Human Biology Student Outline – The Endocrine System
Endocrine System
Text: Human Biology, by Mader. pp. 269-286
1.
Introduction
A.
Endocrine Glands
•
2.
Endocrine vs. Exocrine Glands
B.
Hormones
C.
Target Tissues
Basic Functions
A.
Maintains Homeostasis (Negative Feedback)
Set
Point
Time
B.
Regulates
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Human Biology Student Outline – The Endocrine System
3.
i.
Growth
ii.
Development
iii.
Reproductive Matters
Hypothalamus and Pituitary Gland
A.
Posterior Lobe (Neurohypophysis)
i.
Neurosecretory Cells
ii.
Hormones of the Neurohypophysis
a.
Antidiuretic Hormone (ADH)
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Human Biology Student Outline – The Endocrine System
b.
Oxytocin
•
Positive Feedback Mechanism
Threshold
Stasis
Time
B.
Anterior Lobe (adenohypophysis)
i.
Portal System
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Human Biology Student Outline – The Endocrine System
ii.
a.
Inhibiting Hormones
b.
Releasing Hormones
Hormones of the Adenohypophysis
a.
•
Tropic Hormones
•
Non-tropic Hormones
Growth Hormone (GH)
•
Anabolic Effect
•
Amino Acid Uptake Increase
•
Fat Metabolism
•
Epiphyseal Plate
*
Dwarfism
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Human Biology Student Outline – The Endocrine System
*
4.
Acromegaly
•
Growth-Hormone Releasing Hormone (GHRH)
•
Growth-Hormone Inhibiting Hormone (GHIH)
Thyroid Gland
•
A.
Follicular Cells
Thyroxine and Triiodothyronine
Thyroxine (T4)
i.
ii.
iii.
Triiodothyronine (T3)
Synthesis
a.
Tyrosine
b.
Iodine [
Function
a.
Increase Metabolism
b.
Calorigenic Effect
Thyroid Malfunction
a.
Hyperthyroidism (Graves Disease)
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Human Biology Student Outline – The Endocrine System
b.
c.
Hypothyroidism
•
Cretinism
•
Myxedema
Iodine Deficiency Induced Simple Goiter
Metabolic Rate
Slows Down
Thyroid Secretes
Less Thyroxine
Decreases Neg. Feedback
Pituitary Secretes
Less TSH
Hypothalamus Releases
More TRH
Pituitary Secretes
More TSH
Hypothalamus Releases
Less TRH
Increases Neg. Feedback
Thyroid Secretes
More Thyroxin
Metabolic Rate
Speeds Up
c.
B.
Thyroid-stimulating hormone (TSH)
•
Tropic Hormone
•
Thyrotropin-releasing Hormone (TRH)
•
Simple Goiter
Parafollicular Cells
i.
Calcitonin
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Human Biology Student Outline – The Endocrine System
Put Calcium Regulation Diagram Here
5.
Parathyroid Glands
A.
Parathyroid Hormone
i.
Function
ii.
Mechanisms
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Human Biology Student Outline – The Endocrine System
6.
a.
Calcium Reabsorption
b.
Calcium Reabsorption by Kidney
c.
Digestive Absorption of Calcium and Vitamin D
Adrenal Glands
A.
Adrenal Cortex
i.
General Information
ii.
Anatomy
Stress
Pituitary
Gland
ACTH in blood stimulates
the adrenal cortex
Glucocorticoids
Mineralocorticoids
Epinephrine
Norepinephrine
iii.
Hormones of the Adrenal Gland
a.
Glucocorticoids
•
b.
Cortisol
Mineralocorticoid
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Human Biology Student Outline – The Endocrine System
•
ii.
Aldosterone
Stress and the Adrenal Cortex
STRESS
Adrenal medulla
secretes epinephrine
and norepinephrine
Blood Glucose
Rises
Heart Rate
Increases
Blood flow to
skeletal muscles
Sympathetic
nerve
impulses
Hypothalamus
Respiration
Rate increases
Blood Pressure
Rises
Secretes ACTH-releasing
hormone
Bronchioles
dilate
Adenohypophysis
secretes ACTH
increases
Adrenal cortex
secretes cortisol
Protein is used
for energy and
tissue repair
B.
Adrenal Medulla
i.
Hormones
a.
Epinephrine
b.
