Download The Endocrine System

The Endocrine System
Chapter 18
General Characteristics
includes cells, tissues, and organs that
secrete hormones directly into the body
fluids to help regulate metabolic processes
such as chemical reactions, reproduction,
growth, and development
 The 9 Endocrine glands include the 1.
pituitary (anterior and posterior), 2.
thyroid, 3. parathyroid, 4. adrenal, 5.
pineal, 6. thymus, 7. pancreas, 8. testes,
and 9. ovaries

Hormones


biochemicals secreted by a cell that affect the
function of another cell
3 types:




Steroid – derived from cholesterol (fat)
Peptide – an amino acid based hormone (protein)
Prostaglandins – hormone-like lipids (fat); act more
locally than hormones; only affect organ where
produced
Hormones are released based on the body’s
need and are carried by the blood to the
target cell; controlled by negative feedback
Hormones of Anterior Pituitary
Hormone
Target
tissue
Effects
Adreno corticotropic
hormone (ACTH)
Folliclestimulating
hormone (FSH)
Adrenal
glands
Stimulates production of
steroid hormones
Ovaries and
testes
Regulates development of
male/female gametes
Regulates development of
male/female gametes and
production of testosterone in
testes of males
Luteinizing
hormone (LH)
Ovaries and
testes
Stimulates release of egg from
ovary; stimulates production
of testosterone
Hormones of Anterior Pituitary
(cont).
Hormone
Target tissue Effects
Prolactin
Mammary
glands
Stimulates milk
production in breasts
Growth
hormone or
somatotropin
(GH)
All tissues
stimulates cell growth
and division, particularly
bone and muscle
Hormones of Posterior Pituitary
Hormone
Target
tissue
Effects
Antidiuretic
Kidneys,
Stimulates absorption
hormone (ADH) blood vessels of water (less urine
production) and
thereby regulates
water balance
Oxytocin
Mammary
Stimulates uterine
glands,
contractions, onset of
uterus
labor, and the letting
down of milk to the
breasts.
Hormones of Adrenal Glands
Hormone
Aldosterone
Target tissue
Kidneys
Cortisol
All tissues
Epinephrine and
norepinephrine
Skeletal and
cardiac muscle,
blood vessels
Effects
Maintains blood volume and
pressure (stimulates
kidneys to conserve
sodium, and therefore
retain water)
Controls inflammation,
increases blood glucose
concentration, suppresses
immune response
Initiates response to stress;
increases metabolic rate,
heart rate, blood pressure;
dilates blood vessels; raises
blood glucose levels
Hormones of Pancreas
Hormone
Insulin
Glucagon
Target
tissue
All tissues
Liver, fatty
tissues
Effects
Stimulates conversion
of glucose to glycogen;
lowers blood glucose
levels
Stimulates conversion
of glycogen to glucose;
raises blood glucose
levels
Hormones of Pineal Gland
Hormone
Target tissue Effects
Melatonin
Uncertain,
May regulate biorhythms
possibly testes and moods; may control
and ovaries
onset of puberty
Hormones of Thyroid Gland
Hormone
Target tissue Effects
Calcitonin
Bone tissue
Thyroxine
All tissues
Inhibits release of
calcium from bone;
lowers blood calcium
levels (opposite of
parathyroid hormone)
Raises metabolic rate;
necessary for normal
growth
Hormones of Ovaries
Hormone
Estrogen
Progesterone
Target
tissue
All tissues,
female
reproductive
structures
Uterus,
breasts
Effects
Controls dev. of
secondary sex charac.
and sex organs;
initiates preparation of
uterus for pregnancy
Completes preparation
of uterus for
pregnancy; stimulates
breast dev.
Hormones of Testes
Hormone
Target tissue Effects
Testosterone
All tissues,
male
reproductive
organs
Controls dev. of
secondary sex charac.
and sex organs;
stimulates sperm
formation
Hormones of Parathyroid Gland
Hormone
Target tissue Effects
Parathyroid
hormone (PTH)
Bone tissue,
kidneys
Stimulates breakdown of
bone and release of
calcium into
bloodstream; raises
blood calcium levels
Hormones of Thymus Gland
Hormone
Target tissue Effects
Thymosin
Bone Marrow
Altered in
spleen
Regulates production of
white blood cells
(immunity)
Disorders - Pituitary Gland

