| PITUITARY GLAND Flashcards by Queenie Mae

Term pituitary is derived from both Latin and Greek which means ___. Initial idea was that
pituitary gland secretes ___. Further studies
identified that it was __ that are released by the pituitary gland

“to spit mucus”
mucus
hormones

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aka hypophysis meaning ___ because its structure is situated below the ____

PITUITARY GLAND (HYPOPHYSIS)
- undergrowth
- hypothalamus

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A pea shaped organ
aka ____ because it has the capability to regulate the activity of other endocrine gland
 Located in a small cavity in the sphenoid bone of the skull called____ surrounded by the dura mater
 All pituitary hormones have ____. Its concentration varies depend on the time of the day. ___ meaning time giver. The hormones
released have particular time of the day when it is more active.
 2 major lobes: ___ AND ___

PITUITARY GLAND (HYPOPHYSIS)
- “Master Gland”
- sella turcica or Turkish saddle
- circadian rhythms
- Zeitgeber
- Anterior, Posterior

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____ is located on the lower portion of the
hypothalamus. Within the hypothalamus, there is ___ which connects the adenohypophysis aka Ant. Pituitary gland to the median eminence and to the hypothalamus. It contains both neural and vascular structures.

Pineal gland
Infundibulum or Pituitary stalk
adenohypophysis aka Ant. Pituitary gland

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The_____ below posterior pituitary is
connected to the super optic and paraventricular hypothalamic nuclei. In this vascular network, there is where____
are produced

pituitary stalk
- vasopressin and oxytocin

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The “true endocrine gland” bc majority of the
endocrine hormones that regulate other endocrine gland are released by this.
- Regulates the release and production of hormones
- also secretes ____

ANTERIOR PITUITARY GLAND
(ADENOHYPOPHYSIS)
- Endorphins

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ANTERIOR PITUITARY GLAND
(ADENOHYPOPHYSIS)
Regulates the release and production of hormones:
1.
2.
3
4
5

Somatotrophs - GH
Lactotrophs - Prolactin
Thyrotrophs - TSH
Gonadotrophs – FSH and LH
Corticotrophs – ACTH

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ANTERIOR PITUITARY GLAND
(ADENOHYPOPHYSIS)
Composed of three cell types:

 Chromophobe (50%)
 Acidophilic (40%)
 Basophilic (10%)

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regulates the activity of thyroid, adrenals,
and reproductive glands

 GH, PRL, TSH, FSH, LH, ACTH

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In target gland, the 2 classifications of ant. Pituitary hormones are ___ or _____

tropic or direct effectors.

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– this compound is released on a
distant tissue/organ in which it affects the
release of that endocrine gland for another
hormone

Tropic effector

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its activity directly affects
the peripheral tissue itself.

Direct effector

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Most abundant of all pituitary hormones
TARGET: All cells
Controlled by ___ (promote an increase
production) and ____ (inhibiting hormone which suppresses the release of GH)
- Markedly elevated during sleep (deep sleep)
- Its overall metabolic effect is to metabolize fat
stores while conserving glucose.
- can be direct/indirect

GROWTH HORMONE (SOMATOTROPIN)
- GH-RH
- Somatostatin

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The height of an individual/linear growth is a
consequence of several factors, not only by the GH.
These includes:
1.
2
3

 Genetic potential
 Nutrition
 Presence and absence of disease or other
hormonal effects

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directly increases the blood glucose lvl by stimulating gluconeogenesis 2 in which energy is utilized from noncarbohydrate sources and reduces insulin sensitivity of cells. Also, it causes _____ specifically lipids stored in adipose tissue

Direct GH
- lipolysis

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this is mediated by the insulin-like growth factor (IGF-1) which affects the production of IGF itself. The insulin-like growth factor is
mitogenic and anti-apoptotic
compounds which means it facilitates
cellular cycle/proliferation.

