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Exam 5 Study Guide – PCB3703C

1. Endocrine Information Flow

a. Endocrine system uses hormones___ to travel via the ___bloodstream ___.

b. These will act on target cells to produce a physiologic function.

i. What other system in our body uses information flow? Is it faster or slower than

the endocrine system?

Nervous System uses information flow and is faster than the endocrine system.

2. Types of Hormones, Secretions

a. _____ Endocrine System _______ - is the process of secretion into circulation, i.e. blood

i. __Paracrine ______ - secretions that act on neighboring cells, can be agonistic or

antagonistic

ii. __Autocrine_______ - secretions that act on receptors on the same cell

iii. __Intracrine________ - secretions that act inside the cell without being

“secreted”

b. ____Exocrine________ - is ductless secretion outside of circulation

c. Synergistic effects – hormones working together

d. Permissive effects – enhances target cell to reception of a 2nd hormone, increases its

activity.

e. Antagonistic effects – one hormone will __negate____ another

3. Protein Hormones

a. Bind to a ____cell surface_____ receptor

b. Precursors are amino acids

c. Lipophobic or hydrophilic

d. Travel ______freely________ in blood

e. Examples – GH, Prolactin, PTH, Insulin, ACTH, Glucagon, somatostatin, adrenaline

4. Steroid Hormones

a. Bind to a _______Nuclear________ receptor

b. Precursor is ____Cholesterol__________

c. Lipophilic or hydrophobic

**Study Guide Created by previous SI leader: Robert Lenoci

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d. Travel ____bound to protein__________ in blood

e. Examples – Vitamin D, T3/T4, sex hormones, cortisol

Which of the following is true of protein hormones?

a. They require carrier proteins such as albumin for transportb. They will bind to the membrane receptors of target cellsc. They will bind to nuclear receptors inside target cellsd. They are hydrophobic in naturee. They usually act faster than steroid hormones

5. Reception of Hormones (5 ways discussed)

a. GPCRs – coupled with _GTP_____ for activation/inhibition

i. G protein has __3_ subunits (alpha, beta, gamma)

1. Which one has inhibitory or stimulatory subunits, and binds GDP or GTP?

Alpha subunit

ii. Ligand (hormone) binds -> activates G proteins -> form 2nd messengers (i.e.

_Adenylate Cyclase (AC), cAMP, IP3, Phospholipase C, etc) -> increase/decrease

intracellular energy

b. Growth Factor Receptors – have a binding domain and a _tyrosine kinase__ domain.

i. Cytoplasmic side will act as 2nd messenger, autophosphorylate and active further

pathways.

ii. _Insulin, EGF, IGF__ uses this. ATP is used, transfers Phosphate to signal cascade

for glucose uptake. (What type of channel does insulin activate?) -

c. Cytokine Receptors – Uses __JAK2 domain______, which has intrinsic tyrosine kinase

activity, triggering downstream events.

i. ___Growth Hormone________ uses, binds to binding domain and signals

accessory protein () to trigger things such as proliferation, growth, etc.

d. Ligand-regulated (Guanylyl Cyclase) Receptor – has binding domain, kinase-like

domain, and GC attached on cytoplasmic side.

i. Opens a channel, ion flux acts as a second messenger__.

ii. _Ligand_____binds, ion influx activates Nitric Oxide Synthase, stimulates GC,

elevates cGMP levels allowing cGMP-protein kinases to promote vasorelaxation.


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e. Nuclear Receptors – use _steroid______ hormones

i. Have 3 domains – N-terminal, DNA-binding, C-terminal.

1. N-terminal effects transcription

ii. Steroid Hormone or Thyroid Hormone – Cortisol, Aldosterone, Androgen,

Testosterone, Estrogen, Progesterone, T3, T4, Vitamin D.

1. Diffuses across membrane, binds to cystolic and then nuclear receptor.

When it binds, the __DNA Binding Domain______ domain is exposed and

will interact inside nucleus, producing new mRNA via transcription.

Where does mRNA then go to produce physiologic reactions?

6. Communication with Pituitary from Hypothalamus

a. _Anterior_________ pituitary – uses portal system from hypothalamus, travels via the

__hypothalamal pituitary portal system__________ to here.

b. _Posterior_________ pituitary – uses axonal fibers from paraventricular or supraoptic

nuclei that synapse here.

c. How many lobes does the pituitary have? 3

d. Note- it is important to understand the difference between these two

communications. One involves hormonal activation, the other involves neuronal.

