Transcript 13 Physiologicoanatomical peculiarities of endocrine system

Physiologic anatomical peculiarities of
endocrine system in children.
Methodics of endocrine glands
investigation. Semiotics of hypo- and
hyperfunction of some endocrine
glands and diseases of the endocrine
system.
By Nykytyuk S
The endocrine glands consist of
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1.Hypotalamus
2.Hypophysis
3.the epiphysis
4.the thyroid gland
5.the parathyroid glands
6.the thymus
7.the islands of Langerhans in the pancreas
8.the adrenal glands
9.the gonads (testis and ovaries)
The main function of the endocrine
system
 1.to take an active part in metabolism
 2.influence on water-mineral metabolism
 3.influence on growth and development of a
child
 4.regulation of differentiation of tissues
 5.ensuration of adaptation of the organism to its
enviroment
embriology
 Pituitary,
 thyroid,
 adrenal-begin to function during the intrauterine
period
 The hypophysis is organized at 4 weeks of
gestation
 Starts to secrete ACTH at 9-10 weeks
Close relationship between functions of the endocrine
system and those of the hypotalamus
Major endocrine glands. (Male left, female on the right.)
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1. Pineal gland
2. Pituitary gland
3. Thyroid gland
4. Thymus
5. Adrenal gland
6. Pancreas
7. Ovary
8. Testis
The hypotalamus regulates activity
 The hypotalamus regulates activity of the
hypophysis by producing neurohormones
(releasing hormones).
 Some of them activate and others inhibit
secretion of trophic hormones of the hypophysis
Endocrine glands and the hormones
secreted
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Hypothalamus produces
Thyrotropin-releasing hormone
(TRH)
Gonadotropin-releasing hormone
(GnRH)
Growth hormone-releasing
hormone (GHRH)
Corticotropin-releasing hormone
(CRH)
Somatostatin (SS; also GHIH,
growth factor-inhibiting hormone)
Dopamine (DA)
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Pineal Gland produces
Melatonin
Pineal gland
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The pineal gland is a
reddish-gray body about the
size of a pea (8 mm in
humans), located just rostrodorsal to the superior
colliculus and behind and
beneath the stria medullaris,
between the laterally
positioned thalamic bodies.
It is part of the epithalamus.
Pituitary gland
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The pituitary gland, or
hypophysis, is an endocrine gland
about the size of a pea that sits in a
small, bony cavity (sella turcica) at
the base of the brain.
The pituitary gland secretes
hormones regulating homeostasis,
including trophic hormones that
stimulate other endocrine glands.
It is functionally connected to the
hypothalamus by the median
eminence.
Anterior pituitary (Adenohypophysis)
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The anterior pituitary produces and
secretes:
growth hormone
prolactin
follicle-stimulating hormone
luteinizing hormone
thyroid-stimulating hormone
adrenocorticotropic hormone
endorphins
and other hormones
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It does this in response to releasing
hormones produced by the
hypothalamus. These travel to the
anterior lobe by way of a special
capillary system, called the
hypothalamic-hypophyseal portal
system. These hypothalamic signalling
hormones include:
TRH (thyrotropin-releasing hormone)
CRH (corticotropin-releasing hormone)
DA (dopamine, "prolactin inhibiting
factor"/PIF)
GnRH (gonadotropin-releasing
hormone)
GHRH (growth hormone releasing
hormone)
In new born period
 Concentrations of ACTH, CTG, and TSH
 are high, later they decrease
Late school period
 Concentrations of luteal and follicle-stimulating
hormones increases
Hypofunction of the hypophysis
 Causes pituitary nanism (dwarfism)
Hyperfunction of hypophysis –
(hyperpituitarism)
 Pituitary gigantism and acromegaly
Hypofunction of the
adrenohypophysis
 Hypophyseal cachexia, Simmonds disease
Prolactin
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Prolactin is a peptide hormone
synthesised and secreted by
lactotrope cells in the
adenohypophysis (anterior pituitary
gland). It is also produced in other
tissues including the breast and the
decidua. Pituitary prolactin
secretion is regulated by
neuroendocrine neurons in the
hypothalamus, most importantly by
neurosecretory dopamine neurons
of the arcuate nucleus, which
inhibit prolactin secretion.
