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ENDOCRINE SYSTEM - Coggle Diagram
ENDOCRINE SYSTEM
GLANDS AND HORMONES
HYPOTHALAMUS
responsible for ANS functions
- temp, hunger, thirst, fatigue
not considered an edocrine gland
- but has some endocrine functions
releases hypothalmic hormones
- via hypophyseal-portal system
- these stimulate/inhibit pituitary hormone secretion
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PITUITARY GALND
Posterior Lobe (back)
- doesn't produce hormones
- stores & releases hypothalamic neurons
Anterior Lobe (front)
- produces its own hormones
- releases its own via hypothalamic signals
- communication via hypophyseal capillaries
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PINEAL GLAND
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Produces:
Melatonin
- part of diurnal cycle
- high melatonin = drowsiness
- low melatonin = alertness
THYROID GLAND
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Produces:-Calcitonin - calcium metabolism
- Thyroid Hormone (TH) - glucose oxidation
- Triiodothryonine (T3) - temp, growth, HR
- Thyroxine (T4) - metablolic processes
PARATHYROID GLANDS
located behind the thyroid gland
- number in adults varies from 4 to 8
found in the neck but also throughout thorax
- posterior surface of the thyroid gland
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Produces:Parathyroid Hormone (PTH)
- releases calcium in the blood when levels fall
- affects bones, kidney, intestines in the process
THYMUS GLAND
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diminishes in size with age
- becomes fatty and fibrous
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Produces:
- Thymopoietin - T-cell marker in immune system
- Thymosin - Stimulates production of T-cells
ADRENAL GLANDS
composed of cortex & medulla tissue
- each produces different hormones
Produces:Corticosteriods (cortex - steriod-based)
- Aldosterone - Na+ control via kidneys
- Cortisol - immune response
- Androgens - gonad development
Catecholamines (medulla - AA-based)
- Adrenaline - 'Fight or Flight' response
PANCREAS
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Produces:
Insulin
- lowers blood sugar levels
- converts glucose to fat
Glucagon
- converts glycogen to glucose
- when blood levels lower
GONADS
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Produce:Oestrogen
- secondary female sex characteristics
Proestrone
Testostrone
- secondary male sex characteristics
- sperm production
MECHANISMS OF ACTION
ENDOCRINE SYSTEM
glands that produce chemical messengers
- hormones are secreted into the bloodstream
Control:
- reproduction, growth, development
- homeostasis, metabolism
hormonal stimuli produce the following events:
- alters plasma membrane permeability
- stimulates protein synthesis
- activates or deactivates enzymes
induces secretory activity
- stimulates mitosis
HORMONES
hormones are liquids
- crystalline structure
- chemical messengers for communication
elicit specific responses from target organs
- effect rate is specific - quick or slow acting
Hormones are:
- Steriods (cholesterol)
- Proteins (amino acids)
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CONTROL OF RELEASE
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release is controlled by stimuli that are:
- Humoral - osmotic & solute concentrations
- Neural - hypothalamus & pituitary
- Hormonal - stimulating & inhibiting hormones
release occurs in 3 ways:
- Direct - immediate release
- Delayed - stored hormone release
- Indirect - messengers trigger hormone release
HORMONE ACTION
MECHANISMS OF ACTION
steriod & protein hormones function differently
- based on polarity of hormone
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effects vary as hormones bind to receptors:
- membrane permeability can be altered
- cyclic AMP can be activated
- genes in the nucleus can be activated
receptors can be found:
- plasma membrane (on) - proteins
- sub-membrane (in) - steroids & proteins
HORMONE ACTION
Steriod Hormones (non-polar)
- diffuse directly through plasma membrane
- bind to recpetors in the cytoplasm
- receptor-chaperonin complex binds to DNA
- induces transcriptioin of target genes
Amino Acid Hormones (polar)
- membrane receptors relay messages (ATP required)
- message relayed to sub-membrane receptors
- activates cAMP in the cytoplasm (2nd messenger)
- cAMP triggers response in target cell
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