial, occurs later in life,
control with oral hypoglycemic drugs and
diet
 Tests for Diabetes – blood sample
measured in glucometer – done by patient in
home – normal blood sugar 80-100 mg
Summer 2005 P.16