Post on 07-May-2015
The Endocrine System | Bachelor in Political Science II-1
ENDOCRINE GLANDS
The Endocrine System | Bachelor in Political Science II-1
• Glands - an organ in the human or animal body that secretes particular chemical substances for use in the body or for discharge into the surroundings.
• Target cells - a cell that bears receptors for a hormone, drug, or other signaling molecule, or is the focus of contact by a virus,
phagocyte, nerve fiber, etc.• Receptor - an organ or cell able to respond to light, heat, or other
external stimulus and transmit a signal to a sensory nerve.
• Corpus luteum - a hormone-secreting structure that develops in an ovary after an ovum has been discharged but
degenerates after a few days unless pregnancy has begun.
Definition of Terms
The Endocrine System | Bachelor in Political Science II-1
• Spermatogenesis - the production or development of mature spermatozoa.
• Ovarian follicles - a fluid-filled structure in the mammalian ovary within which an ovum develops before
ovulation.• Biorhythms - a recurring cycle in the physiology or functioning of an
organism, such as the daily cycle of sleeping and waking.
Definition of Terms
The Endocrine System | Bachelor in Political Science II-1
Posterior pituitary gland
• (or neurohypophysis) Comprises the posterior lobe of the pituitary gland which is part of the endocrine system.
The Endocrine System | Bachelor in Political Science II-1
Oxytocin
Secreted Hormones
Location:• Uterus• Mammary glandsFunction: • Stimulates contraction• Stimulates milk ejection
The Endocrine System | Bachelor in Political Science II-1
Antidiuretic hormone (ADH)
Secreted Hormones
Location: KidneysFunction: Stimulates re-
absorption of water; conserves water
The Endocrine System | Bachelor in Political Science II-1
Anterior Pituitary Gland
• Also called the adenohypophysis or pars anterior
• The glandular, anterior lobe that together with the posterior lobe, that makes up the pituitary gland .
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
Growth hormone (GH) Function:• Stimulates growth
by promoting protein synthesis and fat breakdown
The Endocrine System | Bachelor in Political Science II-1
Secreted HormonesAdrenocorticotropic
hormone (ACTH) Location: Adrenal cortex
Function:• Stimulates secretion
of adrenal cortical hormones such as cortisol
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
Thyroid-stimulating hormone (TSH) Location: Thyroid gland
Function:• Stimulates thyroxine
secretion
The Endocrine System | Bachelor in Political Science II-1
Secreted HormonesLuteinizing hormone
(LH)Location: GonadsFunction:• Stimulates ovulation
and corpus luteum formation in females; stimulates secretion of testosterone in males
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
Prolactin (PRL) Location: Mammary glands
Function:• Stimulates milk
production
The Endocrine System | Bachelor in Political Science II-1
Secreted HormonesFollicle-stimulating
hormone (FSH)Location: GonadsFunction:• Stimulates
spermatogenesis in males; stimulates development of ovarian follicles in females
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
Melanocyte-stimulating hormone (MSH)Location: SkinFunction:• Stimulates color
change in reptiles and amphibians; unknown function in mammals
Thyroid Gland
• The thyroid gland is found in the neck, below the thyroid cartilage (which forms the laryngeal prominence, or "Adam's apple")
The Endocrine System | Bachelor in Political Science II-1
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
Thyroxine (thyroid hormone) Location: Most cells
Function:• Stimulates metabolic
rate; essential to normal growth and development
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
CalcitoninLocation: BoneFunction:• Lowers blood calcium
level by inhibiting loss of calcium from bone
Parathyroid Glands
• Small endocrine glands in the neck that produce parathyroid hormone
The Endocrine System | Bachelor in Political Science II-1
The Endocrine System | Bachelor in Political Science II-1
Secreted HormonesParathyroid hormoneLocation:• Bone• Kidneys• Digestive tractFunction:• Raises blood calcium level by stimulating bone
breakdown; stimulates calcium reabsorption in kidneys; activates vitamin D
Adrenal Medulla
• Part of the adrenal gland. It is located at the center of the gland, being surrounded by the adrenal cortex.
The Endocrine System | Bachelor in Political Science II-1
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
Epinephrine (adrenaline) and norepinephrine (noradrenaline)Location: Smooth muscle,cardiac muscle,blood vesselsFunction:• Initiate stress responses; raise heart rate, blood
pressure, metabolic rate; dilate blood vessels; mobilize fat; raise blood glucose level
Adrenal Cortex
• Mediates the stress response through the production of mineral ocorticoids and glucocorticoids, including aldosterone and cortisol respectively
The Endocrine System | Bachelor in Political Science II-1
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
Aldosterone Location: Kidney tubulesFunction:• Maintains proper
balance of Na+ and K+ ions
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
CortisolLocation: Many organsFunction:• Adaptation to long-term
stress; raises blood glucose level; mobilizes fat
Pancreas
• A glandular organ in the digestive system and endocrine system of vertebrates
The Endocrine System | Bachelor in Political Science II-1
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
Insulin Location: Kidney tubules Function:• Lowers blood glucose level; stimulates storage of glycogen in liver
The Endocrine System | Bachelor in Political Science II-1
Secreted HormonesGlucagon Location: Liver, adipose
tissueFunction:• Raises blood glucose level; stimulates breakdown of glycogen in liver
Ovary
• An ovum-producing reproductive organ, often found in pairs as part of the vertebrate female reproductive system
The Endocrine System | Bachelor in Political Science II-1
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
Estradiol Location: GeneralFunctions:• Stimulates development of secondary sexcharacteristics in femalesLocation: Female reproductive structuresFunctions: • Stimulates growth of sex organs at puberty and monthly preparation of uterus for pregnancy
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
Location: UterusFunction:• Completes preparation
for pregnancyLocation: Mammary
glandsFunction:• Stimulates
development
Progesterone
Testis
• The primary functions of the testes are to produce sperm(spermatogenesis) and to produce androgens, primarily testosterone.
The Endocrine System | Bachelor in Political Science II-1
The Endocrine System | Bachelor in Political Science II-1
Secreted Hormones
TestosteroneLocation: Many organsFunctions:• Stimulates development of secondary sexcharacteristics in males and growth spurt at pubertyLocation: Male reproductive structuresFunctions:• Stimulates development of sex organs; stimulatesspermatogenesis
Pineal Gland
• Also known as the pineal body, conarium or epiphysis cerebri
• A small endocrine gland in the vertebrate brain.
The Endocrine System | Bachelor in Political Science II-1
The Endocrine System | Bachelor in Political Science II-1
Secreted HormonesMelatoninLocation: Gonads, pigment cellsFunctions:• Function not well understood; influencespigmentation in some vertebrates; may controlbiorhythms in some animals; may influenceonset of puberty in humans
Target Cells
The Endocrine System | Bachelor in Political Science II-1
What is target cells?
The Endocrine System | Bachelor in Political Science II-1
Three actions are defined to be able to describe how the signal is distributed for a particular hormonal pathway:
• Endocrine action• Paracrine action• Autocrine action
The Endocrine System | Bachelor in Political Science II-1
Two important terms are used to refer to molecules that bind to the hormone-binding sites of receptors:
• Agonists• Antagonists
The Endocrine System | Bachelor in Political Science II-1