Disease States
Relative elevations
 In children with precocious puberty of
pituitary or central origin, LH and FSH
levels may be in the reproductive range
and not at the low levels typically for
their age.
High LH levels
 Persistently high LH levels are
indicative of situations where the
normal restricting feedback from the
gonad is absent, leading to an
unrestricted pituitary production of
both, LH and FSH. While this is typical
in the menopause, it is abnormal in the
reproductive years. There it may be a
sign of:
1. Premature menopause
2. Gonadal dysgenesis, Turner syndrome
3. Castration
4. Swyer syndrome
5. Certain forms of CAH
6. Testicular failure
Deficient LH activity
Diminished secretion of LH can result in failure of gonadal
function (hypogonadism). This condition is typically manifest in
males as failure in production of normal numbers of sperm. In
females, amenorrhea is commonly observed. Conditions with
very low FSH secretions are:
1. Kallmann syndrome
2. Hypothalamic suppression
3. Hypopituitarism
4. Eating disorder
5. Hyperprolactinemia
6. Gonadotropin deficiency
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Growth hormone
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Growth hormone (GH
or somatotropin) is a
polypeptide hormone
synthesised and
secreted by the anterior
pituitary gland which
stimulates growth and
cell reproduction in
humans
Examination of hypophysis
 1. laboratory investigatios of the level of
hypophysis hormones
 2.R-graphy of the cranial Turkish saddle
 3.CT of the brain
Thyroid
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The thyroid (from the Greek word for
"shield", after its shape) is one of the
larger endocrine glands in the body. It
is a double-lobed structure located in
the neck and produces hormones,
principally thyroxine (T4) and
triiodothyronine (T3), that regulate the
rate of metabolism and affect the
growth and rate of function of many
other systems in the body. The
hormone calcitonin is also produced
and controls calcium blood levels.
Iodine is necessary for the production
of both hormones. Hyperthyroidism
(overactive thyroid) and hypothyroidism
(underactive thyroid) are the most
common problems of the thyroid gland.
Thymus
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The thymus plays an
important role in the
development of the
immune system in early
life, and its cells form a
part of the body's normal
immune system. It is
most active before
puberty.
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The thymus of a full-time
fetus, exposed in situ.
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Immature thymocytes undergo a
process of selection, based on the
specificity of their T cell receptors.
This involves selection of T cells
that are functional (positive
selection), and elimination of T
cells that are autoreactive
(negative selection).
Cells that pass both levels of
selection are released into the
bloodstream to perform vital
immune functions.
Pancreas
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The pancreas is an organ in
the digestive and endocrine
system that serves two major
functions: exocrine
(producing pancreatic juice
containing digestive
enzymes) and endocrine
(producing several important
hormones, including insulin).
Pancreas
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1: Head of pancreas
2: Uncinate process of pancreas
3: Pancreatic notch
4: Body of pancreas
5: Anterior surface of pancreas
6: Inferior surface of pancreas
7: Superior margin of pancreas
8: Anterior margin of pancreas
9: Inferior margin of pancreas
10: Omental tuber
11: Tail of pancreas
12: Duodenum
There are four main types of cells in
the islets of Langerhans.
beta cells-Insulin and
Amylin
 alpha cells-Glucagon
 Deltacells-Somatostatin
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PP cells-Pancreatic
polypeptide
50-80% lower blood
sugar
 15-20%raise blood sugar
 3-10%inhibit endocrine
pancreas
 1%inhibit exocrine
pancreas
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Insulin
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The structure of insulin. The lefthand side is a space-filling model
of the insulin monomer, believed to
be biologically active. Carbon is
green, hydrogen white, oxygen red,
and nitrogen blue. On the righthand side is a cartoon of the
hexamer, believed to be the stored
form. A monomer unit is highlighted
with the A chain in blue and the B
chain in cyan. Yellow denotes
disulfide bonds, and magenta
spheres are zinc ions.
