Transcript ST120 Endocrine System

ST120
Concorde Career College, Portland
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Define the term endocrine.
Describe the functions of the endocrine
system.
List and identify the structures of the
endocrine system and describe the function
of each.
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List the endocrine hormones, the source of
each, and the effect each has on the body.
Describe the effect of the hypothalamus on
the endocrine system.
Describe the mechanism by which the
endocrine system helps to maintain
homeostasis.
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Describe common diseases, disorders, and
conditions of the endocrine system including
signs and symptoms, diagnosis, and available
treatment options.
Demonstrate knowledge of medical
terminology related to the endocrine system
verbally and in the written form.
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Exocrine - ducts
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Lacrimal glands
Salivary glands
Sweat glands
Sebaceous
glands
 Pancreas
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Endocrine secretes directly
into bloodstream
The term endocrine refers to a gland that
secrets directly into the bloodstream.
The term exocrine refers to a gland that secrets
directly onto a surface or through a duct.
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The endocrine system produces hormones as
directed by the nervous system.
Hormones are messengers, delivered via the
bloodstream, that have certain effects of
various cells, functions, or organs.
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Amino acid compounds
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Steroids
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Hormone secretion is regulated by a negative
feed back system
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Pineal
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Pituitary
 Anterior lobe
 Posterior lobe
(AKA - Pineal Body)
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Small, flattened,
cone-shaped
structure located
posterior to the
midbrain and
connected to the roof
of the 3rd ventricle.
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Produced by the pineal gland
Melatonin is primarily produced at night
(during darkness)
Melatonin influences the sleep/wake cycle
and seems to delay the onset of puberty
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Small gland
approximately the size of
an olive or a cherry
located in the sella
turcica of the sphenoid
bone
Attached to the
hypothalamus by the
infundibulum (stalk-like
structure)
Divided into anterior and
posterior lobes
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Considered to be the “Master Gland” because
it’s hormones regulate other glands.
AKA - Hypophysis
-tropin - Suffix that indicates hormones that
stimulate other glands.
1. Growth Hormone (GH)
2. Thyroid Stimulating
Hormone (TSH)
3. Adrenocorticotropic
Hormone (ACTH)
4. Prolactin (PRL)
5. Follicle Stimulating
Hormone (FSH)
6. Luteinizing Hormone
(LH)
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General Information
Messages (“releasing hormones”) from the
hypothalamus are received in the anterior
pituitary gland via a portal system
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Produced in the anterior pituitary
AKA - Somatotropin
Acts on most body tissues (primarily bone
and soft tissues)
Produced throughout the lifespan
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Produced in the anterior pituitary
AKA - thyrotropin
Stimulates the thyroid gland to produce
thyroid hormones
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Produced in the anterior pituitary
Stimulates the adrenal cortex
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Produced in the anterior pituitary
Stimulates milk production (lactation)
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Produced in the anterior pituitary
Classified as a gonadotropin
Female - Stimulates ova development in the
ovaries
Male - Stimulates sperm cells in the testes
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Produced in the anterior pituitary
Female - Causes ovulation and sex hormone
secretion
Male - Hormone is referred to as interstitial
cell stimulating hormone (ICSH) and causes
sex hormone secretion
1. Antidiuretic
Hormone
(ADH)
2. Oxytocin
General Information
Posterior pituitary hormones are produced in the
hypothalamus and stored in the posterior pituitary
 Hormone release is controlled by nerve impulses
that travel through a special pathway (tract)
between the hypothalamus and the posterior
pituitary
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Relationship of
Hypothalamus and
Pituitary Gland
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Posterior pituitary hormone
Promotes reabsorption of water from the
kidneys thereby decreasing the amount of
urine excreted
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Posterior pituitary hormone
Causes uterine contraction and milk let down
(ejection) from the breasts
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Gigantism - Overproduction of GH during
childhood.
Acromegaly - Overproduction of GH during
adulthood.
