1. Glands 1. What kind of epithelial tissue is associated with glands. 2
Glands 1. What kind of epithelial tissue is associated with glands? 2. What kind of connective tissue is associated with glands? 3. Are glands controlled by the somatic or autonomic nervous system? 4. What are the 2 categories of glands?

2. Ductless Glands
Diffuse tissue
Pineal gland
Hypothalamus
Pituitary gland
Thyroid gland
Parathyroid glands
(on dorsal aspect
of thyroid gland)
Thymus
Adrenal glands
Pancreas
Ovary (female)
Testis (male)
592

3. Signaling Molecules (Ligands) Chemicals produced by the body that target cells, causing them to change their behavior. Ex. Parathyroid hormone targeting osteoclasts Include: Hormones and Neurotransmitters

4. -Hormones have specific functions.
-Which is target cell?
-Amino acid or steroid based
Matching receptor

5. Functions Internal Control -Coordinate body activities (gametes) -Maintain homeostasis (calcium) -Growth and development -Regulate metabolism -Helps body respond to stress (adrenaline) Works with ANS (Endocrine and ANS are 2 primary systems that regulate the human body) -ANS controls release of hormones -Hormones can initiate or inhibit nerve impulses -Endocrine system slower, but longer lasting

6. Amino Acid Based Hormones -Proteins and peptides. -Most common
Amino Acid Based Hormones -Proteins and peptides -Most common -Bind to surface receptors (G protein linked) because they are water soluble. -Amines -Small, simple, derived from a.a. tyrosine -Most act like protein hormones and bind to surface receptors. (Include: epinephrine, norepinephrine and melatonin) -NOTE: amines produced by the thyroid gland (ex. Thyroxine) will act more like steroid hormones instead of proteins.

7. Protein hormones use G protein linked receptors (2nd messenger Systems) located on the surface of a cell.
Hormone (1st messenger)
binds receptor. 1
Extracellular fluid
Adenylate cyclase
G protein (GS)
cAMP acti-
vates protein
kinases. 5
Receptor
GDP
Inactive
protein kinase
Active
protein
kinase
Receptor
activates G
protein (GS) 2
G protein
activates
adenylate
cyclase. 3
Adenylate
cyclase
converts ATP
to cAMP (2nd
messenger). 4
Hormones that
act via cAMP
mechanisms:
Epinephrine
ACTH
FSH LH
Triggers responses of
target cell (activates
enzymes, stimulates
cellular secretion,
opens ion channel,
etc.)
Glucagon
PTH
TSH
Calcitonin
G protein can be activated or inhibited depending on the hormone.
Cytoplasm
1 hormone can activate more than 1 type of protein kinase, causing multiple responses of target cell.
594

8. Fat soluble hormones: Steroids and thyroid amines
-Cholesterol
-Ovary
-Testes
-Cortex of adrenal gland
Steroid
hormone
Plasma
membrane
Extracellular fluid
The steroid hormone
diffuses through the plasma
membrane and binds an
intracellular receptor. 1
Cytoplasm
Receptor
protein
Receptor-
hormone
complex
The receptor-
hormone complex enters
the nucleus. 2
Hormone
response
elements
Nucleus
The receptor- hormone
complex binds a hormone
response element (a
specific DNA sequence). 3
DNA
Binding initiates
transcription of the
gene to mRNA. 4
mRNA
*Thyroid amine receptor is always bound to the DNA
The mRNA directs
protein synthesis. 5
New protein
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9. Eicosanoids: Hormone-Like; Locally acting (No circulation); Paracrine vs. Autocrine -made of fatty acids from phospholipids -released due to mechanical or chemical stimulation of cell membranes (Except RBC’s) -Bind to surface receptors (G protein linked) -Rapidly inactivated -Production inhibited by aspirin and ibuprofen Prostaglandins -Influence smooth muscle, pain, inflammation Leukotrienes -Respiratory system -Inflammation and bronchoconstriction

