APD Introduction to Organs of the Endocrine System (Lecture 19)

1. Autocrine
2. Paracrine
3. Endocrine

What are the 3 mechanisms for hormonal control?

autocrine

What mechanism of hormonal control causes the cell to release substances that **act on the releasing cell?**

endocrine

What mechanism of hormonal control causes the cell to release substances **into the blood** to reach target organs?

paracrine

What mechanism of hormonal control causes the cell to release substances **into connective tissue** to reach **nearby cells**?

True

True/False: Hormonal feedback may be positive or negative.

1. Corticosteroid binding protein
2. Androgen binding protein

What are 2 examples of specific carrier proteins of hormones?

1. Cell surface receptors
2. Intracellular receptors

What are the 2 signaling pathways of hormones?

intracelullar receptors

What type of signaling pathway for hormones go into the cell & modifies genes?

1. Steroids & thyroid hormone
2. Vitamin D

What are 2 examples of intracellular receptors?

albumin

Most hormones can travel bound to ____________.

1. Second messenger systems
2. Tyrosine kinases

What are 2 examples of cell surface receptors of the hormone signaling pathway?

phototransduction

What important process in eye is considered to involve a secondary messenger system?

Metarhodopsin II

In phototransduction diagrams, what does “R\*” stand for?

sodium; 11-cis; all-trans; transducin; cGMP; GMP; sodium

In the pathway of phototransduction, before light hits rhodopsin, ________ enters through cGMP gated channels (depolarized in the dark). When light hits rhodopsin, ________ retinal converts to ________ retinal and rhodopsin is activated. Activated rhodopsin activates _____ who activates phosphodiesterase. Phosphodiesterase breaks down _____ to _________. With no cGMP bound to channels, _________ entry stops (hyperpolarized).

insulin receptor

What is an important example of tyrosine kinase signaling?

nuclear receptors

What type of receptors regulate transcription and are also known as intracellular receptors?

1. Steroids
2. Thyroid hormone
3. Vitamin D

What are the 3 main ligands of nuclear receptors?

vitamin D; thyroid hormone

During intracellular receptor signaling, what binds inside the cell to increase calcium absorption? What binds inside the cell to ultimately increase heat generation & basal metabolic rate?

1. Steroid hormones
2. Small (poly)peptides & proteins
3. Amino acids & arachidonic acid analogs

What are the 3 main types of hormones?

1. Melanin
2. T3 & T4
3. Catecholamines

Tyrosine becomes what 3 things?

seratonin

What does tryptophan become?

steroid hormones

What are cholesterol-derived hormones?

amino acids & arachidonic acid analogs

What type of hormone includes catecholamines, prostaglandins, seratonin, leukotrienes, and T3 & T4?

1. Hypothalamus
2. Pituitary gland
3. Pineal gland

What are the 3 classic endocrine organs?

infundibulum

What connects the hypothalamus to the pituitary gland?

tuber cinereum

What is the most dorsal portion of the hypothalamus?

median eminence

What part of the hypothalamus is part of the tuber cinereum and connects to the infundibulum?

1. Mammillary bodies
2. Optic chiasm

The tuber cinereum is the section between what 2 structures?

1. Median eminence
2. Mammillary bodies
3. Optic chiasm
4. Tuber cinereum

In the image of the hypothalamus, what is indicated by the following colors:


1. Purple
2. Pink
3. Green
4. Blue (includes part of the purple in the center)

posterior pituitary

What part of the pituitary is made of axons and does not produce hormones?

Hypothalamic-pituitary axis

What important function of the hypothalamus controls release of anterior pituitary hormones and synthesizes & stores posterior pituitary hormones?

hypothalamus

What organ regulates almost all body functions, largely through pituitary hormones?

hypothalamus

Releasing & inhibiting hormones come from what organ location?

1. Anti-diuretic hormone (ADH)
2. Corticotropin __releasing__ hormone (CRH)
3. Gonadotropin __releasing__ hormone (GRH)
4. Growth hormone __releasing__ hormone (GHRH)
5. Growth hormone __inhibiting__ hormone (somatostatin)
6. Oxytocin
7. Prolactin __inhibiting__ hormone (dopamine)
8. Prolacting __releasing__ hormone (PRH)
9. Thyrotropin __releasing__ hormone (TRH)

What are the 9 hormones synthesized in the hypothalamus?