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Large stature
Usually very weak
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Widening of the
bones of the hands,
feet, and face
Largest endocrine gland
Located in the neck
Two main lobes (right and left lateral)
Connected by a narrow band called the isthmus
 A third lobe, of conical shape, called the pyramidal
lobe, frequently arises from the upper part of the
isthmus, or from the adjacent portion of either lobe
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Thyroxine (T4)
 Principal thyroid hormone
 Increases metabolism; required for normal growth and
mental capacity
 Triiodothyronine (T3)
 Secondary thyroid hormone
 Increases metabolism; required for normal growth and
mental capacity
 Calcitonin
 Decreases calcium level in the blood
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Thyroid produces
T4 and T3 in
response to a
signal (TSH) from
the pituitary gland
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Overgrowth of the thyroid gland
Smooth appearance
May or may not cause overproduction of
hormones
Due to lack of iodine in the diet
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AKA neonatal
hypothyroidism
Failure of fetal thyroid to
form
Results in lack of physical
growth and mental
development
Thyroid test required at
birth to detect
Lifetime treatment with
thyroid supplement
Atrophy of the thyroid in
an adult
 Skin becomes dry and a
peculiar swelling occurs
 Patient becomes
mentally and physically
sluggish
 Easily treated with
hormone replacement
therapy
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Most cases due to
Grave’s disease
Exophthalmos
Thyroid storm
Treat either with
 Chemical suppression
 Destruction of thyroid
tissue (radioactive
iodine)
 Surgical removal
Routine blood test
Specialty blood test
(radioactive iodine
uptake)
 Radionuclide scan
(thyroid scan)
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Four tiny glands
located posterior to
the thyroid gland
 Embedded in the
thyroid capsule
 Responsible for
production of
parathyroid hormone
(PTH)
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One of three substances that regulate calcium metabolism
 PTH
▪ Promotes release of calcium from bone
▪ Causes kidney to retain calcium
 Calcitonin
▪ Lowers amount of calcium in circulation by allowing deposit in bone
 Hydroxycholecalciferol
▪ Active hormonal form of vitamin D
▪ Produced in the liver and kidneys
▪ Increases absorption of calcium from the small intestine to raise blood
calcium levels
 All three substances work together to regulate calcium levels in the blood,
maintain bone, and other functions (e.g., strong teeth)
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Positive Trousseau’s
sign may indicate
hypocalcemia due to
hypoparathyroidism
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Positive Chvostek’s
sign may indicate
hypocalcemia due to
hypoparathyroidism
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Caused by inadequate
PTH production, damage
to, or removal of the
parathyroid glands
Excess PTH causes
removal of calcium from
the bone causing
weakening/kidney stones
Two small glands
Located above each
kidney
 Outer portion - cortex
 Inner portion medulla
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Cortex
Medulla
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Three main groups of
hormones
 Glucocorticoids
 Mineralocorticoids
 Sex hormones
(gonadocorticoids)
Main hormone (95%) - cortisol (aka hydrocortisone)
 Maintains carbohydrate reserve by promoting
conservation of glucose instead of protein
 Glucocorticoid production increases during times of
stress
 Suppress inflammatory response
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Main hormone (95%) - Aldosterone
Regulation of electrolyte balance
Control reabsorption of sodium and secretion
of potassium by the kidneys
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Influences development of secondary sex
characteristics
 Male - hair growth on body, deepening of voice,
maturation of sperm cells
 Female - breast development, changes in shape of
pelvis
(Hypofunction of
Adrenal Cortex)
Muscle atrophy
Weakness
Unusual skin
pigmentation
 Electrolyte imbalance
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(Hypersecretion of
Cortisol)
Obesity with round
face
Bruises easily
Muscle weakness
Bone loss
Elevated blood sugar
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Before and after
treatment
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Released in response to sympathetic stimulation
Fight or flight hormones
 Increase blood pressure
 Convert stored glycogen to glucose
 Increase heart rate
 Increase metabolism
 Dilate bronchioles
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Epinephrine (aka Adrenaline) and
Norepinephrine
 Increase blood pressure and heart rate
 Activate cells influenced by sympathetic nervous
system and others
Both an endocrine
and exocrine gland
 Located within the
abdomen
 Produces two primary
hormones
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 Insulin
 Glucagon
•Alpha cells producing glucagon
(15–20% of total islet cells)
•Beta cells producing insulin and
amylin
(65–80%)
•Delta cells producing somatostatin
(3–10%)
•PP cells producing pancreatic
polypeptide
(3–5%)
•Epsilon cells producing ghrelin
(<1%)
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Produced in the beta cells of the islets of Langerhans
Responsible for transport of glucose across plasma
membranes where it is metabolized for energy
Insulin increases the rate that the liver changes glucose into
fat
Lowers blood sugar level
Increases rate that amino acids are converted into proteins
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Produced in the alpha cells of the islets of Langerhans
Works with insulin to regulate blood sugar levels
Causes the liver to release stored glucose into the
bloodstream
Increases the rate at which glucose is made from proteins in
the liver
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Failure of the islet cells to produce an
adequate supply of insulin
Two types
 Type I
 Type II
May be controlled with diet, exercise, insulin
replacement therapy
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Male
 Testes
▪ Testosterone
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Female
 Ovaries
▪ Estrogens
▪ Progesterone
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Stimulates growth of primary sex organs
(testes, penis)
Supports development of secondary sex
characteristics
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Stimulates growth of primary sex organs
(uterus, tubes)
Supports development of secondary sex
characteristics
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Stimulates development of secretory
portions of mammary glands
Prepares uterine lining for implantation of
fertilized ovum
Aids in maintaining pregnancy
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Mass of lymphoid tissue in the mediastinum
above the heart
Produces Thymosin
 Assists in maturation of T lymphocytes after they
leave the thymus and reside in the lymph nodes
throughout the body
Stomach secretes a hormone that simulates digestive
activity
 Kidneys secret erythropoietin which stimulates red blood cell
production in the bone marrow when a decrease in oxygen is
detected
 Atria of the heart produce a substance called atrial
natriuretic peptide (ANP) in response to increases filling of
the atria. ANP increases loss of sodium by the kidneys and
lowers blood pressure
 Placenta produces several hormones during pregnancy
including HCG (measured during a pregnancy test)
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Produced by most body tissues
Act near site of production
 Blood vessel constriction and dilation
 Bronchial constriction and dilation
 Intestinal constriction and relaxation (increased
and decreased peristalsis)
 Many additional functions that are not fully
understood