Endocrine system
Chapter 13
Objectives:
Describe the vital function of the endocrine
system
State the description and primary functions
of the organs and structures of the
endocrine system
Identify some of the hormones produced
Identify medical words
Introduce and review Root words, prefixes
and suffixes in the endocrine system
Contd:
Endocrinology is the study of the
endocrine system
Endocrinologist is a physician who
specializes in the medical practice of
endocrinology
Anatomy and Physiology:
the endocrine system influences
almost every cell, organ, and function
of our bodies.
It is instrumental in regulating mood,
growth and development, tissue
function, metabolism, and sexual
function and reproductive processes.
Contd:
The vital function of the endocrine
system involves the production
and regulation of chemical
substances called
Hormones
The word hormone is derived
from the Greek language
Means to excite or urge on
Contd:
The foundations of the endocrine
system are the hormones and glands.
hormones transfer information and
instructions from one set of cells to
another.
Each type of hormone is designed to
affect only certain cells.
Contd:
Hyposecretion or hypersecretion of
specific hormones can cause or be
associated with many pathological
conditions.
Too much or too little of any hormones
can be harmful to the body
Controlling the production of or
replacing specific hormones can treat
many hormonal conditions
Parts of the Endocrine System:
The major glands that make up
the human endocrine system are:
 the hypothalamus, pituitary,
thyroid, parathyroid's, adrenals,
pineal body, and the reproductive
glands, which include the ovaries
and testes.
Glands: The Hypothalamus
a collection of specialized cells that is
located in the lower central part of the
brain
is the primary link between the
endocrine and nervous systems.
The hypothalamus controls the
pituitary gland by producing chemicals
that either stimulate or suppress
hormone secretions from the pituitary.
The Pituitary Gland:
it is no bigger than a pea
located at the base of the brain just
beneath the hypothalamus
is considered the most important part
of the endocrine system
It's often called the "master gland"
because it makes hormones that
control several other endocrine
glands.
Contd:
The tiny pituitary gland is divided into
two parts: the anterior lobe and the
posterior lobe.
The anterior lobe regulates the
activity of the thyroid, adrenals, and
reproductive glands.
also secretes endorphins, chemicals
that act on the nervous system to
reduce sensitivity to pain.
Contd:
The anterior lobe also
secretes hormones that signal
the ovaries and testes to
make sex hormones.
also controls ovulation and
the menstrual cycle in women.
Contd:
The posterior lobe of the pituitary
releases antidiuretic hormone, which
helps control body water balance
through its effect on the kidneys and
urine output;
Also releases oxytocin, which triggers
the contractions of the uterus that
occur during labor.
The Pineal Gland:
is located in the middle of the
brain.
It secretes melatonin, a hormone
that may help regulate the wakesleep cycle.
Cone shaped structure attached
by a stalk to the posterior wall of
the cerebrum
The Thyroid:
located in the front part of the lower
neck
 is shaped like a bow tie or butterfly
 produces thyroid hormones
These hormones (thyroxine and
triiodothyronine) control the rate at
which cells burn fuels from food to
produce energy.
Contd:
Thyroid hormones also play a key
role in bone growth and the
development of the brain and
nervous system in children.
 The production and release of
thyroid hormones is controlled by
thyrotropin, which is secreted by
the pituitary gland.
Parathyroid:
Are four tiny glands attached to
the thyroid that function together
They release parathyroid
hormone, which regulates the
level of calcium in the blood with
the help of calcitonin, which is
produced in the thyroid.
Pancreas:
The pancreas produces (in addition to
others) two important hormones, insulin
and glucagon.
 They work together to maintain a steady
level of glucose, or sugar, in the blood to
help maintain and store energy
Composed of three major types of cells:
alpha, beta and delta
See page 447 of your text for each function
The Adrenal Glands:
The body has two triangular
adrenal glands, one on top of
each kidney.
 The adrenal glands have two
parts, each of which produces a
set of hormones and has a
different function.
Contd:
The outer part, the adrenal
cortex, produces hormones called
corticosteroids that influence or
regulate salt and water balance in
the body
Also influences the body's
response to stress, metabolism,
the immune system, and sexual
development and function.
Contd:
The inner part, the adrenal medulla,
produces catecholamines, such as
epinephrine.
 Also called adrenaline, epinephrine
It increases blood pressure and heart
rate when the body experiences
stress.
Gonads:
The gonads are the main source of sex
hormones.
In males, they are located in the scrotum.
 Male gonads, or testes, secrete hormones
called androgens, the most important of
which is testosterone.
These hormones regulate body changes
associated with sexual development.
 Working with hormones from the pituitary
gland, testosterone also supports the
production of sperm by the testes.
Contd:
The female gonads, the ovaries, are
located in the pelvis.
They produce eggs and secrete the female
hormones estrogen and progesterone.
 Estrogen is involved in the development of
female sexual features.
 Both estrogen and progesterone are also
involved in pregnancy and the regulation of
the menstrual cycle.
Thymus:
is an organ located in the upper
anterior portion of the chest cavity just
behind the sternum.
The main function of the thymus is to
provide an area for T cell maturation,
and is vital in protecting against
autoimmunity.
Abbreviations:
ADA American diabetes
Association
BMR Basal metabolic rate
DI
Diabetes insipidus
DM
Diabetes mellitus
FBS Fasting blood sugar
GTT Glucose tolerance test
Contd:
IDDM
Insulin-dependant diabetes
mellitus (Type I)
NIDDM Non –insulin dependent
diabetes mellitus (Type 2)
PRL
Prolactin
Adenectomy
Aden
-ectomy
gland
surgical excision
Surgical excision of a gland