Download endocrine system

Chapter 11
ENDOCRINE SYSTEM
FUNCTION OF THE
ENDOCRINE SYSTEM
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
FUNCTION OF THE
ENDOCRINE SYSTEM
• Secretion of hormones or chemical
messengers that coordinate and
direct activities of target cells and
organs
• Major glands of endocrine system
– pituitary - thyroid
- thymus
– pineal
- parathyroid - adrenals
– pancreas - gonads
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
HORMONAL CONTROL
• Negative feedback
– occurs when there is a drop in the
level of a hormone
– triggers a chain reaction of responses
to increase hormones in the blood
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
PITUITARY GLAND
• Located at the base of the brain
and connected to the hypothalamus
• Divided into anterior and posterior
lobes
• Known as the master gland because
of its major influence in body’s
activities
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
HORMONES OF THE
PITUITARY GLAND
• Divided into two lobes
– anterior pituitary lobe is larger and
produces seven hormones
– posterior pituitary lobe is smaller and
consists primarily of nerve fibers and
neuroglial cells
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
THYROID AND
PARATHYROID GLANDS
• Thyroid glands
– Located in the anterior part of neck
– Secretes 3 hormones:
• Thyroxine
• Triiodthyronine
• Calcitonin
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
THYROID AND
PARATHYROID GLANDS
• Parathyroid glands
– Four glands attached to posterior
surface of thyroid
– Stimulate an increase in number and
size of osteoclasts (specialized bone
cells)
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
THYMUS GLAND
• The thymus gland is both an
endocrine gland and lymphatic organ
• The thymus secretes a large
number of hormones
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
ADRENAL GLANDS
• Two adrenal glands located on top
of each kidney; each has two parts
– Cortex - secretes 3 groups corticoids
• Mineralocorticoids
• Glucocorticoids
• Sex hormones
– Medulla - secretes
• epinephrine
• norepinephrine
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
GONADS
• Gonads - sex organs
– Ovaries - female sex organ
• ova
• estrogen and progesterone
– Testes - male sex organ
• sperm
• testosterone
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
PANCREAS
• Located behind stomach
• Functions as:
– Exocrine gland
• Secretes pancreatic juices into small
intestine to become digestive juices
– Endocrine gland
• Produces insulin and glucagon
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
PINEAL GLAND
• Attached to the third ventricle of
the brain
• Produces the hormone melatonin
– Amount of light affects the amount
of melatonin secreted
– Causes body temperature to drop
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
OTHER HORMONES
PRODUCED IN THE BODY
• There are many hormones produced
throughout the body originating
from many different glands and
organs
• Prostaglandins are hormones
secreted in various tissues
throughout the body
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
DISORDERS OF THE
ENDOCRINE SYSTEM
• Endocrine gland disturbances may
be caused by:
– Disease
– Infection
– Hyperactivity
– Hypoactivity
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
PITUITARY DISORDERS
• Hyperfunction of Pituitary
– Gigantism
– Acromegaly
• Hypofunction of Pituitary
– Dwarfism
• Diabetes Insipidus
– Caused by posterior lobe dysfunction
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
THYROID DISORDERS
• Blood tests are done to diagnose
– Hyperthyroidism
• Due to overactivity of thyroid gland
• Hypersecretion of thyroxin
– Hypothyroidism
• Due to inflammation of thyroid gland
• Thyroid isn’t able to secrete enough
thyroxin
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
PARATHYROID DISORDERS
• The parathyroid glands regulate
the use of calcium and phosphorus
• Hyperfunctioning
– Kidney stones
– Calcium taken from bones
• Hypofunctioning
– Tetany - low levels of calcium affects
the nerves
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
ADRENAL DISORDERS
• Hyperfunction of the Adrenal
– Cushing’s syndrome
• Hypofunction of Adrenal Cortex
– Addison’s disease
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
STEROID ABUSE IN SPORTS
• Effects of steroid abuse:
– Liver changes
– Decreased spleen production
– Atrophy of testicles
– Breast enlargement
– Cardiovascular disease
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
PANCREATIC DISORDERS
• Diabetes mellitus
– Ineffective secretion or use of insulin
– Type I - juvenile diabetes
– Type II - adult diabetes
• Treatment
– Glucose monitoring
– Weight reduction
- Diet
- Medication
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.
PANCREATIC DISORDERS
• Tests for Diabetes Mellitus
– Urine samples
– Blood samples
• glucometer (glucose monitor)
• glycosylated hemoglobin (HbA1c)
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.