Hormones

What two hormones act/form on the corpus luteum? Why is this important?

*LH (Luteinizing Hormone)* It helps form and maintain corpus luteum *HcG* prevents menses for the embryo

parathyroid hormone (PTH)

*Source:* parathyroid gland *Stimulus:* low blood calcium *Target:* osteoclasts renal tubules GI tract *Effect:* Increases osteoclast activity to break down bone for more calcium causes renal tubules to keep calcium Causes intestines to absorb more calcium *(-) Feedback:* increased levels of calcium

Prolactin (LTH) Luteotrophic hormone

*Source:* Ant. Pit. *Stimulus:* Decrease in PIH *Target:* Mammary glands & immune system *Effect:* milk production; strengthen immune response *(-) Feedback:* n/a

Growth Hormone (GH, somatotropin)

*Source:* Ant. Pit. *Stimulus:* Increased GHRH, decreased GHIH *Target:* skeletal muscles, bone, other cells *Effect:* growth, increased protein synthesis, glucose metabolism *(-) Feedback:* n/a

Growth hormone-releasing hormone (GHRH)

*Source:* Hypothalamus *Stimulus:* melatonin & sex hormones *Target:* Ant. Pit. *Effect:* stimulates somatotropin production *(-) Feedback:*

somatostatin (GHIH, growth hormone inhibiting hormone)

*Source:* Hypothalamus *Stimulus:* tonic release *Target:* Ant. Pit. *Effect:* Inhibit somatotropin production *(-) Feedback:*

Progesterone

*Source:* corpus luteum, placenta during pregnancy *Stimulus:* LH, hCG *Target:* all cells with DNA *Effect:* secondary sex characteristics, endometrial vascularization *(-) Feedback:* FSH

GIP- (Gastric Inhibiting Peptide) aka "glucose-dependent insulinotropic peptide enterogastrone

*Source:* mucosa cells of duodenum *Stimulus:* chyme and duodenum *Target:* ß pancreatic islet cells (to inhibit stomach peristalsis) *Effect:* triggers insulin secretion and prevents overloading of chyme in the duodenum *(-) Feedback:* n/a

Estrogen

*Source:* ovary follicles, placenta during pregnancy *Stimulus:* FSH *Target:* All cells with DNA *Effect:* secondary sex characteristics, endometrial cell growth *(-) Feedback:* FSH

Testosterone

*Source:* testes, leading cells *Stimulus:* LH *Target:* all cells with DNA *Effect:* secondary sex characteristics, assists with spermatogenesis *(-) Feedback:* LH

2 hormones from the juxtaglomerular cells?

*renin, erythropoietin* *Renin* is released in response to decreased renal blood, low BP, low blood flow, or low Na+ and *Targets Angiotensinogen* in order to convert Angiotensinogen to Angiotensinogen II *erythropoietin* is released in response to decreased blood O₂ *targets bone marrow cells* in order to stimulate RBC production.

what triggers the release of aldosterone

-low blood osmolarity -low blood volume - low Na+ via Angiotensin II

What happens when there is a decreased level of cortisol in the body?

1. The hypothalamus makes CRH (Corticotropin Releasing Hormone) and sends it to its target the Ant. Pit. 2. CRH stimulates the Ant. Pit. to make and release ACTH (Adrenocorticotropic Hormone) which targets the Adrenal Cortex. 3. ACTH in the adrenal cortex stimulates the production of glucocorticoids (particularly cortisol) which then targets all the DNA in the cells.

oxytocin

A hormone released by the posterior pituitary that stimulates uterine contractions during childbirth and milk ejection during breastfeeding. *Source:* Made in hypothalamus, stored in Post. Pit. *Stimulus:* nerve stimulation from cervix, stretch of cervix, suckling of baby on nipple *Target:* uterus, mammary glands *Effect:* uterine contractions during labor, or milk release *(-) Feedback:* Birth, stop nursing

Cholecystokinin (CCK)

