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A control system of the body By way of hormones (chemical messengers)
that are released directly into the blood Hormones control and/or assist processes
like: Reproduction Growth and development Mobilization of body defenses Homeostasis Metabolism
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Pituitary gland Hypothalamus Thyroid gland Parathyroid glands Adrenal glands Pancreas Pineal gland Thymus gland Gonads (ovaries and testes)
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Pineal glandHypothalamusPituitary gland
Thyroid gland
Parathyroid glands
Thymus
Adrenal glands
Pancreas
Ovary (female)
Testis (male)
Some are purely endocrine glands (ductless) Hormones are secreted directly into the blood
Anterior pituitary, thyroid, adrenals, parathyroids
Other glands are mixed glands, with both endocrine and exocrine functions Exocrine glands dump into ducts
pancreas, gonads
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Referred to as the “master endocrine gland” About the size of a pea
Hangs from the hypothalamus in the brain Has two functional lobes
Anterior pituitary—glandular tissue Produces hormones
Posterior pituitary—nervous tissue releases hormones after neural stimulation
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produces releasing and inhibiting hormones These influence pituitary action Such hormones are released into
circulation that connects the hypothalamus to the anterior pituitary
Synthesizes two hormones: oxytocin and antidiuretic hormone Stored in posterior pituitary
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Opticchiasma
Axonterminals
Anterior lobeof the pituitary
Venous drainage
Capillary bed
Posterior lobe of pituitary
Arterial blood supply
Hypothalamus
Hypothalamicneurosecretorycells
ADH Oxytocin
Kidney tubules Mammary glandsUterine muscles
Hormones produced by the hypothalamus are released into blood by nerve impulses
The posterior pituitary stores hormones synthesized by the hypothalamus
Oxytocin Stimulates uterine contractions Causes milk ejection in a breastfeeding
woman
Antidiuretic hormone (ADH) Inhibits urine production (diuresis)
promotes water reabsorption by the kidneys
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Six anterior pituitary hormones endocrine targets (tropic hormones):
1. Thyroid-stimulating hormone (thyrotropic hormone)
2. Adrenocorticotropic hormone3. Follicle-stimulating hormone4. Luteinizing hormone
nonendocrine targets:1. Growth hormone2. Prolactin
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Characteristics of all anterior pituitary hormones They are proteins Use a second-messenger systems Regulated by hormonal stimuli Regulated by feedback inhibition (most
often negative)
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Posterior pituitary
Adrenocorticotropichormone (ACTH)
Adrenal cortexThyrotropichormone (TH)
Thyroid
Follicle-stimulatinghormone (FSH)and luteinizinghormone (LH)
Testes or ovaries
Mammaryglands
Prolactin (PRL)Bones and muscles
Growth hormone (GH)
Anterior pituitary
Releasing hormonessecreted into portalcirculation
Hypothalamus
Growth hormone (GH) growth of skeletal muscles and long bones
Prolactin (PRL) Stimulates/maintains breast milk production
Adrenocorticotropic hormone (ACTH) Regulates endocrine activity of the adrenal cortex
Thyrotropic hormone (TH), A.K.A. thyroid-stimulating hormone (TSH) Influences growth and activity of the thyroid
gland
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Gonadotropic hormones Regulate hormonal activity of the gonads
Follicle-stimulating hormone (FSH) Stimulates follicle development in ovaries Stimulates sperm development in testes
Luteinizing hormone (LH) Triggers ovulation of an egg in females Stimulates testosterone production in males
© 2015 Pearson Education, Inc.
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