7. Ant. Pituitary Hormones – FLAT PG. FSH, LH, ACTH, TSH, Prolactin, GH

8. Post. Pituitary Hormones – AO ADH, Oxytocin


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9. Pituitary Hormones – KNOW ALL OF THESE

Anterior Pituitary -

Hormone Type Action DisorderFollicle Stimulating Hormone (FSH)

protein M & F – maturation of germ cells. M – induces __testes___to bind testosterone and undergo spermatogenesisF – initiates follicle growth, peaks at day 15 of menstruation (ovulation phase)

Leutinizing Hormone (LH)

Protein M – stimulates ___ Leydig ____ Cells to secrete _____testosterone_______, which also inhibits LH prod.F – rupture of follicle, elimination of ovum, migration toward fallopian tube

Xs – premature menopause, polycystic ovary syndrome, turner’s


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-> Ovulation

Adrenocorticotropin Hormone (ACTH)

protein Stimulates production of adrenal cortex hormones (what 3?) – Aldosterone, Androgen, Cortisol

Def – 2nd Addison’sXs - _Cushings Disease Also can be indicative of 1 Addison’s

Thyroid Stimulating Hormone (TSH)

protein Stimulates production of Thyroid hormone (_T3, T4_____)

Hypothyroidismhyperthyroidism

Prolactin protein Inhibited by ___Dopamine______, stimulates milk ___production____________. Suppresses sex hormones (during pregnancy).

Def – dopamine xs, anti-parkinson’s drugs (or schizophrenic drugs. Also can lead to abortion. Prolactinoma – infertility.

Growth Hormone (GH)

protein Stimulates cell proliferation and growth, bone development. Inhibited by __somatostatin__________

Def – _Dwarfism__Xs – _Gigantism______

Posterior Pituitary -

Oxytocin protein Promotes milk __letdown_________, uterine contraction

Oxytocin can be used as treatment for ___delivery_______

Antidiuretic Hormone (ADH)

protein Facilitates __reabsorption___ by acting on collecting tubule of kidney nephrons.

Def – dehydration

10. Hypothalamic Hormones (TDGSGOAC)

TRH (Thyroid Releasing Hormone)

Peptide Stimulates ant. Pituitary to release _TSH___ and __Prolactin___

Hypo/hyper-thyroidism, can lead to infertility (prolactin)

Dopamine Inhibits _Prolactin_______, associated with sleep disorder. Other fx unknown

Def - Sleep disorder (restless leg syndrome)

Gonadotropin-releasing hormone (GnRH)

peptide Stimulates _FSH____ and __LH___ production. In Female, surges just before

Def – during childhood until puberty.


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ovulationSomatostatin peptide Inhibits GH secretions, in

pancreas inhibits insulin/glucagon (later)

Growth-hormone-releasing hormone (GHRH)

Stimulates GH secretions from post. pituitary

OxytocinADH

Produced by hypothalamus

Stored by post. pituitary

Corticotropin releasing hormone (CRH)

Stimulates ACTH secretions from post. pituitary

Def – Addisons Disease Xs – ____Cushings Disease

11. Adrenal Gland

a. Adrenal Cortex (outside) secretes 3 hormones….. _Cortisol____,

__Androgen__________, ___Aldosterone_______. Know the function of each,

symptoms associated with elevated/decreased levels.

i. “Girls From Russia Make Good Soup”

ii. Zona glomerulosa – mineralcorticoids, i.e _Aldosterone___.

iii. Zona __Fasiculata___- glucocorticoids, i.e. __Cortisol_____________.

iv. Zona reticularis - ___Sex Hormones__________, i.e androgen, testosterone,

estrogen.

Aldosterone Function - vasoconstriction, increases BP by Na+ reabsorption, K+ and H+ excretion by nephron.

Disorder – Hyperaldosteronism (Conn’s Disease)

Hypoaldosteronism

Symptoms - hypertension, hypernatremia, hypokalemia, acidic urine

^Opposite.

Androgen (steroid) Stimulates male sex characteristics, axillary hair growth from puberty.

