Endocrine Overview

Front 1

Where are releasing and inhibiting hormones synthesized and released?

Where do they go to?

Back 1

Hypothalamus.

They enter the hypophyseal portal system in the median eminance and then to a secondary capillary bed in the anterior pituitary.

Front 2

All hormones released from the pituitary are _____________ hormones.

Back 2

polypeptide

Front 3

Corticotrophin (adrenocorticotrophic hormone or ACTH):

Where is it made?
What type of hormone?
What does it do?

Back 3

Anterior Pituitary.

Polypeptide.

Stimulates secretion of glucocorticoids (cortisol) and androgens (androstenedione) by the adrenal cortex.

Front 4

Follicle stimulating hormone:

Where is it made?
What type of hormone?
What does it do?

Back 4

Anterior Pituitary.

Polypeptide.

In women it stimulates development of the follicles in the ovaries.
In men it regulates spermatogenesis.

Front 5

Luteinizing hormone (LH):

Where is it made?
What type of hormone?
What does it do?

Back 5

Anterior Pituitary.

Polypeptide.

Women: Triggers ovulation and formation of the corpus luteum, and stimulates the secretion of estrogen and progesterone.
Men: Stimulates testosterone secretion by testes.

Front 6

Prolactin:

Where is it made?
What type of hormone?
What does it do?

Back 6

Anterior Pituitary.

Polypeptide.

Women: Stimulates milk synthesis and secretion (not release).

Front 7

Thyrotrophin (Thyroid Stimulating Hormone or TSH):

Where is it made?
What type of hormone?
What does it do?

Back 7

Anterior Pituitary.

Polypeptide.

Stimulates synthesis and release of thyroid hormone by thyroid follicles.

Stimulated by TRF, inhibited by T4.

Front 8

Growth Hormone (GH, Somatotrophin or Human Growth Hormone (HGH)):

Where is it made?
What type of hormone?
What does it do?

Back 8

Anterior Pituitary.

Polypeptide.

Stimulates body growth (release of somatomedin by liver & lipolysis)

Front 9

Oxytocin:

Where is it made?
What type of hormone?
What does it do?

Back 9

Posterior Pituitary.

Polypeptide.

Triggers milk release in response to suckling. Stimulates smooth muscle contraction of uterus.

Front 10

Vasopressin (ADH):

Where is it made?
What type of hormone?
What does it do?

Back 10

Posterior Pituitary.

Polypeptide.

Increases water retention by distal tubule and collecting ducts of the nephrons by formation of aquaporin channels. Its release is triggered by high plasma osmolarity.

Front 11

Thyroxin (T4):

Polypeptide or steroid?

Back 11

Neither. Made from R-groups of tyrosin, but behaves like a steroid.

Front 12

Tri-iodothyronine (T3):

Polypeptide or steroid?

Back 12

Neither. Made from R-groups of tyrosin, but behaves like a steroid.

Front 13

Hypoadrenalism:

Name for it?
Why does it happen?

Back 13

Addison's Disease.

Result of atrophy of the adrenal cortices.

Front 14

Hyperadrenalism:

Name for it?
Symptoms?

Back 14

Cushing's Syndrome.

Symptoms caused by excess cortisol. Fat deposition in the thoracic and abdominal region, moon face, acne and facial hair.

Front 15

Estrogen (estradiol):

What type of hormone?
Where is it made?
What does it do?

Back 15

Steroid.
Ovaries.

Promotes growth and development of female repro. tract and secondary sexual characteristics.
Inhibits osteoclasts.

Front 16

Progesterone:

What type of hormone?
Where is it made?
What does it do?

Back 16

Steroid.
Ovaries.

Secreted in luteal phase of the ovary.
Stimulates the endometrium of uterus to increase secretions (prepping for fertilization/implantation).

Front 17

Corticotrophin-releasing Hormone (CRH or CRF):
What type of hormone?
Where is it made?
Function?

Back 17

Polypeptide.

Made in the Hypothalamus.

Stimulates the release of ACTH by corticotrophs in the anterior pituitary. This causes the release of cortisol, which helps the body deal with stress.
Released in response to stress.
Peaks at about 8 am as part of diurnal rhythm.