10. Hormones Water Soluble. Lipid Soluble (Proteins, Amines (except TH))
Hormones Water Soluble Lipid Soluble (Proteins, Amines (except TH)) (Steroids, Thyroid Amines (TH), Eicosanoids)
Bind Surface (G Protein Linked) Receptors
Activate Protein Kinases
Possible Results:
Influence mitosis
Cellular secretion
Change membrane permeability
Muscle contraction or relaxation
Etc.
Bind Intracellular Receptors
Receptor-Hormone complex binds DNA to activate genes
Synthesis of new proteins or enzymes for cell
Bind Surface (G Protein Linked) Receptors
Activate Protein Kinases
Possible Results:
Smooth muscle contraction
Inflammation
Pain
Etc.

11. Target Cell Specificity (Activation) Hormones bind to a matching receptor, but their activation of the target cell depends on:
Blood levels of hormone
Number of receptors
Up regulation
Down regulation (drug tolerance)
Affinity (binding strength high or low)

12. Cells decrease numbers of receptors in response to higher levels of a hormone.
Cells increase numbers of receptors in response to low levels of a hormone.

13. Epinephrine has better binding affinity with alpha receptors so therefore will cause a greater response at cells with alpha receptors.

14. Interaction of Hormones at Target Cells
Permissiveness: One hormone cannot exert it’s full effect without another hormone present. (Thyroxine and adrenaline at the heart)
Synergism: 2 or more hormones with the same effects at target cell can work together to amplify their effect.
Antagonism: One hormone opposing the action of another hormone. (insulin vs. glucagon and blood sugar)

15. Hypothalamus Posterior pituitary, Adrenal , Pineal gland
Nutrients and ions
(a) Humoral Stimulus
(b) Neural Stimulus
(c) Hormonal Stimulus
Capillary blood contains
low concentration of Ca2+,
which stimulates... 1
Preganglionic sympathetic
fibers stimulate adrenal
medulla cells... 1
The hypothalamus secretes
hormones that... 1
receptors
Hypothalamus
Capillary (low
Ca2+ in blood)
CNS (spinal cord)
…stimulate
the anterior
pituitary gland
to secrete
hormones
that… 2
Thyroid gland
(posterior view)
Parathyroid
glands
Pituitary
gland
Preganglionic
sympathetic
fibers
Thyroid
gland
Adrenal
cortex
Gonad
(Testis)
Medulla of
adrenal
gland
Parathyroid
glands
PTH
Capillary
…secretion of
parathyroid hormone (PTH)
by parathyroid glands* 2
…to secrete catechola-
mines (epinephrine and
norepinephrine) 2
…stimulate other endocrine
glands to secrete hormones 3
Hypothalamus
601

16. Negative Feedback (Stabilizing) Blood Glucose Pancreas Insulin Secreted Blood glucose Increase cell intake of glucose

17. Positive Feedback (Disruptive) Mother produces milk Baby suckles Stimulates mom to make prolactin More milk production More suckling More milk Etc.