Indirect GH

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Other things that stimulate somatotrophin
production include:

Sleep stages III and IV
Stress
Estrogens
Exercise
Fasting/hypoglycaemia –
Amino acids
GHRELIN (from stomach) –
Stimulates GH secretion

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Stimulates GH secretion
1.
2
3
4

→ dopamine,
endorphins, serotonin, Norepinephrine

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hunger hormone; predominant compound which may be the reason for obesity

GHRELIN (from stomach) –

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GH DISORDERS

 Idiopathic Growth Hormone Deficiency
 Pituitary Adenoma
 Children with pituitary dwarfism retain normal
proportions and show no intellectual abnormalities
 Acromegaly

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One of the possible reasons is due to pituitary
adenoma in which there is a tumor causing
hypopituitarism causing a decrease in the GH
release/secretion.

PITUITARY DWARFISM

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GH insufficiency can be caused by a variety of
reasons such as:
1
2
3
4
5

 A problem in hypothalamus affecting GHRH
 Hypothalamic disease
 Disruption/obstruction of portal system of GH
 Mutation of GHRH
 Diseases involving somatotroph

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Condition in which the GH excess occurs during
adulthood
Not necessarily tall, but has deformities or
abnormalities in the extremities. They have spadelike hands (disproportional size) and obvious changes in facial features.
- Clinical significance: Overgrowth of skeleton bc GH release increases in bones and soft tissues
causing:
1
2
3
4
5

ACROMEGALY
- acral enlargement (overgrowth of
extremities)
- Organomegaly
-Hyperhidrosis – excessive sweating
- Joint disease
- myopathy

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heart/liver (1 or both) making the individuals prone to conditions such as facial coarsening or soft tissue thickening seen in lips, intestinal
polyposis, protruding jaw called prognathism, impaired glucose tolerance (insulin resistance)

Organomegaly

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Hormone release is increased during childhood  Characterized by: Extreme tall stature  Clinical features are the same with acromegaly (facial features is more common with acromegaly). In terms of survival, they can survive up to adulthood but can have CVDs.

GIGANTISM

(potent GH stimulant)

Clonidine

GH DEFICIENCY TESTS  Specimen: preferably ____: complete rest 30 minutes before blood collection

fasting serum

GH DEFICIENCY TESTS

A. Insulin Tolerance Test B. Arginine Stimulation Test

gold standard & confirmatory test for GH DEFICIENCY TESTS

Insulin Tolerance Test

2nd confirmatory test  Failure of GH to rise > 5ng/ml (adults) and >10 ng/ml (child) is abnormal

Arginine Stimulation Test

determine the level of Somatomedin C or insulin- like growth factor 1 (IGF- 1)  IGF-1 is increased in patients with it.  IGF-1 is low in____

Screening Test for Acromegaly - GH deficiency

Glucose Suppression Test – OGTT (75g glucose) or 100g (from Bishop)  Blood is collected every after 30 minutes for 2 hours; fasting sample is required.  In Bishop’s, GH is measured at time:  0  60 mins – 1 st hr  120 mins – 2nd hr  If the GH fails to decline <1 ng/ml, it is ___  A normal response for this test is a suppression of GH <1ng/ml  High glucose conc. should have been able to suppress the GH release and must be undetectable for normal individuals.

Confirmatory Test for Acromegaly - acromegaly

 Important markers in diagnosing fertility and menstrual cycle disorders.  present in the blood of male and female at all ages.  elevation of ___ is a clue in the diagnosis of premature menopause  Increase of it after menopause is due to lack of ___  Both acts synergistically to promote ovulation and for the secretion of ___ and ___

GONADOTROPINS (Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH)) -FSH - estrogen - androgens (androstenedione) - progesterone

Luteinizing Hormone aka ___ or ___

Interstitial cellstimulating hormone (ICSH) or Lutropin

Follicle Stimulating Hormone aka ___

Follitropin

In male, FSH aids in ___

spermatogenesis

In male, Stimulates the development & functional activity of Leydig cells to produce ___

testosterone

In Female, To stimulate growth and maturation of ovarian follicles  Stimulate _____ secretion (estradiol)  Promote via estrogen the endometrial changes on the 1st portion of menstrual cycle called _____

Follicle Stimulating Hormone -estrogen -proliferative/follicular phase

In female, it acts on theca cells to cause the synthesis of ____, __, and ___  Promoting and maintaining the 2nd portion of menstrual cycle ____  Assists in formation of corpus luteum  necessary for ovulation and final follicular growth