A hormone secreted by the samll intestine (duodenum) in response to the presence of fats. It promotes release of bile from the gallbladder and pancreatic juice from the pancreas, and reduces stomach motility. *Source:* mucosa cells of the duodenum *Stimulus:* fatty chyme in the duodenum *Target:* gall bladder, pancreas *Effect:* releases bile and digestive enzymes into the duodenum *(-) Feedback:* n/a

glucagon

A protein hormone secreted by pancreatic cells that raises blood glucose levels *Source:* alpha pancreatic cell *Stimulus:* low blood glucose *Target:* liver *Effect:* glycogenolysis, gluconeogenesis *(-) Feedback:* increased blood glucose

insulin

A protein hormone synthesized in the pancreas that regulates blood sugar levels by facilitating the uptake of glucose into tissues *Source:* ß pancreatic islet cells *Stimulus:* high blood glucose *Target:* liver, skeletal muscles *Effect:* opens glut channels *(-) Feedback:* lower blood glucose

What hormone controls tonicity?

ADH

Epinenphrine

Also called adrenaline, a hormone that stimulates body systems in response to stress. *Source:* Adrenal Gland Medulla *Stimulus:* sympathetic NS stimulation *Target:* a ß receptors *Effect:* EPSP or IPSP *(-) Feedback:*

what does ACE do for RAAS

Angiotensin Converting Enzyme. It converts angiotensin I to angiotensin II

What stimulates the release of aldosterone?

Angiotensin II

what would the effects be of an ACE inhibitor?

Angiotensin converting enzyme inhibitors (ACE inhibitors) are medications that slow (inhibit) the activity of the enzyme ACE, which decreases the production of angiotensin II. As a result, blood vessels enlarge or dilate, and blood pressure is reduced. NOTE: angiotensin II is a powerful vasoconstrictor that is released in response to low BP. ACE helps this process.

Which hormone is released from the duodenal mucosa, targets the stomach, inhibits peristalsis of the stomach's smooth muscles, and prevents too much chyme from entering the duodenum? It also stimulates the secretion of insulin in the pancreas...

GIP (Gastric Inhibiting Peptide- aka Entergasterone)

what triggers the release of gastrin?

Gastrin release is triggered by food entering the stomach. In response, it tells the chief and parietal cells to secrete pepsinogen and HCl to start breaking the food down.

HPG axis

Hypothalamus-pituitary-gonad axis, the negative feedback loop that regulates sex-hormone production. Stimulus: low levels of estrogen, progesterone, testosterone

Prolactin-inhibiting hormone (PIH)

Inhibits secretion of prolactin (LTH) *Source:* Hypothalamus *Stimulus:* tonic nerve signal *Target:* Ant. Pit. *Effect:* Prevents secretion of prolactin *(-) Feedback:* n/a

What does calcitonin do?

Lowers blood calcium levels inhibits osteoclastic activity, blocks Ca++ reabsorption, blocks Ca++ absorption Only during growth periods. Adults use parathyroid hormone after maturation.

what is the target organ for ADH?

Nephron collecting ducts in the kidneys; vascular smooth muscle

Antidiuretic hormone (ADH, vasopressin)

Posterior pituitary; peptide; causes the kidney to retain water *Source:* Made in Hypothalamus, released from Post. Pit. *Stimulus:* hypertonic interstitial fluid *Target:* Nephron's collecting ducts, vascular smooth muscle *Effect:* reabsorption of pure water, vasoconstriction *(-) Feedback:* Isotonic blood and interstitial fluid

What is the pathway for: decreased Na+ but not volume

Renin released from juxtaglomerular cells to angiotensinogen, starting the cascade of renin - angiotensinogen - angiotensin I ~ACE~ angiotensin II - aldosterone

RAAS (renin-angiotensin-aldosterone system)

Renin is released by kidneys in response to decreased blood volume; causes angiotensinogen (made in the liver) to split & produce angiotensin I; lungs convert angiotensin I to angiotensin II; angiotensin II stimulates adrenal gland to release aldosterone & causes an increase in peripheral vasoconstriction Ultimately, aldosterone causes an increase in blood volume.