18. Aka: Adenohypophysis Lots of receptors glandular 601
Figure The hypothalamus controls release of hormones from the pituitary gland in two different ways. (2 of 2)
Anterior Pituitary:
Aka: Adenohypophysis
Lots of receptors
Hypothalamus
Hypothalamic
neurons synthesize
GHRH, GHIH, TRH,
CRH, GnRH, PIH.
Anterior lobe
of pituitary
Superior
hypophyseal
artery
When appropriately stimulated, hypothalamic neurons secrete releasing or inhibiting hormones into the primary capillary plexus. 1 2
Hypothalamic hormones travel through portal veins to the anterior pituitary where
they stimulate or inhibit
release of hormones made in the anterior pituitary.
Hypophyseal
portal system
• Primary capillary
plexus 3
A portal system is two capillary plexuses (beds) connected by veins.
In response to releasing hormones, the anterior pituitary secretes hormones into the secondary capillary plexus. This in turn empties into the general circulation.
• Hypophyseal
portal veins
• Secondary
capillary plexus
GH, TSH, ACTH,
FSH, LH, PRL
Anterior lobe
of pituitary
glandular
601
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19. Aka: Neurohypophysis Neurohormones 600 Posterior Pituitary:
Figure The hypothalamus controls release of hormones from the pituitary gland in two different ways. (1 of 2)
Posterior Pituitary:
Aka: Neurohypophysis
Paraventricular nucleus
Hypothalamus 1
Hypothalamic neurons synthesize oxytocin or antidiuretic hormone (ADH).
Posterior lobe
of pituitary
Optic
chiasma
Supraoptic
nucleus
Infundibulum
(connecting stalk) 2
Oxytocin and ADH are transported down the axons of the hypothalamic- hypophyseal tract to the posterior pituitary.
Inferior
hypophyseal
artery
Hypothalamic-
hypophyseal
tract
Axon terminals
Oxytocin and ADH are stored in axon terminals in the posterior pituitary. 3
Posterior lobe
of pituitary 4
Oxytocin
ADH
When hypothalamic neurons fire, action potentials arriving at the axon terminals cause oxytocin or ADH to be released into the blood.
Neurohormones
© 2013 Pearson Education, Inc.
600

20. Pineal Gland

21. Figure 16.17 Stress and the adrenal gland.
Short-term stress
Prolonged stress
Stress
Adrenaline (epinephrine)
Noradrenaline (norepinephrine)
Nerve impulses
Hypothalamus
CRH (corticotropin-
releasing hormone)
Spinal cord
Corticotropic cells
of anterior pituitary
Preganglionic
sympathetic
fibers
To target in blood
Adrenal cortex
(secretes steroid
hormones)
Adrenal medulla
(secretes amino acid–
based hormones)
ACTH
Catecholamines
(epinephrine and
norepinephrine)
Mineralocorticoids
Glucocorticoids
Short-term stress response
Long-term stress response
• Heart rate increases
• Kidneys retain
sodium and water
• Proteins and fats converted
to glucose or broken down
for energy
• Blood pressure increases
• Bronchioles dilate
• Blood volume and
blood pressure
rise
• Liver converts glycogen to glucose and releases
glucose to blood
• Blood glucose increases
• Immune system
supressed
• Blood flow changes, reducing digestive system activity
and urine output
• Metabolic rate increases
© 2013 Pearson Education, Inc.
617

22. Neural
Hormonal
inhibits

23. Elimination of Hormones Steroid hormones broken down by cell
Elimination of Hormones Steroid hormones broken down by cell. Hormones in circulation filtered by liver and kidneys Half life varies video

24. Clicker Question: Which of the following statements is true. 1
Clicker Question: Which of the following statements is true? 1. Hormones are ONLY secreted by endocrine glands. 2. When adenyl cyclase is activated it converts ATP into cyclic AMP 3. Down-regulation produces an increase in a target cells’ sensitivity to a hormone. 4. Steroid hormones are secreted by the gonads and the adrenal medulla 5. The endocrine system produces more widespread effects than the nervous system. A. 1, 2, 5 B. 2, 3, 4, 5 C. 2, 5 D. 1, 3, 4

25. Figure 16.13 Effects of parathyroid hormone on bone, the kidneys, and the intestine.
Hypocalcemia
(low blood Ca2+)
PTH release from
parathyroid gland
Osteoclast activity
in bone causes Ca2+
and PO43- release
into blood
Ca2+ reabsorption
in kidney tubule
Activation of
vitamin D by kidney
Ca2+ absorption
from food in small
intestine
Ca2+ in blood
Initial stimulus
Physiological response
© 2013 Pearson Education, Inc.
Result
611

26. Figure 16.12a The parathyroid glands.
Pharynx
(posterior
aspect)
Thyroid
gland
Parathyroid
glands
Esophagus
Trachea
© 2013 Pearson Education, Inc.
610

27. Calcitonin Produced by Thyroid Gland
No known physiological role in humans
Antagonist to parathyroid hormone (PTH)
At higher than normal doses
Inhibits osteoclast activity and release of Ca2+ from bone matrix
Stimulates Ca2+ uptake and incorporation into bone matrix
© 2013 Pearson Education, Inc.

