Transcript Ativity 21 - PCC - Portland Community College

Exercise 18
Endocrine System
Glucometer
Portland Community College
BI 232
The endocrine system
• Diverse collection of organs and tissues that
contain endocrine glands.
• Glands secrete chemicals called hormones
into blood capillaries
• Hormones are transported to target cells at a
distant location
• Hormone binds to a specific receptor and
the cell responds to message.
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Endocrine and Exocrine
• Exocrine glands
secrete substances into
ducts, which transport
the secretions internal
cavities of organs or to
surface of the skin.
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Neuroendocrine effect
• The endocrine system
operates in conjunction
with the nervous system to
maintain homeostasis and
to ensure that bodily
functions are carried out
efficiently.
• Nerve impulses can affect
the release of hormones
and hormones can regulate
nerve impulses
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Endocrine Organs in Head
• Pineal gland Secrets:
• Melatonin
• Involved in circadian
rhythms
• Day  melatonin,
Night  melatonin
• Produces sleepiness
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Endocrine Organs in Head
• Hypothalamus produces a
number of releasing hormones
and inhibiting hormones.
• Stored in posterior pituitary
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•
ADH (antidiuretic hormone)
• Reduces urine output by
increasing water reabsorption
in the kidney
• Plays small role in blood
pressure regulation
Oxytocin
• Causes uterine contractions in
labor
• Causes milk let down in
lactating mothers
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Endocrine Organs in Head
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Hypophysis
ACTH (adrenocorticotropic
hormone)
• Regulates the activity of the
cortex of the adrenal gland
TSH (thyroid stimulating hormone)
• Stimulates production and
release of thyroid hormone
GH (growth hormone)
• Stimulates growth of bones,
cartilage, muscle
• Timing and amount released
determines body size
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Endocrine Organs in Head
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PRL (prolactin)
• Stimulates breast development
• Promotes and maintains
lactation after childbirth
FSH (follicle stimulating hormone)
• Causes formation of ovarian
follicles and stimulates them to
produce estrogen
• Stimulates sperm development
in men
LH (luteinizing hormone)
• Initiates ovulation, maintains
corpus luteum
• Regulates testosterone
production in males
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Pituitary
Histology
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Endocrine Organs in Neck
• Thyroid gland secretes:
• Thyroid Hormone
• Regulates metabolic rate of
the entire body
• Important in development
of the nervous system
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Calcitonin
• Decreases bone reabsorption,
lowering serum calcium levels
PTH (parathyroid hormone)
• Increases serum calcium
• Decreases serum phosphorus
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Thyroid Histology
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Thyroid Histology
• Follicular cells
produce the
colloid (contains
precursors to
thyroid hormone)
• Parafollicular
cells secrete
calcitonin
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Parathyroid
Histology
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Endocrine organs in thoracic
• Heart: If blood volume is
elevated above normal, cardiac
muscle cells in the heart was
secrete natriuretic peptides.
• Act on the kidneys to promote
the loss of sodium ions and
water.
• The thymus gland produces
hormones called thymosins that
promote maturation of Tlymphocytes that coordinate the
body’s immune response.
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Endocrine Organs located in
abdominopelvic cavity
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Pancreas secretes:
Insulin
• Released in response to high
blood sugar
• Increases cellular absorption of
glucose
• Increases rate of lipogenesis
and formation of glycogen in
the liver
Glucagon
• Released in response to low
blood sugar
• Elevates blood glucose levels
by promoting the breakdown
of glycogen.
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Pancreas
•Acinar cells secrete
digestive enzymes
(exocrine)
•Islet cells secrete
insulin (beta cells) and
glucagon (alpha cells)
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Adrenal Glands
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Endocrine Organs located in
abdominopelvic cavity
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Adrenal glands secrete:
Glucocorticoids (Cortisone)
• Released in response to stress
• Increases formation of glucose
from protein and fat
breakdown
• Decreases inflammation
Aldosterone
• Increases blood volume by
causing kidneys to retain
sodium (where sodium goes
water goes too) in exchange
for potassium
• Increased blood volume will
increase blood pressure
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Endocrine Organs located in
abdominopelvic cavity
• Androgens
• Are male sex hormones that
are produced in small
quantities and converted to
estrogens (female sex
hormones) when they enter
the blood
• Epinephrine & Norepinephrine
• Fight or flight response
• Increase heart rate, increase
skeletal muscle blood flow,
decrease skin blood flow
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Hormones from the Kidneys
• Erythropoietin
• Stimulates RBC
production
• Calcitriol
• Stimulates calcium and
phosphate absorption
• Stimulates calcium
release from bone
• Inhibits PTH secretion
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Adrenal
Histology
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Adrenal Cortex
Zona
Reticularis:
Androgens
Zona Fasiculata:
Glucocorticoids
(Cortisone)
Zona
Glomerulosa:
Aldosterone
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Gonads
• Ovaries in females
produce estrogens
• Testes in males
produce testosterone
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Ovary
• Have an outer cortex
that contains ovarian
follicles at various
stages of development.
• Each follicle contains
a developing egg cell
called an oocyte
• Inner medulla is a
region of loose
connective tissue
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Testis
• Tunica albuginea is a
fibrous connective
tissue covering.
• Connective tissue
partitions derived from
the tunica albuginea
divide the testes into
lobules
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Testes
• Each lobule of the
testes are three or four
seminiferous tubules.
• Collectively these
cells are called
spermatogenic cells.
• The interstitial areas
contain the interstitial
(Leydig) cells.
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Diabetes
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Type 1: Insulin Dependent Diabetes
AKA: juvenile diabetes
Caused by a lack of insulin
Autoimmune disorder
• Immune system destroys beta cells in the pancreas
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Diabetes
• Type 2: Non-Insulin Dependent
• Caused by an insensitivity of cells to
insulin.
• Diabetes mellitus marked by hyperglycemia
•  urine production (polyuria)
•  thirst (polydipsia)
•  eating (polyphagia)
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Diagnosing Diabetes Mellitus
• Normal blood glucose levels: 70-100 mg/dl
• Diabetes mellitus:
• A fasting glucose level above 140 mg/dl on two
separate occasions, or
• A blood sugar over 200 mg/dl 2 hours after oral
glucose tolerance test with 75gm of glucose
• Impaired Glucose Tolerance (Pre-Diabetes)
• A fasting glucose level between 100-126 mg/dl on two
separate occasions, or
• A blood sugar between 140-200 mg/dl 2 hours after
oral glucose tolerance test with 75gm of glucose
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The End
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