The Endocrine Organs Flashcards
endocrine glands in the cranium
hypothalamus
pituitary gland
pineal gland
best imaging modality for the 3 organs inside the cranium as it is superior in soft tissues studies and it delineates well the zonal anatomy of different organs
MRI
2nd best imaging modality for the 3 organs inside the cranium
CY scan
neck and chest endocrine glands
thyroid gland
parathyroid gland
thymus
in the thyroid and parathyroid glands, ____ is the best screening tool:
a. least expensive
b. readily available
c. easy to perform
d. superior imaging
ultrasound
_____ may also be used depending on the indication you are considering especially when there is new growth around the neck and you want to map out the extent of the lesions
CT scan or MRI
located in the chest, behind the sternum in the mediastinal cavity
thymus
imaging modalities of choice for the thymus
MRI or CT scan
good screening modality for the pancreas
ultrasound
CT scan or MRI may also be done depending on the indication you’re considering
in cases of new growth, ____ would be superior in delineating the extent of the spread of the pancreatic new growth
MRI
2nd best for mapping out the spread of pancreatic lesions
CT scan
- The adrenal glands being enclosed in perirenal fat, is very difficult to visualize in UTZ. It is difficult to differentiate adrenal glands from perirenal fat so ____ is the best imaging modality for a good zonal anatomy of the adrenal glands
- ___ is the 2nd best
- MRI
2. CT scan
for the ovaries and testes, they are best examined by ____ because it does not give out harmful radiation to these organs; it is readily available, easy to perform, and relatively has good image resolution
ultrasound
____ of the ovaries and testes is avoided because they are very sensitive to radiation, so they may cause hazardous effects on the reproductive organs; one of w/c may be infertility especially in very young patients
CT scan
_____ is the next best imaging modality fo further studies of ovary and testis because this gives more defined zonal anatomy of these organs
MRI
- Located below the thalamus and intimately associated w/ both the limbic system & the pituitary gland
- It is a collection of nuclei arranged symmetrically around its floor and lateral walls, and cam be divided into medial and lateral areas
hypothalamus
contains neurosecretory cells that produce hormones (oxytocin and vasopressin/ADH)
supraoptic nucleus (SON)
form part of the hypothalamus and have a role in memory
mammillary bodies
together with its connections to the hypothalamus, acts as the main endocrine interface between CNS and the rest of the body
pituitary gland or hypophysis cerebri
the pituitary gland sits atop the base of the skull in a concavity w/in the sphenoid bone called the ____, immediately below the hypothalamus and optic chiasm
sella turcica (pituitary fossa)
anterior pituitary subparts
pars distalis
pars tuberalis
pars intermedia
largest part of the gland and responsible for synthesis and release of pituitary hormones except for ADH and oxytocin
anterior pituitary
anterior pituitary hormones
growth hormone (somatotropin) TSH ACTH FSH LH prolactin
direct extension from the hypothalamus, connected to it via the infundibular stalk
posterior pituitary
The posterior pituitary does not directly synthesize hormones but rather releases oxytocin and ADH w/c have traveled down the infundibulum in vesicles termed ____
Herring bodies
- A small, pine-cone shaped structure considered to be part of the epithalamus. It is unpaired and situated in the midline
- Situated in the groove between the laterally placed thalamic bodies
pineal gland
the pineal gland produces ____ w/c affects the modulation of wake/sleep patterns and photoperiodic (seasonal) fx
melatonin
though to have a reproductive fx and has been associated w/ the onset of puberty
pineal gland
PLAIN RADIOGRAPH
- Has a predilection for calcification w/c is invariably histologically present in adults but rarely seen below the age of 10yrs
- Calcification is visible on lateral skull x-rays in ____ of adults
pineal gland
2. 50-70%
also calcifies and is visible as a small C-shaped (open part posteriorly) density above and in front of the pineal calcification
habenular commissure
PINEAL GLAND: CT SCAN
- The far higher contrast resolution of CT means that calcification is almost always visible as specks embedded in a small soft tissue nodule similar in density to grey matter
- In children under the age of ___, no calcification is present but prevalence increases rapidly with age, reaching a plateau at about ____
- 5yo; 30yo
- ____ is the modality of choice for pineal gland
- Although MRI’s sensitivity to calcification on conventional sequences is poor, _____ has similar diagnostic power to CT
- MRI
2. susceptibility weighted imaging (SWI)
appears as a small nodule of tissue w/ similar intensity to grey matter; as it lies outside the BBB, it demonstrates vivid contrast enhancement
pineal gland: MRI