Insulin
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Computer-generated
image of insulin
hexamers highlighting
the threefold
symmetry, the zinc
ions holding it
together, and the
histidine residues
involved in zinc
binding.
Insulin (from Latin insula, "island
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", as it is produced in the Islets of
Langerhans in the pancreas) is a
polypeptide hormone that regulates
carbohydrate metabolism. Apart
from being the primary effector in
carbohydrate homeostasis, it has
effects on fat metabolism and it can
change the liver's ability to release
fat stores. Insulin's concentration
has extremely widespread effects
throughout the body.
Glucose test
The World Health Organization
 recognizes three main forms of diabetes: type 1,
 type 2 and
 gestational diabetes (or type 3, occurring during
pregnancy)[1],
 although these three "types" of diabetes are
more accurately considered patterns of
pancreatic failure rather than single diseases.
Endemic cretinizm
Hypotyrosis congenital
Thyroid \\ crisis\\
 1.AN ACUTE ONSET OF HYPERTHERMIA,
 2.TACHYCARDIA
 3.RESTLESSNESS
Hypotyrosis congenital
Laboratory investigation
 Newborns screening for T4
 TSH
 X-ray
delayed bone development
 ECG depressed P and T waves and QRS
complex,low voltage
Hyperthyroidism
Appear in the school period
 1.Emotional lability
 2.tremor
 3.increased appetite
 4.loss of body weight
 5.exophthalmos
 6.eyelid leg
 7.sweating and tachycardia
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Laboratory investigation
 T4 and T3 elevated
 X-ray of bones: osteoporosis and bones
resorption
hypoparathyroidism
 Muscle pains,
 Cramps,
 Numbness, tingling and convulsions
 The teeth are soft and erupt late
 Dry and scaly skin
 Cataracts may occurs
Laboratory findings
 1.low calcium
 2.elevatedphosphorus,
 3.low vitamin D,
 4,Low PTH
 X-ray ;increased metaphyseal thickening
 ECG:prolonged QT interval
Glucocorticoids function
 Affect tissue metabolism
 Increase protein and glucogen content in the
liver
 Influence the immune and nervous systems
Adrenal medulla secretes
 Catecholamines:
 dopamine,
 norepinephrine epinephrine
Cushing s syndrome
Etiology:
 Adrenocortical tumor,
 ACTH-dependent
bilateral hyperplasia
 Pituitary adenoma
 Abnormal production of
ACTH
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Clinical manifestation:
Moon face, a double
chin, a buffalo hump,
obesity,
 masculinization,
 hypertrichosis on the
face and trunk, acne,
clitoral enlargement,
impaired growth and
hypertension.
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Cortisol excess.
 Cortisol
excess as a result of organic causes or
of prolonged cortisone therapy also has an
adverse effect on growth in children.
Ovary
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Ovaries are egg-producing
reproductive organs found in
female organisms. They are
part of the vertebrate female
reproductive system. Ovaries
in females are homologous
to testes in males. The term
gonads refers to the ovaries
in females and testes in
males.
Testicle
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The testicles, or testes
(singular testis), are the
male generative glands.
Male mammals have two
testicles, which are often
contained within an
extension of the
abdomen called the
scrotum.
Grows of thyroid cartilage
 Phase No signs of grows Lо
 Beginning of cartilage projectionL1
 Distinct projection of Adam’s-appleL2
Change of voice timbre
 Phase Childish voiceVо
 Mutation (creaking)of voice V1
 Male timble of voiceV2