28. Figure 16.14a Microscopic structure of the adrenal gland.
Capsule
Zona
glomerulosa
Zona
fasciculata
Adrenal gland
Neural
• Medulla
Cortex
• Cortex
Glandular
Kidney
Zona
reticularis
(Corticosteroids)
-mineralcorticoids
-glucocorticoids
-gonadocorticoids
Medulla
Adrenal
medulla
Drawing of the histology of the
adrenal cortex and a portion of
the adrenal medulla
© 2013 Pearson Education, Inc.
612

29. Glucocorticoids: Cortisol
Released in response to ACTH from Anterior Pituitary following patterns of eating and activity (biological clock), and stress
Helps body resist stress—formation of glucose from fats and proteins
Promotes rises in blood glucose, fatty acids, and amino acids
Increases blood pressure to quickly distribute nutrients to cells
© 2013 Pearson Education, Inc.

30. Excessive levels of glucocorticoids: -Depress cartilage and bone formation -Inhibit inflammation -Depress the immune system -Glucocorticoid drugs (corticosteroids) are given to help with chronic inflammatory disorders (rheumatoid arthritis, dermatitis and autoimmune diseases)

31. Figure 16.17 Stress and the adrenal gland.
Short-term stress
Prolonged stress
Stress
Nerve impulses
Hypothalamus
Biological Clock
CRH (corticotropin-
releasing hormone)
Spinal cord
Corticotropic cells
of anterior pituitary
Preganglionic
sympathetic
fibers
To target in blood
Adrenal cortex
(secretes steroid
hormones)
Adrenal medulla
(secretes amino acid–
based hormones)
ACTH
(Cortisol)
Catecholamines
(epinephrine and
norepinephrine)
Mineralocorticoids
Glucocorticoids
Short-term stress response
Long-term stress response
• Heart rate increases
• Kidneys retain
sodium and water
• Proteins and fats converted
to glucose or broken down
for energy
• Blood pressure increases
• Bronchioles dilate
• Blood volume and
blood pressure
rise
• Liver converts glycogen to glucose and releases
glucose to blood
• Blood glucose increases
• Immune system
supressed (Anti-inflammatory effects)
• Blood flow changes, reducing digestive system activity
and urine output
• Metabolic rate increases
© 2013 Pearson Education, Inc.
617

33. Imbalances of Glucocorticoids
Hypersecretion—Cushing‘s disease
Depresses cartilage and bone formation
Inhibits inflammation
Depresses immune system
Disrupts cardiovascular, neural, and gastrointestinal function
Hyposecretion—Addison's disease
- Decrease in glucose and Na+ levels
- Weight loss, severe dehydration, and hypotension
© 2013 Pearson Education, Inc.

34. Figure 16.16 The effects of excess glucocorticoid.
Patient before onset.
Same patient with Cushing’s
syndrome. The white arrow shows
the characteristic “buffalo hump” of
fat on the upper back.
615
© 2013 Pearson Education, Inc.

35. Gonadocorticoids (Sex Hormones)
Most weak androgens (male sex hormones) converted to testosterone in tissue cells, some to estrogens
May contribute to
Onset of puberty
Appearance of secondary sex characteristics
Sex drive in women
Estrogens in postmenopausal women
© 2013 Pearson Education, Inc.

36. Clicker Question: Which of the following is NOT fat soluble and therefore does not use an intracellular receptor? a. estrogen b. epinephrine c. cortisol d. thyroxine e. gonadocorticoids