Download Endocrine Ch 16-Fall 2016-StudentRevised

1. Endocrine Gland Stimuli …
d. *Hypothalamic-Pituitary-Target
Feedback Loop
 When a hormone is the stimulus for
the release of another hormone, the
Hypothalamus and/or the Pituitary
Gland hormones are involved
 Hypothalamus: has Releasing &
Inhibiting Hormones which travel
directly to the Anterior Pituitary via
special blood vessels
 affect the release of 4 Anterior
Pituitary Hormones
 Anterior Pituitary: Some of its
hormones are Stimulating Hormones
which Regulates the secretion of the
hormones of many other endocrine
glands
1. Endocrine Gland Stimuli …
d. *Hypothalamic-Pituitary-Target Feedback
 Example: Thyroid Releasing
hormone of the hypothalamus
travels to Anterior Pit. Causing it to
release Thyroid Stimulating
Hormone. Then TSH travels to
Thyroid Gland causing it to release
the Thyroid Hormone. Finally the
Thyroid Hormone travels to its
target organs.
 Final Hormone of Feedback
Loop: As it’s levels Increase it will
feeds back to Hypothalamus and
Ant. Pituitary causing them to
decreases hormone secretion
  Rhythmic hormone release:
levels rise and fall in a pattern
SEE OPENSTAX
TEXT PP. 696 &
704 Tables
MAJOR ENDOCRINE GLANDS
III. Pituitary Gland and Hypothalamus
A. HYPOTHALAMUS
- Nervous Sys Control
1. *Hormones that go
to the Anterior Pituitary
- Releasing & Inhibiting
Hormones
- Produced and Released
in Hypothalamus
- Hormones carried by
blood in the
Hypophyseal Portal
System directly to
Anterior Pituitary
1st Capillary Plexus
Hypophseal
Portal Veins
2nd Capillary
Plexus
A. HYPOTHALAMUS …
2. Hypo. Hormones that go
to the Posterior Pituitary
- Posterior Pituitary is made
of nervous tissue and is
really an extension of the
hypothalamus
- The hormones are made
in the hypothalamus and
then move down the
axons into the axon
terminals.
- There they are stored and
released into the
capillaries of the posterior
pituitary whenever an
action potential travels
down the neurons
1
Relationships of Posterior Pituitary & HYPO.
1 Hypothalamas
synthesizes oxytocin
and ADH.
Paraventricular
nucleus
Supraoptic
nucleus
Optic chiasma
Infundibulum
(connecting stalk)
Hypothalamichypophyseal
tract
Axon
terminals
Posterior
lobe of
pituitary
Hypothalamus
2 Oxytocin and ADH
transported along
hypothalamic-hypophyseal
tract to pituitary.
Inferior
hypophyseal artery
3 Oxytocin and ADH
stored in axon terminals
in posterior pituitary.
4 Oxytocin and ADH
Oxytocin
ADH
released into blood
when neurons fire.
(a) Relationship between the posterior pituitary and the hypothalamus
III. Pituitary Gland and Hypothalamus…
B. Pituitary Gland
 Location
 Hormones: 8
 Lobes
 Anterior Lobe:
(adenohypophysis)
Hypophseal
Portal Veins
Infundibulum
 Posterior Lobe:
 Infundibulum
 Hypophyseal Tract:
Figure 9.3
1. Posterior Pituitary
 Hormones made by:
 Hormones released into
capillary bed of Post. Pit.
Hormones: (Direct Affect)
a. ADH:
 Target:
 Stimulus
 Receptors:
 sense osmolarity 
nerve impulse to
neurons with ADH
1. Posterior Pituitary …
a. ADH …
 Problem: as H2O decreases, Blood Pressure _________
 Osmoreceptors send nerve impulse to neurons storing
ADH to cause its release
 Affect of ADH:
 Inhibition via Neg. Feedback: normal H2O & solute levels