glucocorticoids (Cortisol in particular)

Source: Adrenal cortex Stimulus: increased ACTH Target: All cells with DNA Effect: Controls metabolism of glucose; catabolism of proteins (-) Feedback: ACTH, CRH

adrenocorticotropic hormone (ACTH, corticotropin)

Source: Ant. Pit Stimulus: increased CRH Target: Adrenal Cortex Effect: stimulates release of cortisol (-) Feedback:

Thyroid Stimulating Hormone (TSH)

Source: Ant. Pit. Stimulus: TRH increase Target: Thyroid Gland Effect: stimulates thyroid gland growth and T4 production and release (-) Feedback: (TRH)

corticotropin releasing hormone (CRH)

Source: Hypothalamus Stimulus: decreased cortisol Target: Ant. Pit Effect: Stimulates the release of ACTH

Thyrotropin-releasing hormone (TRH)

Source: Hypothalamus Stimulus: decreased levels of T3/T4 Target: Ant. Pit. Effect: stimulates release of TSH (-) Feedback: a hypothalamic hormone that regulates the release of thyroid-stimulating hormone from the anterior pituitary, which in turn stimulates the Thyroid to release T4/T3

Thyroid hormones (T3 and T4)

Stimulates metabolic activity Source: Thyroid gland Stimulus: TSH increase Target: All cells with DNA Effect: maintains metabolic rates and increases metabolism (-) Feedback:

How does the body regulate metabolic rates or increase metabolism? (HPT axis)

T3/T4 maintains/increases metabolism. T3/T4 is released by the Thyroid gland in response to increased levels of TSH. TSH (thyroid stimulating hormone) is released by the anterior pituitary gland in response to increased levels of TRH. TRH is released by the hypothalamus in response to low levels of T3/T4 or when the body needs to increase metabolic rates.

what stimulates the release of TSH?

TRH from hypothalamus

GnRH (gonadotropin-releasing hormone)

a hormone secreted by the hypothalamus that regulates the pituitary's secretion of gonad-stimulating hormones Source: Hypothalamus Stimulus: low levels of estrogen, progesterone, testosterone Target: Ant. Pit. Effect: stimulates release of FSH & LH (-) Feedback:

What hormone controls blood volume?

aldosterone

What ultimately reduces blood pressure?

aldosterone at the end of the RAAS cycle

what is the target organ for GnRH

anterior pituitary gland

luteinizing hormone (LH)

causes ovulation; stimulates the secretion of progesterone by the corpus luteum; causes the secretion of testosterone in the testes Source: Ant. Pit. Stimulus: GnRH Target: follicle in ovaries, Lydia cells in testes Effect: forms/maintains corpus luteum in females and hormone production in both genders (-) Feedback:

what is the target organ for gastrin?

chief and parietal cells

What controls the metabolism of glucose and catabolism of proteins?

cortisol. Cortisol is made by the *adrenal cortex* in response to high levels of ACTH *adrenocorticotropic hormone* made by the anterior pituitary gland. The anterior pituitary gland made the ACTH in response to high levels of CRH made by the hypothalamus. The hypothalamus made CRH (corticotropin Releasing Hormone) in response to decreased levels of cortisol.

What is the pathway for: decreased O₂ in blood

decreased O₂ in the blood stimulates the secretion of erythropoietin from the juxtaglomerular cells. it tells the bone marrow stem cells to amp up RBC production

What stimulates the release of ADH?

dehydration

what triggers the release of cholecystokinin?

fatty chyme in the duodenum

what is the antagonistic hormone of insulin?

glucagon

which hormone is responsible for gluconeogenesis and glycogenolysis

glucagon

what stimulates somatotropin production?

growth hormone-releasing hormone (GHRH) Made in the hypothalamus and targeting the Ant. Pit, GHRH stimulates the Ant. Pit to release somatotropin, which encourages growth, increases protein synthesis, and glucose metabolism.