Androgen Insensitivity Syndrome – inability for body to respond to androgen

Female with male XY, infertility

def – _Androgen Insensitivity Syndrome


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Cortisol Anti-inflammatory, appetite, immune suppressant, increases blood pressure, increases gluconeogenesis, inhibits insulin

Cushing’s Disease / Syndrome

Addison’s Disease

See below

Which of the following is true about androgen?

a. Secreted from the adrenal medullab. Can pass freely through the target cell membranec. Cell surface receptord. Travels in the blood without carrier proteins

12. Adrenal Gland Disordersa. Conn’s Disease: Hyperaldosteronism: Hypernatremia, Hypokalemia, Hypertension

b. Cushing’s Disease “secondary hypercortisolism” – due to elevated _CRH____ or __ACTH____

i. Leads to overproduction of __Cortisol________, also androgen/aldosteroneii. Symptoms – hypertension,*** ___infertility___________, hypernatremia,

hypokalemia, fatigue, weight gain, hyperglycemia, facial hair (woman).

c. Cushing’s Syndrome “primary hypercortisolism” – directly due to overproduction of cortex hormones.

i. Note – Treatment between the two can vary. Cushing’s Disease is a higher order disorder, while Cushing’s Syndrome is a direct impact on adrenal cortex.

d. Addison’s Disease – Can be primary or secondary. Results in deficiency in __Aldosterone, Cortisol, Androgen____________

i. Primary – 1. Causes – problem to adrenal cortex, i.e. irritation, destruction, tumor2. Symptoms – Understand why these symptoms occur…

a. __Hypo______natremiab. __Hyper_____kalemia


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c. __Hypo______glycemiad. __Hypo_____tensione. Hair loss (deficiency in ___androgen___________)

3. Differential Diagnosis – causes __hyperpigmentation______________ as well (secondary does not). Why? There isn’t any negative feedback in secondary!

a. POMC (Proopiomelanocortin) – produced in the __Interior Lobe of the Pituitary (Some in the Anterior Lobe) ___, is stimulated due to feedback from adrenal cortex.

b. POMC is precursor for both __ACTH______, _____MSH_____, and endorphinsc. Therefore, __MSH________ levels increase leading to hyperpigmentation.

ii. Secondary – 1. Causes – problem to hypothalamus or ant. Pituitary2. Symptoms – same as primary3. Differential Diagnosis - __Hyperpigmentation_________ does not occur,

because there are decreased levels of __POMC, CRH, ACTH__ , POMC is

not “able” to produce more…

Which of the following is true about primary Addison’s?

a. ACTH levels decrease leading to hyperpigmentationb. MSH levels are unaffectedc. Deficiency in aldosterone, cortisol, androgen as a result of decreased levels of ACTHd. Increased levels of ACTH and POMC cause hyperpigmentation.

13. Thyroid Gland

a. Produces __T3____ and __T4___, after stimulation via TRH (hypothalamus) and TSH

(ant. Pit)

b. Blood supply by ___superior thyroid____________ artery, branch of external carotid

c. 2 Lobes.


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14. Synthesis of Thyroid Hormone

a. Two precursors are _thyroglobulin_______ and __iodide_____.

b. 1st Step involves transport of ____Iodide______ using a pump.

c. __Iodide_____ is oxidized and converted to _Iodine___ by peroxidase.

d. Combines with ___tyrosine______ residue of thyroglobulin to form MIT or DIT.

i. T3 = _DIT_____ + __MIT_____, aka triiodothyronine

ii. T4 = ___DIT___ + ___DIT____, aka thyroxin

e. Which one is more active? T3

f. Thyroid hormone functions during pregnancy for __CNS____ development, bone

growth, reproductive tract.

g. T4 uses a _Thyroid Binding Globulin____ protein (TBG) to enter target cell, then is

converted to _T3__, joins with binding protein, and enters nucleus, binds to nuclear

receptor and activates genes.

15. Regulation of Thyroid Hormone

a. From Hypothalamus, __TRH______-> stimulates TSH from ___Anterior Lobe of Pituitary

b. TSH acts on follicular cells of thyroid via AC – cAMP, forms T3/T4.

c. T3 downregulates TRH receptors, inhibits TSH secretion.

16. Function/Disorders of Thyroid

a. Functions – regulate metabolism, temperature, increase heart rate, memory/learning,

increases glucose absorption and glycogenolysis, protein synthesis/degradation

b. Hyperthyroidism –

i. “__Graves disease____” – autoimmune, antibody recognizes TSH and binds ->

oversecretion of T3/T4.

