Endocrine Flashcards
What is the connection between the hypothalamus and the posterior pituitary?
Neural
What is the connection between the hypothalamus and the anterior pituitary?
Vascular
What is the vascular system between the hypothalamus and the anterior pituitary?
Hypophyseal portal system
What are the two hormones secreted from the posterior pituitary gland?
Vasopressin
Oxytocin
What does vasopressin do?
increases blood pressure, increases renal water resorption, concentrates the urine
What is GnRH, what does it cause the release of, and what is its target?
Gonandotropin releasing hormone, FSH and LH, Gonads
What is CRH, what does it cause the release of, and what is its target?
Corticotropin-releasing hormone, adrenocorticotropin hormone (ACTH), adrenal cortex
What is TRH, what does it cause the release of, and what is its target?
Thyroid releasing hormone, thyroid stimulating hormone and prolactin, thyroid
What is PRH, what does it cause the release of, and what is its target?
Prolactin releasing hormone, prolactin, mammary glands
What is GHRH, what does it cause the release of, and what is its target?
Growth hormone-releasing hormone, growth hormone, liver and all over
What is the prolactin inhibiting hormone?
dopamine
What is the inhibiting hormone of growth hormone and thyroid stimulating hormone?
GIH / somatostatin
What does the parathyroid gland do?
Regulates calcium and phosphorus homeostasis and bone metabolism
What does the thyroid gland do?
Regulates tissue and energy metabolism
What are the correct terms for absorbing in the kidney, GI, and bones?
Absorption
Reabsorption
Resorption
What are the 3 minerals of bone?
Calcium, phosphorus, and magnesium
What are the 3 types of calcium in the blood of bones?
Protein-bound calcium
Active Calcium
Complexed calcium
What are the 3 hormones of calcium regulation?
PTH
Calcitonin
Vitamin D
What are the 3 parathyroid cells?
Chief cells
Clear cells
Oxyphil cells
What cells detect changes in calcium and produce the most?
Chief cells
What are the 4 functions of PTH
Increase blood calcium
Decrease blood phosphorus
Increase bone remodeling
Increases Vitamin D activation
What 3 things stimulate PTH and what inhibits PTH
Hypocalcemia
Hyperphosphatemia
Magnesium levels stimulate
Vitamin D and hypercalcemia inhibit
How many targets does PTH have and what are they?
Kidney and bone
What effect does PTH have on kidneys
Calcium reabsorption
inhibit Phosphorus reabsorption
Increase vitamin D synthesis
What role does PTH have on bones?
Increase bone resorption
PTH acts to activate osteoclasts
***Phosphorus is also released in this process (urinated through kidney)
What role does the proximal tube have in reabsorption?
Inhibits Na/Pi transporter to not allow reabsorption of phosphate
What role does the loop of Henle have in calcium homeostasis
Increases Na/K/Cl cotransporter, making lumen more positive which increases transport of Ca and Mg
What role do tubular cells have on calcium homeostasis?
PTH activates hydroxylase which activated vitamin D
What organ and which cells produce calcitonin?
Parafollicular cells (c cells) of thyroid
What is released in the stomach that activates C cells
Gastrin is released in response to calcium which causes C cells to release calcitonin
What role does calcitonin play during lactation
Calcitonin helps to make sure that too much bone isnt being resorbed
What additional hormone is released during lactation from the mammary gland?
PTHrP Parathyroid hormone-related peptide
What does vitamin D do in calcium homeostasis?
A little confusing but it modulates it to make sure that not too much calcium from bone is being used, increased calcium AND phosphorus as well as reducing PTH secretion
What is a vitamin D deficiency called in youth?
Adults?
Rickets
Osteomalacia
What is the precursor to vitamin D?
Cholesterol
What activates vitamin D in the kidney?
PTH
What is the active form of vitamin D and what is the inactive form?
calcidio and calcitriol
What is the active and inactive form of TH?
T4 = inactive
T3 = active
What cell makes thyroid
Where is thyroid stored?
Follicular cells
Follicle colloid
What element does thyroid hormone require?
Iodine
What role does iodine play in T4 secretion?
T4 is made in follicular cells and exported to colloid
TSH stimulates increase in iodine transport into colloid
iodine binds precursor then moved out into circulation
Some T3 is also secreted
How is T3 inactivated?
cleaved to T2
How is most thyroid hormone found in the blood?
Protein bound
What is hyperthyroidism
High TH which increases metabolic function
What is hypothyroidism?
Low circulating TH which decreases metabolic activity
How would you not superimpose the mandible in a VD view of the head? And what is it used for?
Open mouth VD, allows for view of nasal cavity
What is an additional way to check the nasal cavities of dogs?
Intraoral dorsal ventral image (place plate in dog’s mouth)
What is a rostrocaudal image used for?
To look at frontal sinuses
Tip nose away from tube to look at tympanic bulla
How do you place a marker in a dorsal-ventral oblique view (or any oblique view)
The marker closets to the anatomy indicates side
What is are main images taken for large animals?
Dorsal ventral
lateral images
How can you tell the difference between lateral and oblique images?
Not a perfect imposition
Has two labels
What are reasons to radiograph the skull and spine?
Trauma
Masses or swellings
Ear disease
Nasal and parasinus disease
Teeth
What is the best way for a dog to lie during cervical x rays
When the dog’s spine is as straight as possible
What does the marker on a lateral image represent?
Which side of the body is closest to the table
How is a cervical ventral dorsal image done on small animals
Put into a trough
May need to aim beam towards thorax to highlight disk changes
When are DV / VD images done in large animals?
ONLY when they are small