what triggers the release of insulin?

high blood glucose

human chorionic gonadotropin (hCG)

hormone produced by the placenta to sustain pregnancy by stimulating the ovaries to produce estrogen and progesterone *Source:* embryonic cells after fertilization *Stimulus:* embryonic cells *Target:* corpus luteum *Effect:* prevents menses *(-) Feedback:* n/a

HPA axis

hypothalamic-pituitary-adrenal axis In response to stress or trauma, the body produces hormones that will ultimately release cortisol. Cortisol mobilizes glucose to provide the body with enough energy during stressful periods.

what is the pathway for hypertonic interstitial fluid?

hypothalamus - post pit - ADH released - renal collecting duct

HPT axis

hypothalamus releases Thyrotropin Releasing Hormone (TRH), anterior pituitary releases TSH (Thyroid Stimulating Hormone) TSH stimulates thyroid to synthesize T4, T4 converted to T3 in liver and brain T3 maintains metabolic rates and increases metabolism.

melanocyte-stimulating hormone (MSH)

increases the production of melanin in melanocytes of the skin *Source:* Pituitary gland *Stimulus:* sunlight *Target:* melanocytes *Effect:* increases melanin, pigment production, increases appetite *(-) Feedback:* n/a

Where is the plasma protein angiotensinogen made?

liver

What is the target organ for insulin?

liver, skeletal muscles

what is stimulates the release of parathyroid hormone

low blood calcium

what is the target organ for secretin?

mucosa cells in the duodenum

What is the effect of secretin?

neutralizes acid It decreases acid secretion in the stomach and stimulates bicarbonate secretion in the pancreas

what is the pathway for the stimulus of low blood Ca++

parathyroid - osteoclasts, GI tract, renal tubules

erythropoietin

released by the kidney that stimulates the production of red blood cells by the bone marrow. *Source:* Juxtaglomerular cells *Stimulus:* decreased blood O₂ *Target:* Bone marrow stem cells *Effect:* increased RBC production *(-) Feedback:* increased blood O₂

secretin

released in response to ACIDIC chyme It promotes the release of bicarbonate from the pancreas to act as a buffer. *Source:* mucosa cells of the duodenum *Stimulus:* ACIDIC chyme in duodenum *Target:* stomach, pancreas *Effect:* decreases acid secretion in stomach and stimulates bicarbonate secretion in pancreas *(-) Feedback:* neutralized acid

gastrin

secreted by G cells; stimulates stomach acid secretion, motility and emptying *Source:* G cells (in gastric pits) *Stimulus:* gastric distention, vagus nerve reflex *Target:* chief cells, parietal cells *Effect:* secretes pepsinogen and HCl *(-) Feedback:* n/a

Follicle-stimulating hormone (FSH, folliculotropin)

secreted by the anterior pituitary gland to stimulate maturation of the egg cell (ovum) Source: Ant. Pit. Stimulus: GnRH levels Target: Gonads Effect: FSH- gamete production; LH- hormone production (-) Feedback:

Which hormone targets duodenal mucosa in the stomach and pancreas to decrease acid secretion and stimulate bicarbonate production in the pancreas?

secretin

what will your body do if its interstitial fluid becomes hypertonic?

the hypothalamus makes ADH and stores it in the posterior pituitary. When it detects hypertonicity, ADH then travels to the Nephron's collecting ducts, where pure water is reabsorbed, maintaining an ideal tonicity.

What does TSH stimulate?

thyroid gland

what is the target for TSH hormone?

thyroid gland

Hypothyroid symptoms

• Lethargic • Cold • Weight Gain • Constipation • Dry Skin • Puffiness around eyes • Edema • prolonged menstruation in women

what stimulates the release of renin?

↓ BP (JG cells) ↓ Na+ delivery (MD cells) ↓ Blood flow/volume ↑ sympathetic tone (β1 receptors)