ENDOCRINE SYSTEM WORKSHEET
1. State the primary function of the endocrine system in the human body.
 It works with nervous system for integration and control.
2. Describe the physiological mechanism of the endocrine system. Explain
the role of hormones, the hypothalamus, and the anterior pituitary gland
in your answer.
i) Hormones:
 Act as messengers that stimulate response in targeted organs
ii) Hypothalamus:
 Secretes releasing and inhibiting hormones for regulating secretions of
the anterior pituitary gland.
iii) Anterior pituitary:
 Secretes tropic hormones that regulate other endocrine organs.
3. Compile a table showing components of the endocrine system, location,
secretion(s) and principal function(s) of each organ/gland.
Include hypothalamus, anterior lobe of pituitary gland, posterior lobe of
pituitary gland, pineal gland, thymus gland, follicular cells of thyroid
gland, C cells (calcitonin or parafollicular cells) of thyroid gland,
parathyroid glands, adrenal medulla, adrenal cortex, alpha () cells of
pancreatic islet, beta () cells of pancreatic islet, delta () cells of
pancreatic islet, granulosa cells in wall of ovarian follicle, corpus luteum
of ovary, interstitial cells (between seminiferous tubules) of testes,
sustentacular (Sertoli cells) of seminiferous tubules on the table.
Components
of endocrine
system
Hypothalamus
Location
Secretion


Floor & wall of
3rd ventricle
brain


Anterior
pituitary


Posterior
pituitary


Inferior to
hypothalamus
In Sella turcica
Inferior to
hypothalamus
In Sella turcica
Produce and
secrete releasing
and inhibiting
hormones
Anti-diuretic
hormone (ADH)
Oxytocin (OT)
Tropic hormones e.g.
gonadotropins such as
FSH
Function of secretions

Regulate
secretion of
anterior
pituitary

Regulate
secretion of
other
endocrine
organs
Increase
water
retention
Stimulates
contractions
and
propulsion
Promotes
bonding

ADH


OT


Pineal

Roof of third
ventricle

Thymosin
Superior to
Thymopoietin
the heart
(mediastinum) Thymulin

Inferior and
posterior to
stomach
Thymus
Pancreatic
Islet
Serotonin converts to
melatonin at night
To prevent
depression, prevent
sleeplessness
 Regulate
development
later
activation of T
lymphocytes

Glucagon


Insulin


somatostatin

Increases
blood sugar
level
Lowers blood
sugar
Modulates
secretion of
alpha
(glucagon)
and beta cells
Follicular cells
of Thyroid
gland

Anterior to
trachea

Thyroid hormones
(T3&T4)

Increase
metabolic
rate
C cells of
Thyroid gland

In thyroid
gland
Adjacent to
thyroid
follicles

Calcitonin

Increases
bone calcium
levels
Decreases
blood calcium
levels
Posterior
surface of
thyroid


Parathyroid
gland


Parathyroid
hormone (PTH)


Increases
blood calcium
levels
Promotes
synthesis of
calcitriol
(vitamin D)
Adrenal
medulla

Superior to
the kidney


Epinephrine
Norepinephrine

Allows the
body to
respond to
stress e.g. by
increasing
blood flow
Adrenal cortex

Superior to
kidney

Corticosteroids

-
aldosterone

Control
electrolyte
balance
Promotes
sodium
retention and
potassium
excretion
-
cortisol

Stimulates fat
and protein
and release
fatty acid and
glucose

Increases
blood sugar
level
Pancreas:
Alpha cell of
pancreatic
islet


In loop of
duodenum
Inferior and
posterior to
stomach

Glucagon
Delta cell of
pancreatic
islet

Somatostatin

Modulates
secretion of
alpha and
Beta cells
Beta cell of
pancreatic
islet
Ovary

Insulin

Lowers blood
sugar

Inhibin


Estradiol


Progesterone

Suppresses
FSH secretion
Promote
development
of female
reproductive
system
Thickens
endometrium
and maintains
pregnancy

Testosterone

Promotes
development
of male
reproductive
system

Inhibin

Suppresses
FSH secretion

Testes:
Interstitial
cells (between
seminiferous
tubules) of
testes

Sustentacular
(Sertoli cells)
of
seminiferous
tubules in
testes

Pelvic region
of female
Scrotal sac
Scrotal sac
4. Distinguish between hyperglycemic and hypoglycemic hormones.
 Hyperglycemic hormones increase blood glucose level while
hypoglycemic hormones decrease blood glucose level
5. Name a) two hyperglycemic hormones and b) one hypoglycemic
hormone.
a) Hyperglycemic hormones
i.
Glucagon
ii.
Epinephrine
b) Hypoglycemic hormone
Insulin
6. Describe medical problems associated with endocrine disorders of the
thyroid follicular cells and adrenal cortex.
Thyroid disorders:
 Congenital hypothyroidism – deficiency of thyroid hormone from
birth
 Myxedema- adult hypothyroidism which is caused by low thyroid
hormone
 Endemic goiter- enlargement of thyroid gland (deficiency of
iodine, no TH, no feedback and high thyroid stimulating hormone
 Toxic goiter (Graves’ disease) autoimmune disorder that causes
hyperthyroidism, or overactive thyroid. With this disease, your
immune system attacks the thyroid and causes it to make more
thyroid hormone than your body needs. Antibodies mimic TSH
Adrenal cortex disorders:
 Cushing syndrome- a condition that occurs from prolonged exposure
to high cortisol levels
 Adrenogenital syndrome- genetic conditions limiting hormone
production in the adrenal gland
7. What is acromegaly?
 Abnormal growth of the hands, feet, and face caused by
overproduction of growth hormone by the pituitary gland in adults. The
thickening of bones and soft tissues occurs.
8. Explain feedback control of the pituitary gland by target organs.
 Negative feedback inhibition occurs.