Luteinizing Hormone - androgens, estrogens, progesterone. - (luteal phase)

lack of FSH and LH in both male and female  inability to conceive after 1 year of unprotected intercourse

INFERTILITY

 Aka: __ - Main stimulus for the uptake of iodide by the thyroid gland done via the sodium iodide transporter mechanism - Significant for organification/reduction of iodine  Stimulates thyroid hormone synthesis of ___ and ____  Stimulates growth and vascularity of thyroid gland  Stimulates growth of follicular cells of___  Promotes coupling of tyrosines and promotes proteolytic release of thyroid hormone  Blood levels may contribute in the evaluation of infertility

TSH (THYROID STIMULATING HORMONE) - Thyrotropin -Thyroxine (T4) and Triiodothyronine (T3) - thyroid 4

TSH secretion is suppressed by: 1 2 3

 Thyroid hormone  Glucocorticoids  Estrogens

Other compounds affecting TSH release 1 2 3

1 Acute inflammatory cytokines such as IL1, IL6, TNF - stimulate ACTH release but suppress TRH and TSH 2 Endorphins, serotonin & dopamine - suppress TSH 3 Norepinephrine - stimulates TSH release

derivative of POMC (propiomelanocortin)  acts on adrencal cortex causing stimulation of its growth and secretion of corticosteroids (cortisol). - Produced in response to low serum cortisol; regulator of adrenal androgen synthesis  Highest level is between 6-8AM; lowest level is between 6-11PM  Specimen for testing should not be allowed to have contact with glass bc it is easily oxidized and readily absorbs glass  Specimen Requirement: Blood should be collected into _____. It must be immediately placed in ice and centrifuge at __(must be maintained). o Some lab uses stabilizers like ___  Increased Levels: ___, ____ and ___

ACTH (ADRENOCORTICOTROPIC HORMONE) - prechilled polysterene (plastic) tubes containing EDTA - 4oC temp -protease inhibitors - Addison’s disease, ectopic tumors, after protein-rich meals

hypersecretion of ACTH - leads to bilateral adrenal hyperplasia and cortisol overproduction

CUSHING’S DISEASE

Signs & symptoms:  fullness or rounding of face (moon facie)  distinct: buffalo hump – added fat at the back of the neck  prone to bruises  abdominal striae (stretch marks)  Obesity!!!  Plethora – reddening of cheeks

CUSHING’S DISEASE

Directly a problem involving the adrenal gland  may be caused by secondary (ACTH) or tertiary (CRH) adrenal insufficiency  hyposecretion of glucocorticoids and aldosterone

ADDISON’S DISEASE

Signs & symptoms  extreme fatigue  leads to weight loss and decreased appetite  hyperpigmentation  low BP  craves for increased intake of Na; hypoglycemia  prone to muscle joint paints  irritability and behavioral effect (as if there’s mental illness)  hair loss  sexual dysfunction

ADDISON’S DISEASE

Pituitary lactogenic hormone  In terms of structure, it is related to GH and human placental lactogen  Stress Hormone  Functions in the initiation and maintenance of lactation (stimulated by breastfeeding) and breast tissue development  release can also be stimulated in cases of:___ and ___  Also acts in conjunction with__ and ____  Major Inhibitory Factor: ___  Highest level: 4AM-8AM; 8PM-10PM  Increased Level: ___, ___ ___ ___  Aldomet, phenothiazines, reserpine, TCA (tricycline anti-depressants), some anti-psychotic drugs =___ ; antagonize the effects of dopamine

PROLACTIN - Chest wall disease and stress - estrogen & progesterone - Dopamine - Menstrual irregularity, infertility, amenorrhea and galactorrhea - HYPERPROLACTINEMIA

 Post-partum hypopituitarism due to haemorrhage or shock in a pregnant female at the time of delivery  a type of pituitary ischemia

SHEEHAN’S SYNDROME

inappropriate production of breast milk due to hypersecretion of PRL  Symptoms: irregular menstruation, menopausal symptoms, milk discharges, difficulty in getting erection, breast tenderness and enlargement

GALACTORRHEA

Shows that the px have normal prolactin.  Occurs for those who have been pregnant for several times  No significant pathologic implication

