mr. franco's website - endocrine system 2009...parathyroid glands secrete parathyroid hormone...
TRANSCRIPT
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The Endocrine System
A. Regulates long term metabolic
processes
B. Releases hormones from
endocrine cells
1. Hormones are chemicals
2. Alter metabolism of cells
3. Release regulated by
negative feedback
4. Act on target cells
I. Overview of the Endocrine System
A. Amino acid derivatives
(epinephrine, thyroid
hormones)
B. Peptides and proteins
1. Chains of amino acids
2. Insulin, ADH
C. Lipid derivatives
1. Steroids (testosterone)
2. Eicosanoids (prostaglandins)
II. Three Families of Hormones
A. Receptors are hormone binding proteins
B. Triggers action on a target cell
III. Hormone Receptors
A. Extracellular Receptors
1. Located in cell membrane
2. Targeted by
a) Amino acid derivatives
b) Peptides
c) Eicosanoids
3. Operates through a
second messenger such
as cyclic-AMP
IV. Classes of Hormone Receptor Membrane receptor
G protein (inactive)
Cytoplasm
Nuclear envelope
Nuclear pore
Nucleus
DNA
Cell membrane
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Membrane receptor
Hormone- receptor complex
First messengers (E, NE, peptide hormones, and eicosanoids)
Cell membrane
G protein (inactive)
Cytoplasm
Nuclear envelope
Nuclear pore
Nucleus
DNA
Membrane receptor
Hormone- receptor complex
First messengers (E, NE, peptide hormones, and eicosanoids)
Cell membrane
G protein (inactive)
G protein (activated)
Activates adenylate cyclase
Cytoplasm
Nuclear envelope
Nuclear pore
Nucleus
DNA
Membrane receptor
Hormone- receptor complex
First messengers (E, NE, peptide hormones, and eicosanoids)
Cell membrane
G protein (inactive)
G protein (activated)
Activates adenylate cyclase
Cytoplasm ATP cAMP
Acts as second
messenger
Activates kinase Nuclear envelope
Nuclear pore
Nucleus
DNA
Membrane receptor
Hormone- receptor complex
First messengers (E, NE, peptide hormones, and eicosanoids)
Cell membrane
G protein (inactive)
G protein (activated)
Activates adenylate cyclase
Cytoplasm ATP cAMP
Acts as second
messenger
Activates kinase
Alterations in enzyme activity;
opens ion channels
Nuclear envelope
Nuclear pore
Nucleus
DNA
Membrane receptor
Hormone- receptor complex
First messengers (E, NE, peptide hormones, and eicosanoids)
Cell membrane
G protein (inactive)
G protein (activated)
Activates adenylate cyclase
Cytoplasm ATP cAMP
Acts as second
messenger
Activates kinase
Alterations in enzyme activity;
opens ion channels
TARGET CELL RESPONSE
Nuclear envelope
Nuclear pore
Nucleus
DNA
B. Intracellular Receptors
1. Located in cytoplasm or
nucleus
2. Targeted by steroid and
thyroid hormones
3. Operates through
changes in gene
expression
4. Thyroid hormones also
act on mitochondria
IV. Classes of Hormone Receptor
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A. Hormones directly enter capillaries
1. Most hormones travel free in
solution
2. Steroid, thyroid hormones bind to
blood proteins for transport
B. Hormones are inactivated by
1. Binding to cell receptors
2. Removal by liver, kidney cells
3. Breakdown by extracellular
enzymes
V. Hormone Secretion and Distribution VI. Control of Endocrine Secretion
A. Humoral Stimuli: Ca2+ controls
parathyroid hormone and calcitonin
release
B. Hormonal Stimuli: thyroid stimulating
hormone triggers thyroid hormone
release
C. Neural Stimuli: epinephrine release from
adrenals
VII. The Hypothalamus and
Endocrine Control
A. Secretes hormones directly
B. Secretes regulatory
hormones to control pituitary
gland
C. Autonomic centers exert
direct control of adrenal
medullae
VIII. The Pituitary Gland A. Also called the hypophysis
B. Releases nine important hormones
C. Two lobes
VIII. The Pituitary Gland 1. Anterior Pituitary