1. Symptoms – weight loss, nervousness, headache, sleep disorder,

cardiovascular disorder. Enlarged thyroid called “_goiter___”

2. Differential diagnosis – no hypernatremia ______

c. Hypothyroidism-


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i. Primary – occurs directly in ___thyroid______ gland

ii. Secondary – occurs indirectly in _hypothalamus_____ or _Ant. Lobe of

Pituitary________

1. Differential Diagnosis – in primary, we have decreased __T3, T4_______,

giving feedback to produce more _TRH____ or ___TSH___. In secondary,

this cannot occur, because the deficiency is already there..

iii. Symptoms- weight ___gain__, sleep disorder, weakness, dry hair/skin

iv. Congenital Hypothyroidism – a result of maternal thyroid problems, deficiency

in T3/T4 lead to poor ___thyroid__ development in fetus, leading to short

stature, mental retardation, brittle bones.

17. Parathyroid Gland: 4 glands

a. __Are__ located posterior to thyroid. ___Chief___ cells release parathyroid hormone

(PTH).

b. Principle function of PTH is to regulate blood __Calcium___ levels.

c. What 3 places does PTH act to increase _Calcium___ levels?

i. 1 Bone

ii. 2 Epithelial Cells of Small Intestine

iii. 3 Kidney: Reabsorption

d. Reabsorption with vitamin D –

i. PTH converts _25__-hydroxycholecalciferol to ___1-25_-dihydroxycholecalciferol

(active form).

ii. This acts on the ___bone______ to promote _Ca__ reabsorption.

e. T/F – Parathyroid hormone decreases phosphate reabsorption by proximal tubule.

f. What are some important things that calcium performs?

i. Action Potential, Muscle Contraction, etc

g. Hyperparathyroidism - _hyper____calcemia, abnormal extrasystole of myocardium, HR

increase, irritated CNS, osteoporosis

h. Hypoparathyroidism - __hypo___calcemia, muscle weakness, vitamin _D_ deficiency


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i. Can occur from a ____thyroidectomy____ if pt is removed as well.

18. Pancreas

a. 3 types of cells here produce 3 different hormones.

b. Alpha cells produce -> __Glucagon______, functions to increase ___glucose____levels.

Acts on the __liver____ to increase gluconeogenesis and glycogenolysis (know what

each process leads too).

i. __hypo___glycemia stimulates secretions.

c. Beta cells produce -> ___Insulin______, functions to decrease __blood glucose__ levels.

Promotes uptake into target cells.

i. __Glucose__ Binds to its receptor (growth-factor, tyrosine-kinase receptor), that

initiates a signal cascade to promote translocation of __GLUT4____ channels to

the surface of the cell. These channels open and allow an ___increase___ of

glucose, which is used by the cell for __energy/cell respiration_____.

ii. This type of transport is _____facilitated Diffusion

iii. __Insulinoma________ - tumor to beta cells, increases secretions leading to

hypoglycemia, which can lead to coma.

d. Delta cells produce -> _Somatostatin____< suppresses the action of the other 2

pancreatic hormones. Works to maintain constant levels of blood glucose.

19. Hyperglycemia

a. Know difference between type I and type II diabetes.

Type 1 Diabetes: Autoimmune destruction of beta cells in pancreas, deficiency of

Insulin

Treat: Insulin Replacement

Type 2 Diabetes: Receptor Insensitivity to Insulin, (Can be caused by obesity).

Treated with exercise, diet, and Metformin.


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b. Symptoms – vasculopathy, calcification, hemorrhage, can lead to myocardial infarction.

In GI, can lead to malabsorption. In kidneys, can lead to ____nephropathy_____. Over

350 mg/dL_____ produces glucouria.

i. Thirst due to dehydration / frequent urination -> __polydypsia,

polyurea_________

c. Type I Treatment – insulin replacement via _IV_____ or __subdural_____. Cannot use

oral because…

d. Type II Treatment – because insulin resistance, hormone therapy is ineffective. Must

treat using exercise and diet. Metformin can work as well.

20. Placental Hormones

a. 1st hormone secreted during pregnancy - _hCG______

Progesterone Steroid hormone

Prepares endometrium for implantation of fertilized ovum into uterine wall. In pregnancy, maintains uterine lining by preventing menstruation.

After delivery, levels are very low.

Estrogen Steroid hormone

M- development of spermF – prepares endometrium for regeneration after menstruation. Breast development.

Used to prevent osteoporosis in post-menopausal women.

