ENDO FINAL (copy)

What secretes gastrin?

G cells

What hormone is stimulated by the following:

• Food in the stomach

• Gastric distention

• Elevated pH

• Vagal stimulation

Gastrin

What is gastrin inhibited by?

1) Secretin

2) GIP

3) Somatostatin

4) H+ (low pH/high acidity)

What does gastrin stimulate in the body?

• Gastric acid secretion/intrinsic factor (parietal cells)

• Secretion of pepsinogen (chief cells)

• Secretion of bile & pancreatic enzymes

What hormone is related to Zollinger-Ellison syndrome?

Gastrin

What secretes CCK?

I cells

What stimulates the secretion of CCK?

Chyme w/ fatty acids & amino acids

What effects does CCK have on the body?

• Gallbladder cxt

• Release of pancreatic enzymes

• Secretion of bicarb from pancreas

Secretin is secreted by ____

S cells

What stimulates the release of secretin?

Acidic chyme

What hormone inhibits gastrin and gastric acid secretion?

Secretin

What hormone is released by K cells?

Gastric inhibitory polypeptide (GIP)

What effects does GIP have on the body?

• Reduces gastric acid & intestinal motility

• Stimulates insulin release

What secretes glucagon-like peptide (GLP-1)?

L cells of the small intestine

What hormone increases satiety and increases the release of insulin?

GLP-1

What hormone does PP cells of the pancreas release?

Pancreatic polypeptide

What hormone is stimulated by CCK and gastrin?

Pancreatic polypeptide

What hormone inhibits pancreatic exocrine secretion and gallbladder contraction?

Pancreatic polypeptide

What hormone works synergistically with GLP-1?

Peptide YY

Where is somatostatin released?

D cells

What is the effect of vasoactive intestinal peptide (VIP) on the body?

Increases H2O & electrolyte secretion from the pancreas and gut

What hormone is associated with WDHA syndrome?

Vasoactive intestinal peptide (VIP)

What are LH and FSH released by?

Gonadotrophs of anterior pituitary

What mechanism is used by LH and FSH?

Adenylyl cyclase

What stimulates the release of LH and FSH?

GnRH (phospholipase C)

What inhibits FSH?

Inhibin

What hormones has the following effects on the body?

• Production of estrogen, progesterone, & testosterone

• Oogenesis & spermatogenesis

FSH & LH

What hormone is secreted by sertoli cells?

Antimullerian hormone (AMH)

What hormone is stimulated by FSH and the testis?

AMH→ anti mullerian hormone

What is the primary function of AMH?

• Induces regression of embryonic mullerian ducts

• Expresses aromatase

What secretes testosterone?

• Leydig cells → Males

• Theca cells → Females

What hormone is stimulated by LH?

Testosterone

What are the primary effects of testosterone on the body?

• Development of Wolffian ducts

• Maintains cholesterol levels

What is estrogen secreted by?

Granulosa cells

What stimulates the release of estrogen?

FSH

What is the primary effect of estrogen on the female body?

Thickens endometrium of the uterus & growth of the uterus

What secretes progesterone?

Granulosa cells

What hormone stimulates the release of progesterone?

FSH

What are the primary effects of progesterone on the body?

• Prepares endometrium to receive and nourish an implanted fertilized egg

• Maintains secretory activity of the uterus during luteal phase

Where is ADH released from?

Supraoptic nucleus of hypothalamus

What stimulates the release of ADH?

• Decrease in blood pressure/volume

• Increase in blood osmolarity

What inhibits ADH?

Vasopressin receptor antagonist (VRA)

What hormone increases H2O reabsorption in the principal cells of the kidney?

ADH

Where is oxytocin released?

Paraventricular nucleus of the hypothalamus

What mechanism does oxytocin use?

Phospholipase C

What hormone is stimulated by the following?

• Labor

• Milk let-down

• Love

Oxytocin

What is the primary function of oxytocin?

Stimulates:

1. Uterine contraction & dilation of the cervix

2. Milk ejection reflex (let-down)

What releases growth hormone (hGH)?

Somatotrophs of anterior pituitary

What mechanism does growth hormone use?

Tyrosine kinase

What stimulates the release of hGH?

Growth hormone releasing hormone (GHRH)

What hormone is inhibited by GHIH/GIH/Somatostatin?

hGH

What tissue does growth hormone effect?

1. Adipose (lipolysis)

2. Liver (gluconeogenesis & glycogenolysis)

3. Skeletal muscle (protein synthesis)

4. Bone (+OB/-OC)

What hormone is released by lactotrophs of the anterior pituitary?

Prolactin (PRL)

What mechanism does prolactin (PRL) use?

Tyrosine kinase

What stimulates the release of prolactin?