a) Thyroid-Stimulating Hormone (TSH)
• Triggers thyroid hormone release
b) Adrenocorticotropic Hormone (ACTH)
• Stimulates glucocorticoid release from adrenal gland
VIII. The Pituitary Gland c) Follicle-Stimulating Hormone (FSH)
• Stimulates estrogen secretion, egg production (females), sperm production (males)
d) Luteinizing Hormone (LH)
• Triggers ovulation, progestin production (females), androgen production (males)
e) Prolactin (PRL)
• Stimulates mammary gland development and milk secretion
f) Growth hormone (hGH)
• Stimulates cell growth
g) Melanocyte Stimulating Hormone (MSH)
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VIII. The Pituitary Gland 2. Posterior Pituitary Hormones
a) Antidiuretic Hormone (ADH)
1) Reduces water loss in the urine
2) Increases thirst
b) Oxytocin
1) Stimulates uterine contraction, milk delivery
2) Stimulates prostate gland smooth muscle
VIII. The Pituitary Gland • Pituitary Hormones and Their Targets
IX. The Thyroid Gland A. Lies near thyroid cartilage of larynx
B. Has a rich blood supply
C. Consists of two lobes connected by the
isthmus
IX. The Thyroid Gland D. Thyroid Follicles
1. Produce and store colloid (needs iodine)
2. Two forms, thyroxine (T4) and triiodothyronine (T3)
a) Increases metabolism and heat production (calorigenic
effect) in most cells
b) Required for normal development
IX. The Thyroid Gland E. C Cells
1. Scattered outside of
follicle epithelium
2. Also called parafollicular
cells
3. Secrete calcitonin
a) Lowers blood Ca2+
levels
b) Inhibits osteoclasts of
bone
c) Increases urinary
calcium loss
4. Triggered by high blood
Ca2+ level
X. The Parathyroid Glands A. Four glands on thyroid posterior
B. Chief cells produce parathyroid hormone
C. Low blood Ca2+ triggers secretion
D. PTH raises blood Ca2+
1. PTH speeds bone breakdown by osteoclasts
2. Increases dietary absorption
3. Slows loss in kidney
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HOMEOSTASIS DISTURBED
Rising calcium levels in blood HOMEOSTASIS
Normal calcium levels
(8.5-11 mg/dl)
Thyroid gland produces calcitonin
HOMEOSTASIS DISTURBED
Rising calcium levels in blood HOMEOSTASIS
Normal calcium levels
(8.5-11 mg/dl)
Thyroid gland produces calcitonin
Increased excretion of calcium in kidneys
HOMEOSTASIS DISTURBED
Rising calcium levels in blood HOMEOSTASIS
Normal calcium levels
(8.5-11 mg/dl)
Thyroid gland produces calcitonin
Increased excretion of calcium in kidneys
Calcium deposition in bone (inhibition of osteoclasts)
Blood calcium levels decline
HOMEOSTASIS DISTURBED
Rising calcium levels in blood HOMEOSTASIS
Normal calcium levels
(8.5-11 mg/dl)
Thyroid gland produces calcitonin
Increased excretion of calcium in kidneys
Calcium deposition in bone (inhibition of osteoclasts)
Blood calcium levels decline
HOMEOSTASIS DISTURBED
Rising calcium levels in blood
HOMEOSTASIS RESTORED
HOMEOSTASIS
Normal calcium levels
(8.5-11 mg/dl)
HOMEOSTASIS
Normal calcium levels
(8.5-11 mg/dl) HOMEOSTASIS DISTURBED
Falling calcium levels in blood
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HOMEOSTASIS
Normal calcium levels
(8.5-11 mg/dl) HOMEOSTASIS DISTURBED
Falling calcium levels in blood
Parathyroid glands secrete
parathyroid hormone (PTH)
HOMEOSTASIS
Normal calcium levels
(8.5-11 mg/dl) HOMEOSTASIS DISTURBED
Falling calcium levels in blood
Release of stored calcium from bone
(stimulation of osteoclasts, inhibition
of osteoblasts)
Parathyroid glands secrete
parathyroid hormone (PTH)
HOMEOSTASIS
Normal calcium levels
(8.5-11 mg/dl) HOMEOSTASIS DISTURBED
Falling calcium levels in blood
Release of stored calcium from bone
(stimulation of osteoclasts, inhibition
of osteoblasts)
Enhanced reabsorption
of calcium in kidneys
Parathyroid glands secrete
parathyroid hormone (PTH)
HOMEOSTASIS
Normal calcium levels