thyroid gland is a single midline endocrine organ in the anterior neck responsible for thyroid hormone production w/c lies in the ___ completely enveloped by ____ (middle layer of the ____)
visceral space
pretracheal fascia
deep cervical fascia
the thyroid extends from ____ and lies anterior to the ______ of the larynx and the _____
C5 to T1
thyroid and cricoid cartilages
5 or 6 tracheal rings
- The thyroid is a butterfly or “H”-shaped and is composed of 2 lobes, each w/ superior and inferior poles
- The lateral lobes are connected in the midline by a narrow ____ w/c is adherent to the ____ tracheal rings
- Each lobe measures approx. ____ in length
- Average weight: ____
- isthmus; 2nd-4th
- 4cm
- 25g
It plays a role in bone growth and development of the brain and nervous system in children. Helps maintain normal BP, HR, digestion, muscle tone, and reproductive fx; Increased catecholamine effect
thyroid gland
Has a homogenous appearance, the capsule may appear as thin hyperechoic line
thyroid gland: ultrasound
are endocrine glands located in the visceral space of the neck; they produce parathyroid hormone w/c controls calcium homestasis
parathyroid gland
located in the posterior aspect of the middle third of the thyroid gland
superior parathyroid gland
located in the lateral to the inferior pole of the thyroid gland
inferior parathyroid gland
____ are the predominant parathyroid imaging techniques w/ cross-sectional (CT/MRI) imaging usually reserved to confirm the anatomical position of etopic parathyroid adenomas
UTZ and nuclear medicine
- T-cell producing lymphoid organ in the anterior mediastinum that plays a role in the dev’t of the immune system, particularly the maturation of T-cells
- It typically has a retrosternal location and hence can mimic retrosternal pathology
thymus gland
relatively large in infancy (weighing 25g at birth), grows considerably immediately after birth, and reaches a maximal weight in adolescence between 12 and 19yo (35g)
thymus gland
- It gradually involutes w/ age (between 20 and 60yrs) w/ progressive fatty replacement of the cellular components (15g at 60yo)
- Fatty replacement starts at puberty and occurs more rapidly in ___.
- There can be a wide variation of size between patients
thymus gland
2. males
- Imaging the thymus gland on plain radiograph, the thymus is seen as a _____ frequently towards the right of the mediastinum
- It has no mass effect on vascular structures or airway
- The size can vary w/ inspirations
- triangular sail (thymic sail sign)
- On CT scan, ____ is a uniformly sof tissue density, approx. 80 HU and isoattenuating to surrounding muscle
- There is a smooth outline w/ convex borders in childhood and ig it is triangular in adulthood
- Small blood vessels may be seen traversing it
thymus gland
unit of CT scan density
Hounsfield
retroperitoneal organ that has both endocrine (production of hromones s/a insulin, glucagon, and somatostatin) and exocrine fx (involved in digestion by its production of pancreatic juice)
pancreas
may have the shape of a dumbbell, tadpole, or sausage
pancreas
will just reveal the anatomic structure of the pancreas not the functional anatomy
UTZ
- Paired organs of the endocrine system
- Often symmetric in shape
- Sit on top of kidneys on both sides
- Each gland is enclosed in perirenal fascia and each has a body and 2 limbs: medial limb and lateral limb
adrenal gland
the right adrenal gland is usually more ____ in shape while the leftd adrenal gland is more ____
pyramidal
crescentic
produces hormones called corticosteroids (cortisol, corticosterone, aldosterone, and androgens) and these regulate the body’s metabolism, balance of salt and water in the body, immune system, and sexual fx
outer adrenal cortex
produces the hormones called the catecholamines (epinephrine and norepinephrine) w/c help the body cope w/ physical and emptional stress by increasing the HR and BP; catecholamines are the fight and flight hormones
inner adrenal medulla
CT and MRI: the adrenal glands enhance after contrast administration to approximately ____
a. ____: appears as a linear, V-shape or comma-shape
b. ____: appears as triangular or Y-shape
50-60 HU
a. right adrenal gland
b. left adrenal gland
- paired female gonads of the reproductive and organ systems; they lie within the ovarian fossa on the posterior wall of the true pelvis
- produce estrogen and progesterone thag control the dev’t of female characteristics, and they are also involved in reproductive fx
ovaries
OVARIES
- Full bladder
- First-line investigation
- Homogeneous echotexture w/ a central echogenic medulla
ultrasounds
testes secrete hormones called ____, the most important of which is ____ which affect many male characteristics (sexual dev’t, growth of facial and pubic hair), as well as sperm production
adrogens
testosterone
- The normal testes have a homogenous, moderately echogenic pattern
- A testes is surrounded by a thin echogenic fibrous band, w/c represents the visceral component of the tunica vaginalis and the tunca albuginea
UTZ