Front 18

Prolactin-inhibiting hormone (PIH, Dopamine or DA):
What type of hormone?
Where is it made?
Function?

Back 18

Neither (made from tyrosine).
Hypothalamus.

Inhibits the release of prolactin by lactotrophs in the ant. pit.

Front 19

Growth-Hormone-Releasing Hormone (GHRH or GHRF):
What type of hormone?
Where is it made?
Function?

Back 19

Polypeptide.
Hypothalamus.

Stimulates the secretion of HGH by somatotrophs of the Ant. Pit.

Front 20

Growth-Hormone-Inhibiting Hormone (GHIH or Somatostatin):
What type of hormone?
Where is it made?
Function?

Back 20

Polypeptide.
Hypothalamus.

Inhibits secretion of HGH by somatotrophs of the anterior pituitary.

Front 21

Gonadotrophin-Releasing Hormone (GnRH or GnRF):
What type of hormone?
Where is it made?
Function?

Back 21

Polypeptide.
Hypothalamus.

Stimulates secretion of LH and FSH by gonadotrophs of the ant. pit.
Triggers the onset of puberty.

Front 22

Thryrotrophin-Releasing Hormone (TRH or TRF):
What type of hormone?
Where is it made?
Function?

Back 22

Polypeptide.
Hypothalamus.

Stimulates secretion of TSH by thyrotrophs in the anterior pituitary.
TRF secretion is stimulated by prolonged cold.

Front 23

Oxytocin:
What type of hormone?
Where is it made?
Function?

Back 23

Polypeptide.
Hypothalamus, released from posterior pituitary.

Smooth muscle contraction and milk release.

Front 24

Vasopressin (Antidiuretic Hormone or ADH):
What type of hormone?
Where is it made?
Function?

Back 24

Polypeptide.
Hypothalamus.

Synthesized by cells of the supraoptic nucleus of the hypothalamus, and transported down their axons for release in the posterior pituitary.

Front 25

Exopthalmus, bulging eyes and cold tolerance are symptoms of what?

Back 25

Hyperthyroidism.

Front 26

Myxedema and atherosclerosis are symptoms of what?

Back 26

Hypothyroidism.
If it occurs in utero or in the early neonate it can result in dwarfism or cretinism.

Front 27

Calcitonin:
What type of hormone?
Where is it made?
What stimulates its production?
Function?

Back 27

Polypeptide.
In the parafollicular cells of the thyroid gland.

Made in response to elevated plasma levels of calcium.

Acts to lower plasma calcium concentration (opposite of PTH).
Inhibits osteoclast activity and number.

Front 28

Parathyroid Hormone (parathormone or PTH):
What type of hormone?
Where is it made?
What stimulates its production?
Function?

Back 28

Polypeptide.
Made in the parathyroid glands.

Stimulated by low plasma calcium (<2.4mM).

Stimulates osteoclast activity.
Stimulates kidney to retain calcium and lose phosphate (increase calcium but keeps phosphate level the same).
Stimulates the kidney to make 1,25 dihydroxy vitamin D3 (active form).

Front 29

Cortisol (glucorticoid):
What type of hormone?
Where is it made?
What stimulates its production?
Function?

Back 29

Steroid.
Cortex of Adrenal Glands.

Released by the cells of the Zona Fasciculata in response to ACTH.

Stimulates gluconeogenesis.
Elevates blood glucose.
Mobilizes fats and amino acids.
Provides anti-inflammatory actions upon injection.

Allows epinephrine to work.

Front 30

Aldosterone (mineralocorticoid):
What type of hormone?
Where is it made?
What stimulates its production?
Function?

Back 30

Steroid.
Cortex of Adrenal Glands (Zona glomerulosa).

Angiotensin II and increased potassium stimulate its release.

Increases sodium retention and potassium loss in the kidney by acting at the collecting duct and distal tubule.
Water retention is then enhanced.

Front 31

Androgens:
What are 4 types?
Where are they made?
Function (men/women)?

Back 31

1. Testosterone
2. Androstenedione*
3. Hydroxyprogesterone
4. Dehydroepiandrosterone (DHEA)

Made in Zona Reticularis of Cortex of Adrenal Glands.

