1. Endocrine Anatomy I Flashcards
ENDOCRINE SYSTEM
• A few, widely separated glands that form discrete anatomical organs; and
• Other, smaller groups of cells located in organs belonging to other systems
From the anatomical perspective…
Endocrine glands are distinguished by one fundamental characteristic: they do not have ____, but instead, discharge their secretions directly into the ____. Consequently, endocrine tissue is particularly ____!
ducts
bloodstream
vascular
The endocrine system (along with the nervous and immune systems), facilitates communication, integration and regulation of body functions, interacting with target cells and tissues, many distant, by releasing ____ into the bloodstream
hormones
PITUITARY GLAND (Hypophysis cerebri)
- Reddish-grey, ____ body; weight ca. 500 mg.
- Lies within the ____ of the sphenoid, at center of ____
- Covered superiorly by a ____ of dura matter
ovoid
hypohyseal fossa
sella turcica
diaphragma sella
The pituitary is continuous with the ____, a hollow, conical, inferior process of the
____ of the hypothalamus
The pituitary gland is actually two closely associated endocrine organs that differ in their origin, structure and function:
- Neurohypophysis= ____
- Adenohypophysis= ____
infundibulum
tuber cinereum
posterior pituitary
anterior pituitary
The neurohypophysis is a ____ downgrowth connected with the hypothalamus
Both include parts of the ____ (stalk)
The adenohypophysis is an ____ derivative of the ____
diencephalic
infundibulum
ectodermal
stomodeum
The stalk of the pituitary has a central ____ that contains neural hypophyseal connections and is continuous with the ____ of the tuber cinereum
The highly vascular adenohypophysis
consists of ____ cells of varying size and shape arranged in cords or irregular follicles between that lie thin walled ____
infundibular stem
median eminence
epithelial
vascular sinusoids
Axons from neurons located in ____, including ____ neurons of the supraoptic and paraventricular nuclei, pass to the main mass of the ____ in the ____ tract
hypothalamic nuclei
magnocellular
neurohypophysis
hypothalamic-hypophyseal
Axons from neurons located in hypothalamic nuclei, including magnocellular neurons of the supraoptic and paraventricular nuclei, pass to the main mass of the neurohypophysis in the
hypothalamic-hypophyseal tract
superior hypophyseal
arteries, arising from the ____ portion of each ____, contribute bilaterally to formation of a ____ around the
infundibulum
cerebral
ICA
vascular plexus
Axons from ____ cells in the paraventricular nucleus, as well as axons from other ____ nuclei, course toward the ____
as releasing/inhibiting hormones regulating anterior pituitary hormones
A single \_\_\_\_ artery, arising from the cavernous portion of each \_\_\_\_, divides on each side into medial and lateral branches, which anastomose across the midline and form an \_\_\_\_ around the infundibulum
parvocellular
hypothalmic
adenohypohysis
inferior hypophyseal
ICA
arterial ring
Blood in the hypophyseal arteries enters capillaries contributing to the ____ SYSTEM allowing fast hormonal communication between ____ and ____
hypophyseal portal
hypothalamus
pituitary
Hormones that enter the neurohypophysis via the ____ tract may be released into a spray of capillaries arising from the ____ and enter the hypophyseal portal system
- ____ (ADH)
- ____
hormones secreted by the adenohypophysis are released into the sinusoids and drain via ____
portal vessels descend toward the ____, opening into vascular sinusoids lying between the secretory cords in the ____
the portal system carries hormone releasing factors controlling the secretory cycles of cells in the ____ adenohypophysis
hypothalamic-hypophyseal tract
superior hypophyseal arteries
vasopressin
oxytocin
hypophyseal veins
pars anterior
adenohypophysis
pars anterior
The venous drainage of the pituitary is directed:
• To the ____
• To ____
hypothalamus
venous dural sinuses
Major ant pit hormones:
- ____
- ____
- ____
- ____
- ____