Norepinephrine
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Gluconeogenesis
for energy
Insulin to brain
to ensure
glucose supply
Human Biology Student Outline – The Endocrine System
c.
C.
7.
Adrenocorticotropic hormone (ACTH)
•
Tropic Hormone
•
Adrenal Cortex
•
Glucocorticoids
•
Corticotropin-releasing Hormone (CRT)
Diseases of the Adrenal Cortex
i.
Addisons Disease
ii.
Cushing Syndrome
Pancreas
A.
Introduction
i.
B.
Mixed Gland
a.
Exocrine Gland
b.
Endocrine Gland
Hormones
i.
ii.
Glucagon
a.
Alpha Cells
b.
Glycogenolysis
Insulin
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Human Biology Student Outline – The Endocrine System
a.
Beta Cells
Blood Glucose Regulation
High Blood Sugar
Level
6. The liv er responds to the glucagon
by break ing down glycogen and
releasing gluc ose into the blood (7).
Hence, blood glucos e
conc entration rises to normal
7. G lucos e
released
Homeos tasis is
into
res tored ! ! !
blood
6. The liver responds
to the insulin by taking the glucos e
out of the blood (7) and manufac turing
glycogen. Henc e, the blood gluc ose
c oncentration drops to normal.
7. G lucos e
remov ed
from
blood
Homeostas is is
restored ! ! !
Low Blood Sugar
Level
5. Glucagon now enters
into blood and c omes
in contact with liver
1.
Injes ted dietary c arbohydrates
enter deuodenum from
stomach (not v isible here)
5. Insulin now enters
into blood and c omes
in contact with liver
1. During times of fasting
(such as when y ou are
sleeping), no dietary
carbohydrates enter
diges tive tract.
4. P anc reas (beta cells)
identify the s tres s and
sec retes insulin
4. Pancreas (alpha c ells )
identify stress
(low blood sugar), and
s ecretes glucagon
3. Monosacharides, s uch as glucos e
enter into c irculation resulting in
elev ated blood glucose conc entration
3. Blood glucose
concentration drops
2. Carbohy drates are
brok en down into
monos acharides and absorbed
C.
2. Carbohydrates are
abs ent, and monosac harides
are not releas ed nor abs orbed.
Diseases
i.
Diabetes Mellitus
a.
Symptoms
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Human Biology Student Outline – The Endocrine System
300 -
Glucose Tolerance Test
250200Blood Glucose
(mg/dl blood) 150100-
renal threshol d
50-
D iabetic
N on-Di abeti c
0-
0
1
2
3
Time after Glucose Administration (hours)
•
c.
8.
Glucose Tolerance Test
Types of Diabetes
•
Type I Diabetes (Insulin-dependent)
•
Type II diabetes (Noninsulin-dependent)
Other Sources of Hormones
A.
Kidneys
i.
b.
Erythropoietin
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Human Biology Student Outline – The Endocrine System
Chemorec eptors
Efferent Pathway
(Erythropoietin)
Control
Center
Stress
(Reduc ed O
2
in blood)
Effec tor
(Red Bone
Marrow Stimulated)
Effec t
(Red Blood
Cell Production)
Homeostasis
Restored
(O2 concentration in blood increas es)
B.
Pineal Gland
i.
9.
Growth Factors vs. Hormones
A.
10.
Melatonin
Example: Epidermal Growth Factor
Mechanisms of Hormone Control
•
Steroid Hormones
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Human Biology Student Outline – The Endocrine System
CH2OH
C
CH3
CH3 CH3
CH
O
OH
CH3
CH2
CH2
Cort isol
CH2
CH CH3
CH3
HO
O CH2OH
CH3
H
HO
Cholesterol
C
C
O
HO
Aldost erone
HO
•
A.
Peptide Hormone
Water Soluble Hormones
ii.
Mechanism
ATP
Inactiv e
Enzy me 1
cAMP
(Secondary
Messenger)
Act iv e
Enzy me 1
Inactiv e
Enzy me 4
Altered
Cell Function
ii.
B.
Examples
Lipid Soluble Hormones
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Act iv e
Enzy me 4
Inactiv e
Enzy me 2
Act iv e
Enzy me 2
Inactiv e
Act iv e Enzy me 3
Enzy me 3
Human Biology Student Outline – The Endocrine System
C
D
F
B
G
A
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E