(8.5-11 mg/dl) HOMEOSTASIS DISTURBED
Falling calcium levels in blood
Release of stored calcium from bone
(stimulation of osteoclasts, inhibition
of osteoblasts)
Enhanced reabsorption
of calcium in kidneys
Stimulation of calcitriol production
at kidneys; enhanced Ca2+, PO4
3-
absorption by digestive tract
Parathyroid glands secrete
parathyroid hormone (PTH)
Blood calcium levels
increase
HOMEOSTASIS
Normal calcium levels
(8.5-11 mg/dl)
HOMEOSTASIS RESTORED
HOMEOSTASIS DISTURBED
Falling calcium levels in blood
Release of stored calcium from bone
(stimulation of osteoclasts, inhibition
of osteoblasts)
Enhanced reabsorption
of calcium in kidneys
Stimulation of calcitriol production
at kidneys; enhanced Ca2+, PO4
3-
absorption by digestive tract
Parathyroid glands secrete
parathyroid hormone (PTH)
Blood calcium levels
increase
XI. The Adrenal Glands A. Lie along superior border of each
kidney
B. Surrounded by fibrous capsule
C. Made of two parts
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XI. The Adrenal Glands 1. Adrenal Cortex
(corticosteroids)
a) Glucocorticoids (cortisol)
1) Stimulated by ACTH
2) Affect glucose
metabolism
b) Mineralocorticoids
(aldosterone)
1) Stimulated by
angiotensin II
2) Restricts loss of water,
Na+ in urine, sweat,
digestive tract, saliva
c) Androgens (male hormone)
XI. The Adrenal Glands 2. Adrenal Medulla
a) Nerves stimulate hormone
secretion
b) Produces two related
hormones
1) Epinephrine (adrenaline)
2) Norepinephrine
(noradrenaline)
c) Increases heart rate and
force, releases glucose, fatty
acids into blood, opens
airways
XII. The Pineal Gland
A. Located deep within the brain
B. Synthesizes melatonin
1. Establishes daily wake-sleep cycle
2. Inhibits reproductive function
3. Protects neural tissue from free radicals
XIII. The Pancreas A. Exocrine and endocrine cells
B. Endocrine cells organized into islets of
Langerhans
C. Islet cells secrete insulin and glucagon
1. Insulin produced by beta cells
2. Glucagon produced by alpha cells
D. Exocrine cells secrete enzyme-rich
digestive fluid
XIII. The Pancreas E. Actions of Insulin and Glucagon
1. Insulin
a) Lowers blood glucose
b) Increases glucose uptake, storage, and use by target cells
c) Targets liver, muscle, fat cells
2. Glucagon
a) Raises blood glucose concentration
b) Increases glycogen breakdown and glucose synthesis
c) Targets liver cells
HOMEOSTASIS DISTURBED
Rising blood glucose levels HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
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Beta cells secrete insulin
HOMEOSTASIS DISTURBED
Rising blood glucose levels HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
Beta cells secrete insulin
Increased rate of glucose transport
into target cell
HOMEOSTASIS DISTURBED
Rising blood glucose levels HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
Beta cells secrete insulin
Increased rate of glucose transport
into target cell
Increased rate of glucose utilization
and ATP generation
HOMEOSTASIS DISTURBED
Rising blood glucose levels HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
Beta cells secrete insulin
Increased rate of glucose transport
into target cell
Increased rate of glucose utilization
and ATP generation
HOMEOSTASIS DISTURBED
Rising blood glucose levels HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
Increased conversion of glucose to glycogen (liver, skeletal muscle)
Beta cells secrete insulin
Increased rate of glucose transport
into target cell
Increased rate of glucose utilization
and ATP generation
HOMEOSTASIS DISTURBED
Rising blood glucose levels HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
Increased conversion of glucose to glycogen (liver, skeletal muscle)
Increased amino acid absorption and
protein synthesis