- ____
Major pit hormones:
- ____
- ____
GNRH somatostatin CRH GnRH TRH PIH
oxytocin
ADH
The pineal gland is a feature of the ____,
lying at the posterior end of the ____
epithalamus
third ventricle
Note that the pineal modifies activity of both ____ and ____ and that pineal secretions may reach these targets via EITHER
____ or the ____
The pineal is bathed in ____ through a small pineal recess projecting into the stalk of the gland
neurohypophysis adenohypophysis CSF blood stream CSF
Glandular function is regulated by inputs from the ____ of the Hypothalamus responsible for controlling ____
suprachiasmatic nucleus (SCN) circadian rhythms
The pineal gland produces ____, a ____-derived hormone that modulates sleep patterns in both circadian and seasonal cycles
The pineal has an extensive blood supply provided by ____ branches of the ____
Which essential amino acid is a precursor? ____
melatonin
seratonin
choroidal
posterior cerebral artery
tryptophan
Pinealocytes, highly modified ____, synthesize ____ and secrete it into a surrounding network of fenestrated capillaries
It is suggested that the Pinealocytes are derived (phylogenetically)
from ____ cells and in fact, melatonin production
IS stimulated by ____ and inhibited by ____
NOTE : calcifications called ____ or “brain sand” increase with age- implicated in dementia
neurons
melatonin
photoreceptor
darkness
light
acervuli
Venous drainage of the pineal is directed toward the ____
great cerebral vein (great vein of galen)
Recall that the thyroid:
• Located in the ____
• Lies deep to the ____ muscles, which must be retracted in order to access the gland during life
• Is found, along with related viscera, in a fascial compartment formed by the ____ and ____ layers of the ____
anterior cervical triangle infrahyoid (cervical strap) pretracheal buccopharyngeal deep cervical fascia
Recall that the developing thyroid descends
through the neck during development, passing
anterior to elements of the laryngeal skeleton
and reaching its final position, with obliteration of
the ____ DUCT by the ____ week of embryonic development
thyroglossal duct
eighth
LINGUAL THYROID
• Most common form of ____
Firm, pink red midline mass encountered just posterior to ____
Initial identification often by dental practitioners
ectopic thyroid
foramen cecum
Lingual thyroid
Ectopic thyroid tissue in the median plane is often the only thyroid tissue, so…
Removal may leave the patient on ____ for life
thyroid replacement medication
Approximately 50% of all individuals present with a ____
of the thyroid, (usually) extending ____ from the isthmus of the gland
Excision of the pyramidal lobe may provide a surgical challenge in total ____
The pyramidal lobe may be encountered during, and complicate, emergency ____
pyramidal lobe
superiorly
thyroidectomy
cricothyrotomy
THYROGLOSSAL CYSTS
• result from the failure of the ____ duct to regress completely
• These ____-filled cavities present clinically as firm, irregular ____ neck masses.
thyroglossal
fluid
firm
The posteromedial aspects of the left and right lobes are attached to the ____ cartilage via ____
The ligament effectively suspends the gland from the ____.
cricoid
ligamentous attachments (berry’s ligament)
airway
GOITER
(due to ____ deficiency) may lead to enlargement
of the thyroid gland in all directions except ____, leading to compression of:
• ____
• ____
• ____
iodine superiorly trachea esophagus recurrent laryngeal nerves
The thyroid gland is said to have the ____ blood supply per unit of tissue
of any organ in the body
superior thyroid artery from the ____
inferior thyroid artery from the ____
greatest
external carotid
thyrocervical trunk
Unique among the endocrine glands, the epithelial cells of the thyroid form ____; the outer wall of each vesicle is adjacent to an abundant ____, and the hollow within the vesicle serves as a storehouse for ____ until it is needed by the rest of the body
When present, the thyroid ima artery arises from either the ____ or the ____.