Testosterone Steroid M – secondary sex characteristics, development of genetalia, descent of testis

def – infertility. Xs – prostate cancer

21. Prostaglandin

a. _Fatty Acid______ precursor. Arachidonic acid -> prostaglandin via _cyclooxidase_____

b. Stimulates both vasoconstriction or vasodilation. Can be harmful to _temperature_____

center, resulting in fever.

i. Vasodilation – PGI2 or PGE2.

ii. Vasoconstriction – PGF2alpha or TXA2.

c. Treat fever using _cyclooxidase___ Inhibitors, such as aspirin, NSAIDs,

_Indomethacin_________, ibuprofen.


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d. Prepares cervix for delivery, also male erection.

22. Pineal Gland – located in posterior _3rd___ ventricle of brain

a. Production of __Melatonin______ from serotonin.

b. Regulates sleep, increased levels during _darkness_________.

23. Spermatogenesis – development of sperm from germ cells. Starts with ___birth_______.

a. Starts with spermatogonia, mitotically divides to form __primary_____ spermatocyte.

b. Then undergoes 1st meiotic division to form two ___secondary_______ spermatocytes.

c. Then undergoes 2nd meiotic division to form four ___spermatid_______.

d. Then undergo spermiogenesis to form four mature sperm.

e. What cells regulate spermatogenesis? __Sertoli_____ cells.

24. Structure of Sperm

a. At end of head is called _acrosome________, which contains acrosin, prostaglandin,

ACE. What do these function for?

25. Male Reproductive System

a. Hypothalamus releases __GnRH_____, which stimulates secretions of LH and FSH.

b. Sertoli Cells – regulates spermatogenesis. Also secrete _Inhibin_____, which controls

spermatogenesis by inhibiting FSH or GnRH. FSH acts on sertoli cells to form receptors

to respond to testosterone.

i. Inhibin inhibits FSH

c. Leydig cells – secrete _Testosterone_______ after LH binds. Testosterone then binds to

the sertoli cells. Testosterone also inhibits LH release.

i. Testosterone inhibits LH

26. Fertility

a. Semen contains __Zinc, prostaglandin, calcim, fructose, and mucous that function to

protect sperm environment in female reproductive tract.

b. Erection – blood fills corpus cavernosus by activation of _parasympathetic______

nervous system, vasodilation.

i. Mediated by NO.

c. Emission – ___sympathetic_____ nervous system.


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d. Ejaculation – both.

27. Oogenesis

a. Germ cells -> ___oogonia______. Undergo mitosis to form _primary______ oocyte

during intrauterine life.

b. Begins first meiotic division before birth, which is why females have shorter

reproductive life (limited oocytes). In suspended state until puberty, by secretion of

__Oocyte Maturation Inhibitory Factor_________ (OMI).

c. Puberty triggers 2nd meiotic division, forming _secondary_____ oocyte, which can be

fertilized by sperm to form an ovum.

28. Klinefelter’s - _XXY_____, genotype is male but has feminine characteristics. Intersexuality /

infertility.

29. How many chromosomes does an oocyte have? A sperm? A zygote? 23. 23. 46.

30. Menstruation

a. What are the 3 phases of the cycle?

b. Days 0-5 -> Follicular: Dev of Follicle by FSH

c. Day 14 -> LH levels spike just before _formation of corpus luteum__(Luteal Phase)_

d. Day 14-28 -> endometrium builds back up. Secretory Phase

31. Pregnancy –

a. hCG important for maintaining endometrium by corpus luteum for secretion of

progesterone during 1st trimester. After 1st trimester of pregnancy, placenta takes over

the progesterone secretion because degeneration of corpus luteum. Placenta also

secretes other hormones

32. Immune –

a. __Innate_____ immunity – 1st line of defense, nonspecific. Involves neutrophils,

macrophages, etc.

b. _Adaptive_____ immunity – takes longer, more specific. Involves T and B cells, i.e.

antigen antibody interactions.

33. Fever – temperature center is located in __Hypothalamus__________.


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a. ___Prostaglandin E2____ triggers fever (pyrogen), which is synthesized from

arachidonic acid by action of _Cyclooxidase_(C.O)____.

b. Aspirin – fever suppressor by inhibiting _C.O_____.

34. Lymphocytes –

a. ___T and B Cells____ – adaptive

b. __NK (natural killer) cells___ – respond to viruses, innate immunity.

35. Immunoglobulins (GAMED)

a. IgA_ - most common in saliva/ breast milk secretions

b. IgE_ - most common in allergic reactions.

c. IgG_ - crosses placental barrier to give fetal immunity.

36. Complement – coats antigens to mark for macrophages to detect, called

_opsonization________.

37. Immune disorders (from this section) –

a. Type II diabetes, Graves Disease


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