Transcript Endocrine System - McCulloch Intermediate School

Endocrine System
Structure of the
Endocrine System
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A network of Endocrine glands
– Ductless (tubeless) organs or groups of cells that
secrete hormones directly into the blood stream
– Hormones – chemical substances that are
produced in glands and help regulate many of
your body’s functions
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Hormones are secreted by the endocrine
glands and carried by the blood to their
destinations
Glands of the Endocrine
System
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Thyroid – produces hormones
that regulate metabolism, body
heat, and bone growth
Parathyroid glands – produce a
hormone that regulates the
body’s calcium and phosphorus
balance
Testes – male reproductive
glands produce testosterone
Ovaries – female reproductive
glands estrogen & progesteron
Glands of the
Endocrine System
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Hypothalamus
– Links the endocrine system with
the nervous system
– Stimulates the pituitary gland
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Pineal gland – regulates sleep
cycles
Thymus gland – regulates the
development of the immune
system
Pancreas – a gland that serves
both the digestive and the
endocrine systems
– Regulates the level of glucose in
the blood (glucagon and insulin)
Pituitary Gland
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Regulates and controls the activities of
all other endocrine glands
“master gland”
Has 3 lobes (sections)
– Anterior lobe
– Intermediate lobe
– Posterior lobe
Anterior Lobe
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Produces 6 hormones
– Somatotropic – stimulates normal body growth
– Thyroid-stimulating hormone (TSH) – stimulates thyroid
– Adrenocorticotropic hormone (ACTH) – stimulates
production of hormones in the adrenal glands
– 2 hormones stimulate all other sex hormones
– Follicle-stimulating hormone (FSH) and Lutenizing
hormone (LH) control the growth, development and
functions of the gonads
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Gonads – ovaries and testes
In females
– FSH – stimulates cells in ovaries to produce estrogen
– LH – responsible for ovulation and stimulates ovaries to produce
progesterone
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In males
– LH – stimulates cells in testes to produce testosterone
– FSH – controls the production of sperm
Intermediate lobe
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Secretes melanocyte-stimulating
hormone (MSH)
– Controls darkening of the skin –
stimulates skin pigments
Posterior lobe
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Secretes antidiuretic homone (ADH)
– Regulates the balance of water in the
body
– Produces Oxytocin
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Stimulates uterine contractions during the
birthing process
Adrenal Glands
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Glands that help the body recover from stress
and respond to emergencies
Each gland has 2 parts
– Adrenal cortex
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Secretes a hormone that inhibits the amount of sodium
excreted in urine and maintains blood volume and
pressure
Secretes a hormone that aids in the metabolism
– Adrenal medulla
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Controlled by the hypothalamus and the autonomic
nervous system
– Secretes epinephrine and nor-epinephrine
Problems of the Endocrine
System
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Diabetes – the pancreas secretes little or no insulin
Graves disease – hyperthyroidism – overactive or
enlarged thyroid
– Symptoms – nervousness, weight loss, increases thirst, rapid
heartbeat, and intolerance for heat
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Cushing’s disease – overproduction of adrenal hormones
– Symptoms – round face, humped upper back, thin and easily
bruised skin, and fragile bones
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Goiter – enlarged thyroid – caused by a lack of iodine in
the diet
Growth disorders – abnormal amounts of growth
hormone
Care of the Endocrine
System
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Eat nutritious meals
Get enough sleep
Avoid stress