vesicles capillary network thyroid hormone aortic arch branchiocephalic trunk
Recall the proximity of the thyroid arteries to the branches
of ____ responsible for the innervation of the larynx and the resultant vulnerability
of those nerves to iatrogenic injury in ____
CN X
thyroidectomy
A ____ envelops the thyroid gland
glandular venous plexus
Superior and middle thyroid veins drain into the ____…
IJV
..but the
INFERIOR THYROID VEIN
drains to the
____ in the ____
left brachiocephalic vein
superior mediastinum
PARATHYROID GLANDS
Though closely associated
with the thyroid, the (normally) ____ parathyroid glands differ in both origin and physiology…
…the parathyroids are derived from the walls of the____ and ____ pharyngeal pouches
four
third
fourth
PARATHYROID GLANDS
The glands are small, flattened ovals, found above and below the entry into the thyroid of the ____
These arteries provide
the ____ blood supply to the parathyroids
Venous drainage is to the
____
____ hormone
exerts control over
the calcium content of
the blood, with implications for nervous and muscular function as well as the integrity of the bony skeleton
While ____ innervation of these glands is abundant, it is purely ____ as parathyroid secretion is hormonally regulated
The glands are carefully spared in ____
inferior thyroid arteries primary thyroid venous plexus parathyroid sympathetic vasomotor thyroidectomy
The THYMUS is a T-cell producing ____ lymphoid organ vital to the the development and maturation of the immune system during childhood
Derived from the
____ pharyngeal pouches
the thymus descends during development, thus ____ (accessory) thymic tissue is a possibility
A ____ in fact attaches thyroid and thymus
primary
third
ectopic
thyrothymic ligament
Relatively large in infancy, the thymus ____ in size through adolescence and gradually ____ beginning around age 20, with progressive ____ replacement through adulthood
increases
involutes
fatty
When sizeable, the thymus consists of two ____ lobes, touching (and sometimes uniting into a single mass) in the ____. At this stage, the gland will be situated partly in the ____ and partly in the ____.
Arterial supply from the
____ and internal thoracic arteries.
Venous drainage via the
____, internal thoracic, and ____.
asymmetric
midline
thorax
neck
inferior thyroid
left brachiocephalic
inferior thryoid veins
Similar to the thyroid, accessory thymic tissue may be located anywhere along the path of descent form the ____ pharyngeal pouch of the ____ ducts.
The thymus was once worshipped as the “seat of the soul” by the ancient Greeks!
third
thymopharyngeal
Beyond vasomotor function, the role of the ____ nervous system in the biology of the thymus is poorly understood
Note that the ____ nerves innervate the loose fibrous connective tissue capsule of the gland.
In the adult, that ____ is usually what distinguishea the atrophied thymus from surrounding tissues
Thymic remnants are a feature of both the ____ and ____
in the adult
sympathetic phrenic capsule superior anterior mediastinum
SUPRARENAL (ADRENAL) GLANDS
- ____ retroperitoneal glands
- Surrounded by ____ and enclosed by renal fascia by which they attach to the ____
- Associated with the ____ of the kidneys
- Composed of cords of epithelial cells with abundant ____ between the cords
- Each features an outer ____ and central ____
primary perirenal fat crura of the diaphragm superior poles capillaries cortex medulla
The suprarenal glands are roughly ____ in shape
The right suprarenal
is normally ____ in shape…
… while the left suprarenal is normally ____
triangular
pyramidal
semilunar
The adrenal cortex and medulla are really two ____ endocrine glands which have become closely associated
Each has a unique function and developmental history
MEDULLA arises from some of the ____ cells that give rise to the ____ ganglia and is permeated with capillaries and sinusoids
CORTEX arises directly by proliferation of ____ epithelium and secretes ____ and androgens
separate
neural crest
peripheral sympathetic
mesodermal
coelomic epithelium
corticosteroids
The ____ seems to be the only endocrine gland whose activity is controlled entirely by nerve impulses…
… as preganglionic sympathetic fibers from ____ nerves end directly on ____ cells, rather than on postganglionic neurons located in either paravertebral or prevertebral ganglia
The effects of ____, secreted by the medulla, are complementary to those of the sympathetic nervous system
suprarenal medulla
thoracic splanchnic
medullary chromaffin
epinephrine
Each gland receives THREE suprarenal arteries
• SUPERIOR- from the ____
• MIDDLE- from the ____
• INFERIOR- from the ____
inferior phrenic a
abdominal aorta
renal artery
The RIGHT suprarenal vein drains directly into the
____
The LEFT suprarenal vein drains directly into the
____
inferior vena cava
left renal vein
Lymphatic drainage of the suprarenal glands is abundant and directed toward ____ NODES
lumbar