Diabetes insipidus – deficiency of ADH;
characterized by large volumes of dilute
urine and constant thirst; usually caused
by an injury to the head, complications
with brain surgery, or a brain tumor; can
be genetic
Disorders - Pituitary Gland (dwarfism)

Pituitary Dwarfism – any person who is under 4’ 10”
tall is considered a dwarf. Is caused by a deficiency of
HGH in adolescence; limbs proportional and normal
mental development; but may not develop adult sex
features. 10,000 to 15,000 in U.S.

Achondroplasia - is the most common type of
dwarfism. It is characterized by abnormal body
proportions. Affected individuals have arms and legs
that are very short, while the torso is nearly normal
size. Caused by mutation on chromosome 3 effects
cartilage formation. 80% of dwarves
Achondroplasia
Disorders - Pituitary Gland (gigantism)
Gigantism – overproduction of HGH in
adolescence; height may exceed 8 ft; rare,
usually result of tumor (or small tumors);
other hormones of pituitary gland usually
affected so other hormone-related
problems. Top 1% in height.
 Acromegaly – overproduction of HGH after
puberty and growth plates have fused can
cause type 2 diabetes, high blood pressure,
increased risk of cardiovascular disease,
and arthritis.

12 yr old boy with mother
8 ft 11 inches
Disorders - Pancreas

Diabetes mellitus – insulin deficiency; inhibits
conversion of glucose to glycogen therefore blood
sugar is too high; results in excess urine output; also,
cells use protein for energy instead of sugar so body
tissues waste away; results are weight loss, hunger,
fatigue, dehydration


Type I – juvenile – autoimmune disease; immune system
attacks cells that synthesize insulin; treatment – insulin
injections
Type II – adult – usually appears after age 40; usually in
overweight adults; body cells lose sensitivity to insulin;
treatment – controlling diet, exercise, maintaining healthy
body weight
Diabetes
Hypoglycemia – low blood sugar (can cause
diabetic coma). No energy
 Hyperglycemia – high blood sugar (can cause
the rupture of blood vessels, blurred vision,
thirst, hunger, and frequent urination.
 Gestational Diabetes – Diabetes during
pregnancy caused by high level of production of
FSH and LH which blocks the effectiveness.
Typically not a problem after pregnancy and
does not usually cause birth defects like normal
diabetes if managed correctly.

Disorders - Thyroid

Graves’ disease (hyperthyroidism) – elevated
metabolic rate; restlessness; overeating; eyes
protrude b/c of swelling in the tissues behind
them; thyroid gland enlarges causes swelling
in neck called a goiter

Hypothyroidism – in infants called Cretinism –
stunted growth, abnormal bone formation;
mental retardation; low body temp;
sluggishness; in adults called Myxedema –
lethargy; hair loss; low metabolic rate; obesity;
more common in females
Goiter
Disorders – Adrenal gland
Cushing’s syndrome – hypersecretion of
cortisol; alters carb and protein metabolism
and electrolyte balances; upper body obesity;
rounded face; increased fat around neck;
thinning arms and legs
 Addison’s disease – hyposecretion of cortisol
and aldosterone; weight loss; dehydration;
muscle weakness; fatigue; low blood
pressure; darkening of skin; JFK had this
disease

Cushings syndrome
Same patient 2 yrs later after treatment
Disorders – Parathyroid

Kidney stones – too much PTH; stimulates
osteoclast activity; bones soften, deform;
excess calcium in body fluids results in
abnormal storage of calciumkidney
stones