| PITUITARY GLAND Flashcards
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
aka hypophysis meaning ___ because its structure is situated below the ____
PITUITARY GLAND (HYPOPHYSIS)
- undergrowth
- hypothalamus
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
____ 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
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
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
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
ANTERIOR PITUITARY GLAND
(ADENOHYPOPHYSIS)
Composed of three cell types:
Chromophobe (50%)
Acidophilic (40%)
Basophilic (10%)
regulates the activity of thyroid, adrenals,
and reproductive glands
GH, PRL, TSH, FSH, LH, ACTH
In target gland, the 2 classifications of ant. Pituitary hormones are ___ or _____
tropic or direct effectors.
– this compound is released on a
distant tissue/organ in which it affects the
release of that endocrine gland for another
hormone
Tropic effector
its activity directly affects
the peripheral tissue itself.
Direct effector
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
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
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
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
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
Stimulates GH secretion
1.
2
3
4
→ dopamine,
endorphins, serotonin, Norepinephrine
hunger hormone; predominant compound which may be the reason for obesity
GHRELIN (from stomach) –
GH DISORDERS
Idiopathic Growth Hormone Deficiency
Pituitary Adenoma
Children with pituitary dwarfism retain normal
proportions and show no intellectual abnormalities
Acromegaly
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
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
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
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
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