Men: Testosterone
Women: Produces sex drive

Overactivity can lead to prococious (early) puberty in men and masculinization in women.

Front 32

In the Adrenal Medulla, what is the ratio of epinephrine to norepinephrine?

Back 32

20 epinephrine: 1 NE

Front 33

This can be used in the adrenal medulla to make tyrosine.

Back 33

Phenylalanine.

Front 34

Epinephrine:
What type of hormone?
Where is it made?
Function?

Back 34

Neither (made from tyrosine).
In the Adrenal Medulla.

Fight of Flight (vasoconstriction, increased cardiac output, etc.)

Front 35

Norepinephrine:
What type of hormone?
Where is it made?
Function?

Back 35

Neither (made from tyrosine).
Adrenal Medulla.

Fight of Flight (vasoconstriction, increased cardiac output, etc.). Lower receptor affinity than Epinephrine.

Front 36

Dopamine:
What type of hormone?
Where is it made?
Function?

Back 36

Neither (made from tyrosine).
Adrenal Medulla.

Many functions in the brain.

Front 37

Relaxin:
What type of hormone?
Where is it made?
Function?

Back 37

Polypeptide.
Ovaries.

Relaxes the cervix and pelvic ligaments during parturition.

Front 38

Inhibin:
What type of hormone?
Where is it made?
Function?

Back 38

Polypeptide.
Ovaries.

Inhibits FSH and LH.

Front 39

Chorionic Gonadotrophin (hCG):
What type of hormone?
Where is it made?
Function?

Back 39

Polypeptide.
Placenta.

Supports the developing placenta.

Front 40

Placental Lactogen (PL or chorionic somatomammotropin):
What type of hormone?
Where is it made?
Function?

Back 40

Polypeptide.
Placenta.

Promotes the release of fat stores and inhibits glucose utilization in the mother.

Front 41

Estriol (a form of estrogen):
What type of hormone?
Where is it made?
Function?

Back 41

Steroid.
Placenta.

Enlarge the uterus and breasts.
Relaxes the joints along the birlth canal.

Front 42

Progesterone:
What type of hormone?
Where is it made?
Function?

Back 42

Steroid.
Placenta.

Maintains the nutrition of the embryo.
Decreases uterine contractility.
Stimulates breast development.

Front 43

Testosterone:
What type of hormone?
Where is it made?
Function?

Back 43

Steroid.
Testes.

Stimulated by LH from anterior pituitary.
Assist FSH in stimulating sperm formation and development.
Development of male secondary sex characteristics.

Front 44

Inhibin:
What type of hormone?
Where is it made?
Function?

Back 44

Polypeptide.
Testes.

Acts to further release of FSH and LH by anterior pituitary.
Slows down spermatogenesis.

Front 45

Renin:
What type of hormone?
Where is it made?
Function?

Back 45

Polypeptide.
Kidney.

Stimulates kidney to retain sodium and water.
Potent stimulus for aldosterone release.

Front 46

Erythropoietin:
What type of hormone?
Where is it made?
Function?
Stimulus?

Back 46

Polypeptide.
Kidney.

Stimulates RBC synthesis in bone marrow.

Hypoxia is a potent stimulus.

Front 47

1, 25-dihydroxycholecalciferol (Vit. D):
What type of hormone?
Where is it made?
Function?
Stimulus?

Back 47

Steroid.
Kidney.

Acts to increase calcium absorption from the gut.

Stimulated by PTH.

Front 48

Atrial Natiuretic Polypeptide (ANP):
What type of hormone?
Where is it made?
Function?

Back 48

Polypeptide.
Heart.

Increases sodium excretion by the kidneys (increases water loss in the urine).
Helps reduce blood pressure.

Front 49

Cytokines:
What type of hormone?
Where is it made?
Function?

Back 49

Polypeptides.
Macrophages.

Participate in B and T cell activity in immune response.

Front 50

Melatonin:
What type of hormone?
Where is it made?
Function?

Back 50

Polypeptide.
Pineal Gland.

Decreases FSH and LH secretion by the anterior pituitary.