Download Hormones

pp 1031-1042

Homeostasis: maintaining stable internal
environment
How is this done?

Last step of the series controls the first

A secondary substance increases production
of the initial substance
 Ex. Earth’s Temperature and ice caps
 Ex. Oxytocin and contractions

A secondary substance inhibits production of
the initial stimulating substance
A = Insulin
B = glucagon (sugar)

Communication
system that controls
metabolism, growth,
development

Uses chemical
messengers
(hormones)


Glands: organs that secrete hormones
Hormones: chemical messengers that act on
target cells

Relies on circulatory
system to send chemical
message.




Size of a pea
Produces hormones that affects other glands
(thyroid, gonads, adrenal glands)
controls growth, metabolism, sexual
development, and reproduction
Known as “master gland”

Growth hormone or GH - GH stimulates growth in childhood and is important for maintaining a healthy
body composition. In adults it is also important for maintaining muscle mass and bone mass. It can affect
fat distribution in the body.

Adrenocorticotropin or ACTH - ACTH stimulates production of cortisol by the adrenal glands. Cortisol, a
so-called "stress hormone," is vital to survival. It helps maintain blood pressure and blood glucose levels.

Thyroid-stimulating hormone or TSH - TSH stimulates the thyroid gland to make thyroid hormones,
which, in turn, control (regulate) the body's metabolism, energy, growth and development, and nervous
system activity.

Luteinizing hormone or LH - LH regulates testosterone in men and estrogen in women. (gonadotropin)

Follicle-stimulating hormone or FSH - FSH promotes sperm production in men and stimulates the
ovaries to release eggs (ovulate) in women. LH and FSH work together to allow normal function of the
ovaries or testes. (gonadotropin)

Oxytocin - Oxytocin causes milk letdown in nursing mothers and contractions during childbirth.

Antidiuretic hormone or ADH - ADH, also called vasopressin, is stored in the back part of the pituitary
gland and regulates water balance. If this hormone is not secreted properly, this can lead to problems of
sodium (salt) and water balance, and could also affect the kidneys so that they do not work as well.
Pituitary Disorder
• Gigantism: over
production of
growth hormone
• Tallest man
recorded: 8 ft 11 in



Butterfly-shaped that surrounds trachea
Produces thyroxin and calcitonin
Regulates heart rate, blood pressure, body
temperature, and metabolism



Triangle shaped and located on top of
kidneys
Produces adrenaline
Responds to stress

Produces insulin and glucagons to regulate
blood sugar levels

Thymus: stimulates
formation of white
blood cells (T-cells)

Gonads: sex hormones
Feature
Organs involved
Type of Signal
(electrical or chemical)
Rate of Transfer
(fast or slow?)
Voluntary or
Involuntary?
Examples of Processes
Controlled
Endocrine
Nervous System