1. Prolactin releasing hormone (PRH)

2. Thyrotrophin releasing hormone (TRH)

What inhibits prolactin?

Dopamine (PIH)

What is the primary effect of prolactin on the body?

1. Lactogenesis

2. Inhibition of ovulation

What releases thyroid-stimulating hormone (TSH)?

Thyrotrophs of anterior pituitary

What mechanism does TSH use?

Adenylyl cyclase

What stimulates the release of TSH?

Thyrotrophin releasing hormone (TRH)

What is the primary effect of thyroid stimulating hormone?

Production of T3 & T4 from thyroid gland

What hormone is released by corticotrophs of anterior pituitary?

Adrenocortical hormone (ACTH)

What mechanism is used by ACTH?

Adenylyl cyclase

What stimulates the release of ACTH?

Corticotrophin releasing hormone (CRH)

What is the primary effect of ACTH on the body?

Production of aldosterone, cortisol, and androgens adrenal gland

What hormone is released by the arcuate nucleus of the hypothalamus?

Growth hormone releasing hormone (GHRH)

What stimulates the release of GHRH?

• Hypoglycemia

• Exercise (increased amino acids in blood)

• Healthy stress

Where is PRH, TRH, and CRH all released from?

Paraventricular nucleus

What does Thyrotrophin releasing hormone (TRH) stimulate the release of?

1. TSH

2. PRL

What mechanism does corticotrophin releasing hormone (CRH) use?

Adenylyl cyclase

Where is GnRH produced?

Arcuate nucleus

What inhibits GnRH?

Increase in prolactin levels

Where is GHIH/GIH/somatostatin produced?

Arcuate nucleus

What mechanism does GHIH use?

Peptide hormone

What stimulates GHIH?

1. Hyperglycemia

2. High fatty acid levels

Where is dopamine/PIH produced?

Arcuate nucleus

What is the primary effect of PIH in the body?

Inhibits prolactin via inhibiting adenylyl cyclase mechanism

What pathologies are associated with ADH?

1. Central diabetes insipidus → Low ADH, High aldosterone (hypothalamus/pituitary issue)

2. Nephrogenic diabetes insipidus → High ADH (receptor issue by principal cells in kidneys)

3. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) → High ADH (causes hypervolemia → cerebral edema)

What conditions are associated with growth hormone?

1. Dwarfism → Low GH, Kids

2. Giantism → High GH, kids (pituitary ademona)

3. Adult growth hormone deficiency (AGHD) → Low GH, adults

4. Acromegaly → High GH, adults

What mechanism does TSH use?

Adenylyl cyclase

What is the primary action of TSH?

Regulate growth & secretion of thyroid gland

What mechanism does ACTH use?

Adenylyl cyclase

Where does ACTH act and what effects does it have at those locations?

1. Zona glomerulosa (ZG) → Aldosterone (weak)

2. Zona fasciculata (ZF) → Cortisol

3. Zona reticularis (ZR) → Adrenal androgens

What is secreted by the follicular epithelial cells of the thyroid gland?

T3 & T4

What effects does T3/T4 have on the body?

Liver

• Glycogenolysis & gluconeogenesis (increase blood sugar)

Muscle

• Increase protein synthesis

Adipose

• Lipolysis

Bone

• Increase OB

What is secreted by C cells (parafollicular cells)?

Calcitonin

What mechanism does calcitonin use?

Adenylyl cyclase

What stimulates the release of calcitonin?

High blood calcium levels

What is the primary effect of calcitonin in the body?

Lowers blood calcium levels (Increases osteoblastic activity)

What is parathyroid hormone produced by?

Chief cells

What stimulates the production of PTH?

Low blood calcium

What does PTH do in the body?

Increases blood calcium levels

• Increasing osteoclastic activity

• increases calcium reabsorption from the kidneys & small intestine

What is secreted by the zona glomerulosa?

Aldosterone

What stimulates the production of aldosterone?

RAAS (low BP, AT II, high blood K+)

What is the primary effect of aldosterone?

Increases renal tubular reabsorption of Na⁺ & secretion of K⁺

What is the most common cause of hyperthyroidism?

Grave’s hyperthyroidism

What would you expect blood levels to look like for the different types of hyperthyroidism?

1. Primary → High T3/T4, TSH low (Thyroid issue)

2. Secondary → High T3/T4, TSH normal/high (Ant pituitary issue)

What does Joe-Basedow syndrome cause and what hormone does it effect?

Iodine-induced thyrotoxicosis

Thyroid hormone

What pathology is caused by thyroid-stimulating immunoglobulins crossing the placenta?

Neonatal hyperthyroidism

What is the difference between primary and secondary hypothyroidism?

1. Primary → T3/T4 low, TSH high (Thyroid issue)

2. Secondary → T3/T4 low, TSH low (Ant pituitary issue)