Beta cells secrete insulin
Increased rate of glucose transport
into target cell
Increased rate of glucose utilization
and ATP generation
Blood glucose concentration
declines
HOMEOSTASIS DISTURBED
Rising blood glucose levels HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
Increased conversion of glucose to glycogen (liver, skeletal muscle)
Increased amino acid absorption and
protein synthesis
Increased fat synthesis
(adipose tissue)
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Beta cells secrete insulin
Increased rate of glucose transport
into target cell
Increased rate of glucose utilization
and ATP generation
Blood glucose concentration
declines
HOMEOSTASIS DISTURBED
Rising blood glucose levels
HOMEOSTASIS RESTORED HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
Increased conversion of glucose to glycogen (liver, skeletal muscle)
Increased amino acid absorption and
protein synthesis
Increased fat synthesis
(adipose tissue)
HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
HOMEOSTASIS DISTURBED
Declining blood glucose levels
HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
HOMEOSTASIS DISTURBED
Declining blood glucose levels
Alpha cells secrete
glucagon
HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
HOMEOSTASIS DISTURBED
Declining blood glucose levels
Increased breakdown of glycogen to glucose (liver, skeletal muscle)
Alpha cells secrete
glucagon
HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
HOMEOSTASIS DISTURBED
Declining blood glucose levels
Increased breakdown of glycogen to glucose (liver, skeletal muscle)
Increased breakdown of fats to fatty acids
(adipose tissue)
Alpha cells secrete
glucagon
HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl)
HOMEOSTASIS DISTURBED
Declining blood glucose levels
Increased breakdown of glycogen to glucose (liver, skeletal muscle)
Increased breakdown of fats to fatty acids
(adipose tissue)
Increased synthesis and release of glucose (liver)
Alpha cells secrete
glucagon
Blood glucose concentration
rises
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HOMEOSTASIS
Normal glucose levels
(70-110 mg/dl) HOMEOSTASIS
RESTORED
HOMEOSTASIS DISTURBED
Declining blood glucose levels
Increased breakdown of glycogen to glucose (liver, skeletal muscle)
Increased breakdown of fats to fatty acids
(adipose tissue)
Increased synthesis and release of glucose (liver)
Alpha cells secrete
glucagon
Blood glucose concentration
rises
XIV. Endocrine Functions of Other
Organs A. Intestines- Secretes hormones to control digestion
B. Kidneys (3 hormones)
1. Calcitriol—Stimulates calcium and phosphate absorption in intestine
2. Erythropoietin (EPO)—Stimulates red blood cell production by bone marrow
3. Renin—Enzyme that leads to angiotensin II that triggers aldosterone from adrenal cortex
XIV. Endocrine Functions of Other
Organs C. Heart- Secretes atrial natriuretic
peptide (ANP) to lower blood
volume or blood pressure
D. Thymus- Secretes thymosins that
control immune system defenses
E. Adipose tissue (fat cells)
1. Secretes leptin to control
appetite
2. Secretes resistin to reduce
insulin response
XIV. Endocrine Functions of Other
Organs F. Testis (male gonad)
1. Interstitial cells secrete androgens (testosterone)
2. Sustentacular cells secrete inhibin (anterior pituitary)
G. Ovary (female gonad)
1. Follicle cells secrete estrogens and inhibin
2. Corpus luteum cells secrete estrogens and progesterone
H. Placenta- Secretes several hormones in pregnancy
XV. Hormones and Behavior A. Sex hormones
1. Testosterone fosters aggressiveness
2. Estrogen fosters sexual receptivity
B. Thyroid hormones
1. Excess leads to nervousness, restlessness
2. Deficiency leads to sluggishness
C. Antidiuretic hormone: Leads to feeling of thirst, water
intake