Pituitary Gland Flashcards
Pituitary gland
-Anterior pituitary (_____) – derived from the epithelial tissue of the embryonic _____.
adenohypophysis
oral cavity
During embryonic development, the roof of the ____ bulges (downwards or upwards ?) (____) to form a tiny, ___-like structure known as ___, which then fuses with the ____ portion of the pituitary gland
Failure of the above process to occur normally may lead to an abnormal pituitary structure or the formation of ___ and ____
Roof; mouth
Upwards; invaginates
bubble; Rathke’s pouch
posterior
cysts and clefts
The anterior pituitary accounts for approximately ____% of the total mass of the gland and includes two major parts:
- Pars distalis – (smaller or larger?) , ____ portion
- Pars tuberalis – highly ____ sheath wrapped around the _____
- A third (intermediate) region of the pituitary gland is often recognisable and this is known as the ______ and is usually present as a (thin or thick?) band of tissue that marks the point where the ____ and ____ ——
70-80
Larger; bulbous
vascular; infundibular stalk.
pars intermedia;Thin
anterior and posterior pituitaries fuse
Hormones of the posterior pituitary
-____ and _____ are concentrated and stored in the pars _____ before being released into the blood when required.
ADH and oxytocin
nervosa
Posterior pituitary hormones are amine hormones
T/F
F
Peptide
Posterior pituitary hormones are peptide hormones and, as they are produced by _____, they are often called ______
neurons
neuropeptides.
Antidiuretic hormone
- ADH plays a vital role in regulating ___ balance and_____
- Specialised ___receptors located in the hypothalamus continually monitor the _____ of the blood.
- When the body loses water dehydration may occur and the _____ rises.
- This is detected by the ____ osmoreceptors, which initiate the release of ADH from the _____.
fluid
blood pressure.
osmo
solute concentration
plasma solute concentration
hypothalamic
posterior pituitary
ADH primarily acts on the ____
-This ____ the volume of urine produced, resulting in the urine being (lighter or darker?) and ____ concentrated.
kidneys
reduces
darker
more highly
By ____ fluid reabsorption back into the blood, ADH helps normalise the ______ of the blood.
Increasing
solute concentration
ADH is also released after a drop in blood volume or pressure.
T/F
T
normalisation of blood pressure is further enhanced by ADH acting as a powerful vasodilator
T/F
F
Vasopressor
ADH-induced vasoconstriction, particularly in the_____ (_____), further increases and normalises blood pressure
peripheral arterioles; small arteries
(Increased or Reduced ?) secretion of ADH can lead to diabetes _____
Reduced
insipidus (DI).
diabetes insipidus (DI)
-Patients with DI cannot _____ their urine, resulting in _____.
-Large volumes of urine (_-_L/ day) are usually produced
-if not treated, this can lead to ____
-two major types are recognised:
_______ and _____
concentrate
polyuria
3-20
severe dehydration.
Neurogenic; nephrogenic
DI is (common or rare?) , affecting around 1 in _____ people
Rare
25,000
Neurogenic or ____ DI is caused by the ____secretion of ___ by the posterior pituitary. This is most often due to ____ ,____ affecting the hypothalamus or pituitary or, more rarely,____; treated with _____
central
under
ADH
trauma
tumors
infections
desmopressin
desmopressin is a _____of ____
synthetic analogue
ADH
Nephrogenic DI is a rarer form, in which patients usually have ___ ADH synthesis and secretion, but their kidneys are ______ to the effects of ADH – most commonly due to _____ or ___-induced kidney damage
normal
insensitive
kidney disease
drug
Which type of diabetes insupidus has a more complex treatment
Nephrogenic
Oxytocin
-Oxytocin is released into the blood at high concentration towards the (start or end?) of the ____ period and initiates ___ by stimulating____ of the ______
End
gestational
parturition
contractions
Myometrium
Myometrium is the ____ layer of the uterus
muscular
Oxytocin secretion is regulated by a ______ feedback mechanism, whereby increased oxytocin stimulates more-powerful _____, which in turn stimulate ______
positive
myometrial contractions
the release of more oxytocin
Oxytocin also stimulates the ‘ _____ reflex’ in lactating mothers; here the ____ muscle linings of the ____ in the breast contract, making milk available to the baby during ____.
this is regulated by ____ feedback
letdown
smooth
milk ducts
suckling
positive
______ is often referred to as ‘the love hormone’ because it plays an important role in promoting ______
-it is also thought to facilitate _____ between partners.
Oxytocin
mother/baby bonding
pair bonding
oxytocin can reduce anxiety
T/F
T
oxytocin can promote maternal behaviour
T/F
T
The _____ pituitary produces a far greater range of hormones than the ______ pituitary.
Anterior
Posterior
Hormones of the anterior pituitary
-The anterior pituitary’s cells are usually classified into five major types based on the nature of their secretions.
-These are listed below with their hormonal secretions:
● _____ – ____ or growth hormone (GH)
●____ – prolactin
●____ – thyroid-stimulating hormone (TSH)
●_____ – adrenocorticotropic hormone (ACTH) and ________ hormone
●______ – follicle-stimulating hormone (FSH) and luteinising hormone (LH).
Somatotrophs
somatotropin
Lactotrophs
Thyrotrophs
Corticotropths
melanocytestimulating hormone (MSH)
Gonadotrophs
Growth hormone
- the primary function of GH is to promote ______
- Most famously, GH promotes the widening of the growth plates in the _____ of the long bones of the skeleton, which results in elongation of the major bones of the ___and ____, progressively increasing ____.
- GH also enhances _____ uptake from the blood into cells, increasing the rate of ____ synthesis in tissues such as muscle; this is why it is known as an _____ hormone.
bodily growth.
epiphyses
arms and legs
height
amino acid
protein; anabolic
Thyroid hormones T3 and T4 (thyroxine), which regulate metabolism, are necessary for GH to exert its effects efficiently.
T/F
T
The anabolic effects of GH are also enhanced by the presence of other anabolic hormones such as ____.
testosterone
GH also stimulates the growth of bone but not any major internal organs
T/F
F
It does
Deficiency of GH during childhood may result in______; this is characterised by below-average growth and, commonly, an underdeveloped ___ of the____ and prominent _____.
pituitary dwarfism
bridge of the nose
forehead
Unlike achondroplastic dwarfism, pituitary dwarfism, although associated with reduced height, is characterised by _____
normal bodily proportions.
achondroplastic dwarfism is a genetic disorder
T/F
T
_____is available to treat children who are deficient in GH.
-It is usually injected ____, __times a day, and growth rate and potential side-effects then carefully monitored
Recombinant human GH
subcutaneously
once
Elevated secretion of GH in childhood often leads to _____, in which rapid growth of the long bones can result in an adult height of >_____.
gigantism
2.4m
Elevated secretion of GH in adults, after their epiphyseal growth plates have fused, can lead to _____, in which the ____, ____ and some ___ features (particularly the ____) can grow abnormally large and usually out of normal proportion
acromegaly
hands; feet;facial
lower jawbone
Prolactin
- Prolactin (___genic hormone) initiates milk secretion (lactation) in breast tissue.
- By itself, prolactin has a (weak or strong ?) effect, but during pregnancy prolactin levels increase and it acts synergistically with other hormones including ____,____,and____ , to promote the enlargement and engorgement of the ____ in preparation for lactation.
lacto
Weak
oestrogens, progesterone and cortisol
breasts
It has been hypothesised that the release of prolactin is regulated and fine-tuned by the antagonistic actions of a _____ hormone and a ______hormone, both of which are thought to be produced by the _____
prolactin releasing
prolactin-inhibiting
hypothalamus