1. Anti-diuretic hormone (ADH)
2. Oxytocin

What 2 hormones synthesized in the hypothalamus are released in the posterior pituitary?

releasing

Excitatory anterior pituitary control involves (releasing/inhibitory) hormones.

**R**eleasing

**O**xytocin

**A**nti-diuretic hormone

**D**opamine

**S**omatostatin

What is the pneumonic for remembering what is made in the hypothalamus?

dopamine

What inhibitory anterior pituitary control hormone inhibits prolactin release?

1. Dopamine
2. Somatostatin

What 2 hormones are inhibitory hormones that are under anterior pituitary control?

1. Arcuate nucleus
2. Paraventricular nucleus
3. Preoptic area/Periventricular area
4. Supraoptic nucleus
5. Suprachiasmatic nucleus
6. Lateral Hypothalamic area
7. Ventromedial nucleus

What are the 7 hypothalamic nuclei?

1. Growth hormone releasing hormone (GHRH)
2. Gonadotropin releasing hormone (GnRH)
3. Thyrotropin releasing hormone (TRH)
4. Dopamine

What 4 hormones are made in the arcuate hypothalamic nucleus?

1. Gonadotropin releasing hormone (GnRH)
2. Somatostatin

What hormones are made in the preoptic area of the periventricular region of the hypothalamus?

1. Arcuate nucleus
2. Preoptic/Periventricular region

In what 2 nuclei of the hypothalamus is gonadotropin releasing hormone (GnRH) made?

1. Anti-diuretic hormone (ADH)
2. Oxytocin
3. Corticotropin releasing hormone (CRH)

What 3 hormones are synthesized in the paraventricular nucleus of the hypothalamus?

1. Anti-diuretic hormone (ADH)
2. Oxytocin

What 2 hormones are synthesized in the supraoptic nucleus of the hypothalamus?

1. Paraventricular nucleus
2. Supraoptic nucleus

What 2 nuclei within the hypothalamus are responsible for synthesizing ADH & oxytocin?

suprachiasmatic nucleus

What nucleus of the hypothalamus is responsible for circadian rhythm control?

1. Arcuate nucleus
2. Preoptic/periventricular area

What 2 hypothalamic nuclei are part of the anterior pituitary axis ONLY?

Supraoptic nucleus

What hypothalamic nucleus is part of posterior pituitary release only?

Paraventricular nucleus

What hypothalamic nucleus partakes in both posterior pituitary release and the anterior pituitary axis?

1. Suprachiasmatic nucleus
2. Lateral hypothalamic area
3. Ventromedial nucleus

What are the 3 non-pituitary nuclei of the hypothalamus?

lateral hypothalamic area

What hypothalamic nuclei controls your hunger and is a target for ghrelin?

ventromedial nucleus

What hypothalamic nuclei controls how full you feel and targets ghrelin & leptin?

adenohypophysis

What is another term for anterior pituitary?

6

The anterior pituitary synthesizes and releases ___ main hormones.

1. Neurohypophysis
2. Pars nervosa

What is are 2 other terms for posterior pituitary?

hypothalamus

The posterior releases hormones made by the __________.

False--axons & support tissue

True/False: The posterior pituitary is made up of gland tissue.

Pars distalis

What is the main portion of the anterior pituitary, anatomically?

1. Pars distalis
2. Pars tuberalis

What are the 2 parts of anterior pituitary?

1. Corticotrophs
2. Gonadotrophs
3. Lactotrophs
4. Somatotrophs
5. Thyrotrophs

What are the 5 cell types via immunocytochemistry of the pars distalis (anterior pituitary)?

1. Corticotrophs
2. Lactotrophs
3. Gonadotrophs
4. Thyrotrophs
5. Somatotrophs
6. Gonadotrophs
7. Corticotrophs

Identify which cells of the pars distalis are responsible for releasing the following hormones.


1. Adrenocorticotropic hormone (ACTH)
2. Prolactin (PRL)
3. Luteinizing hormone (LH)
4. Thyroid stimulating hormone (TSH)
5. Growth hormone (GH)
6. Follicular stimulating hormone (FSH)
7. Endorphins

**F**ollicle stimulating hormone

**L**uteinizing hormone

**A**drenocorticotropic hormone (ACTH)

**T**hyroid stimulating hormone (TSH)

**P**rolactin

**E**ndorphins

**G**rowth hormone

What is the pneumonic to remember what the anterior pituitary makes?

capillary plexus

The _________________ supplies the pars distalis with hypothalamic hormones.

