CLINICAL CHEMSTRY 2: Endocrinology

HYPOTHALAMUS

Located in the brain; Below the THALAMUS, Above the PITUITARY

HYPOTHALAMUS

Acts as a master regulator of many critical bodily functions

HYPOTHALAMUS

Links your nervous system to your Endocrine System

FUNCTION OF HYPOTHALAMUS

Maintains homeostasis; Keeps body environment stable by regulating body temp, thirst, water balance and even sleep and wake cycle

FUNCTION OF HYPOTHALAMUS

It regulates your Circadian Rythm, Hunger and Apetite

FUNCTION OF HYPOTHALAMUS

Controls Endocrine system; Since it secrete/ release/ produce inhibiting and secreting hormones

PURPOSE OF RELEASING AND INHIBITING HORMONES

Control Anterior Pituitary Gland (TRH)

Thyrotropin Releasing Hormone (TRH)

Stimulates the release of Thyroid-Stimulating Hormone (TSH) to produce Thyroid Hormones

HYPOTHALAMUS

Releases Antidiuretic Hormone (ADH) and Oxytocin

ADH and Oxytocin

Known as Posterior Pituitary Hormones but they are produced by the Hypothalamus

ADH and Oxytocin

Hormones released in the Posterior Piuitary Gland

HYPOTHALAMUS

Regulates Autonomic Nervous System (Sympathetic & Parasympathetic Responses)

HYPOTHALAMUS

Acts as body’s thermostat; detect changes in blood temperature- trigger sweating/ shivering

HYPOTHALAMUS

Signals hunger/ fullness

HYPOTHALAMUS

Important in water balance due to its OSMORECEPTORS

OSMORECEPTORS of HYPOTHALAMUS

Detects the changes in blood osmolality

HYPOTHALAMUS

Connecting to its osmoreceptors, the reason why it helps in regulating with the release of ADH (Kidney Water Reabsorption)

HYPOTHALAMUS

Regulates emotional and sexual behavior via limbic system (emotions, bonding, libido)

HYPOTHALAMIC HORMONES

Also called as “Hypophysiotropic Hormones”

Thyroid-stimulating Hormone

Meaning of TSH

Gonadtropin-releasing Hormone

Meaning of GnRH

Corticotropin-releasing Hormone

Meaning of CRH

Growth-Hormone-Releasing Hormone

Meaning of GHRH

ANTERIOR PITUITARY GLAND

Targeted by Hypothalamic Releasing Hormones

TRH

Stimulate TSH and Prolactin release

GnRH

Stimulate FSH and LH

CRH

Stimulate ACTH release

GHRH

Stimulate GH release

PRF

Stimulates Prolactin release

Prolactin Releasing Factor

Meaning of PRF

TRH, GnRH, CRH, GHRH and PRF (TGC CP)

Examples of Hypothalamic Releasing Hormones

SOMATOSTATIN & DOPAMINE

Examples of Hypothalamic Inhibitory Hormones

SOMATOSTATIN

Inhibits GH and TSH

DOPAMINE

Inhibits Prolactin and TSH release

OXYTOCIN & ADH (VASOPRESSIN)

Examples of Hypothalamic Neurohormones

SOMATOSTATIN

Also known as GHIH (Growth Hormone Inhibiting Hormone)

ADH & Oxytocin

Produced by the Hypothalamus but stored and released in the Posterior Pituitary Gland

PINEAL GLAND

Located also in the Brain; Also known as “Epiphysis Cerebri”

PINEAL GLAND

It is a tiny “P-shaped” Endocrine Gland that can be found in the middle of the brain; beneath the back part of Corpus collusm