b. Oxytocin
 Target:
 Stimulus:
 Occurs during Child Birth. Occurs during child birth.
1. Posterior Pituitary…
Hormones …
 b. Oxytocin …
 Information is sent to
hypothalamus via nervous
system and Oxytocin is
released.
 Regulation:
 Regulation:
 Inhibition: Birth ends
the stretching and stops
+ cycle
2. Anterior Pituitary
a. Overview:
i) Biochemical: All 6 are proteins (or peptides)
ii) Hormone Mechanism: second-messenger systems
iii) Stimulus:
iv) 2 of the Ant. Pit Hormones go directly to target organs =
Non-stimulating Hormones
• Hypothalamus Hormone  Ant. Pit. Hormones (2 hormones)
 Target Organ
v) 4 of the Anterior Pituitary Hormones: act as the hormonal
stimulus for other Endocrine Glands = Stimulating
hormones
• Hypothalamus Hormone Ant. Pit. Stimulating Hormones
 Endocrine Gland  Target Organ & Cells
• Regulation: Via Neg. Feedback– usually the last hormone
in the chain inhibits production of the other hormones
Anterior Pituitary Hormones
Non-stimulating
Hormones
Stimulating Hormones
b. Non-stimulating Hormones
i) Growth Hormone
Hypothalmic hormone 
non-stimulating hormone 
target
 Target:
 Action:
 Protein synthesis & tissue building: growth of
 Metabolic Effects:
 Regulation:
 Stimulation:
 Inhibition
 GH feeds back to Hypothalamus
 Synergism: Thyroid Hormone
• Growth hormone disorders
** Students Do ** p. 708
 Pituitary dwarfism  Gigantism
 Acromegaly
age 9
age 16
age 33
age 52
2. Anterior Pituitary …
e. Non-stimulating Hormone …
ii) Prolactin (PRL)
 Target:
 Action:
 Stimulus:
 Regulation: Hormonal
 Inhibition:
 PIH = Dopamine
2. Anterior Pituitary …
c. Stimulating Hormones
= Tropic Hormones
 Function:
i) Thyroid-Stimulating Hormone = Thyrotropin
 Target:
 Stimulus:
 Action:
 Regulation: Hormonal
 Stimulation:
 Inhibition: increasing Thyroid Hormone feed
back to Hyp. & Pituitary
ii) Adrenocorticotropic Hormone (corticotrophin)=
ACTH
 Target:
 Action:
 Regulationn:
 Stimulation:
 CRH =
 Stress:
 Inhibition: increasing Cortisol
iii) Gonadotropins: FSH and LH
 FSH = Follicle-Stimulating Hormone
 Target:
 Action:

 Synergism w/ LH: Ovarian Follicle maturation
f. Stimulating Hormones
iii) Gonadotropins: FSH …
 Regulation:
 Stimulation:H
 Inhibition: Gonadal Hormones
 LH = Lutenizing Hormone
 Target:
 Stimulus:
 Action:
 Synergism w/ FSH:
 Hormone secretion and Ovulation
 Regulation:
 Stimulation:
 Inhibition: Gonadal Hormones
IV. Thyroid Gland
A. Overview
1. Location & Structure:
2. Microscopic:
a) Follicles
b)Parafollicular cells:
B. Thyroxine
1. Active forms: T4 & T3
2. Production
 Important: Iodine deficiencey
IV. Thyroid Gland …
B. Thyroxine …
3. Actions: ↑
 ↑
 Growth
4. Regulation:
 Release:
 Inhibition: increasing Thyroid H. on
Pit & Hy
Histology of the Thyroid Gland
Follicle
Colloid
C. Thyroxine …
D. Thyroid Hormone Disorders
Students Do
1. Goiters:
2. Hypothyroidism
3. Hyperthyroidism
 Grave”s Disease:
IV. Thyroid Gland …
E. Calcitonin (insignificant)
1. Production at:
2. Target:
3. Actions:
a. Inhibits:
b. ↑
c. Antagonistic to
3. Regulation:
a. Stimulation:
b. Inhibition: decreasing
blood levels of Ca+2
V. Parathyroid Glands & Parathyroid hormone
A. Location:
B. Antagonistic to
C. Histology & Production Site:
Parathyroid
Gland
Thyroid Gland
D. Target:
Thyroid and Parathyroid
V. Parathyroid Gland & Hormone …
E. Actions
1. Activates
2. Stimulate
3. Vitamin D:
F. Regulation: Humoral
 Release:
 Inhibition: increasing Ca+2 blood levels
G. Importance:
VI. Adrenal Glands
A. Overview
1. Location:
2. Parts
a. Adrenal Cortex
 Tissue:
 Hormones: Aldosterone
(Mineralocorticoids), Cortisol
(Glucocorticoids), Sex
hormones
 Layers: 3 (next slide)
b. Adrenal Medulla
 Tissue:
 Hormones:
Epinephrine &
Norepinephrine
Parts & Layers of Adrenal Gland
Hormones
Layers
= Capsule
= Zona
Glomerulosa
= Zona
Fasiculata
Adrenal
Cortex
= Zona
Reticularis
Round clusters
Columns
Irregular
Columns
with white
spaces
Round
clusters,
blood
vessels
Lab Tips: Appearance of cells
Adrenal Cortex (Glomerulosa and fasciculata)
B. ADRENAL CORTEX
1. Mineralocorticoids
a. Target:
b. Aldosterone
i) Layer:
iii) Target:
 Juxtaglomerular
Complex
iv) Stimulus:
1) increasing
2) low blood
b. Aldosterone …
v) Actions: Direct
Indirectly:
vi) Regulation: Multiple Factors
 Release:
 Humoral: decreased Na+ and increased K+
 Stress  Hormonal: CRH  ATCH 
Aldosterone
b. Aldosterone …
iv) Regulation …
 Release …
 Kidney: Renin-AngiotensinAldosterone Mechanism
 Juxtaglomerular
Complex:
 angiotensin II formed 
Stimulates:
 Inhibition: when decreasing K+
and increasing blood volume
and BP
Most common stimuli
2. Glucocorticoids
a. Layer:
b. Cortisol (significant amounts)
i) Target:
II) Stimulus: Hormonal
Long-term Stress  CRH 
ACTH
iii) Actions:
 Break-down of:
 Decrease Immune System
Activity
Adrenal Cortex – zona fasciculata
2. Glucocorticoids …
iv) Regulation: CRH (hypo)  ACTH (ant. pit.)
Cortisol
 Inhibition: Hormonal via rising Cortisol levels
-
3. Gonadocorticoids
 Layer:
 Hormone: Androgens–levels
normally low
 Females: sex drive maybe
4. Adrenal cortex disorders
 Masculinization–
hypersecretion of sex hormones
 Beard and male distribution
of hair growth
Students Do
 Cushing’s syndrome–
C. Adrenal Medulla
1. Cells of: Chromaffin Cells = Modified Sympathetic
Ganglionic neurons
2. Hormones: Catecholamines
epinephrine & norepinephrine
3. Target:
4. Actions:
- “Fight or Flight”
- brief response
Adrenal Medulla …
‘fight or flight’ …
Short term
Stress
Hypothalamus
Nerve impulses
Spinal cord
Preganglionic
sympathetic
fibers
Adrenal
medulla
Catecholamines
(epinephrine and
norepinephrine)
Short-term
stress response
1. Increased heart rate
2. Increased blood pressure
3. Liver converts glycogen to
glucose and releases glucose
to blood
4. Dilation of bronchioles
5. Changes in blood flow
patterns, leading to increased
alertness and decreased
digestive and kidney activity
6. Increased metabolic rate
Figure 9.13, step 5
Zona reticularis and medulla
VII. Pancreas
A. Location:
B. Hormones/Cells: β and α cells 
Insulin producers
Glucagon producers
VII. Pancreas …
C. Regulation:
D. Target:
E. Insulin
1. Regulation: Humoral
 Stimulation:
 Inhibition: Low blood glucose
2. Actions:
 Enhances membrane transport
 Inhibits glycogen breakdown
 Once glucose is in cells
 Energy needs met:
 Excess  Glycogen and then fat
2. Actions …
 Other Actions: Fat storage & Protein synthesis
Insulin Action
Insulin-secreting
cells of the pancreas
activated; release
insulin into the
blood
Elevated
blood sugar
levels
Stimulus:
rising blood
glucose levels
(e.g., after
eating four
jelly doughnuts)
Uptake of glucose
from blood is enhanced in most
body cells
Liver takes up
glucose and stores
it as glycogen
Homeostasis: Normal blood glucose
levels (90 mg/100ml)
Blood glucose
levels decline
to set point;
stimulus for
insulin release
diminishes
Figure 9.15, step 7
F. Glucagon
- Actions
Homeostasis: Normal blood glucose
levels (90 mg/100ml)
Stimulus:
declining blood
glucose levels
(e.g., after
skipping a meal)
Low blood
sugar levels
Rising blood
glucose levels
return blood sugar
to homeostatic set
point; stimulus for
glucagon release
diminishes
Liver breaks down
glycogen stores and
releases glucose to
the blood
Glucagon-releasing
cells of pancreas
activated;
release glucagon
into blood; target
is the liver
Figure 9.15, step 12
G. Disorders of the Pancreas STUDENTS DO
1. Diabetes mellitus (Hyperglycemia)
 Type 1–
 Type 2 –
 Effects:
VIII. Pineal Gland
 Location:
 Secretes:
 Stimulus:
 Actions:

Depression in the
dark
IX. Gonads & Placenta
A. Ovaries – produce:
 steroid hormone
 Estrogens
 Progesterone
B. Testes – produce:
 Produce androgens
(testosterone)
C. Placenta – hormones
produced (like hCG) to
maintain pregnancy and
manage delivery
X. Hormone Secretion By Other Organs


Parts of small intestine, stomach, kidneys, heart
Nearly all cells release hormones if damaged
A. Kidneys
1. Erythropoietin
2. Renin  Angiotensin II
Normal blood oxygen levels
Reduced O2
levels in blood
More
RBCs
Kidney releases
erythropoietin
Enhanced
erythropoiesis
Erythropoietin
stimulates
Red bone
marrow
X. Hormone Secretion By Other Organs …
B. HEART
1. Atrial Natriuretic Peptide (ANP)
C. Gastrointestinal Tract 3
D. Thymus Gland
 Produces thymosin
 Helps develop immune system
E. Liver
1. Thriombopoetin
 END of PPT
 Extra Slides
 Review Questions