From hypothalamus; autonomic nervous system

What is the nerve supply for the posterior pituitary? Anterior pituitary?

portal; 2

The blood supply of the pituitary gland is a _______ system where there are ___ capillary beds BEFORE reaching the heart.

anterior

Blood draining from the hypothalamus carries hypothalamic releasing or inhibitory hormones to ________________ pituitary.

posterior pituitary

What pituitary gland contains unmyelinated axons of cell bodies located in the hypothalamus?

1. Supraoptic nuclei
2. Paraventricular nuclei

What 2 nuclei make up the posterior pituitary gland?

False

True/False: ADH & oxytocin have pituitary nuclei.

1. Follicular stimulating hormone (FSH)
2. Luteinizing hormone (LH)
3. Adrenocorticotropic hormone (ACTH)
4. Thyroid stimulating hormone (TSH)
5. Growth hormone (GH)

Releasing hormones of the hypothalamus & pituitary are pro-release for what 5 anterior pituitary hormones?

prolactin

Dopamine inhibits the release of what anterior pituitary hormone?

growth hormone (GH)

Somatostatin inhibits release of what anterior pituitary hormone?

1. Arcuate nuclei
2. Preoptic/Periventricular area
3. Ventromedial nuclei

What 3 hypothalamic nuclei regulate secretion of the ANTERIOR pituitary?

1. Supraoptic nucleus
2. Paraventricular nucleus

What hypothalamic nuclei have axons that project into the posterior pituitary?

1. Zona glomerulosa
2. Zona fasciculata
3. Zona reticularis

What are the 3 layers of the adrenal cortex?

Zona glomerulosa; Zona fasciculata; Zona reticularis

What layer of the adrenal cortex is responsible for salt? Sugar? Sex?

sympathetic

Adrenal medulla involves (parasympathetic/sympathetic) functions.

1. Epinephrine
2. Norepinephrine

What 2 hormones come from chromaffin cells of the adrenal medulla?

1. Zona glomerulosa
2. Zona reticularis
3. Zona fasciculata

Identify which layer of the adrenal cortex each hormone is made.


1. Mineralocorticoids
2. Androgens/gonadocorticoids
3. Glucocorticoids (mainly synthesized)

Aldosterone

What is an example of mineralcorticoid?

cortisol

What is an example of a glucocorticoid?

DHEA

What is an example of an androgen/gonadocorticoid?

1. Capsule
2. Zona glomerulsa
3. Zona fasciculata
4. Zona reticularis
5. Medulla

Identify the following areas/structures in the image of a microscopic section of the adrenal gland.


1. Red section
2. Blue section
3. Orange section
4. Green section
5. Purple section

fenestrated sinusoidal capillaries

What principal distribution of blood supply of the adrenal gland supplies the cortex and sinusoids of the adrenal medulla?

medulla

Hormones from the adrenal cortex drain into the adrenal _____________.

Chromaffin cells

What are the main cells of the adrenal medulla?

1. Epinephrine
2. Norepinephrine

What 2 hormones are made from chromaffin cells?

1. T3 (triiodothyoronine)
2. T4 (tetraiodothyronine)

Follicular cells of the thyroid gland synthesize what 2 components?

parafollicular cells

What cells of the thyroid gland __secrete__ calcitonin?

False

True/False: You can live without parathyroid hormone.

follicular cells

What cells of the thyroid make thyroid hormones?

calcitonin (parafollicular cells)

The cells surrounding follicular cells make ___________.

2

There are ____ pairs of parathyroid glands on each thyroid lobe.

1. Principal (chief) cells
2. Oxyphil cells

What are the 2 cell types present in the parathyroid gland?

principal (chief) cells

What cells of the parathyroid gland secrete parathyroid hormone?

parathyroid hormone

What hormone is basically opposite calcitonin?

True

True/False: Parathyroid glands are on the thyroid gland.

Retinohypothalamic tract

What tract present in the pineal gland contains ganglion cells (with melanopsin) that communicates with light levels?

suprachiasmatic nucleus; secretion of melatonin by pineal gland

What nucleus of the hypothalamus communicates with the pineal gland? What does this result in?