LH, FSH, TSH, ACTH, GH, and PRL

Hormones associated in Anterior Pituitary Gland

Luteinizing Hormone

Meaning of LH

Follicle-Stimulating Hormone

Meaning of FSH

Thyroid-Stimulating Hormone

Meaning of TSH

Adenocortiocotropic Hormone

Meaning of ACTH

Growth Hormone

Meaning of GH

Prolactin

Meaning of PRL

LH

Triggers ovution and corpus luteum formation; stimulates testosterone

FSH

Assists the ovarian follicle development in females and spermatoctytes in males

TSH

Stimulates the Thyroid Gland to release Thyroid Hormones (T3 and T4)

ACTH

Stimulates adrenal cortex

GH

Promotes Growth and Development

PRL

Stimulates lactation and mammary gland development in nursing mothers

Gonads (Ovaries and Testes)

Target Gland of LH and FSH

Thyroid Gland

Target gland of TSH

Adrenal Cortex

Target Gland of ACTH

Muscles, Bone, and Liver

Target gland of GH

Mammary Gland

Target gland of PRL

Estrogen and Testosterone

Feedback when LH target the Gonads (oavries and testes)

Inhibin

Feedback when FSH targets the gonads (ovaries and testes)

T3 and T4

Feedback when then TSH targets the Thyroid Gland

Cortisol

Feedback when ACTH targets the Adrenal Cortex

IGF-1 (Insulin Growth Factor-1)

Feedback when GH target muscles, bone and liver

Dopamine

Feedback when PRL targets mammary gland

Anterior Pituitary (Adenohyphophesis)

Provides the secondary control and stimulation

Primary, Secondary and Tertiary

Types of Endocrine Disorders

Primary Endocrine Disorder

The disorder is in the gland secreting itself

Secondary Endocrine Disorder

The problem is with your Pituitary Gland

Stimulating Hormones (TROPINS)

Anterior Pituitary (Adenohypophesis) generally secretes what?

Gonadotropins

LH and FSH are what type of tropins?

Tyrotropin

Other name of TSH in the class of Tropins

Corticotropins

ACTH is what type of tropins?

Anterior Pituitary

Produces glycoprotein hormones that are also called “Tropins”

PINEAL GLAND

Controls circadian cycle, sleep and wakefulness by secreting the hormone Melatonin

MELATONIN

Hormone secreted by the Pineal Gland

N-Acetyl-5-hydroxytryptamine

Other name of Melatonin

Melatonin

It is synthesized from Tryptophan (an amino acid derivative)

Melatonin

Secreted during the dark period of the day (night time)

60-70 pg/mL (Adults)

Reference Value of Melatonin

Melatonin

Regulates circadian rythm and sleep patterns: High at night and Low at daytime

Melatonin

Inhibits pituitary gonadal axis; low levels of melatonin for the maturation of the gonads (sex organs)

Melatonin

High levels of this hormone causes delay of set of puberty since low levels are needed in order for gonads to mature

Melatonin

Can be treatment of Insomnia and jetlag

Aging

Decreases your melatonin levels

Induce sleep and lessen depression

Therapeutic use of melatonin

Melatonin

Used for protection against free radicals/ Has antioxidant properties

Serotonin

Direct precursor of melatonin

Serotonin

It is a neurotransmitter synthesized from tryptopahan

Serotonin

Useful in diagnosis of Carcinoid syndrome

5-HIAA

It is the metabolite of serotonin that can be excereted in the urine

Serotonin

Building block of Melatonin (It is made to make Melatonin)

Serotonin

Its not a Hormone but rather, a neurotransmitter

Anti-depressants

What disrupts serotonin if you take these and affects sleep patterns

Serotonin

It is synthesized using Tryptophan

5-HIAA (5-hydroxyindole acetic acid)

If the body metabolizes serotonin, what is its metabolite/ product?

Urine

If talking about metabolites, what sample do you measure these?

Purpose of determining 5-HIAA

Used to diagnose carcinoid syndrome/tumors

Sequence of production of melatonin

5-HIAA —> Serotonin —> Melatonin

24-hour Urine

What sample is used to measure the amount/presence of 5-HIAA