Idiopathic Galactorrhea

absence of menstrual cycle in females due to hypersecretion of PRL

AMENORRHEA

inability to attain penile erection in males due to hypersecretion of PRL

IMPOTENCE

 derived from the brain neuroectodermis  Capable of releasing the hormone but not capable of producing it. Hormones produced by it are controlled by the CNS

POSTERIOR PITUITARY (NEUROHYPOPHYSIS)

POSTERIOR PITUITARY (NEUROHYPOPHYSIS) 2 Hormones:

1. Oxytocin 2. Antidiuretic Hormone (ADH)

aka ___  Acts on the distal convoluted tubule and collecting tubule of the kidneys.  Decreases production of urine; facilitates H2O reabsorption  ____ is the principal regulator of ADH secretion  Increases ____ (Potent pressor agent)  ___ inhibits release of it  This explains why every time a person drinks alcoholic drinks it causes an increased urge to urinate  Diagnostic Test: _____  Urine osmolality does not rise >300 mOsm/kg

ANTIDIURETIC HORMONE - Arginine vasopressin -Osmolality of blood - blood pressure - Ethanol - Overnight water deprivation Test (concentration test)

 in mellitus - ___  in insipidus -

glucose ADH

Deficient in ADH Result in polyuria

DIABETES INSIPIDUS

CLINICAL PICTURE DIABETES INSIPIDUS 1 2 3 4

1. Normoglycemia 2. Polyuria with low S.G 3. Polydipsia 4. Polyphagia – occasional

2 TYPES OF DIABETES INSIPIDUS

True Diabetes Insipidus Nephrogenic Diabetes Insipidus

Deficient ADH with normal ADH receptor.  True if the problem is directly with ADH. This may be due to hypothalamic/pituitary disease

True Diabetes Insipidus

Normal ADH with normal ADH receptor but with renal resistance to ADH action  Kidney is not responding

Nephrogenic Diabetes Insipidus

Normal ADH with normal ADH receptor - Failure of the kidneys to respond to normal/ elevated ADH levels - Urine output: >2.5 L - Treatment___  Diagnostic test: __

Nephrogenic DiabeteS Insipidus - Desmopressin (dDAVP) - Water deprivationtest

Caused by distractive hypothalamic lesion or infundibular lesion  Deficiency of ADH with normal ADH receptor, due to hypothalamic or pituitary disease  Failure of the pituitary gland to secrete ADH  Large volume of urine is excreted (3-20L/day)

True Diabetes Insipidus

There is pathologic ADH excess which may be caused by different conditions. This causes H2O retention → causing reduced plasma osmolality and hyponatremia and eventually leading to edema

SIADH (Syndrome of Inappropriate ADH) secretion

autonomous sustained production of AVP in the absence of known stimuli for its release  Causes: stress, malignancy (leukemia), pulmonary disorders (hypoxia, pneumonia, and emphysema) drug therapies (anticonvulsants, anti-neoplastic drugs, and ACE inhibitors), CNS diseases (brain tumor, meningitis, encephalitis or CNS abscess), prolonged seizures or psychiatric diseases  decreased urine volume, increased sodium concentration and urine osmolality  Ectopic tumor production of ADH: small cell carcinoma of the lung  Diagnosis: ___

Syndrome of Inappropriate ADH Secretion (SIADH) - Water load test

Very similar in ADH composition - ___ secreted by the magnocellular neurons of hypothalamus, secreted in association with a carrier protein  The gene is responsible for the release of 2 proteins: ___ and ___  Unique bc its secretion responds to positive feedback loop mechanism bc the circulating level of it perpetuates further hormone secretion  Stimulates contraction of gravid uterus (____) and muscle contraction (during delivery and lactation)  Released in response to neutral stimulation of receptors in birth canal, uterus and breast touch receptors.  Synthetic preparations of oxytocin (such as pitocin) are used to increase weak uterine contractions during labor and aid in lactation

OXYTOCIN - Nanopeptide - oxytocin and neurophysin 1 - Fergusson reflex

OXYTOCIN Actions

UTERUS at PARTURITION BREAST during LACTATION

UTERUS at PARTURITION

 MYOMETRIAL cells contract  Delivery of baby

BREAST during LACTATION

 MYOEPITHELIAL cells contract  Milk ejection

| PITUITARY GLAND Flashcards

(71 cards)